From 0376602894fdf60e5176e166237f029d2cb43af6 Mon Sep 17 00:00:00 2001
From: Myles <mylescomputer@gmail.com>
Date: Wed, 23 Mar 2016 14:00:48 +0000
Subject: [PATCH] Update TODO list, add pipeline cache

---
 README.md                                     | 12 ++----------
 pom.xml                                       |  2 +-
 .../api/protocol/ProtocolRegistry.java        | 19 +++++++++++++++++--
 3 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 7f9eecb66..294d58ab0 100644
--- a/README.md
+++ b/README.md
@@ -3,16 +3,8 @@
 
 This is an experimental branch, but soon to be live.
 
-
-The things which stop this from going live:
-
-Need to implement debug mode using deprecated PacketType for english
-
-and then javadocs.
-
-
-It would be nice to have a Pipeline cache so it doesn't have to figure it out all the time.
-(and to ensure it uses the shortest pipeline)
+(The only issues would be really really complex protocol pipelines...) 
+(But I don't see them happening any time soon)
 
 License:
 --------
diff --git a/pom.xml b/pom.xml
index 2be236da3..cda788d3a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>us.myles</groupId>
     <artifactId>viaversion</artifactId>
-    <version>0.6.8-SNAPSHOT</version>
+    <version>0.7.0-ALPHA</version>
     <packaging>jar</packaging>
 
     <name>ViaVersion</name>
diff --git a/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java b/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java
index 1cac43b46..e6b459958 100644
--- a/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java
+++ b/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java
@@ -10,6 +10,7 @@ public class ProtocolRegistry {
     public static int SERVER_PROTOCOL = -1;
     // Input Version -> Output Version & Protocol (Allows fast lookup)
     private static Map<Integer, Map<Integer, Protocol>> registryMap = new HashMap<>();
+    private static Map<Pair<Integer, Integer>, List<Pair<Integer, Protocol>>> pathCache = new HashMap<>();
 
     static {
         // Register built in protocols
@@ -25,6 +26,10 @@ public class ProtocolRegistry {
      * @param output    The output server version it converts to.
      */
     public static void registerProtocol(Protocol protocol, List<Integer> supported, Integer output) {
+        // Clear cache as this may make new routes.
+        if (pathCache.size() > 0)
+            pathCache.clear();
+
         for (Integer version : supported) {
             if (!registryMap.containsKey(version)) {
                 registryMap.put(version, new HashMap<Integer, Protocol>());
@@ -97,7 +102,17 @@ public class ProtocolRegistry {
      * @return The path it generated, null if it failed.
      */
     public static List<Pair<Integer, Protocol>> getProtocolPath(int clientVersion, int serverVersion) {
-        // TODO: Cache
-        return getProtocolPath(new ArrayList<Pair<Integer, Protocol>>(), clientVersion, serverVersion);
+        Pair<Integer, Integer> protocolKey = new Pair<>(clientVersion, serverVersion);
+        // Check cache
+        if (pathCache.containsKey(protocolKey)) {
+            return pathCache.get(protocolKey);
+        }
+        // Generate path
+        List<Pair<Integer, Protocol>> outputPath = getProtocolPath(new ArrayList<Pair<Integer, Protocol>>(), clientVersion, serverVersion);
+        // If it found a path, cache it.
+        if (outputPath != null) {
+            pathCache.put(protocolKey, outputPath);
+        }
+        return outputPath;
     }
 }