Upstream Merge

build.gradle.kts

@@ -84,10 +84,3 @@ if (!project.hasProperty("gitCommitHash")) {
         "no_git_id"
     }
 }
-
-//buildScan {
-//    setTermsOfServiceUrl("https://gradle.com/terms-of-service")
-//    setTermsOfServiceAgree("yes")
-//
-//    publishAlways()
-//}

buildSrc/src/main/kotlin/CommonConfig.kt

@@ -21,8 +21,7 @@ fun Project.applyCommonConfiguration() {
     }
     configurations.all {
         resolutionStrategy {
-            cacheChangingModulesFor(10, "minutes")
+            cacheChangingModulesFor(5, "minutes")
         }
     }
-
 }

buildSrc/src/main/kotlin/PlatformConfig.kt

@@ -121,3 +121,8 @@ fun Project.applyShadowConfiguration() {
         minimize()
     }
 }
+
+val CLASSPATH = listOf("truezip", "truevfs", "js")
+    .map { "$it.jar" }
+    .flatMap { listOf(it, "WorldEdit/$it") }
+    .joinToString(separator = " ")

buildSrc/src/main/kotlin/Versions.kt

@@ -7,6 +7,7 @@ object Versions {
     const val AUTO_VALUE = "1.6.5"
     const val JUNIT = "5.5.0"
     const val MOCKITO = "3.0.0"
+    const val LOGBACK = "1.2.3"
 }
 
 // Properties that need a project reference to resolve:

worldedit-bukkit/build.gradle.kts

@@ -76,7 +76,7 @@ tasks.named<Copy>("processResources") {
 
 tasks.named<Jar>("jar") {
     manifest {
-        attributes("Class-Path" to "truezip.jar WorldEdit/truezip.jar js.jar WorldEdit/js.jar",
+        attributes("Class-Path" to CLASSPATH,
                 "WorldEdit-Version" to project.version)
     }
 }

worldedit-core/build.gradle.kts

@@ -27,6 +27,7 @@ configurations.all {
 dependencies {
     "compile"(project(":worldedit-libs:core"))
     "compile"("de.schlichtherle:truezip:6.8.3")
+    "compile"("net.java.truevfs:truevfs-profile-default_2.13:0.12.1")
     "compile"("org.mozilla:rhino:1.7.11")
     "compile"("org.yaml:snakeyaml:1.23")
     "compile"("com.google.guava:guava:21.0")
@@ -46,6 +47,8 @@ dependencies {
     "annotationProcessor"("com.google.guava:guava:21.0")
     "compileOnly"("com.google.auto.value:auto-value-annotations:${Versions.AUTO_VALUE}")
     "annotationProcessor"("com.google.auto.value:auto-value:${Versions.AUTO_VALUE}")
+    "testImplementation"("ch.qos.logback:logback-core:${Versions.LOGBACK}")
+    "testImplementation"("ch.qos.logback:logback-classic:${Versions.LOGBACK}")
     "compile"("co.aikar:fastutil-lite:1.0")
     "compile"("com.github.luben:zstd-jni:1.4.3-1")
     "compileOnly"("net.fabiozumbi12:redprotect:1.9.6")

worldedit-core/src/legacy/java/com/sk89q/worldedit/blocks/MobSpawnerBlock.java

@@ -31,6 +31,7 @@ import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.world.block.BaseBlock;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.storage.InvalidFormatException;
+
 import java.util.HashMap;
 import java.util.Map;
 

worldedit-core/src/main/java/com/sk89q/worldedit/LocalConfiguration.java

@@ -25,14 +25,21 @@ import com.sk89q.worldedit.extent.NullExtent;
 import com.sk89q.worldedit.function.mask.BlockMask;
 import com.sk89q.worldedit.function.mask.BlockMaskBuilder;
 import com.sk89q.worldedit.util.formatting.component.TextUtils;
+import com.sk89q.worldedit.util.io.file.ArchiveNioSupports;
 import com.sk89q.worldedit.util.logging.LogFormat;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.block.BlockTypes;
 import com.sk89q.worldedit.world.registry.LegacyMapper;
 import com.sk89q.worldedit.world.snapshot.SnapshotRepository;
+import com.sk89q.worldedit.world.snapshot.experimental.SnapshotDatabase;
+import com.sk89q.worldedit.world.snapshot.experimental.fs.FileSystemSnapshotDatabase;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
@@ -44,6 +51,8 @@ import java.util.Set;
  */
 public abstract class LocalConfiguration {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(LocalConfiguration.class);
+
     public boolean profile = false;
     public boolean traceUnflushedSessions = false;
     public Set<String> disallowedBlocks = new HashSet<>();
@@ -55,7 +64,9 @@ public abstract class LocalConfiguration {
     public int defaultMaxPolyhedronPoints = -1;
     public int maxPolyhedronPoints = 20;
     public String shellSaveType = "";
+    public boolean snapshotsConfigured = false;
     public SnapshotRepository snapshotRepo = null;
+    public SnapshotDatabase snapshotDatabase = null;
     public int maxRadius = -1;
     public int maxSuperPickaxeSize = 5;
     public int maxBrushRadius = 6;
@@ -193,6 +204,29 @@ public abstract class LocalConfiguration {
         return new File(".");
     }
 
+    public void initializeSnapshotConfiguration(String directory, boolean experimental) {
+        // Reset for reload
+        snapshotRepo = null;
+        snapshotDatabase = null;
+        snapshotsConfigured = false;
+        if (!directory.isEmpty()) {
+            if (experimental) {
+                try {
+                    snapshotDatabase = FileSystemSnapshotDatabase.maybeCreate(
+                        Paths.get(directory),
+                        ArchiveNioSupports.combined()
+                    );
+                    snapshotsConfigured = true;
+                } catch (IOException e) {
+                    LOGGER.warn("Failed to open snapshotDatabase", e);
+                }
+            } else {
+                snapshotRepo = new SnapshotRepository(directory);
+                snapshotsConfigured = true;
+            }
+        }
+    }
+
     public String convertLegacyItem(String legacy) {
         String item = legacy;
         try {
@@ -211,6 +245,7 @@ public abstract class LocalConfiguration {
 
         return item;
     }
+
     public void setDefaultLocaleName(String localeName) {
         this.defaultLocaleName = localeName;
         if (localeName.equals("default")) {

worldedit-core/src/main/java/com/sk89q/worldedit/LocalSession.java

@@ -38,7 +38,6 @@ import com.boydti.fawe.util.StringMan;
 import com.boydti.fawe.util.TextureHolder;
 import com.boydti.fawe.util.TextureUtil;
 import com.boydti.fawe.wrappers.WorldWrapper;
-import com.google.common.base.Function;
 import com.google.common.collect.Lists;
 import com.sk89q.jchronic.Chronic;
 import com.sk89q.jchronic.Options;
@@ -154,7 +153,7 @@ public class LocalSession implements TextureHolder {
 
     private transient VirtualWorld virtual;
     private transient BlockVector3 cuiTemporaryBlock;
-    private transient List<Countable> lastDistribution;
+    private transient List<Countable<BlockState>> lastDistribution;
     private transient World worldOverride;
     private transient boolean tickingWatchdog = false;
     private transient boolean hasBeenToldVersion;
@@ -896,7 +895,7 @@ public class LocalSession implements TextureHolder {
 
     /**
      * Get the position use for commands that take a center point
-     * (i.e., //forestgen, etc.).
+     * (i.e. //forestgen, etc.).
      *
      * @param actor the actor
      * @return the position to use
@@ -1485,6 +1484,17 @@ public class LocalSession implements TextureHolder {
         return editSession;
     }
 
+    private void prepareEditingExtents(EditSession editSession, Actor actor) {
+        editSession.setFastMode(fastMode);
+        /*
+        editSession.setReorderMode(reorderMode);
+        */
+        if (editSession.getSurvivalExtent() != null) {
+            editSession.getSurvivalExtent().setStripNbt(!actor.hasPermission("worldedit.setnbt"));
+        }
+        editSession.setTickingWatchdog(tickingWatchdog);
+    }
+
     /**
      * Checks if the session has fast mode enabled.
      *
@@ -1566,7 +1576,6 @@ public class LocalSession implements TextureHolder {
 
     /**
      * Get the TextureUtil currently being used
-     * @return
      */
     @Override
     public TextureUtil getTextureUtil() {
@@ -1601,14 +1610,14 @@ public class LocalSession implements TextureHolder {
      *
      * @return block distribution or {@code null}
      */
-    public List<Countable> getLastDistribution() {
+    public List<Countable<BlockState>> getLastDistribution() {
         return lastDistribution == null ? null : Collections.unmodifiableList(lastDistribution);
     }
 
     /**
      * Store a block distribution in this session.
      */
-    public void setLastDistribution(List<Countable> dist) {
+    public void setLastDistribution(List<Countable<BlockState>> dist) {
         lastDistribution = dist;
     }
 
@@ -1630,14 +1639,4 @@ public class LocalSession implements TextureHolder {
         }
     }
 
-    private void prepareEditingExtents(EditSession editSession, Actor actor) {
-        editSession.setFastMode(fastMode);
-        /*
-        editSession.setReorderMode(reorderMode);
-        */
-        if (editSession.getSurvivalExtent() != null) {
-            editSession.getSurvivalExtent().setStripNbt(!actor.hasPermission("worldedit.setnbt"));
-        }
-        editSession.setTickingWatchdog(tickingWatchdog);
-    }
 }

worldedit-core/src/main/java/com/sk89q/worldedit/command/LegacySnapshotCommands.java

@@ -0,0 +1,203 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// $Id$
+
+package com.sk89q.worldedit.command;
+
+import com.sk89q.worldedit.LocalConfiguration;
+import com.sk89q.worldedit.LocalSession;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.extension.platform.Actor;
+import com.sk89q.worldedit.util.formatting.component.PaginationBox;
+import com.sk89q.worldedit.util.formatting.text.Component;
+import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
+import com.sk89q.worldedit.util.formatting.text.event.ClickEvent;
+import com.sk89q.worldedit.util.formatting.text.event.HoverEvent;
+import com.sk89q.worldedit.util.formatting.text.format.TextColor;
+import com.sk89q.worldedit.world.World;
+import com.sk89q.worldedit.world.snapshot.InvalidSnapshotException;
+import com.sk89q.worldedit.world.snapshot.Snapshot;
+import com.sk89q.worldedit.world.storage.MissingWorldException;
+
+import java.io.File;
+import java.io.IOException;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+/**
+ * Legacy snapshot command implementations. Commands are still registered via
+ * {@link SnapshotCommands}, but it delegates to this class when legacy snapshots are in use.
+ */
+class LegacySnapshotCommands {
+
+    private static final DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss z");
+
+    private final WorldEdit we;
+
+    LegacySnapshotCommands(WorldEdit we) {
+        this.we = we;
+    }
+
+    void list(Actor actor, World world, int page) throws WorldEditException {
+        LocalConfiguration config = we.getConfiguration();
+
+        try {
+            List<Snapshot> snapshots = config.snapshotRepo.getSnapshots(true, world.getName());
+
+            if (!snapshots.isEmpty()) {
+                actor.print(new SnapshotListBox(world.getName(), snapshots).create(page));
+            } else {
+                actor.printError(TranslatableComponent.of("worldedit.restore.none-found-console"));
+
+                // Okay, let's toss some debugging information!
+                File dir = config.snapshotRepo.getDirectory();
+
+                try {
+                    WorldEdit.logger.info("WorldEdit found no snapshots: looked in: "
+                        + dir.getCanonicalPath());
+                } catch (IOException e) {
+                    WorldEdit.logger.info("WorldEdit found no snapshots: looked in "
+                        + "(NON-RESOLVABLE PATH - does it exist?): "
+                        + dir.getPath());
+                }
+            }
+        } catch (MissingWorldException ex) {
+            actor.printError(TranslatableComponent.of("worldedit.restore.none-for-world"));
+        }
+    }
+
+    void use(Actor actor, World world, LocalSession session, String name) {
+        LocalConfiguration config = we.getConfiguration();
+
+        // Want the latest snapshot?
+        if (name.equalsIgnoreCase("latest")) {
+            try {
+                Snapshot snapshot = config.snapshotRepo.getDefaultSnapshot(world.getName());
+
+                if (snapshot != null) {
+                    session.setSnapshot(null);
+                    actor.printInfo(TranslatableComponent.of("worldedit.snapshot.use.newest"));
+                } else {
+                    actor.printError(TranslatableComponent.of("worldedit.restore.none-found"));
+                }
+            } catch (MissingWorldException ex) {
+                actor.printError(TranslatableComponent.of("worldedit.restore.none-for-world"));
+            }
+        } else {
+            try {
+                session.setSnapshot(config.snapshotRepo.getSnapshot(name));
+                actor.printInfo(TranslatableComponent.of("worldedit.snapshot.use", TextComponent.of(name)));
+            } catch (InvalidSnapshotException e) {
+                actor.printError(TranslatableComponent.of("worldedit.restore.not-available"));
+            }
+        }
+    }
+
+    void sel(Actor actor, World world, LocalSession session, int index) {
+        LocalConfiguration config = we.getConfiguration();
+
+        if (index < 1) {
+            actor.printError(TranslatableComponent.of("worldedit.snapshot.index-above-0"));
+            return;
+        }
+
+        try {
+            List<Snapshot> snapshots = config.snapshotRepo.getSnapshots(true, world.getName());
+            if (snapshots.size() < index) {
+                actor.printError(TranslatableComponent.of("worldedit.snapshot.index-oob", TextComponent.of(snapshots.size())));
+                return;
+            }
+            Snapshot snapshot = snapshots.get(index - 1);
+            if (snapshot == null) {
+                actor.printError(TranslatableComponent.of("worldedit.restore.not-available"));
+                return;
+            }
+            session.setSnapshot(snapshot);
+            actor.printInfo(TranslatableComponent.of("worldedit.snapshot.use", TextComponent.of(snapshot.getName())));
+        } catch (MissingWorldException e) {
+            actor.printError(TranslatableComponent.of("worldedit.restore.none-for-world"));
+        }
+    }
+
+    void before(Actor actor, World world, LocalSession session, ZonedDateTime date) {
+        LocalConfiguration config = we.getConfiguration();
+
+        try {
+            Snapshot snapshot = config.snapshotRepo.getSnapshotBefore(date, world.getName());
+
+            if (snapshot == null) {
+                actor.printError(TranslatableComponent.of(
+                    "worldedit.snapshot.none-before",
+                    TextComponent.of(dateFormat.withZone(session.getTimeZone()).format(date)))
+                );
+            } else {
+                session.setSnapshot(snapshot);
+                actor.printInfo(TranslatableComponent.of("worldedit.snapshot.use", TextComponent.of(snapshot.getName())));
+            }
+        } catch (MissingWorldException ex) {
+            actor.printError(TranslatableComponent.of("worldedit.restore.none-for-world"));
+        }
+    }
+
+    void after(Actor actor, World world, LocalSession session, ZonedDateTime date) {
+        LocalConfiguration config = we.getConfiguration();
+
+        try {
+            Snapshot snapshot = config.snapshotRepo.getSnapshotAfter(date, world.getName());
+            if (snapshot == null) {
+                actor.printError(TranslatableComponent.of(
+                    "worldedit.snapshot.none-after",
+                    TextComponent.of(dateFormat.withZone(session.getTimeZone()).format(date)))
+                );
+            } else {
+                session.setSnapshot(snapshot);
+                actor.printInfo(TranslatableComponent.of("worldedit.snapshot.use", TextComponent.of(snapshot.getName())));
+            }
+        } catch (MissingWorldException ex) {
+            actor.printError(TranslatableComponent.of("worldedit.restore.none-for-world"));
+        }
+    }
+
+    private static class SnapshotListBox extends PaginationBox {
+        private final List<Snapshot> snapshots;
+
+        SnapshotListBox(String world, List<Snapshot> snapshots) {
+            super("Snapshots for: " + world, "/snap list -p %page%");
+            this.snapshots = snapshots;
+        }
+
+        @Override
+        public Component getComponent(int number) {
+            final Snapshot snapshot = snapshots.get(number);
+            return TextComponent.of(number + 1 + ". ", TextColor.GOLD)
+                .append(TextComponent.of(snapshot.getName(), TextColor.LIGHT_PURPLE)
+                    .hoverEvent(HoverEvent.of(HoverEvent.Action.SHOW_TEXT, TextComponent.of("Click to use")))
+                    .clickEvent(ClickEvent.of(ClickEvent.Action.RUN_COMMAND, "/snap use " + snapshot.getName())));
+        }
+
+        @Override
+        public int getComponentsSize() {
+            return snapshots.size();
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/command/LegacySnapshotUtilCommands.java

@@ -0,0 +1,136 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.command;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.LocalConfiguration;
+import com.sk89q.worldedit.LocalSession;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.extension.platform.Actor;
+import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
+import com.sk89q.worldedit.world.DataException;
+import com.sk89q.worldedit.world.World;
+import com.sk89q.worldedit.world.snapshot.InvalidSnapshotException;
+import com.sk89q.worldedit.world.snapshot.Snapshot;
+import com.sk89q.worldedit.world.snapshot.SnapshotRestore;
+import com.sk89q.worldedit.world.storage.ChunkStore;
+import com.sk89q.worldedit.world.storage.MissingWorldException;
+
+import java.io.File;
+import java.io.IOException;
+
+class LegacySnapshotUtilCommands {
+
+    private final WorldEdit we;
+
+    LegacySnapshotUtilCommands(WorldEdit we) {
+        this.we = we;
+    }
+
+    void restore(Actor actor, World world, LocalSession session, EditSession editSession,
+        String snapshotName) throws WorldEditException {
+        LocalConfiguration config = we.getConfiguration();
+
+        Region region = session.getSelection(world);
+        Snapshot snapshot;
+
+        if (snapshotName != null) {
+            try {
+                snapshot = config.snapshotRepo.getSnapshot(snapshotName);
+            } catch (InvalidSnapshotException e) {
+                actor.printError(TranslatableComponent.of("worldedit.restore.not-available"));
+                return;
+            }
+        } else {
+            snapshot = session.getSnapshot();
+        }
+
+        // No snapshot set?
+        if (snapshot == null) {
+            try {
+                snapshot = config.snapshotRepo.getDefaultSnapshot(world.getName());
+
+                if (snapshot == null) {
+                    actor.printError(TranslatableComponent.of("worldedit.restore.none-found-console"));
+
+                    // Okay, let's toss some debugging information!
+                    File dir = config.snapshotRepo.getDirectory();
+
+                    try {
+                        WorldEdit.logger.info("WorldEdit found no snapshots: looked in: "
+                            + dir.getCanonicalPath());
+                    } catch (IOException e) {
+                        WorldEdit.logger.info("WorldEdit found no snapshots: looked in "
+                            + "(NON-RESOLVABLE PATH - does it exist?): "
+                            + dir.getPath());
+                    }
+
+                    return;
+                }
+            } catch (MissingWorldException ex) {
+                actor.printError(TranslatableComponent.of("worldedit.restore.none-for-world"));
+                return;
+            }
+        }
+
+        ChunkStore chunkStore;
+
+        // Load chunk store
+        try {
+            chunkStore = snapshot.getChunkStore();
+            actor.printInfo(TranslatableComponent.of("worldedit.restore.loaded", TextComponent.of(snapshot.getName())));
+        } catch (DataException | IOException e) {
+            actor.printError(TranslatableComponent.of("worldedit.restore.failed", TextComponent.of(e.getMessage())));
+            return;
+        }
+
+        try {
+            // Restore snapshot
+            SnapshotRestore restore = new SnapshotRestore(chunkStore, editSession, region);
+            //player.print(restore.getChunksAffected() + " chunk(s) will be loaded.");
+
+            restore.restore();
+
+            if (restore.hadTotalFailure()) {
+                String error = restore.getLastErrorMessage();
+                if (!restore.getMissingChunks().isEmpty()) {
+                    actor.printError(TranslatableComponent.of("worldedit.restore.chunk-not-present"));
+                } else if (error != null) {
+                    actor.printError(TranslatableComponent.of("worldedit.restore.block-place-failed"));
+                    actor.printError(TranslatableComponent.of("worldedit.restore.block-place-error", TextComponent.of(error)));
+                } else {
+                    actor.printError(TranslatableComponent.of("worldedit.restore.chunk-load-failed"));
+                }
+            } else {
+                actor.printInfo(TranslatableComponent.of("worldedit.restore.restored",
+                    TextComponent.of(restore.getMissingChunks().size()),
+                    TextComponent.of(restore.getErrorChunks().size())));
+            }
+        } finally {
+            try {
+                chunkStore.close();
+            } catch (IOException ignored) {
+            }
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/command/PaintBrushCommands.java

@@ -19,6 +19,9 @@
 
 package com.sk89q.worldedit.command;
 
+import static java.util.Objects.requireNonNull;
+import static org.enginehub.piston.part.CommandParts.arg;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.sk89q.worldedit.LocalSession;
@@ -37,13 +40,13 @@ import com.sk89q.worldedit.function.factory.Paint;
 import com.sk89q.worldedit.function.pattern.Pattern;
 import com.sk89q.worldedit.internal.annotation.Direction;
 import com.sk89q.worldedit.internal.command.CommandRegistrationHandler;
-import com.sk89q.worldedit.internal.expression.Expression;
 import com.sk89q.worldedit.regions.factory.RegionFactory;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
 import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.util.formatting.text.format.TextColor;
 import com.sk89q.worldedit.util.formatting.text.format.TextDecoration;
+import java.util.stream.Collectors;
 import org.enginehub.piston.CommandManager;
 import org.enginehub.piston.CommandManagerService;
 import org.enginehub.piston.CommandParameters;
@@ -54,11 +57,6 @@ import org.enginehub.piston.inject.Key;
 import org.enginehub.piston.part.CommandArgument;
 import org.enginehub.piston.part.SubCommandPart;
 
-import java.util.stream.Collectors;
-
-import static java.util.Objects.requireNonNull;
-import static org.enginehub.piston.part.CommandParts.arg;
-
 @CommandContainer(superTypes = CommandPermissionsConditionGenerator.Registration.class)
 public class PaintBrushCommands {
 
@@ -104,7 +102,7 @@ public class PaintBrushCommands {
         double radius = requireNonNull(RADIUS.value(parameters).asSingle(double.class));
         double density = requireNonNull(DENSITY.value(parameters).asSingle(double.class)) / 100;
         RegionFactory regionFactory = REGION_FACTORY.value(parameters).asSingle(RegionFactory.class);
-        BrushCommands.setOperationBasedBrush(player, localSession, Expression.compile(Double.toString(radius)),
+        BrushCommands.setOperationBasedBrush(player, localSession, radius,
             new Paint(generatorFactory, density), regionFactory, "worldedit.brush.paint");
     }
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/RegionCommands.java

@@ -260,7 +260,7 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.curve")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void curve(Actor actor, EditSession editSession,
+    public int curve(Actor actor, EditSession editSession,
                      @Selection Region region,
                      @Arg(desc = "The pattern of blocks to place")
                          Pattern pattern,
@@ -269,8 +269,8 @@ public class RegionCommands {
                      @Switch(name = 'h', desc = "Generate only a shell")
                          boolean shell) throws WorldEditException {
         if (!(region instanceof ConvexPolyhedralRegion)) {
-            actor.printError(TranslatableComponent.of("worldedit.curve.convex-only"));
+            actor.printError(TranslatableComponent.of("worldedit.curve.invalid-type"));
-            return;
+            return 0;
         }
         checkCommandArgument(thickness >= 0, "Thickness must be >= 0");
 
@@ -280,6 +280,7 @@ public class RegionCommands {
         int blocksChanged = editSession.drawSpline(pattern, vectors, 0, 0, 0, 10, thickness, !shell);
 
         actor.printInfo(TranslatableComponent.of("worldedit.curve.changed", TextComponent.of(blocksChanged)));
+        return blocksChanged;
     }
 
     @Command(
@@ -290,7 +291,7 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.replace")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void replace(Actor actor, EditSession editSession, @Selection Region region,
+    public int replace(Actor actor, EditSession editSession, @Selection Region region,
                        @Arg(desc = "The mask representing blocks to replace", def = "")
                            Mask from,
                        @Arg(desc = "The pattern of blocks to replace with")
@@ -300,6 +301,7 @@ public class RegionCommands {
         }
         int affected = editSession.replaceBlocks(region, from, to);
         actor.printInfo(TranslatableComponent.of("worldedit.replace.replaced", TextComponent.of(affected)));
+        return affected;
     }
 
     @Command(
@@ -309,11 +311,12 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.overlay")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void overlay(Actor actor, EditSession editSession, @Selection Region region,
+    public int overlay(Actor actor, EditSession editSession, @Selection Region region,
                        @Arg(desc = "The pattern of blocks to overlay")
                             Pattern pattern) throws WorldEditException {
         int affected = editSession.overlayCuboidBlocks(region, pattern);
         actor.printInfo(TranslatableComponent.of("worldedit.overlay.overlaid", TextComponent.of(affected)));
+        return affected;
     }
 
     @Command(
@@ -363,9 +366,10 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.naturalize")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void naturalize(Actor actor, EditSession editSession, @Selection Region region) throws WorldEditException {
+    public int naturalize(Actor actor, EditSession editSession, @Selection Region region) throws WorldEditException {
         int affected = editSession.naturalizeCuboidBlocks(region);
         actor.printInfo(TranslatableComponent.of("worldedit.naturalize.naturalized", TextComponent.of(affected)));
+        return affected;
     }
 
     @Command(
@@ -375,11 +379,12 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.walls")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void walls(Actor actor, EditSession editSession, @Selection Region region,
+    public int walls(Actor actor, EditSession editSession, @Selection Region region,
                      @Arg(desc = "The pattern of blocks to set")
                          Pattern pattern) throws WorldEditException {
         int affected = editSession.makeWalls(region, pattern);
         actor.printInfo(TranslatableComponent.of("worldedit.walls.changed", TextComponent.of(affected)));
+        return affected;
     }
 
     @Command(
@@ -390,11 +395,12 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.faces")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void faces(Actor actor, EditSession editSession, @Selection Region region,
+    public int faces(Actor actor, EditSession editSession, @Selection Region region,
                      @Arg(desc = "The pattern of blocks to set")
                          Pattern pattern) throws WorldEditException {
         int affected = editSession.makeCuboidFaces(region, pattern);
         actor.printInfo(TranslatableComponent.of("worldedit.faces.changed", TextComponent.of(affected)));
+        return affected;
     }
 
     @Command(
@@ -405,7 +411,7 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.smooth")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void smooth(Actor actor, EditSession editSession, @Selection Region region,
+    public int smooth(Actor actor, EditSession editSession, @Selection Region region,
                       @Arg(desc = "# of iterations to perform", def = "1")
                           int iterations,
                       @Arg(desc = "The mask of blocks to use as the height map", def = "")
@@ -418,14 +424,16 @@ public class RegionCommands {
         if (volume >= limit.MAX_CHECKS) {
             throw FaweCache.MAX_CHECKS;
         }
+        int affected = 0;
         try {
             HeightMap heightMap = new HeightMap(editSession, region, mask, snow);
             HeightMapFilter filter = new HeightMapFilter(new GaussianKernel(5, 1.0));
-        int affected = heightMap.applyFilter(filter, iterations);
+            affected = heightMap.applyFilter(filter, iterations);
             actor.printInfo(TranslatableComponent.of("worldedit.smooth.changed", TextComponent.of(affected)));
         } catch (Throwable e) {
             throw new RuntimeException(e);
         }
+        return affected;
     }
 
     @Command(
@@ -605,13 +613,20 @@ public class RegionCommands {
         @Arg(def = "", desc = "Regenerate with biome") BiomeType biome,
         @Arg(def = "", desc = "Regenerate with seed") Long seed) throws WorldEditException {
         Mask mask = session.getMask();
+        boolean success;
+        try {
             session.setMask((Mask) null);
             session.setSourceMask((Mask) null);
-        world.regenerate(region, editSession);
+            success = world.regenerate(region, editSession);
-//        editSession.regenerate(region, biome, seed);
+        } finally {
             session.setMask(mask);
             session.setSourceMask(mask);
+        }
+        if (success) {
         actor.printInfo(TranslatableComponent.of("worldedit.regen.regenerated"));
+        } else {
+            actor.printError(TranslatableComponent.of("worldedit.regen.failed"));
+        }
     }
 
     @Command(
@@ -624,7 +639,7 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.deform")
     @Logging(ALL)
     @Confirm(Confirm.Processor.REGION)
-    public void deform(Actor actor, LocalSession session, EditSession editSession,
+    public int deform(Actor actor, LocalSession session, EditSession editSession,
                       @Selection Region region,
                       @Arg(desc = "The expression to use", variable = true)
                           List<String> expression,
@@ -660,8 +675,10 @@ public class RegionCommands {
                 ((Player) actor).findFreePosition();
             }
             actor.printInfo(TranslatableComponent.of("worldedit.deform.deformed", TextComponent.of(affected)));
+            return affected;
         } catch (ExpressionException e) {
             actor.printError(TextComponent.of(e.getMessage()));
+            return 0;
         }
     }
 
@@ -676,9 +693,9 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.hollow")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void hollow(Actor actor, EditSession editSession,
+    public int hollow(Actor actor, EditSession editSession,
                       @Selection Region region,
-                       @Range(from=0, to=Integer.MAX_VALUE) @Arg(desc = "Thickness of the shell to leave", def = "0")
+                      @Range(from = 0, to = Integer.MAX_VALUE) @Arg(desc = "Thickness of the shell to leave", def = "0")
                           int thickness,
                       @Arg(desc = "The pattern of blocks to replace the hollowed area with", def = "air")
                           Pattern pattern,
@@ -687,6 +704,7 @@ public class RegionCommands {
         Mask finalMask = mask == null ? new SolidBlockMask(editSession) : mask;
         int affected = editSession.hollowOutRegion(region, thickness, pattern, finalMask);
         actor.printInfo(TranslatableComponent.of("worldedit.hollow.changed", TextComponent.of(affected)));
+        return affected;
     }
 
     @Command(
@@ -714,18 +732,20 @@ public class RegionCommands {
     @CommandPermissions("worldedit.region.flora")
     @Logging(REGION)
     @Confirm(Confirm.Processor.REGION)
-    public void flora(Actor actor, EditSession editSession, @Selection Region region,
+    public int flora(Actor actor, EditSession editSession, @Selection Region region,
                      @Arg(desc = "The density of the forest", def = "5")
                          double density) throws WorldEditException {
         checkCommandArgument(0 <= density && density <= 100, "Density must be in [0, 100]");
+        density = density / 100;
         FloraGenerator generator = new FloraGenerator(editSession);
         GroundFunction ground = new GroundFunction(new ExistingBlockMask(editSession), generator);
         LayerVisitor visitor = new LayerVisitor(asFlatRegion(region), minimumBlockY(region), maximumBlockY(region), ground);
-        visitor.setMask(new NoiseFilter2D(new RandomNoise(), density / 100));
+        visitor.setMask(new NoiseFilter2D(new RandomNoise(), density));
         Operations.completeLegacy(visitor);
 
         int affected = ground.getAffected();
         actor.printInfo(TranslatableComponent.of("worldedit.flora.created", TextComponent.of(affected)));
+        return affected;
     }
 
 }

worldedit-core/src/main/java/com/sk89q/worldedit/command/SchematicCommands.java

@@ -213,11 +213,11 @@ public class SchematicCommands {
     public void load(Actor actor, LocalSession session,
                      @Arg(desc = "File name.")
                          String filename,
-                     @Arg(desc = "Format name.", def = "")
+                     @Arg(desc = "Format name.", def = "sponge")
                          String formatName) throws FilenameException {
         LocalConfiguration config = worldEdit.getConfiguration();
 
-        ClipboardFormat format = formatName != null ? ClipboardFormats.findByAlias(formatName) : null;
+        ClipboardFormat format = ClipboardFormats.findByAlias(formatName);
         InputStream in = null;
         try {
             URI uri;
@@ -537,7 +537,7 @@ public class SchematicCommands {
     )
     @CommandPermissions("worldedit.schematic.list")
     public void list(Actor actor, LocalSession session,
-                     @ArgFlag(name = 'p', desc = "Page to view.", def = "-1")
+                     @ArgFlag(name = 'p', desc = "Page to view.", def = "1")
                          int page,
                      @Switch(name = 'd', desc = "Sort by date, oldest first")
                          boolean oldFirst,
@@ -571,15 +571,6 @@ public class SchematicCommands {
         final boolean hasShow = false;
 
         //If player forgot -p argument
-        if (page == -1) {
-            page = 1;
-            if (args.size() != 0) {
-                String lastArg = args.get(args.size() - 1);
-                if (MathMan.isInteger(lastArg)) {
-                    page = Integer.parseInt(lastArg);
-                }
-            }
-        }
         boolean playerFolder = Settings.IMP.PATHS.PER_PLAYER_SCHEMATICS;
         UUID uuid = playerFolder ? actor.getUniqueId() : null;
         List<File> files = UtilityCommands.getFiles(dir, actor, args, formatName, playerFolder, oldFirst, newFirst);

worldedit-core/src/main/java/com/sk89q/worldedit/command/SelectionCommands.java

@@ -19,22 +19,15 @@
 
 package com.sk89q.worldedit.command;
 
-import com.boydti.fawe.config.Caption;
-import com.google.common.base.Strings;
-
 import static com.sk89q.worldedit.command.util.Logging.LogMode.POSITION;
 import static com.sk89q.worldedit.command.util.Logging.LogMode.REGION;
 
-import com.sk89q.worldedit.extent.Extent;
+import com.boydti.fawe.config.Caption;
-import com.sk89q.worldedit.function.block.BlockDistributionCounter;
-import com.sk89q.worldedit.function.operation.Operations;
-import com.sk89q.worldedit.function.visitor.RegionVisitor;
-import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.boydti.fawe.object.clipboard.URIClipboardHolder;
 import com.boydti.fawe.object.mask.IdMask;
 import com.boydti.fawe.object.regions.selector.FuzzyRegionSelector;
 import com.boydti.fawe.object.regions.selector.PolyhedralRegionSelector;
-import com.boydti.fawe.util.ExtentTraverser;
+import com.google.common.base.Strings;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.LocalSession;
 import com.sk89q.worldedit.WorldEdit;
@@ -50,9 +43,12 @@ import com.sk89q.worldedit.entity.Player;
 import com.sk89q.worldedit.extension.platform.Actor;
 import com.sk89q.worldedit.extension.platform.Locatable;
 import com.sk89q.worldedit.extension.platform.permission.ActorSelectorLimits;
-import com.sk89q.worldedit.extent.AbstractDelegateExtent;
+import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.extent.clipboard.Clipboard;
+import com.sk89q.worldedit.function.block.BlockDistributionCounter;
 import com.sk89q.worldedit.function.mask.Mask;
+import com.sk89q.worldedit.function.operation.Operations;
+import com.sk89q.worldedit.function.visitor.RegionVisitor;
 import com.sk89q.worldedit.internal.annotation.Direction;
 import com.sk89q.worldedit.internal.annotation.MultiDirection;
 import com.sk89q.worldedit.math.BlockVector2;
@@ -72,31 +68,32 @@ import com.sk89q.worldedit.session.ClipboardHolder;
 import com.sk89q.worldedit.util.Countable;
 import com.sk89q.worldedit.util.Location;
 import com.sk89q.worldedit.util.formatting.component.CommandListBox;
+import com.sk89q.worldedit.util.formatting.component.InvalidComponentException;
+import com.sk89q.worldedit.util.formatting.component.PaginationBox;
 import com.sk89q.worldedit.util.formatting.component.SubtleFormat;
 import com.sk89q.worldedit.util.formatting.component.TextComponentProducer;
+import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.util.formatting.text.event.ClickEvent;
+import com.sk89q.worldedit.util.formatting.text.event.HoverEvent;
 import com.sk89q.worldedit.util.formatting.text.format.TextColor;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.block.BlockState;
+import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.item.ItemType;
 import com.sk89q.worldedit.world.item.ItemTypes;
 import com.sk89q.worldedit.world.storage.ChunkStore;
 import java.io.File;
 import java.net.URI;
 import java.util.List;
-import com.sk89q.worldedit.util.formatting.component.PaginationBox;
-import com.sk89q.worldedit.util.formatting.component.InvalidComponentException;
-import com.sk89q.worldedit.util.formatting.text.Component;
 import java.util.Optional;
-import com.sk89q.worldedit.util.formatting.text.event.HoverEvent;
 import java.util.stream.Stream;
 import org.enginehub.piston.annotation.Command;
 import org.enginehub.piston.annotation.CommandContainer;
-import com.sk89q.worldedit.world.block.BlockType;
 import org.enginehub.piston.annotation.param.Arg;
-import org.enginehub.piston.annotation.param.Switch;
 import org.enginehub.piston.annotation.param.ArgFlag;
+import org.enginehub.piston.annotation.param.Switch;
 import org.enginehub.piston.exception.StopExecutionException;
 
 /**
@@ -306,9 +303,6 @@ public class SelectionCommands {
             session.setTool(itemType, SelectionWand.INSTANCE);
             player.printInfo(TranslatableComponent.of("worldedit.wand.selwand.info"));
         }
-        if (!player.hasPermission("fawe.tips"))
-            System.out.println("TODO FIXME tips");
-//            TranslatableComponent.of("fawe.tips.tip.sel.list").or(TranslatableComponent.of("fawe.tips.tip.select.connected"), TranslatableComponent.of("fawe.tips.tip.set.pos1"), TranslatableComponent.of("fawe.tips.tip.farwand"), TranslatableComponent.of("fawe.tips.tip.discord")).send(player);
     }
 
     @Command(
@@ -480,8 +474,7 @@ public class SelectionCommands {
 
                 region = clipboard.getRegion();
                 BlockVector3 size = region.getMaximumPoint()
-                        .subtract(region.getMinimumPoint()).
+                        .subtract(region.getMinimumPoint()).add(1, 1, 1);
-                                add(1, 1, 1);
                 BlockVector3 origin = clipboard.getOrigin();
 
                 String sizeStr = size.getBlockX() + "*" + size.getBlockY() + "*" + size.getBlockZ();
@@ -500,7 +493,6 @@ public class SelectionCommands {
             for (Component line : session.getRegionSelector(world).getSelectionInfoLines()) {
                 actor.print(line);
             }
-
         }
         BlockVector3 size = region.getMaximumPoint()
                 .subtract(region.getMinimumPoint())
@@ -529,34 +521,34 @@ public class SelectionCommands {
         desc = "Get the distribution of blocks in the selection"
     )
     @CommandPermissions("worldedit.analysis.distr")
-    public void distr(Actor actor, World world, LocalSession session, EditSession editSession,
+    public void distr(Actor actor, World world, LocalSession session,
                       @Switch(name = 'c', desc = "Get the distribution of the clipboard instead")
                               boolean clipboardDistr,
                       @Switch(name = 'd', desc = "Separate blocks by state")
                               boolean separateStates,
                       @ArgFlag(name = 'p', desc = "Gets page from a previous distribution.", def = "")
                               Integer page) throws WorldEditException {
-        List<Countable> distribution;
+        List<Countable<BlockState>> distribution;
 
         Region region;
         if (page == null) {
             Extent extent;
             if (clipboardDistr) {
                 Clipboard clipboard = session.getClipboard().getClipboard(); // throws if missing
-                extent = clipboard;
+                BlockDistributionCounter count = new BlockDistributionCounter(clipboard, separateStates);
-                region = clipboard.getRegion();
+                RegionVisitor visitor = new RegionVisitor(clipboard.getRegion(), count);
+                Operations.completeBlindly(visitor);
+                distribution = count.getDistribution();
             } else {
-                extent = editSession;
+                try (EditSession editSession = session.createEditSession(actor)) {
-                region = session.getSelection(world);
+                    distribution = editSession
+                        .getBlockDistribution(session.getSelection(world), separateStates);
+                }
             }
-            if (separateStates)
-                distribution = (List) extent.getBlockDistributionWithData(region);
-            else
-                distribution = (List) extent.getBlockDistribution(region);
             session.setLastDistribution(distribution);
             page = 1;
         } else {
-            distribution = (List) session.getLastDistribution();
+            distribution = session.getLastDistribution();
             if (distribution == null) {
                 actor.printError(TranslatableComponent.of("worldedit.distr.no-previous"));
                 return;
@@ -572,69 +564,6 @@ public class SelectionCommands {
         actor.print(res.create(page));
     }
 
-    public static class BlockDistributionResult extends PaginationBox {
-
-        private final List<Countable> distribution;
-        private final int totalBlocks;
-        private final boolean separateStates;
-
-        public BlockDistributionResult(List<Countable> distribution, boolean separateStates) {
-            this(distribution, separateStates, "//distr -p %page%" + (separateStates ? " -d" : ""));
-        }
-
-        public BlockDistributionResult(List<Countable> distribution, boolean separateStates, String pageCommand) {
-            super("Block Distribution", pageCommand);
-            this.distribution = distribution;
-            // note: doing things like region.getArea is inaccurate for non-cuboids.
-            this.totalBlocks = distribution.stream().mapToInt(Countable::getAmount).sum();
-            this.separateStates = separateStates;
-            setComponentsPerPage(7);
-        }
-
-        @Override
-        public Component getComponent(int number) {
-            Countable<BlockState> c = distribution.get(number);
-            TextComponent.Builder line = TextComponent.builder();
-
-            final int count = c.getAmount();
-
-            final double perc = count / (double) totalBlocks * 100;
-            final int maxDigits = (int) (Math.log10(totalBlocks) + 1);
-            final int curDigits = (int) (Math.log10(count) + 1);
-            line.append(String.format("%s%.3f%%  ", perc < 10 ? "  " : "", perc), TextColor.GOLD);
-            final int space = maxDigits - curDigits;
-            String pad = Strings.repeat(" ", space == 0 ? 2 : 2 * space + 1);
-            line.append(String.format("%s%s", count, pad), TextColor.YELLOW);
-
-            final BlockState state = c.getID();
-            final BlockType blockType = state.getBlockType();
-            TextComponent blockName = TextComponent.of(blockType.getName(), TextColor.GRAY);
-            TextComponent toolTip;
-            if (separateStates && state != blockType.getDefaultState()) {
-                toolTip = TextComponent.of(state.getAsString(), TextColor.GRAY);
-                blockName = blockName.append(TextComponent.of("*", TextColor.GRAY));
-            } else {
-                toolTip = TextComponent.of(blockType.getId(), TextColor.GRAY);
-            }
-            blockName = blockName.hoverEvent(HoverEvent.of(HoverEvent.Action.SHOW_TEXT, toolTip));
-            line.append(blockName);
-
-            return line.build();
-        }
-
-        @Override
-        public int getComponentsSize() {
-            return distribution.size();
-        }
-
-        @Override
-        public Component create(int page) throws InvalidComponentException {
-            super.getContents().append(TranslatableComponent.of("worldedit.distr.total", TextColor.GRAY, TextComponent.of(totalBlocks)))
-                    .append(TextComponent.newline());
-            return super.create(page);
-        }
-    }
-
     @Command(
         name = "/sel",
         aliases = { ";", "/desel", "/deselect" },
@@ -751,4 +680,67 @@ public class SelectionCommands {
         session.setRegionSelector(world, newSelector);
         session.dispatchCUISelection(actor);
     }
+
+    public static class BlockDistributionResult extends PaginationBox {
+
+        private final List<Countable<BlockState>> distribution;
+        private final int totalBlocks;
+        private final boolean separateStates;
+
+        public BlockDistributionResult(List<Countable<BlockState>> distribution, boolean separateStates) {
+            this(distribution, separateStates, "//distr -p %page%" + (separateStates ? " -d" : ""));
+        }
+
+        public BlockDistributionResult(List<Countable<BlockState>> distribution, boolean separateStates, String pageCommand) {
+            super("Block Distribution", pageCommand);
+            this.distribution = distribution;
+            // note: doing things like region.getArea is inaccurate for non-cuboids.
+            this.totalBlocks = distribution.stream().mapToInt(Countable::getAmount).sum();
+            this.separateStates = separateStates;
+            setComponentsPerPage(7);
+        }
+
+        @Override
+        public Component getComponent(int number) {
+            Countable<BlockState> c = distribution.get(number);
+            TextComponent.Builder line = TextComponent.builder();
+
+            final int count = c.getAmount();
+
+            final double perc = count / (double) totalBlocks * 100;
+            final int maxDigits = (int) (Math.log10(totalBlocks) + 1);
+            final int curDigits = (int) (Math.log10(count) + 1);
+            line.append(String.format("%s%.3f%%  ", perc < 10 ? "  " : "", perc), TextColor.GOLD);
+            final int space = maxDigits - curDigits;
+            String pad = Strings.repeat(" ", space == 0 ? 2 : 2 * space + 1);
+            line.append(String.format("%s%s", count, pad), TextColor.YELLOW);
+
+            final BlockState state = c.getID();
+            final BlockType blockType = state.getBlockType();
+            TextComponent blockName = TextComponent.of(blockType.getName(), TextColor.LIGHT_PURPLE);
+            TextComponent toolTip;
+            if (separateStates && state != blockType.getDefaultState()) {
+                toolTip = TextComponent.of(state.getAsString(), TextColor.GRAY);
+                blockName = blockName.append(TextComponent.of("*", TextColor.LIGHT_PURPLE));
+            } else {
+                toolTip = TextComponent.of(blockType.getId(), TextColor.GRAY);
+            }
+            blockName = blockName.hoverEvent(HoverEvent.of(HoverEvent.Action.SHOW_TEXT, toolTip));
+            line.append(blockName);
+
+            return line.build();
+        }
+
+        @Override
+        public int getComponentsSize() {
+            return distribution.size();
+        }
+
+        @Override
+        public Component create(int page) throws InvalidComponentException {
+            super.getContents().append(TranslatableComponent.of("worldedit.distr.total", TextColor.GRAY, TextComponent.of(totalBlocks)))
+                    .append(TextComponent.newline());
+            return super.create(page);
+        }
+    }
 }

worldedit-core/src/main/java/com/sk89q/worldedit/command/SnapshotCommands.java

@@ -259,7 +259,7 @@ public class SnapshotCommands {
         public Component getComponent(int number) {
             final Snapshot snapshot = snapshots.get(number);
             return TextComponent.of(number + 1 + ". ", TextColor.GOLD)
-                    .append(TextComponent.of(snapshot.getName(), TextColor.GRAY)
+                    .append(TextComponent.of(snapshot.getName(), TextColor.LIGHT_PURPLE)
                             .hoverEvent(HoverEvent.of(HoverEvent.Action.SHOW_TEXT, TextComponent.of("Click to use")))
                             .clickEvent(ClickEvent.of(ClickEvent.Action.RUN_COMMAND, "/snap use " + snapshot.getName())));
         }

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/parser/mask/ExpressionMaskParser.java

@@ -61,8 +61,8 @@ public class ExpressionMaskParser extends InputParser<Mask> {
             exp.setEnvironment(env);
             if (context.getActor() != null) {
                 SessionOwner owner = context.getActor();
-                Integer timeout = WorldEdit.getInstance().getSessionManager().get(owner).getTimeout();
+                IntSupplier timeout = () -> WorldEdit.getInstance().getSessionManager().get(owner).getTimeout();
-                return new ExpressionMask(exp, timeout::intValue);
+                return new ExpressionMask(exp, timeout);
             }
             return new ExpressionMask(exp);
         } catch (ExpressionException e) {

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/parser/mask/OffsetMaskParser.java

@@ -32,8 +32,6 @@ import com.sk89q.worldedit.math.BlockVector3;
 
 import java.util.stream.Stream;
 
-import java.util.stream.Stream;
-
 public class OffsetMaskParser extends InputParser<Mask> {
 
     public OffsetMaskParser(WorldEdit worldEdit) {

worldedit-core/src/main/java/com/sk89q/worldedit/function/mask/BlockMaskBuilder.java

@@ -37,9 +37,9 @@ public class BlockMaskBuilder {
     }
 
     private boolean filterRegex(BlockType blockType, PropertyKey key, String regex) {
-        Property property = blockType.getProperty(key);
+        Property<Object> property = blockType.getProperty(key);
         if (property == null) return false;
-        List values = property.getValues();
+        List<Object> values = property.getValues();
         boolean result = false;
         for (int i = 0; i < values.size(); i++) {
             Object value = values.get(i);
@@ -52,10 +52,10 @@ public class BlockMaskBuilder {
     }
 
     private boolean filterOperator(BlockType blockType, PropertyKey key, Operator operator, CharSequence value) {
-        Property property = blockType.getProperty(key);
+        Property<Object> property = blockType.getProperty(key);
         if (property == null) return false;
         int index = property.getIndexFor(value);
-        List values = property.getValues();
+        List<Object> values = property.getValues();
         boolean result = false;
         for (int i = 0; i < values.size(); i++) {
             if (!operator.test(index, i) && has(blockType, property, i)) {
@@ -151,7 +151,7 @@ public class BlockMaskBuilder {
                             throw new SuggestInputParseException("No value for " + input, input, () -> {
                                 HashSet<String> values = new HashSet<>();
                                 types.stream().filter(t -> t.hasProperty(fKey)).forEach(t -> {
-                                    Property p = t.getProperty(fKey);
+                                    Property<Object> p = t.getProperty(fKey);
                                     for (int j = 0; j < p.getValues().size(); j++) {
                                         if (has(t, p, j)) {
                                             String o = p.getValues().get(j).toString();
@@ -220,8 +220,8 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    private boolean has(BlockType type, Property property, int index) {
+    private <T> boolean has(BlockType type, Property<T> property, int index) {
-        AbstractProperty prop = (AbstractProperty) property;
+        AbstractProperty<T> prop = (AbstractProperty<T>) property;
         long[] states = bitSets[type.getInternalId()];
         if (states == null) return false;
         int localI = index << prop.getBitOffset() >> BlockTypesCache.BIT_OFFSET;
@@ -247,10 +247,7 @@ public class BlockMaskBuilder {
     private boolean optimizedStates = true;
 
     public boolean isEmpty() {
-        for (long[] bitSet : bitSets) {
+        return Arrays.stream(bitSets).noneMatch(Objects::nonNull);
-            if (bitSet != null) return false;
-        }
-        return true;
     }
 
     public BlockMaskBuilder() {
@@ -283,7 +280,7 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public BlockMaskBuilder remove(BlockStateHolder state) {
+    public <T extends BlockStateHolder<T>> BlockMaskBuilder remove(BlockStateHolder<T> state) {
         BlockType type = state.getBlockType();
         int i = type.getInternalId();
         long[] states = bitSets[i];
@@ -308,7 +305,7 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public BlockMaskBuilder filter(BlockStateHolder state) {
+    public <T extends BlockStateHolder<T>> BlockMaskBuilder filter(BlockStateHolder<T> state) {
         filter(state.getBlockType());
         BlockType type = state.getBlockType();
         int i = type.getInternalId();
@@ -351,8 +348,8 @@ public class BlockMaskBuilder {
                 continue;
             }
             List<AbstractProperty<?>> properties = (List<AbstractProperty<?>>) type.getProperties();
-            for (AbstractProperty prop : properties) {
+            for (AbstractProperty<?> prop : properties) {
-                List values = prop.getValues();
+                List<?> values = prop.getValues();
                 for (int j = 0; j < values.size(); j++) {
                     int localI = j << prop.getBitOffset() >> BlockTypesCache.BIT_OFFSET;
                     if (states == ALL || FastBitSet.get(states, localI)) {
@@ -376,7 +373,7 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public BlockMaskBuilder add(BlockStateHolder state) {
+    public <T extends BlockStateHolder<T>> BlockMaskBuilder add(BlockStateHolder<T> state) {
         BlockType type = state.getBlockType();
         int i = type.getInternalId();
         long[] states = bitSets[i];
@@ -391,8 +388,8 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public <T extends BlockStateHolder> BlockMaskBuilder addBlocks(Collection<T> blocks) {
+    public <T extends BlockStateHolder<T>> BlockMaskBuilder addBlocks(Collection<T> blocks) {
-        for (BlockStateHolder block : blocks) add(block);
+        for (BlockStateHolder<T> block : blocks) add(block);
         return this;
     }
 
@@ -401,8 +398,8 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public <T extends BlockStateHolder> BlockMaskBuilder addBlocks(T... blocks) {
+    public <T extends BlockStateHolder<T>> BlockMaskBuilder addBlocks(T... blocks) {
-        for (BlockStateHolder block : blocks) add(block);
+        for (BlockStateHolder<T> block : blocks) add(block);
         return this;
     }
 
@@ -429,8 +426,8 @@ public class BlockMaskBuilder {
             if (!typePredicate.test(type)) {
                 continue;
             }
-            for (AbstractProperty prop : (List<AbstractProperty<?>>) type.getProperties()) {
+            for (AbstractProperty<?> prop : (List<AbstractProperty<?>>) type.getProperties()) {
-                List values = prop.getValues();
+                List<?> values = prop.getValues();
                 for (int j = 0; j < values.size(); j++) {
                     int localI = j << prop.getBitOffset() >> BlockTypesCache.BIT_OFFSET;
                     if (states == null || !FastBitSet.get(states, localI)) {
@@ -448,12 +445,12 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public BlockMaskBuilder add(BlockType type, Property property, int index) {
+    public <T> BlockMaskBuilder add(BlockType type, Property<T> property, int index) {
-        AbstractProperty prop = (AbstractProperty) property;
+        AbstractProperty<T> prop = (AbstractProperty<T>) property;
         long[] states = bitSets[type.getInternalId()];
         if (states == ALL) return this;
 
-        List values = property.getValues();
+        List<T> values = property.getValues();
         int localI = index << prop.getBitOffset() >> BlockTypesCache.BIT_OFFSET;
         if (states == null || !FastBitSet.get(states, localI)) {
             if (states == null) {
@@ -465,11 +462,11 @@ public class BlockMaskBuilder {
         return this;
     }
 
-    public BlockMaskBuilder filter(BlockType type, Property property, int index) {
+    public <T> BlockMaskBuilder filter(BlockType type, Property<T> property, int index) {
-        AbstractProperty prop = (AbstractProperty) property;
+        AbstractProperty<T> prop = (AbstractProperty<T>) property;
         long[] states = bitSets[type.getInternalId()];
         if (states == null) return this;
-        List values = property.getValues();
+        List<T> values = property.getValues();
         int localI = index << prop.getBitOffset() >> BlockTypesCache.BIT_OFFSET;
         if (states == ALL || FastBitSet.get(states, localI)) {
             if (states == ALL) {
@@ -537,8 +534,8 @@ public class BlockMaskBuilder {
                 }
                 int set = 0;
                 int clear = 0;
-                for (AbstractProperty prop : (List<AbstractProperty<?>>) type.getProperties()) {
+                for (AbstractProperty<?> prop : (List<AbstractProperty<?>>) type.getProperties()) {
-                    List values = prop.getValues();
+                    List<?> values = prop.getValues();
                     for (int j = 0; j < values.size(); j++) {
                         int localI = j << prop.getBitOffset() >> BlockTypesCache.BIT_OFFSET;
                         if (FastBitSet.get(bitSet, localI)) set++;

worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/ExpressionHelper.java

@@ -35,14 +35,6 @@ import static com.sk89q.worldedit.antlr.ExpressionLexer.ID;
 
 public class ExpressionHelper {
 
-    /**
-     * The argument should be wrapped in a {@link LocalSlot.Constant} before being passed.
-     */
-    public static final String WRAPPED_CONSTANT = "<wrapped constant>";
-
-    private ExpressionHelper() {
-    }
-
     public static void check(boolean condition, ParserRuleContext ctx, String message) {
         if (!condition) {
             throw evalException(ctx, message);
@@ -68,8 +60,6 @@ public class ExpressionHelper {
         check(iterations <= 256, ctx, "Loop exceeded 256 iterations");
     }
 
-    // Special argument handle names
-
     public static void checkTimeout() {
         if (Thread.interrupted()) {
             throw new ExpressionTimeoutException("Calculations exceeded time limit.");
@@ -106,6 +96,12 @@ public class ExpressionHelper {
             "got " + ctx.args.size());
     }
 
+    // Special argument handle names
+    /**
+     * The argument should be wrapped in a {@link LocalSlot.Constant} before being passed.
+     */
+    public static final String WRAPPED_CONSTANT = "<wrapped constant>";
+
     /**
      * If this argument needs a handle, returns the name of the handle needed. Otherwise, returns
      * {@code null}. If {@code arg} isn't a valid handle reference, throws.
@@ -155,4 +151,7 @@ public class ExpressionHelper {
         return tryAs(ctxs.get(0), rule);
     }
 
+    private ExpressionHelper() {
+    }
+
 }

worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/Functions.java

@@ -22,8 +22,8 @@ package com.sk89q.worldedit.internal.expression;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSetMultimap;
-import com.google.common.collect.SetMultimap;
 import com.google.common.collect.Multimaps;
+import com.google.common.collect.SetMultimap;
 import com.google.common.primitives.Doubles;
 import com.sk89q.worldedit.internal.expression.LocalSlot.Variable;
 import com.sk89q.worldedit.math.Vector3;

worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/invoke/CompilingVisitor.java

@@ -22,7 +22,11 @@ package com.sk89q.worldedit.internal.expression.invoke;
 import com.google.common.collect.SetMultimap;
 import com.sk89q.worldedit.antlr.ExpressionBaseVisitor;
 import com.sk89q.worldedit.antlr.ExpressionParser;
-import com.sk89q.worldedit.internal.expression.*;
+import com.sk89q.worldedit.internal.expression.BreakException;
+import com.sk89q.worldedit.internal.expression.EvaluationException;
+import com.sk89q.worldedit.internal.expression.ExecutionData;
+import com.sk89q.worldedit.internal.expression.ExpressionHelper;
+import com.sk89q.worldedit.internal.expression.LocalSlot;
 import it.unimi.dsi.fastutil.doubles.Double2ObjectLinkedOpenHashMap;
 import it.unimi.dsi.fastutil.doubles.Double2ObjectMap;
 import org.antlr.v4.runtime.CommonToken;
@@ -40,9 +44,35 @@ import java.util.function.DoubleBinaryOperator;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
-import static com.sk89q.worldedit.antlr.ExpressionLexer.*;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.ASSIGN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.DIVIDE;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.DIVIDE_ASSIGN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.EQUAL;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.EXCLAMATION_MARK;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.GREATER_THAN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.GREATER_THAN_OR_EQUAL;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.INCREMENT;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.LEFT_SHIFT;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.LESS_THAN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.LESS_THAN_OR_EQUAL;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.MINUS;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.MINUS_ASSIGN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.MODULO;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.MODULO_ASSIGN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.NEAR;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.NOT_EQUAL;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.PLUS;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.PLUS_ASSIGN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.POWER_ASSIGN;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.RIGHT_SHIFT;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.TIMES;
+import static com.sk89q.worldedit.antlr.ExpressionLexer.TIMES_ASSIGN;
 import static com.sk89q.worldedit.internal.expression.ExpressionHelper.WRAPPED_CONSTANT;
-import static com.sk89q.worldedit.internal.expression.invoke.ExpressionHandles.*;
+import static com.sk89q.worldedit.internal.expression.invoke.ExpressionHandles.CALL_BINARY_OP;
+import static com.sk89q.worldedit.internal.expression.invoke.ExpressionHandles.DOUBLE_TO_BOOL;
+import static com.sk89q.worldedit.internal.expression.invoke.ExpressionHandles.IS_NULL;
+import static com.sk89q.worldedit.internal.expression.invoke.ExpressionHandles.NEW_LS_CONSTANT;
+import static com.sk89q.worldedit.internal.expression.invoke.ExpressionHandles.NULL_DOUBLE;
 import static java.lang.invoke.MethodType.methodType;
 
 /**
@@ -50,26 +80,6 @@ import static java.lang.invoke.MethodType.methodType;
  */
 class CompilingVisitor extends ExpressionBaseVisitor<MethodHandle> {
 
-    private static final MethodHandle BREAK_STATEMENT =
-            ExpressionHandles.dropData(MethodHandles.throwException(Double.class, BreakException.class)
-                    .bindTo(BreakException.BREAK));
-    private static final MethodHandle CONTINUE_STATEMENT =
-            ExpressionHandles.dropData(MethodHandles.throwException(Double.class, BreakException.class)
-                    .bindTo(BreakException.CONTINUE));
-    private static final double[] factorials = new double[171];
-    /**
-     * Method handle (ExecutionData)Double, returns null.
-     */
-    private static final MethodHandle DEFAULT_RESULT =
-            ExpressionHandles.dropData(MethodHandles.constant(Double.class, null));
-
-    static {
-        factorials[0] = 1;
-        for (int i = 1; i < factorials.length; ++i) {
-            factorials[i] = factorials[i - 1] * i;
-        }
-    }
-
     /*
      * General idea is that we don't need to pass around variables, they're all in ExecutionData.
      * We do need to pass that around, so most MethodHandles will be of the type
@@ -82,38 +92,6 @@ class CompilingVisitor extends ExpressionBaseVisitor<MethodHandle> {
         this.functions = functions;
     }
 
-    // Usable AlmostEqual function, based on http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
-    private static boolean almostEqual2sComplement(double a, double b, long maxUlps) {
-        // Make sure maxUlps is non-negative and small enough that the
-        // default NAN won't compare as equal to anything.
-        //assert(maxUlps > 0 && maxUlps < 4 * 1024 * 1024); // this is for floats, not doubles
-
-        long aLong = Double.doubleToRawLongBits(a);
-        // Make aLong lexicographically ordered as a twos-complement long
-        if (aLong < 0) aLong = 0x8000000000000000L - aLong;
-
-        long bLong = Double.doubleToRawLongBits(b);
-        // Make bLong lexicographically ordered as a twos-complement long
-        if (bLong < 0) bLong = 0x8000000000000000L - bLong;
-
-        final long longDiff = Math.abs(aLong - bLong);
-        return longDiff <= maxUlps;
-    }
-
-    private static double factorial(double x) throws EvaluationException {
-        final int n = (int) x;
-
-        if (n < 0) {
-            return 0;
-        }
-
-        if (n >= factorials.length) {
-            return Double.POSITIVE_INFINITY;
-        }
-
-        return factorials[n];
-    }
-
     private Token extractToken(ParserRuleContext ctx) {
         List<TerminalNode> children = ctx.children.stream()
             .filter(TerminalNode.class::isInstance)
@@ -222,6 +200,13 @@ class CompilingVisitor extends ExpressionBaseVisitor<MethodHandle> {
         );
     }
 
+    private static final MethodHandle BREAK_STATEMENT =
+        ExpressionHandles.dropData(MethodHandles.throwException(Double.class, BreakException.class)
+            .bindTo(BreakException.BREAK));
+    private static final MethodHandle CONTINUE_STATEMENT =
+        ExpressionHandles.dropData(MethodHandles.throwException(Double.class, BreakException.class)
+            .bindTo(BreakException.CONTINUE));
+
     @Override
     public MethodHandle visitBreakStatement(ExpressionParser.BreakStatementContext ctx) {
         return BREAK_STATEMENT;
@@ -474,6 +459,24 @@ class CompilingVisitor extends ExpressionBaseVisitor<MethodHandle> {
         });
     }
 
+    // Usable AlmostEqual function, based on http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
+    private static boolean almostEqual2sComplement(double a, double b, long maxUlps) {
+        // Make sure maxUlps is non-negative and small enough that the
+        // default NAN won't compare as equal to anything.
+        //assert(maxUlps > 0 && maxUlps < 4 * 1024 * 1024); // this is for floats, not doubles
+
+        long aLong = Double.doubleToRawLongBits(a);
+        // Make aLong lexicographically ordered as a twos-complement long
+        if (aLong < 0) aLong = 0x8000000000000000L - aLong;
+
+        long bLong = Double.doubleToRawLongBits(b);
+        // Make bLong lexicographically ordered as a twos-complement long
+        if (bLong < 0) bLong = 0x8000000000000000L - bLong;
+
+        final long longDiff = Math.abs(aLong - bLong);
+        return longDiff <= maxUlps;
+    }
+
     @Override
     public MethodHandle visitPostfixExpr(ExpressionParser.PostfixExprContext ctx) {
         MethodHandle value = evaluateForValue(ctx.expr);
@@ -486,6 +489,29 @@ class CompilingVisitor extends ExpressionBaseVisitor<MethodHandle> {
             "Invalid text for post-unary expr: " + ctx.op.getText());
     }
 
+    private static final double[] factorials = new double[171];
+
+    static {
+        factorials[0] = 1;
+        for (int i = 1; i < factorials.length; ++i) {
+            factorials[i] = factorials[i - 1] * i;
+        }
+    }
+
+    private static double factorial(double x) throws EvaluationException {
+        final int n = (int) x;
+
+        if (n < 0) {
+            return 0;
+        }
+
+        if (n >= factorials.length) {
+            return Double.POSITIVE_INFINITY;
+        }
+
+        return factorials[n];
+    }
+
     @Override
     public MethodHandle visitAssignment(ExpressionParser.AssignmentContext ctx) {
         int type = extractToken(ctx.assignmentOperator()).getType();
@@ -594,6 +620,12 @@ class CompilingVisitor extends ExpressionBaseVisitor<MethodHandle> {
         return ExpressionHandles.call(data -> ExpressionHandles.getSlotValue(data, source));
     }
 
+    /**
+     * Method handle (ExecutionData)Double, returns null.
+     */
+    private static final MethodHandle DEFAULT_RESULT =
+        ExpressionHandles.dropData(MethodHandles.constant(Double.class, null));
+
     @Override
     protected MethodHandle defaultResult() {
         return DEFAULT_RESULT;

worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/invoke/ExpressionHandles.java

@@ -20,7 +20,12 @@
 package com.sk89q.worldedit.internal.expression.invoke;
 
 import com.google.common.base.Throwables;
-import com.sk89q.worldedit.internal.expression.*;
+import com.sk89q.worldedit.internal.expression.BreakException;
+import com.sk89q.worldedit.internal.expression.CompiledExpression;
+import com.sk89q.worldedit.internal.expression.EvaluationException;
+import com.sk89q.worldedit.internal.expression.ExecutionData;
+import com.sk89q.worldedit.internal.expression.ExpressionHelper;
+import com.sk89q.worldedit.internal.expression.LocalSlot;
 import it.unimi.dsi.fastutil.doubles.Double2ObjectMap;
 import it.unimi.dsi.fastutil.doubles.Double2ObjectMaps;
 import org.antlr.v4.runtime.ParserRuleContext;
@@ -34,18 +39,22 @@ import java.util.Objects;
 import java.util.function.DoubleBinaryOperator;
 import java.util.function.Supplier;
 
-import static com.sk89q.worldedit.internal.expression.ExpressionHelper.*;
+import static com.sk89q.worldedit.internal.expression.ExpressionHelper.check;
-import static java.lang.invoke.MethodHandles.*;
+import static com.sk89q.worldedit.internal.expression.ExpressionHelper.checkIterations;
+import static com.sk89q.worldedit.internal.expression.ExpressionHelper.checkTimeout;
+import static com.sk89q.worldedit.internal.expression.ExpressionHelper.getErrorPosition;
+import static java.lang.invoke.MethodHandles.collectArguments;
+import static java.lang.invoke.MethodHandles.constant;
+import static java.lang.invoke.MethodHandles.dropArguments;
+import static java.lang.invoke.MethodHandles.insertArguments;
+import static java.lang.invoke.MethodHandles.permuteArguments;
+import static java.lang.invoke.MethodHandles.throwException;
 import static java.lang.invoke.MethodType.methodType;
 
 class ExpressionHandles {
 
     static final MethodType COMPILED_EXPRESSION_SIG = methodType(Double.class, ExecutionData.class);
-    static final MethodHandle IS_NULL;
+
-    static final MethodHandle DOUBLE_TO_BOOL;
-    static final MethodHandle CALL_BINARY_OP;
-    static final MethodHandle NEW_LS_CONSTANT;
-    static final MethodHandle NULL_DOUBLE = dropData(constant(Double.class, null));
     private static final MethodHandle EVAL_EXCEPTION_CONSTR;
     private static final MethodHandle CALL_EXPRESSION;
     private static final MethodHandle GET_VARIABLE;
@@ -54,6 +63,13 @@ class ExpressionHandles {
     private static final MethodHandle SIMPLE_FOR_LOOP_IMPL;
     private static final MethodHandle SWITCH_IMPL;
 
+    static final MethodHandle IS_NULL;
+    static final MethodHandle DOUBLE_TO_BOOL;
+    static final MethodHandle CALL_BINARY_OP;
+    static final MethodHandle NEW_LS_CONSTANT;
+
+    static final MethodHandle NULL_DOUBLE = dropData(constant(Double.class, null));
+
     static {
         MethodHandles.Lookup lookup = MethodHandles.lookup();
         try {
@@ -90,7 +106,9 @@ class ExpressionHandles {
         }
     }
 
-    private ExpressionHandles() {
+    @FunctionalInterface
+    interface Invokable {
+        Object invoke(MethodHandle handle) throws Throwable;
     }
 
     static Object safeInvoke(MethodHandle handle, Invokable invokable) {
@@ -331,9 +349,7 @@ class ExpressionHandles {
         return evaluated;
     }
 
-    @FunctionalInterface
+    private ExpressionHandles() {
-    interface Invokable {
-        Object invoke(MethodHandle handle) throws Throwable;
     }
 
 }

worldedit-core/src/main/java/com/sk89q/worldedit/internal/util/Substring.java

@@ -19,10 +19,10 @@
 
 package com.sk89q.worldedit.internal.util;
 
-import static com.google.common.base.Preconditions.checkArgument;
-
 import java.util.Objects;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
 /**
  * An explicit substring. Provides the range from which it was taken.
  */

worldedit-core/src/main/java/com/sk89q/worldedit/math/geom/Polygons.java

@@ -35,7 +35,7 @@ public final class Polygons {
     }
 
     /**
-     * Calculates the polygon shape of a cylinder, which can then be used for e.g., intersection detection.
+     * Calculates the polygon shape of a cylinder which can then be used for e.g. intersection detection.
      *
      * @param center the center point of the cylinder
      * @param radius the radius of the cylinder

worldedit-core/src/main/java/com/sk89q/worldedit/math/transform/AffineTransform.java

@@ -341,11 +341,6 @@ public class AffineTransform implements Transform, Serializable {
         }
     }
 
-    @Override
-    public String toString() {
-        return String.format("Affine[%g %g %g %g, %g %g %g %g, %g %g %g %g]}", m00, m01, m02, m03, m10, m11, m12, m13, m20, m21, m22, m23);
-    }
-
     /**
      * Returns if this affine transform is representing a horizontal flip.
      */
@@ -354,5 +349,10 @@ public class AffineTransform implements Transform, Serializable {
         return m00 * m22 - m02 * m20 < 0;
     }
 
+    @Override
+    public String toString() {
+        return String.format("Affine[%g %g %g %g, %g %g %g %g, %g %g %g %g]}", m00, m01, m02, m03, m10, m11, m12, m13, m20, m21, m22, m23);
+    }
+
 
 }

worldedit-core/src/main/java/com/sk89q/worldedit/regions/AbstractRegion.java

@@ -19,7 +19,6 @@
 
 package com.sk89q.worldedit.regions;
 
-import com.boydti.fawe.FaweCache;
 import com.boydti.fawe.object.collection.BlockVectorSet;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;

worldedit-core/src/main/java/com/sk89q/worldedit/regions/selector/ConvexPolyhedralRegionSelector.java

@@ -21,7 +21,6 @@ package com.sk89q.worldedit.regions.selector;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.IncompleteRegionException;
 import com.sk89q.worldedit.LocalSession;
 import com.sk89q.worldedit.extension.platform.Actor;
@@ -37,6 +36,7 @@ import com.sk89q.worldedit.regions.polyhedron.Triangle;
 import com.sk89q.worldedit.regions.selector.limit.SelectorLimits;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.world.World;
 
 import java.util.ArrayList;

worldedit-core/src/main/java/com/sk89q/worldedit/regions/selector/CuboidRegionSelector.java

@@ -37,11 +37,12 @@ import com.sk89q.worldedit.util.formatting.text.TextComponent;
 import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.world.World;
 
-import javax.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 /**
  * Creates a {@code CuboidRegion} from a user's selections.
  */
@@ -156,7 +157,6 @@ public class CuboidRegionSelector implements RegionSelector, CUIRegion {
         checkNotNull(session);
         checkNotNull(pos);
 
-        //TODO Re-add better translation
         if (position1 != null && position2 != null) {
             player.printInfo(TranslatableComponent.of(
                     "worldedit.selection.cuboid.explain.primary-area",
@@ -176,7 +176,6 @@ public class CuboidRegionSelector implements RegionSelector, CUIRegion {
         checkNotNull(session);
         checkNotNull(pos);
 
-        //TODO Re-add better translation
         if (position1 != null && position2 != null) {
             player.printInfo(TranslatableComponent.of(
                     "worldedit.selection.cuboid.explain.secondary-area",

worldedit-core/src/main/java/com/sk89q/worldedit/regions/selector/EllipsoidRegionSelector.java

@@ -19,8 +19,6 @@
 
 package com.sk89q.worldedit.regions.selector;
 
-import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
-
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.sk89q.worldedit.IncompleteRegionException;
@@ -37,12 +35,14 @@ import com.sk89q.worldedit.regions.RegionSelector;
 import com.sk89q.worldedit.regions.selector.limit.SelectorLimits;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.world.World;
 
-import javax.annotation.Nullable;
 import java.util.ArrayList;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 /**
  * Creates a {@code EllipsoidRegionSelector} from a user's selections.
  */

worldedit-core/src/main/java/com/sk89q/worldedit/regions/selector/ExtendingCuboidRegionSelector.java

@@ -19,13 +19,13 @@
 
 package com.sk89q.worldedit.regions.selector;
 
-import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.LocalSession;
 import com.sk89q.worldedit.extension.platform.Actor;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.RegionSelector;
 import com.sk89q.worldedit.regions.selector.limit.SelectorLimits;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.world.World;
 
 import javax.annotation.Nullable;

worldedit-core/src/main/java/com/sk89q/worldedit/regions/selector/Polygonal2DRegionSelector.java

@@ -21,7 +21,6 @@ package com.sk89q.worldedit.regions.selector;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.IncompleteRegionException;
 import com.sk89q.worldedit.LocalSession;
 import com.sk89q.worldedit.extension.platform.Actor;
@@ -37,6 +36,7 @@ import com.sk89q.worldedit.regions.RegionSelector;
 import com.sk89q.worldedit.regions.selector.limit.SelectorLimits;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
 import com.sk89q.worldedit.world.World;
 
 import java.util.Collections;

worldedit-core/src/main/java/com/sk89q/worldedit/regions/shape/WorldEditExpressionEnvironment.java

@@ -21,8 +21,8 @@ package com.sk89q.worldedit.regions.shape;
 
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.extent.Extent;
-import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.internal.expression.ExpressionEnvironment;
+import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.MutableVector3;
 import com.sk89q.worldedit.math.Vector3;
 

worldedit-core/src/main/java/com/sk89q/worldedit/session/SessionManager.java

@@ -34,16 +34,20 @@ import com.sk89q.worldedit.command.tool.SelectionWand;
 import com.sk89q.worldedit.command.tool.Tool;
 import com.sk89q.worldedit.entity.Player;
 import com.sk89q.worldedit.event.platform.ConfigurationLoadEvent;
+import com.sk89q.worldedit.extension.platform.Locatable;
 import com.sk89q.worldedit.session.request.Request;
 import com.sk89q.worldedit.session.storage.JsonFileSessionStore;
 import com.sk89q.worldedit.session.storage.SessionStore;
 import com.sk89q.worldedit.session.storage.VoidStore;
 import com.sk89q.worldedit.util.concurrency.EvenMoreExecutors;
-import com.sk89q.worldedit.extension.platform.Locatable;
 import com.sk89q.worldedit.util.eventbus.Subscribe;
 import com.sk89q.worldedit.world.gamemode.GameModes;
 import com.sk89q.worldedit.world.item.ItemType;
 import com.sk89q.worldedit.world.item.ItemTypes;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.Nullable;
 import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
@@ -53,9 +57,6 @@ import java.util.Timer;
 import java.util.TimerTask;
 import java.util.UUID;
 import java.util.concurrent.Callable;
-import javax.annotation.Nullable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Session manager for WorldEdit.

worldedit-core/src/main/java/com/sk89q/worldedit/session/request/RequestExtent.java

@@ -34,8 +34,9 @@ import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BaseBlock;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
-import java.util.List;
+
 import javax.annotation.Nullable;
+import java.util.List;
 
 public class RequestExtent implements Extent {
 

worldedit-core/src/main/java/com/sk89q/worldedit/util/PropertiesConfiguration.java

@@ -127,9 +127,8 @@ public class PropertiesConfiguration extends LocalConfiguration {
         LocalSession.MAX_HISTORY_SIZE = Math.max(15, getInt("history-size", 15));
 
         String snapshotsDir = getString("snapshots-dir", "");
-        if (!snapshotsDir.isEmpty()) {
+        boolean experimentalSnapshots = getBool("snapshots-experimental", false);
-            snapshotRepo = new SnapshotRepository(snapshotsDir);
+        initializeSnapshotConfiguration(snapshotsDir, experimentalSnapshots);
-        }
 
         path.getParentFile().mkdirs();
         try (OutputStream output = new FileOutputStream(path)) {

worldedit-core/src/main/java/com/sk89q/worldedit/util/collection/LocatedBlockList.java

@@ -19,8 +19,6 @@
 
 package com.sk89q.worldedit.util.collection;
 
-import com.google.common.collect.Iterators;
-import com.sk89q.worldedit.WorldEdit;
 import com.google.common.collect.Iterators;
 import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.math.BlockVector3;

worldedit-core/src/main/java/com/sk89q/worldedit/util/collection/MoreStreams.java

@@ -0,0 +1,83 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.collection;
+
+import com.google.common.collect.AbstractIterator;
+
+import java.util.Iterator;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.function.Predicate;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Additionally stream facilities.
+ */
+public class MoreStreams {
+
+    /**
+     * Emit elements from {@code stream} until {@code predicate} returns {@code false}.
+     */
+    public static <T> Stream<T> takeWhile(Stream<T> stream, Predicate<T> predicate) {
+        return takeUntil(stream, predicate.negate());
+    }
+
+    /**
+     * Emit elements from {@code stream} until {@code predicate} returns {@code true}.
+     */
+    public static <T> Stream<T> takeUntil(Stream<T> stream, Predicate<T> predicate) {
+        Spliterator<T> spliterator = stream.spliterator();
+        Iterator<T> iter = new AbstractIterator<T>() {
+
+            private Iterator<T> source = Spliterators.iterator(spliterator);
+
+            @Override
+            protected T computeNext() {
+                Iterator<T> src = requireNonNull(source);
+                if (!src.hasNext()) {
+                    return done();
+                }
+                T next = src.next();
+                if (predicate.test(next)) {
+                    return done();
+                }
+                return next;
+            }
+
+            private T done() {
+                // allow GC of source
+                source = null;
+                return endOfData();
+            }
+        };
+        int chars = spliterator.characteristics();
+        // Not SIZED, Not SUBSIZED
+        chars &= ~(Spliterator.SIZED | Spliterator.SUBSIZED);
+        return StreamSupport.stream(Spliterators.spliterator(
+            iter, spliterator.estimateSize(), chars
+        ), stream.isParallel()).onClose(stream::close);
+    }
+
+    private MoreStreams() {
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/concurrency/LazyReference.java

@@ -71,4 +71,5 @@ public class LazyReference<T> {
             refInfo.lock.unlock();
         }
     }
+
 }

worldedit-core/src/main/java/com/sk89q/worldedit/util/eventbus/EventBus.java

@@ -20,8 +20,6 @@
 package com.sk89q.worldedit.util.eventbus;
 
 import com.google.common.collect.HashMultimap;
-
-import static com.google.common.base.Preconditions.checkNotNull;
 import com.google.common.collect.Multimap;
 import com.google.common.collect.SetMultimap;
 import org.slf4j.Logger;
@@ -37,6 +35,8 @@ import java.util.Set;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 /**
  * Dispatches events to listeners, and provides ways for listeners to register
  * themselves.

worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/TextUtils.java

@@ -47,6 +47,7 @@ public class TextUtils {
         }
         return builder.build();
     }
+
     /**
      * Gets a Java Locale object by the Minecraft locale tag.
      *

worldedit-core/src/main/java/com/sk89q/worldedit/util/function/IORunnable.java

@@ -0,0 +1,32 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.function;
+
+import java.io.IOException;
+
+/**
+ * I/O runnable type.
+ */
+@FunctionalInterface
+public interface IORunnable {
+
+    void run() throws IOException;
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/io/file/ArchiveNioSupport.java

@@ -0,0 +1,40 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.io.file;
+
+import java.io.IOException;
+import java.nio.file.FileSystem;
+import java.nio.file.Path;
+import java.util.Optional;
+
+/**
+ * Something that can provide access to an archive file as a file system.
+ */
+public interface ArchiveNioSupport {
+
+    /**
+     * Try to open the given archive as a file system.
+     *
+     * @param archive the archive to open
+     * @return the path for the root of the archive, if available
+     */
+    Optional<Path> tryOpenAsDir(Path archive) throws IOException;
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/io/file/ArchiveNioSupports.java

@@ -0,0 +1,99 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.io.file;
+
+import com.google.common.collect.ImmutableList;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Optional;
+import java.util.ServiceLoader;
+import java.util.stream.Stream;
+
+public class ArchiveNioSupports {
+
+    private static final List<ArchiveNioSupport> SUPPORTS;
+
+    static {
+        ImmutableList.Builder<ArchiveNioSupport> builder = ImmutableList.builder();
+        try {
+            builder.add(TrueVfsArchiveNioSupport.getInstance());
+        } catch (NoClassDefFoundError ignore) {
+            // No TrueVFS available. That's OK.
+        }
+        SUPPORTS = builder.add(ZipArchiveNioSupport.getInstance())
+            .addAll(ServiceLoader.load(ArchiveNioSupport.class))
+            .build();
+    }
+
+    public static Optional<Path> tryOpenAsDir(Path archive) throws IOException {
+        for (ArchiveNioSupport support : SUPPORTS) {
+            Optional<Path> fs = support.tryOpenAsDir(archive);
+            if (fs.isPresent()) {
+                return fs;
+            }
+        }
+        return Optional.empty();
+    }
+
+    private static final ArchiveNioSupport COMBINED = ArchiveNioSupports::tryOpenAsDir;
+
+    /**
+     * Get an {@link ArchiveNioSupport} that combines all known instances.
+     * @return a combined {@link ArchiveNioSupport} instance
+     */
+    public static ArchiveNioSupport combined() {
+        return COMBINED;
+    }
+
+    /**
+     * If root contains a folder with the same name as {@code name}, and no regular files,
+     * returns the path to that folder. Otherwise, return the root path.
+     *
+     * <p>
+     * This method is used to provide equal outputs for archives that do and do not contain
+     * their name as part of their root folder.
+     * </p>
+     *
+     * @param root the root path
+     * @param name the name that might exist inside root
+     * @return the corrected path
+     */
+    public static Path skipRootSameName(Path root, String name) throws IOException {
+        Path innerDir = root.resolve(name);
+        if (Files.isDirectory(innerDir)) {
+            try (Stream<Path> files = Files.list(root)) {
+                // The reason we check this, is that macOS creates a __MACOSX directory inside
+                // its zip files. We want to allow this to pass if that exists, or a similar
+                // mechanism, but fail if there are regular files, since that indicates that
+                // it may not be the right thing to do.
+                if (files.allMatch(Files::isDirectory)) {
+                    return innerDir;
+                }
+            }
+        }
+        return root;
+    }
+
+    private ArchiveNioSupports() {
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/io/file/MorePaths.java

@@ -0,0 +1,68 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.io.file;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Streams;
+
+import java.nio.file.Path;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.Deque;
+import java.util.Spliterator;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class MorePaths {
+
+    /**
+     * Starting with the first path element, add elements until reaching this path.
+     */
+    public static Stream<Path> iterPaths(Path path) {
+        Deque<Path> parents = new ArrayDeque<>(path.getNameCount());
+        // Push parents to the front of the stack, so the "root" is at the front
+        Path next = path;
+        while (next != null) {
+            parents.addFirst(next);
+            next = next.getParent();
+        }
+        // now just iterate straight over them
+        return ImmutableList.copyOf(parents).stream();
+    }
+
+    /**
+     * Create an efficiently-splittable spliterator for the given path elements.
+     *
+     * <p>
+     * Since paths are so small, this is only useful for preventing heavy computations
+     * on later parts of the stream from occurring when using
+     * {@link Streams#findLast(IntStream)}, and not for parallelism.
+     * </p>
+     *
+     * @param path the path to create a spliterator for
+     * @return the spliterator
+     */
+    public static Spliterator<Path> optimizedSpliterator(Path path) {
+        return Arrays.spliterator(Streams.stream(path).toArray(Path[]::new));
+    }
+
+    private MorePaths() {
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/io/file/TrueVfsArchiveNioSupport.java

@@ -0,0 +1,59 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.io.file;
+
+import com.google.common.base.Splitter;
+import com.google.common.collect.ImmutableSet;
+import net.java.truevfs.access.TArchiveDetector;
+import net.java.truevfs.access.TPath;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.Optional;
+import java.util.Set;
+
+public final class TrueVfsArchiveNioSupport implements ArchiveNioSupport {
+
+    private static final TrueVfsArchiveNioSupport INSTANCE = new TrueVfsArchiveNioSupport();
+
+    public static TrueVfsArchiveNioSupport getInstance() {
+        return INSTANCE;
+    }
+
+    private static final Set<String> ALLOWED_EXTENSIONS = ImmutableSet.copyOf(
+        Splitter.on('|').split(TArchiveDetector.ALL.getExtensions())
+    );
+
+    private TrueVfsArchiveNioSupport() {
+    }
+
+    @Override
+    public Optional<Path> tryOpenAsDir(Path archive) throws IOException {
+        String fileName = archive.getFileName().toString();
+        int dot = fileName.indexOf('.');
+        if (dot < 0 || dot >= fileName.length() || !ALLOWED_EXTENSIONS.contains(fileName.substring(dot + 1))) {
+            return Optional.empty();
+        }
+        TPath root = new TPath(archive).getFileSystem().getPath("/");
+        return Optional.of(ArchiveNioSupports.skipRootSameName(
+            root, fileName.substring(0, dot)
+        ));
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/io/file/ZipArchiveNioSupport.java

@@ -0,0 +1,53 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.io.file;
+
+import java.io.IOException;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.util.Optional;
+
+public final class ZipArchiveNioSupport implements ArchiveNioSupport {
+
+    private static final ZipArchiveNioSupport INSTANCE = new ZipArchiveNioSupport();
+
+    public static ZipArchiveNioSupport getInstance() {
+        return INSTANCE;
+    }
+
+    private ZipArchiveNioSupport() {
+    }
+
+    @Override
+    public Optional<Path> tryOpenAsDir(Path archive) throws IOException {
+        if (!archive.getFileName().toString().endsWith(".zip")) {
+            return Optional.empty();
+        }
+        FileSystem zipFs = FileSystems.newFileSystem(
+            archive, getClass().getClassLoader()
+        );
+        return Optional.of(ArchiveNioSupports.skipRootSameName(
+            zipFs.getPath("/"), archive.getFileName().toString()
+                .replaceFirst("\\.zip$", "")
+        ));
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/time/FileNameDateTimeParser.java

@@ -0,0 +1,110 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.time;
+
+import com.google.common.collect.Streams;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.util.io.file.MorePaths;
+
+import javax.annotation.Nullable;
+import java.nio.file.Path;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+
+/**
+ * Parses date-times by looking at the file name. File names without a time
+ * will use 00:00:00.
+ *
+ * <p>
+ * Elements may be separated by a space, dash, or colon.
+ * The date and time may additionally be separated by a 'T'.
+ * Only the year must have all digits, others may omit padding
+ * zeroes.
+ * </p>
+ *
+ * <p>
+ * Valid file name examples:
+ * <ul>
+ *     <li>{@code 2019-06-15}</li>
+ *     <li>{@code 2019-06-15 10:20:30}</li>
+ *     <li>{@code 2019-06-15 10:20:30}</li>
+ *     <li>{@code 2019-06-15T10:20:30}</li>
+ *     <li>{@code 2019 06 15 10 20 30}</li>
+ *     <li>{@code 2019-06-15-10-20-30}</li>
+ *     <li>{@code 2019-6-1-1-2-3}</li>
+ * </ul>
+ * </p>
+ */
+public class FileNameDateTimeParser implements SnapshotDateTimeParser {
+
+    private static final FileNameDateTimeParser INSTANCE = new FileNameDateTimeParser();
+
+    public static FileNameDateTimeParser getInstance() {
+        return INSTANCE;
+    }
+
+    private static final String SEP = "[ \\-_:]";
+
+    private static final Pattern BASIC_FILTER = Pattern.compile(
+        "^(?<year>\\d{4})" + SEP + "(?<month>\\d{1,2})" + SEP + "(?<day>\\d{1,2})" +
+            // Optionally:
+            "(?:" + "[ \\-_:T]" +
+            "(?<hour>\\d{1,2})" + SEP + "(?<minute>\\d{1,2})" + SEP + "(?<second>\\d{1,2})" +
+            ")?"
+    );
+
+    private FileNameDateTimeParser() {
+    }
+
+    @Nullable
+    @Override
+    public ZonedDateTime detectDateTime(Path path) {
+        // Make this perform a little better:
+        Matcher matcher = Streams.findLast(
+            StreamSupport.stream(MorePaths.optimizedSpliterator(path), false)
+                .map(p -> BASIC_FILTER.matcher(p.toString()))
+                .filter(Matcher::find)
+        ).orElse(null);
+        if (matcher != null) {
+            int year = matchAndParseOrZero(matcher, "year");
+            int month = matchAndParseOrZero(matcher, "month");
+            int day = matchAndParseOrZero(matcher, "day");
+            int hour = matchAndParseOrZero(matcher, "hour");
+            int minute = matchAndParseOrZero(matcher, "minute");
+            int second = matchAndParseOrZero(matcher, "second");
+            return ZonedDateTime.of(year, month, day, hour, minute, second,
+                0, ZoneId.systemDefault());
+        }
+        return null;
+    }
+
+    private static int matchAndParseOrZero(Matcher matcher, String group) {
+        String match = matcher.group(group);
+        if (match == null) {
+            return 0;
+        }
+        return Integer.parseInt(match);
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/time/ModificationDateTimeParser.java

@@ -0,0 +1,52 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.time;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+public class ModificationDateTimeParser implements SnapshotDateTimeParser {
+
+    private static final ModificationDateTimeParser INSTANCE = new ModificationDateTimeParser();
+
+    public static ModificationDateTimeParser getInstance() {
+        return INSTANCE;
+    }
+
+    private ModificationDateTimeParser() {
+    }
+
+    @Override
+    public ZonedDateTime detectDateTime(Path path) {
+        if (!Files.exists(path)) {
+            return null;
+        }
+        try {
+            return Files.getLastModifiedTime(path).toInstant().atZone(ZoneId.systemDefault());
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/time/SnapshotDateTimeParser.java

@@ -0,0 +1,45 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.time;
+
+import javax.annotation.Nullable;
+import java.nio.file.Path;
+import java.time.ZonedDateTime;
+
+/**
+ * Instances of this interface try to determine an {@link ZonedDateTime} from a given
+ * {@link Path}.
+ */
+public interface SnapshotDateTimeParser {
+
+    /**
+     * Attempt to detect an ZonedDateTime from a path.
+     *
+     * <p>
+     * The path is not guaranteed to exist.
+     * </p>
+     *
+     * @param path the path
+     * @return date-time, if it can be parsed
+     */
+    @Nullable
+    ZonedDateTime detectDateTime(Path path);
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/translation/TranslationManager.java

@@ -19,8 +19,6 @@
 
 package com.sk89q.worldedit.util.translation;
 
-import static java.util.stream.Collectors.toMap;
-
 import com.google.common.collect.Maps;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
@@ -29,6 +27,7 @@ import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.renderer.FriendlyComponentRenderer;
 import com.sk89q.worldedit.util.io.ResourceLoader;
+
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -43,6 +42,8 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
+import static java.util.stream.Collectors.toMap;
+
 /**
  * Handles translations for the plugin.
  *

worldedit-core/src/main/java/com/sk89q/worldedit/world/AbstractWorld.java

@@ -153,6 +153,7 @@ public abstract class AbstractWorld implements World {
     @Override
     public void setWeather(WeatherType weatherType, long duration) {
     }
+
     private class QueuedEffect implements Comparable<QueuedEffect> {
         private final Vector3 position;
         private final BlockType blockType;

worldedit-core/src/main/java/com/sk89q/worldedit/world/NullWorld.java

@@ -69,6 +69,7 @@ public class NullWorld extends AbstractWorld {
     public String getId() {
         return "null";
     }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
         return false;

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/BundledBlockRegistry.java

@@ -23,11 +23,12 @@ import com.sk89q.worldedit.registry.state.Property;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockType;
 
-import javax.annotation.Nullable;
 import java.util.Collections;
 import java.util.Map;
 import java.util.OptionalInt;
 
+import javax.annotation.Nullable;
+
 /**
  * A block registry that uses {@link BundledBlockData} to serve information
  * about blocks.

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/LegacyMapper.java

@@ -56,15 +56,7 @@ import java.util.Map;
 public final class LegacyMapper {
 
     private static final Logger log = LoggerFactory.getLogger(LegacyMapper.class);
-    private static LegacyMapper INSTANCE = new LegacyMapper();
+    private static LegacyMapper INSTANCE;
-
-    static {
-        try {
-            INSTANCE.loadFromResource();
-        } catch (Throwable e) {
-            log.warn("Failed to load the built-in legacy id registry", e);
-        }
-    }
 
     private final Int2ObjectArrayMap<Integer> blockStateToLegacyId4Data = new Int2ObjectArrayMap<>();
     private final Int2ObjectArrayMap<Integer> extraId4DataToStateId = new Int2ObjectArrayMap<>();
@@ -80,6 +72,12 @@ public final class LegacyMapper {
      * Create a new instance.
      */
     private LegacyMapper() {
+        try {
+            loadFromResource();
+        } catch (Throwable e) {
+            log.warn("Failed to load the built-in legacy id registry", e);
+        }
+
     }
 
     /**
@@ -95,9 +93,8 @@ public final class LegacyMapper {
         if (url == null) {
             throw new IOException("Could not find legacy.json");
         }
-        String source = Resources.toString(url, Charset.defaultCharset());
+        String data = Resources.toString(url, Charset.defaultCharset());
-        LegacyDataFile dataFile = gson.fromJson(source, new TypeToken<LegacyDataFile>() {
+        LegacyDataFile dataFile = gson.fromJson(data, new TypeToken<LegacyDataFile>() {}.getType());
-        }.getType());
 
         DataFixer fixer = WorldEdit.getInstance().getPlatformManager().queryCapability(Capability.WORLD_EDITING).getDataFixer();
         ParserContext parserContext = new ParserContext();
@@ -110,49 +107,51 @@ public final class LegacyMapper {
             Integer combinedId = getCombinedId(blockEntry.getKey());
             final String value = blockEntry.getValue();
             blockEntries.put(id, value);
-            BlockState blockState = null;
+
+            BlockState state = null;
             try {
-                blockState = BlockState.get(null, blockEntry.getValue());
+                state = BlockState.get(null, blockEntry.getValue());
-                BlockType type = blockState.getBlockType();
+                BlockType type = state.getBlockType();
                 if (type.hasProperty(PropertyKey.WATERLOGGED)) {
-                    blockState = blockState.with(PropertyKey.WATERLOGGED, false);
+                    state = state.with(PropertyKey.WATERLOGGED, false);
                 }
-            } catch (InputParseException e) {
+            } catch (InputParseException f) {
                 BlockFactory blockFactory = WorldEdit.getInstance().getBlockFactory();
+                // if fixer is available, try using that first, as some old blocks that were renamed share names with new blocks
                 if (fixer != null) {
                     try {
                         String newEntry = fixer.fixUp(DataFixer.FixTypes.BLOCK_STATE, value, 1631);
-                        blockState = blockFactory.parseFromInput(newEntry, parserContext).toImmutableState();
+                        state = blockFactory.parseFromInput(newEntry, parserContext).toImmutableState();
-                    } catch (InputParseException f) {
+                    } catch (InputParseException e) {
                     }
                 }
                 // if it's still null, the fixer was unavailable or failed
-                if (blockState == null) {
+                if (state == null) {
                     try {
-                        blockState = blockFactory.parseFromInput(value, parserContext).toImmutableState();
+                        state = blockFactory.parseFromInput(value, parserContext).toImmutableState();
-                    } catch (InputParseException f) {
+                    } catch (InputParseException e) {
                     }
                 }
                 // if it's still null, both fixer and default failed
-                if (blockState == null) {
+                if (state == null) {
                     log.debug("Unknown block: " + value);
                 } else {
                     // it's not null so one of them succeeded, now use it
-                    blockToStringMap.put(blockState, id);
+                    blockToStringMap.put(state, id);
-                    stringToBlockMap.put(id, blockState);
+                    stringToBlockMap.put(id, state);
                 }
             }
-            if (blockState != null) {
+            if (state != null) {
-                blockArr[combinedId] = blockState.getInternalId();
+                blockArr[combinedId] = state.getInternalId();
-                blockStateToLegacyId4Data.put(blockState.getInternalId(), (Integer) combinedId);
+                blockStateToLegacyId4Data.put(state.getInternalId(), (Integer) combinedId);
-                blockStateToLegacyId4Data.putIfAbsent(blockState.getInternalBlockTypeId(), combinedId);
+                blockStateToLegacyId4Data.putIfAbsent(state.getInternalBlockTypeId(), combinedId);
             }
         }
         for (int id = 0; id < 256; id++) {
             int combinedId = id << 4;
             int base = blockArr[combinedId];
             if (base != 0) {
-                for (int data = 0; data < 16; data++, combinedId++) {
+                for (int data_ = 0; data_ < 16; data_++, combinedId++) {
                     if (blockArr[combinedId] == 0) blockArr[combinedId] = base;
                 }
             }
@@ -166,14 +165,14 @@ public final class LegacyMapper {
                 value = fixer.fixUp(DataFixer.FixTypes.ITEM_TYPE, value, 1631);
                 type = ItemTypes.get(value);
             }
-            if (type != null) {
+            if (type == null) {
+                log.debug("Unknown item: " + value);
+            } else {
                 try {
                     itemMap.put(getCombinedId(id), type);
-                    continue;
+                } catch (Exception ignored) {
-                } catch (Exception e) {
                 }
             }
-            log.debug("Unknown item: " + value);
         }
     }
 
@@ -289,7 +288,10 @@ public final class LegacyMapper {
         return combinedId == null ? null : new int[] { combinedId >> 4, combinedId & 0xF };
     }
 
-    public final static LegacyMapper getInstance() {
+    public static LegacyMapper getInstance() {
+        if (INSTANCE == null) {
+            INSTANCE = new LegacyMapper();
+        }
         return INSTANCE;
     }
 

worldedit-core/src/main/java/com/sk89q/worldedit/world/registry/SimpleItemMaterial.java

@@ -19,7 +19,7 @@
 
 package com.sk89q.worldedit.world.registry;
 
-class SimpleItemMaterial implements ItemMaterial {
+public class SimpleItemMaterial implements ItemMaterial {
 
     private int maxStackSize;
     private int maxDamage;

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/SnapshotRepository.java

@@ -22,6 +22,7 @@
 package com.sk89q.worldedit.world.snapshot;
 
 import com.sk89q.worldedit.world.storage.MissingWorldException;
+
 import javax.annotation.Nullable;
 import java.io.File;
 import java.io.FilenameFilter;

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/Snapshot.java

@@ -0,0 +1,62 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental;
+
+import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.world.DataException;
+import com.sk89q.worldedit.world.chunk.Chunk;
+import com.sk89q.worldedit.world.storage.ChunkStoreHelper;
+
+import java.io.Closeable;
+import java.io.IOException;
+
+/**
+ * Represents a world snapshot.
+ */
+public interface Snapshot extends Closeable {
+
+    SnapshotInfo getInfo();
+
+    /**
+     * Get the chunk information for the given position. Implementations may ignore the Y-chunk
+     * if its chunks are only stored in 2D.
+     *
+     * @param position the position of the chunk
+     * @return the tag containing chunk data
+     */
+    CompoundTag getChunkTag(BlockVector3 position) throws DataException, IOException;
+
+    /**
+     * Get the chunk information for the given position.
+     *
+     * @see #getChunkTag(BlockVector3)
+     * @see ChunkStoreHelper#getChunk(CompoundTag)
+     */
+    default Chunk getChunk(BlockVector3 position) throws DataException, IOException {
+        return ChunkStoreHelper.getChunk(getChunkTag(position));
+    }
+
+    /**
+     * Close this snapshot. This releases the IO handles used to load chunk information.
+     */
+    @Override
+    void close() throws IOException;
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/SnapshotComparator.java

@@ -0,0 +1,35 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental;
+
+import java.util.Comparator;
+
+public class SnapshotComparator {
+
+    private static final Comparator<Snapshot> COMPARATOR =
+        Comparator.comparing(Snapshot::getInfo);
+
+    public static Comparator<Snapshot> getInstance() {
+        return COMPARATOR;
+    }
+
+    private SnapshotComparator() {
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/SnapshotDatabase.java

@@ -0,0 +1,81 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental;
+
+import java.io.IOException;
+import java.net.URI;
+import java.time.ZonedDateTime;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+import static com.sk89q.worldedit.util.collection.MoreStreams.takeWhile;
+
+/**
+ * Handler for querying snapshot storage.
+ */
+public interface SnapshotDatabase {
+
+    /**
+     * Get the URI scheme handled by this database.
+     */
+    String getScheme();
+
+    /**
+     * Get a snapshot by name.
+     *
+     * @param name the name of the snapshot
+     * @return the snapshot if available
+     */
+    Optional<Snapshot> getSnapshot(URI name) throws IOException;
+
+    /**
+     * Get all snapshots by world, unsorted. The stream should be
+     * {@linkplain Stream#close() closed}, as it may allocate filesystem or network resources.
+     *
+     * @param worldName the name of the world
+     * @return a stream of all snapshots for the given world in this database
+     */
+    Stream<Snapshot> getSnapshots(String worldName) throws IOException;
+
+    default Stream<Snapshot> getSnapshotsNewestFirst(String worldName) throws IOException {
+        return getSnapshots(worldName).sorted(SnapshotComparator.getInstance().reversed());
+    }
+
+    default Stream<Snapshot> getSnapshotsOldestFirst(String worldName) throws IOException {
+        return getSnapshots(worldName).sorted(SnapshotComparator.getInstance());
+    }
+
+    default Stream<Snapshot> getSnapshotsBefore(String worldName, ZonedDateTime date) throws IOException {
+        return takeWhile(
+            // sorted from oldest -> newest, so all `before` are at the front
+            getSnapshotsOldestFirst(worldName),
+            snap -> snap.getInfo().getDateTime().isBefore(date)
+        );
+    }
+
+    default Stream<Snapshot> getSnapshotsAfter(String worldName, ZonedDateTime date) throws IOException {
+        return takeWhile(
+            // sorted from newest -> oldest, so all `after` are at the front
+            getSnapshotsNewestFirst(worldName),
+            snap -> snap.getInfo().getDateTime().isAfter(date)
+        );
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/SnapshotInfo.java

@@ -0,0 +1,90 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental;
+
+import com.google.common.collect.ComparisonChain;
+
+import java.net.URI;
+import java.time.ZonedDateTime;
+import java.util.Objects;
+
+/**
+ * Information about a snapshot, such as name and date.
+ */
+public final class SnapshotInfo implements Comparable<SnapshotInfo> {
+
+    public static SnapshotInfo create(URI name, ZonedDateTime dateTime) {
+        return new SnapshotInfo(name, dateTime);
+    }
+
+    private final URI name;
+    private final ZonedDateTime dateTime;
+
+    private SnapshotInfo(URI name, ZonedDateTime dateTime) {
+        this.name = name;
+        this.dateTime = dateTime;
+    }
+
+    public URI getName() {
+        return name;
+    }
+
+    public String getDisplayName() {
+        if (name.getScheme().equals("snapfs")) {
+            // Stored raw as the scheme specific part
+            return name.getSchemeSpecificPart();
+        }
+        return name.toString();
+    }
+
+    public ZonedDateTime getDateTime() {
+        return dateTime;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        SnapshotInfo that = (SnapshotInfo) o;
+        return Objects.equals(name, that.name) &&
+            Objects.equals(dateTime, that.dateTime);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, dateTime);
+    }
+
+    @Override
+    public String toString() {
+        return "SnapshotInfo{" +
+            "name='" + name + '\'' +
+            ",date=" + dateTime +
+            '}';
+    }
+
+    @Override
+    public int compareTo(SnapshotInfo o) {
+        return ComparisonChain.start()
+            .compare(dateTime, o.dateTime)
+            .compare(name, o.name)
+            .result();
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/SnapshotRestore.java

@@ -0,0 +1,202 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental;
+
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.MaxChangedBlocksException;
+import com.sk89q.worldedit.math.BlockVector2;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.regions.CuboidRegion;
+import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.world.DataException;
+import com.sk89q.worldedit.world.chunk.Chunk;
+import com.sk89q.worldedit.world.storage.ChunkStore;
+import com.sk89q.worldedit.world.storage.MissingChunkException;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A snapshot restore operation.
+ */
+public class SnapshotRestore {
+
+    private final Map<BlockVector2, ArrayList<BlockVector3>> neededChunks = new LinkedHashMap<>();
+    private final Snapshot snapshot;
+    private final EditSession editSession;
+    private ArrayList<BlockVector2> missingChunks;
+    private ArrayList<BlockVector2> errorChunks;
+    private String lastErrorMessage;
+
+    /**
+     * Construct the snapshot restore operation.
+     *
+     * @param snapshot The {@link Snapshot} to restore from
+     * @param editSession The {@link EditSession} to restore to
+     * @param region The {@link Region} to restore to
+     */
+    public SnapshotRestore(Snapshot snapshot, EditSession editSession, Region region) {
+        this.snapshot = snapshot;
+        this.editSession = editSession;
+
+        if (region instanceof CuboidRegion) {
+            findNeededCuboidChunks(region);
+        } else {
+            findNeededChunks(region);
+        }
+    }
+
+    /**
+     * Find needed chunks in the axis-aligned bounding box of the region.
+     *
+     * @param region The {@link Region} to iterate
+     */
+    private void findNeededCuboidChunks(Region region) {
+        BlockVector3 min = region.getMinimumPoint();
+        BlockVector3 max = region.getMaximumPoint();
+
+        // First, we need to group points by chunk so that we only need
+        // to keep one chunk in memory at any given moment
+        for (int x = min.getBlockX(); x <= max.getBlockX(); ++x) {
+            for (int y = min.getBlockY(); y <= max.getBlockY(); ++y) {
+                for (int z = min.getBlockZ(); z <= max.getBlockZ(); ++z) {
+                    BlockVector3 pos = BlockVector3.at(x, y, z);
+                    checkAndAddBlock(pos);
+                }
+            }
+        }
+    }
+
+    /**
+     * Find needed chunks in the region.
+     *
+     * @param region The {@link Region} to iterate
+     */
+    private void findNeededChunks(Region region) {
+        // First, we need to group points by chunk so that we only need
+        // to keep one chunk in memory at any given moment
+        for (BlockVector3 pos : region) {
+            checkAndAddBlock(pos);
+        }
+    }
+
+    private void checkAndAddBlock(BlockVector3 pos) {
+        if (editSession.getMask() != null && !editSession.getMask().test(pos))
+            return;
+
+        BlockVector2 chunkPos = ChunkStore.toChunk(pos);
+
+        // Unidentified chunk
+        if (!neededChunks.containsKey(chunkPos)) {
+            neededChunks.put(chunkPos, new ArrayList<>());
+        }
+
+        neededChunks.get(chunkPos).add(pos);
+    }
+
+    /**
+     * Get the number of chunks that are needed.
+     *
+     * @return a number of chunks
+     */
+    public int getChunksAffected() {
+        return neededChunks.size();
+    }
+
+    /**
+     * Restores to world.
+     *
+     * @throws MaxChangedBlocksException
+     */
+    public void restore() throws MaxChangedBlocksException {
+
+        missingChunks = new ArrayList<>();
+        errorChunks = new ArrayList<>();
+
+        // Now let's start restoring!
+        for (Map.Entry<BlockVector2, ArrayList<BlockVector3>> entry : neededChunks.entrySet()) {
+            BlockVector2 chunkPos = entry.getKey();
+            Chunk chunk;
+
+            try {
+                // This will need to be changed if we start officially supporting 3d snapshots.
+                chunk = snapshot.getChunk(chunkPos.toBlockVector3());
+                // Good, the chunk could be at least loaded
+
+                // Now just copy blocks!
+                for (BlockVector3 pos : entry.getValue()) {
+                    try {
+                        editSession.setBlock(pos, chunk.getBlock(pos));
+                    } catch (DataException e) {
+                        // this is a workaround: just ignore for now
+                    }
+                }
+            } catch (MissingChunkException me) {
+                missingChunks.add(chunkPos);
+            } catch (IOException | DataException me) {
+                errorChunks.add(chunkPos);
+                lastErrorMessage = me.getMessage();
+            }
+        }
+    }
+
+    /**
+     * Get a list of the missing chunks. restore() must have been called
+     * already.
+     *
+     * @return a list of coordinates
+     */
+    public List<BlockVector2> getMissingChunks() {
+        return missingChunks;
+    }
+
+    /**
+     * Get a list of the chunks that could not have been loaded for other
+     * reasons. restore() must have been called already.
+     *
+     * @return a list of coordinates
+     */
+    public List<BlockVector2> getErrorChunks() {
+        return errorChunks;
+    }
+
+    /**
+     * Checks to see where the backup succeeded in any capacity. False will
+     * be returned if no chunk could be successfully loaded.
+     *
+     * @return true if there was total failure
+     */
+    public boolean hadTotalFailure() {
+        return missingChunks.size() + errorChunks.size() == getChunksAffected();
+    }
+
+    /**
+     * Get the last error message.
+     *
+     * @return a message
+     */
+    public String getLastErrorMessage() {
+        return lastErrorMessage;
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/fs/FileSystemSnapshotDatabase.java

@@ -0,0 +1,300 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental.fs;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.net.UrlEscapers;
+import com.sk89q.worldedit.util.function.IORunnable;
+import com.sk89q.worldedit.util.io.Closer;
+import com.sk89q.worldedit.util.io.file.ArchiveNioSupport;
+import com.sk89q.worldedit.util.io.file.MorePaths;
+import com.sk89q.worldedit.util.time.FileNameDateTimeParser;
+import com.sk89q.worldedit.util.time.ModificationDateTimeParser;
+import com.sk89q.worldedit.util.time.SnapshotDateTimeParser;
+import com.sk89q.worldedit.world.snapshot.experimental.Snapshot;
+import com.sk89q.worldedit.world.snapshot.experimental.SnapshotDatabase;
+import com.sk89q.worldedit.world.snapshot.experimental.SnapshotInfo;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.URI;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.ZonedDateTime;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.ServiceLoader;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Implements a snapshot database based on a filesystem.
+ */
+public class FileSystemSnapshotDatabase implements SnapshotDatabase {
+
+    private static final Logger logger = LoggerFactory.getLogger(FileSystemSnapshotDatabase.class);
+
+    private static final String SCHEME = "snapfs";
+
+    private static final List<SnapshotDateTimeParser> DATE_TIME_PARSERS =
+        new ImmutableList.Builder<SnapshotDateTimeParser>()
+            .add(FileNameDateTimeParser.getInstance())
+            .addAll(ServiceLoader.load(SnapshotDateTimeParser.class))
+            .add(ModificationDateTimeParser.getInstance())
+            .build();
+
+    public static ZonedDateTime tryParseDate(Path path) {
+        return tryParseDateInternal(path)
+            .orElseThrow(() -> new IllegalStateException("Could not detect date of " + path));
+    }
+
+    private static Optional<ZonedDateTime> tryParseDateInternal(Path path) {
+        return DATE_TIME_PARSERS.stream()
+            .map(parser -> parser.detectDateTime(path))
+            .filter(Objects::nonNull)
+            .findFirst();
+    }
+
+    public static URI createUri(String name) {
+        return URI.create(SCHEME + ":" + UrlEscapers.urlFragmentEscaper().escape(name));
+    }
+
+    public static FileSystemSnapshotDatabase maybeCreate(
+        Path root,
+        ArchiveNioSupport archiveNioSupport
+    ) throws IOException {
+        Files.createDirectories(root);
+        return new FileSystemSnapshotDatabase(root, archiveNioSupport);
+    }
+
+    private final Path root;
+    private final ArchiveNioSupport archiveNioSupport;
+
+    public FileSystemSnapshotDatabase(Path root, ArchiveNioSupport archiveNioSupport) {
+        checkArgument(Files.isDirectory(root), "Database root is not a directory");
+        this.root = root.toAbsolutePath();
+        this.archiveNioSupport = archiveNioSupport;
+    }
+
+    private SnapshotInfo createSnapshotInfo(Path fullPath, Path realPath) {
+        // Try full for parsing out of file name, real for parsing mod time.
+        ZonedDateTime date = tryParseDateInternal(fullPath).orElseGet(() -> tryParseDate(realPath));
+        return SnapshotInfo.create(createUri(fullPath.toString()), date);
+    }
+
+    private Snapshot createSnapshot(Path fullPath, Path realPath, @Nullable IORunnable closeCallback) {
+        return new FolderSnapshot(
+            createSnapshotInfo(fullPath, realPath), realPath, closeCallback
+        );
+    }
+
+    public Path getRoot() {
+        return root;
+    }
+
+    @Override
+    public String getScheme() {
+        return SCHEME;
+    }
+
+    @Override
+    public Optional<Snapshot> getSnapshot(URI name) throws IOException {
+        if (!name.getScheme().equals(SCHEME)) {
+            return Optional.empty();
+        }
+        // drop the / in the path to make it absolute
+        Path rawResolved = root.resolve(name.getSchemeSpecificPart());
+        // Catch trickery with paths:
+        Path realPath = rawResolved.normalize();
+        if (!realPath.startsWith(root)) {
+            return Optional.empty();
+        }
+        Optional<Snapshot> result = tryRegularFileSnapshot(root.relativize(realPath), realPath);
+        if (result.isPresent()) {
+            return result;
+        }
+        if (!Files.isDirectory(realPath)) {
+            return Optional.empty();
+        }
+        return Optional.of(createSnapshot(root.relativize(realPath), realPath, null));
+    }
+
+    private Optional<Snapshot> tryRegularFileSnapshot(Path fullPath, Path realPath) throws IOException {
+        Closer closer = Closer.create();
+        Path root = this.root;
+        Path relative = root.relativize(realPath);
+        Iterator<Path> iterator = null;
+        try {
+            while (true) {
+                if (iterator == null) {
+                    iterator = MorePaths.iterPaths(relative).iterator();
+                }
+                if (!iterator.hasNext()) {
+                    return Optional.empty();
+                }
+                Path relativeNext = iterator.next();
+                Path next = root.resolve(relativeNext);
+                if (!Files.isRegularFile(next)) {
+                    // This will never be it.
+                    continue;
+                }
+                Optional<Path> newRootOpt = archiveNioSupport.tryOpenAsDir(next);
+                if (newRootOpt.isPresent()) {
+                    root = newRootOpt.get();
+                    if (root.getFileSystem() != FileSystems.getDefault()) {
+                        closer.register(root.getFileSystem());
+                    }
+                    // Switch path to path inside the archive
+                    relative = root.resolve(relativeNext.relativize(relative).toString());
+                    iterator = null;
+                    // Check if it exists, if so open snapshot
+                    if (Files.exists(relative)) {
+                        return Optional.of(createSnapshot(fullPath, relative, closer::close));
+                    }
+                    // Otherwise, we may have more archives to open.
+                    // Keep searching!
+                }
+            }
+        } catch (Throwable t) {
+            throw closer.rethrowAndClose(t);
+        }
+    }
+
+    @Override
+    public Stream<Snapshot> getSnapshots(String worldName) throws IOException {
+        /*
+         There are a few possible snapshot formats we accept:
+           - a world directory, identified by <worldName>/level.dat
+           - a world archive, identified by <worldName>.ext
+             * does not need to have level.dat inside
+           - a timestamped directory, identified by <stamp>, that can have
+             - the two world formats described above, inside the directory
+           - a timestamped archive, identified by <stamp>.ext, that can have
+             - the same as timestamped directory, but inside the archive.
+           - a directory with the world name, but no level.dat
+             - inside must be timestamped directory/archive, with the world inside that
+
+           All archives may have a root directory with the same name as the archive,
+           minus the extensions. Due to extension detection methods, this won't work properly
+           with some files, e.g. world.qux.zip/world.qux is invalid, but world.qux.zip/world isn't.
+         */
+        return Stream.of(
+            listWorldEntries(Paths.get(""), root, worldName),
+            listTimestampedEntries(Paths.get(""), root, worldName)
+        ).flatMap(Function.identity());
+    }
+
+    private Stream<Snapshot> listWorldEntries(Path fullPath, Path root, String worldName) throws IOException {
+        logger.debug("World check in: {}", root);
+        return Files.list(root)
+            .flatMap(candidate -> {
+                logger.debug("World trying: {}", candidate);
+                // Try world directory
+                String fileName = candidate.getFileName().toString();
+                if (isSameDirectoryName(fileName, worldName)) {
+                    // Direct
+                    if (Files.exists(candidate.resolve("level.dat"))) {
+                        logger.debug("Direct!");
+                        return Stream.of(createSnapshot(
+                            fullPath.resolve(fileName), candidate, null
+                        ));
+                    }
+                    // Container for time-stamped entries
+                    try {
+                        return listTimestampedEntries(
+                            fullPath.resolve(fileName), candidate, worldName
+                        );
+                    } catch (IOException e) {
+                        throw new UncheckedIOException(e);
+                    }
+                }
+                // Try world archive
+                if (Files.isRegularFile(candidate)
+                    && fileName.startsWith(worldName + ".")) {
+                    logger.debug("Archive!");
+                    try {
+                        return tryRegularFileSnapshot(
+                            fullPath.resolve(fileName), candidate
+                        ).map(Stream::of).orElse(null);
+                    } catch (IOException e) {
+                        throw new UncheckedIOException(e);
+                    }
+                }
+                logger.debug("Nothing!");
+                return null;
+            });
+    }
+
+    private boolean isSameDirectoryName(String fileName, String worldName) {
+        if (fileName.lastIndexOf('/') == fileName.length() - 1) {
+            fileName = fileName.substring(0, fileName.length() - 1);
+        }
+        return fileName.equalsIgnoreCase(worldName);
+    }
+
+    private Stream<Snapshot> listTimestampedEntries(Path fullPath, Path root, String worldName) throws IOException {
+        logger.debug("Timestamp check in: {}", root);
+        return Files.list(root)
+            .filter(candidate -> {
+                ZonedDateTime date = FileNameDateTimeParser.getInstance().detectDateTime(candidate);
+                return date != null;
+            })
+            .flatMap(candidate -> {
+                logger.debug("Timestamp trying: {}", candidate);
+                // Try timestamped directory
+                if (Files.isDirectory(candidate)) {
+                    logger.debug("Timestamped directory");
+                    try {
+                        return listWorldEntries(
+                            fullPath.resolve(candidate.getFileName().toString()), candidate, worldName
+                        );
+                    } catch (IOException e) {
+                        throw new UncheckedIOException(e);
+                    }
+                }
+                // Otherwise archive, get it as a directory & unpack it
+                try {
+                    Optional<Path> newRoot = archiveNioSupport.tryOpenAsDir(candidate);
+                    if (!newRoot.isPresent()) {
+                        logger.debug("Nothing!");
+                        return null;
+                    }
+                    logger.debug("Timestamped archive!");
+                    return listWorldEntries(
+                        fullPath.resolve(candidate.getFileName().toString()),
+                        newRoot.get(),
+                        worldName
+                    );
+                } catch (IOException e) {
+                    throw new UncheckedIOException(e);
+                }
+            });
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/fs/FolderSnapshot.java

@@ -0,0 +1,166 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.world.snapshot.experimental.fs;
+
+import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.worldedit.math.BlockVector2;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.function.IORunnable;
+import com.sk89q.worldedit.world.DataException;
+import com.sk89q.worldedit.world.snapshot.experimental.Snapshot;
+import com.sk89q.worldedit.world.snapshot.experimental.SnapshotInfo;
+import com.sk89q.worldedit.world.storage.ChunkStoreHelper;
+import com.sk89q.worldedit.world.storage.LegacyChunkStore;
+import com.sk89q.worldedit.world.storage.McRegionChunkStore;
+import com.sk89q.worldedit.world.storage.McRegionReader;
+import com.sk89q.worldedit.world.storage.MissingChunkException;
+
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Stream;
+import java.util.zip.GZIPInputStream;
+
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Snapshot based on a world folder. Extracts chunks from the region folder.
+ *
+ * <p>
+ * Note that the Path can belong to another filesystem. This allows easy integration with
+ * zips due to Java's built-in zipfs support.
+ * </p>
+ */
+public class FolderSnapshot implements Snapshot {
+
+    /**
+     * Object used by {@code getRegionFolder(Path)} to indicate that the path does not exist.
+     */
+    private static final Object NOT_FOUND_TOKEN = new Object();
+
+    private static Object getRegionFolder(Path folder) throws IOException {
+        Path regionDir = folder.resolve("region");
+        if (Files.exists(regionDir)) {
+            checkState(Files.isDirectory(regionDir), "Region folder is actually a file");
+            return regionDir;
+        }
+        // Might be in a DIM* folder
+        try (Stream<Path> paths = Files.list(folder)) {
+            Optional<Path> path = paths
+                .filter(Files::isDirectory)
+                .filter(p -> p.getFileName().toString().startsWith("DIM"))
+                .map(p -> p.resolve("region"))
+                .filter(Files::isDirectory)
+                .findFirst();
+            if (path.isPresent()) {
+                return path.get();
+            }
+        }
+        // Might be its own region folder, check if the appropriate files exist
+        try (Stream<Path> paths = Files.list(folder)) {
+            if (paths
+                .filter(Files::isRegularFile)
+                .anyMatch(p -> {
+                    String fileName = p.getFileName().toString();
+                    return fileName.startsWith("r") &&
+                        (fileName.endsWith(".mca") || fileName.endsWith(".mcr"));
+                })) {
+                return folder;
+            }
+        }
+        return NOT_FOUND_TOKEN;
+    }
+
+    private final SnapshotInfo info;
+    private final Path folder;
+    private final AtomicReference<Object> regionFolder = new AtomicReference<>();
+    private final @Nullable IORunnable closeCallback;
+
+    public FolderSnapshot(SnapshotInfo info, Path folder, @Nullable IORunnable closeCallback) {
+        this.info = info;
+        // This is required to force TrueVfs to properly resolve parents.
+        // Kinda odd, but whatever works.
+        this.folder = folder.toAbsolutePath();
+        this.closeCallback = closeCallback;
+    }
+
+    public Path getFolder() {
+        return folder;
+    }
+
+    @Override
+    public SnapshotInfo getInfo() {
+        return info;
+    }
+
+    private Optional<Path> getRegionFolder() throws IOException {
+        Object regFolder = regionFolder.get();
+        if (regFolder == null) {
+            Object update = getRegionFolder(folder);
+            if (!regionFolder.compareAndSet(null, update)) {
+                // failed race, get existing value
+                regFolder = regionFolder.get();
+            } else {
+                regFolder = update;
+            }
+        }
+        return regFolder == NOT_FOUND_TOKEN ? Optional.empty() : Optional.of((Path) regFolder);
+    }
+
+    @Override
+    public CompoundTag getChunkTag(BlockVector3 position) throws DataException, IOException {
+        BlockVector2 pos = position.toBlockVector2();
+        Optional<Path> regFolder = getRegionFolder();
+        if (!regFolder.isPresent()) {
+            Path chunkFile = getFolder().resolve(LegacyChunkStore.getFilename(pos, "/"));
+            if (!Files.exists(chunkFile)) {
+                throw new MissingChunkException();
+            }
+            return ChunkStoreHelper.readCompoundTag(() ->
+                new GZIPInputStream(Files.newInputStream(chunkFile))
+            );
+        }
+        Path regionFile = regFolder.get().resolve(McRegionChunkStore.getFilename(pos));
+        if (!Files.exists(regionFile)) {
+            // Try mcr as well
+            regionFile = regionFile.resolveSibling(
+                regionFile.getFileName().toString().replace(".mca", ".mcr")
+            );
+            if (!Files.exists(regionFile)) {
+                throw new MissingChunkException();
+            }
+        }
+        try (InputStream stream = Files.newInputStream(regionFile)) {
+            McRegionReader regionReader = new McRegionReader(stream);
+            return ChunkStoreHelper.readCompoundTag(() -> regionReader.getChunkInputStream(pos));
+        }
+    }
+
+    @Override
+    public void close() throws IOException {
+        if (closeCallback != null) {
+            closeCallback.run();
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/snapshot/experimental/package-info.java

@@ -0,0 +1,30 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Experimental, in-testing, snapshot API. Do NOT rely on this API in plugin releases, as it will
+ * move to the existing snapshot package when testing is complete.
+ *
+ * <p>
+ * The existing snapshot API will be removed when this API is made official. It aims to have 100%
+ * compatibility with old snapshot storage, bar some odd date formats.
+ * </p>
+ */
+package com.sk89q.worldedit.world.snapshot.experimental;
+// TODO Un-experimentalize when ready.

worldedit-core/src/main/java/com/sk89q/worldedit/world/storage/ChunkStore.java

@@ -25,6 +25,7 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.world.DataException;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.chunk.Chunk;
+
 import java.io.Closeable;
 import java.io.IOException;
 

worldedit-core/src/main/java/com/sk89q/worldedit/world/storage/LegacyChunkStore.java

@@ -23,6 +23,7 @@ import com.sk89q.jnbt.CompoundTag;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.world.DataException;
 import com.sk89q.worldedit.world.World;
+
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;

worldedit-core/src/main/java/com/sk89q/worldedit/world/storage/McRegionChunkStore.java

@@ -20,8 +20,6 @@
 package com.sk89q.worldedit.world.storage;
 
 import com.sk89q.jnbt.CompoundTag;
-import com.sk89q.jnbt.NBTInputStream;
-import com.sk89q.jnbt.Tag;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.world.DataException;
 import com.sk89q.worldedit.world.World;
@@ -67,19 +65,11 @@ public abstract class McRegionChunkStore extends ChunkStore {
 
     @Override
     public CompoundTag getChunkTag(BlockVector2 position, World world) throws DataException, IOException {
+        return ChunkStoreHelper.readCompoundTag(() -> {
             McRegionReader reader = getReader(position, world.getName());
 
-        InputStream stream = reader.getChunkInputStream(position);
+            return reader.getChunkInputStream(position);
-        Tag tag;
+        });
-
-        try (NBTInputStream nbt = new NBTInputStream(stream)) {
-            tag = nbt.readNamedTag().getTag();
-            if (!(tag instanceof CompoundTag)) {
-                throw new ChunkStoreException("CompoundTag expected for chunk; got " + tag.getClass().getName());
-            }
-
-            return (CompoundTag) tag;
-        }
     }
 
     /**