Rewrite ViewFlag.filter with Stream API to reduce copies of lists

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/Trace.java

@@ -35,6 +35,7 @@ import java.io.*;
 import java.lang.ref.SoftReference;
 import java.util.*;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 import java.util.zip.GZIPInputStream;
 
 public class Trace {
@@ -202,13 +203,14 @@ public class Trace {
             return;
         }
 
-        List<TNTPoint> workingRecords = new ArrayList<>(records);
         Set<ViewFlag> flagList = playerTraceShowData.getEffectiveViewFlags();
 
         // Apply filters
+        Stream<TNTPoint> workingRecordsStream = records.stream();
         for (ViewFlag flag : flagList) {
-            workingRecords = flag.filter(workingRecords);
+            workingRecordsStream = flag.filter(workingRecordsStream);
         }
+        List<TNTPoint> workingRecords = workingRecordsStream.collect(Collectors.toList());
 
         // Bundle records at unique positions
         List<List<TNTPoint>> bundles = bundleRecords(workingRecords, playerTraceShowData.getBundleFilter());

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/rendering/ViewFlag.java

@@ -31,6 +31,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * A settable flag that changes how a trace is rendered
@@ -48,52 +49,44 @@ public abstract class ViewFlag {
 
     public static ViewFlag EXPLOSION = new ViewFlag(true, false, "explosion", "e") {
         @Override
-        public List<TNTPoint> filter(List<TNTPoint> records) {
-            return records.stream()
-                    .filter(TNTPoint::isExplosion)
-                    .collect(Collectors.toList());
+        public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
+            return records.filter(TNTPoint::isExplosion);
         }
     };
 
     public static ViewFlag IGNITE = new ViewFlag(true, true, "ignite", "i") {
         @Override
-        public List<TNTPoint> filter(List<TNTPoint> records) {
-            return records.stream()
-                    .filter(record -> record.isAfterFirstExplosion())
-                    .collect(Collectors.toList());
+        public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
+            return records.filter(record -> record.isAfterFirstExplosion());
         }
     };
 
     public static ViewFlag SOURCE = new ViewFlag(true, false, IGNITE, "source", "s") {
         @Override
-        public List<TNTPoint> filter(List<TNTPoint> records) {
-            return records.stream()
-                    .filter(record -> record.getFuse() == 80)
-                    .collect(Collectors.toList());
+        public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
+            return records.filter(record -> record.getFuse() == 80);
         }
     };
 
     public static ViewFlag BUILD_DESTROY_ONLY = new ViewFlag(true, false, "build-destroy-only") {
         @Override
-        public List<TNTPoint> filter(List<TNTPoint> records) {
-            return records.stream()
-                    .filter(record -> record.getHistory().get(record.getHistory().size() - 1).isDestroyedBuildArea())
-                    .collect(Collectors.toList());
+        public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
+            return records.filter(record -> record.getHistory().get(record.getHistory().size() - 1).isDestroyedBuildArea());
         }
     };
 
     public static ViewFlag TESTBLOCK_DESTROY_ONLY = new ViewFlag(true, false, "testblock-destroy-only") {
         @Override
-        public List<TNTPoint> filter(List<TNTPoint> records) {
-            return records.stream()
-                    .filter(record -> record.getHistory().get(record.getHistory().size() - 1).isDestroyedTestBlock())
-                    .collect(Collectors.toList());
+        public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
+            return records.filter(record -> record.getHistory().get(record.getHistory().size() - 1).isDestroyedTestBlock());
         }
     };
 
     public static ViewFlag MICROMOTION = new ViewFlag(true, false, "micromotion", "m") {
         @Override
-        public List<TNTPoint> filter(List<TNTPoint> records) {
+        public Stream<TNTPoint> filter(Stream<TNTPoint> stream) {
+            List<TNTPoint> records = stream.collect(Collectors.toList());
+            ;
             Set<Integer> seen = new HashSet<>();
             Set<TNTPoint> toRemove = new HashSet<>();
 
@@ -119,7 +112,7 @@ public abstract class ViewFlag {
                 records.removeAll(record.getHistory());
             }
 
-            return records;
+            return records.stream();
         }
     };
 
@@ -239,7 +232,7 @@ public abstract class ViewFlag {
      * @param records Records to be filtered
      * @return Filtered records
      */
-    public List<TNTPoint> filter(List<TNTPoint> records) {
+    public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
         return records;
     }
 

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/rendering/dynamicflags/AtFlag.java

@@ -22,8 +22,7 @@ package de.steamwar.bausystem.features.tracer.rendering.dynamicflags;
 import de.steamwar.bausystem.features.tracer.TNTPoint;
 import de.steamwar.bausystem.features.tracer.rendering.ViewFlag;
 
-import java.util.List;
-import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * A view flag for rendering a trace only in a given time intervall
@@ -56,9 +55,7 @@ public class AtFlag extends ViewFlag {
     }
 
     @Override
-    public List<TNTPoint> filter(List<TNTPoint> records) {
-        return records.stream()
-                .filter(record -> record.getTicksSinceStart() >= start && record.getTicksSinceStart() <= end)
-                .collect(Collectors.toList());
+    public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
+        return records.filter(record -> record.getTicksSinceStart() >= start && record.getTicksSinceStart() <= end);
     }
 }

BauSystem_Main/src/de/steamwar/bausystem/features/tracer/rendering/dynamicflags/IsolateFlag.java

@@ -23,9 +23,8 @@ import de.steamwar.bausystem.features.tracer.TNTPoint;
 import de.steamwar.bausystem.features.tracer.rendering.ViewFlag;
 
 import java.util.HashSet;
-import java.util.List;
 import java.util.Set;
-import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * A flag for rendering only the records of specific tnts
@@ -53,10 +52,8 @@ public class IsolateFlag extends ViewFlag {
     }
 
     @Override
-    public List<TNTPoint> filter(List<TNTPoint> records) {
+    public Stream<TNTPoint> filter(Stream<TNTPoint> records) {
         if (tntToIsolate.isEmpty()) return records;
-        return records.stream()
-                .filter(record -> tntToIsolate.contains(record.getTntId()))
-                .collect(Collectors.toList());
+        return records.filter(record -> tntToIsolate.contains(record.getTntId()));
     }
 }