separating event proxy generation to improve resilience against bad transformers

Mumfrey
1 parent 00d2ffc1
Showing 4 changed files with 95 additions and 67 deletions
java/client/com/mumfrey/liteloader/client/api/LiteLoaderCoreAPIClient.java
java/common/com/mumfrey/liteloader/launch/RealmsJsonUpdateThread.java
java/common/com/mumfrey/liteloader/transformers/event/EventInjectionTransformer.java
java/common/com/mumfrey/liteloader/transformers/event/EventProxyTransformer.java
@@ -22,9 +22,10 @@ import com.mumfrey.liteloader.interfaces.ObjectFactory;
  */
 public class LiteLoaderCoreAPIClient extends LiteLoaderCoreAPI
 {
-	private static final String PKG_LITELOADER_CLIENT   = LiteLoaderCoreAPI.PKG_LITELOADER + ".client";
+	private static final String PKG_LITELOADER_CLIENT = LiteLoaderCoreAPI.PKG_LITELOADER + ".client";
 	private static final String[] requiredTransformers = {
+		LiteLoaderCoreAPI.PKG_LITELOADER + ".transformers.event.EventProxyTransformer",
 		LiteLoaderCoreAPI.PKG_LITELOADER + ".launch.LiteLoaderTransformer",
 		LiteLoaderCoreAPIClient.PKG_LITELOADER_CLIENT + ".transformers.CrashReportTransformer"
 	};
@@ -106,11 +106,7 @@ public class RealmsJsonUpdateThread extends Thread
 	private boolean writeLocalVersionJson(Map<String, ?> localJson)
 	{
-		File versionDir = new File(this.versionsDir, this.version);
-		if (!versionDir.exists() || !versionDir.isDirectory()) return false;
-		
-		File versionJsonFile = new File(versionDir, this.version + ".json");
-		
+		File versionJsonFile = this.getLocalVersionJsonFile();
 		FileWriter writer = null;
 		try
@@ -227,11 +223,8 @@ public class RealmsJsonUpdateThread extends Thread
 	@SuppressWarnings("unchecked")
 	private Map<String, ?> getLocalVersionJson()
 	{
-		File versionDir = new File(this.versionsDir, this.version);
-		if (!versionDir.exists() || !versionDir.isDirectory()) return null;
-		
-		File versionJsonFile = new File(versionDir, this.version + ".json");
-		if (!versionJsonFile.exists()) return null;
+		File versionJsonFile = this.getLocalVersionJsonFile();
+		if (versionJsonFile == null || !versionJsonFile.exists()) return null;
 		FileReader reader = null; 
@@ -254,13 +247,22 @@ public class RealmsJsonUpdateThread extends Thread
 	private boolean isLocalJsonUpToDate()
 	{
-		File versionDir = new File(this.versionsDir, this.version);
-		if (!versionDir.exists() || !versionDir.isDirectory()) return false;
-		
-		File versionJsonFile = new File(versionDir, this.version + ".json");
-		if (!versionJsonFile.exists()) return false;
+		File versionJsonFile = this.getLocalVersionJsonFile();
+		if (versionJsonFile == null || !versionJsonFile.exists()) return false;
 		long deltaTime = System.currentTimeMillis() - versionJsonFile.lastModified();
 		return deltaTime < 86400000;
 	}
+
+	/**
+	 * @return
+	 */
+	private File getLocalVersionJsonFile()
+	{
+		File versionDir = new File(this.versionsDir, this.version);
+		if (!versionDir.exists() || !versionDir.isDirectory()) return null;
+		
+		File versionJsonFile = new File(versionDir, this.version + ".json");
+		return versionJsonFile;
+	}
 }
@@ -10,14 +10,11 @@ import java.util.Set;
 import java.util.TreeSet;
 import org.objectweb.asm.ClassWriter;
-import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.AbstractInsnNode;
 import org.objectweb.asm.tree.ClassNode;
-import org.objectweb.asm.tree.InsnNode;
 import org.objectweb.asm.tree.MethodNode;
 import org.objectweb.asm.util.CheckClassAdapter;
-import com.mumfrey.liteloader.core.runtime.Obf;
 import com.mumfrey.liteloader.transformers.ClassTransformer;
 import com.mumfrey.liteloader.util.log.LiteLoaderLogger;
@@ -59,7 +56,7 @@ public abstract class EventInjectionTransformer extends ClassTransformer
 	/**
 	 * Multiple event injection transformers may exist but to allow co-operation the events themselves are registered
 	 * statically. The first EventInjectionTransformer instance to be created becomes the "master" and is actually responsible
-	 * for injecting the events and transforming the EventProxy class.
+	 * for injecting the events
 	 */
 	private static EventInjectionTransformer master;
@@ -156,23 +153,6 @@ public abstract class EventInjectionTransformer extends ClassTransformer
 	{
 		if (EventInjectionTransformer.master == this)
 		{
-			if (transformedName != null && transformedName.startsWith(Obf.EventProxy.name))
-			{
-				int dollarPos = transformedName.indexOf('$');
-				int proxyIndex = (dollarPos > -1) ? Integer.parseInt(transformedName.substring(dollarPos + 1)) : 0;
-				if (proxyIndex != 1)
-				{
-					try
-					{
-						return this.transformEventProxy(transformedName, basicClass, proxyIndex);
-					}
-					catch (Throwable th)
-					{
-						th.printStackTrace();
-					}
-				}
-			}
-			
 			if (basicClass != null && EventInjectionTransformer.eventMappings.containsKey(transformedName))
 			{
 				return this.injectEvents(basicClass, EventInjectionTransformer.eventMappings.get(transformedName));
@@ -182,36 +162,6 @@ public abstract class EventInjectionTransformer extends ClassTransformer
 		return basicClass;
 	}
-	private byte[] transformEventProxy(String transformedName, byte[] basicClass, int proxyIndex)
-	{
-		ClassNode classNode = this.getProxyByteCode(transformedName, basicClass, proxyIndex);
-		return this.writeClass(Event.populateProxy(classNode, proxyIndex == 0 ? 1 : proxyIndex));
-	}
-
-	private ClassNode getProxyByteCode(String transformedName, byte[] basicClass, int proxyIndex)
-	{
-		if (proxyIndex == 0 || basicClass != null)
-		{
-			ClassNode classNode = this.readClass(basicClass, true);
-
-			for (MethodNode method : classNode.methods)
-			{
-				// Strip the sanity code out of the EventProxy class initialiser
-				if ("<clinit>".equals(method.name))
-				{
-					method.instructions.clear();
-					method.instructions.add(new InsnNode(Opcodes.RETURN));
-				}
-			}		
-			
-			return classNode;
-		}
-		
-		ClassNode classNode = new ClassNode();
-		classNode.visit(50, Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC, transformedName.replace('.', '/'), null, "java/lang/Object", null);
-		return classNode;
-	}
-
 	private byte[] injectEvents(byte[] basicClass, Map<String, Map<Event, InjectionPoint>> mappings)
 	{
 		if (mappings == null) return basicClass;
+package com.mumfrey.liteloader.transformers.event;
+
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.ClassNode;
+import org.objectweb.asm.tree.InsnNode;
+import org.objectweb.asm.tree.MethodNode;
+
+import com.mumfrey.liteloader.core.runtime.Obf;
+import com.mumfrey.liteloader.transformers.ClassTransformer;
+
+/**
+ * Transformer responsible for transforming/generating the EventProxy inner classes, separated from the Event Transformer
+ * itself so that we can place it higher up the tranformer chain to avoid broken mod transformers screwing things up.
+ * 
+ * @author Adam Mummery-Smith
+ */
+public class EventProxyTransformer extends ClassTransformer
+{
+	public EventProxyTransformer()
+	{
+	}
+	
+	@Override
+	public byte[] transform(String name, String transformedName, byte[] basicClass)
+	{
+		if (transformedName != null && transformedName.startsWith(Obf.EventProxy.name))
+		{
+			int dollarPos = transformedName.indexOf('$');
+			int proxyIndex = (dollarPos > -1) ? Integer.parseInt(transformedName.substring(dollarPos + 1)) : 0;
+			if (proxyIndex != 1)
+			{
+				try
+				{
+					return this.transformEventProxy(transformedName, basicClass, proxyIndex);
+				}
+				catch (Throwable th)
+				{
+					th.printStackTrace();
+				}
+			}
+		}
+		
+		return basicClass;
+	}
+
+	private byte[] transformEventProxy(String transformedName, byte[] basicClass, int proxyIndex)
+	{
+		ClassNode classNode = this.getProxyByteCode(transformedName, basicClass, proxyIndex);
+		return this.writeClass(Event.populateProxy(classNode, proxyIndex == 0 ? 1 : proxyIndex));
+	}
+
+	private ClassNode getProxyByteCode(String transformedName, byte[] basicClass, int proxyIndex)
+	{
+		if (proxyIndex == 0 || basicClass != null)
+		{
+			ClassNode classNode = this.readClass(basicClass, true);
+
+			for (MethodNode method : classNode.methods)
+			{
+				// Strip the sanity code out of the EventProxy class initialiser
+				if ("<clinit>".equals(method.name))
+				{
+					method.instructions.clear();
+					method.instructions.add(new InsnNode(Opcodes.RETURN));
+				}
+			}		
+			
+			return classNode;
+		}
+		
+		ClassNode classNode = new ClassNode();
+		classNode.visit(50, Opcodes.ACC_PUBLIC | Opcodes.ACC_STATIC, transformedName.replace('.', '/'), null, "java/lang/Object", null);
+		return classNode;
+	}
+}