Waterfall/BungeeCord-Patches/0052-Speed-up-some-common-exceptions.patch

From 9439649fae593bf183d39fa3337457ef60a91acf Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Mon, 25 Nov 2019 19:54:06 +0000
Subject: [PATCH] Speed up some common exceptions


diff --git a/api/src/main/java/io/github/waterfallmc/waterfall/utils/FastException.java b/api/src/main/java/io/github/waterfallmc/waterfall/utils/FastException.java
new file mode 100644
index 00000000..11e103cb
--- /dev/null
+++ b/api/src/main/java/io/github/waterfallmc/waterfall/utils/FastException.java
@@ -0,0 +1,19 @@
+package io.github.waterfallmc.waterfall.utils;
+
+// This is basically a copy of QuietException
+public class FastException extends RuntimeException {
+
+    public FastException(String message) {
+        super(message);
+    }
+
+    @Override
+    public synchronized Throwable initCause(Throwable cause) {
+        return this;
+    }
+
+    @Override
+    public synchronized Throwable fillInStackTrace() {
+        return this;
+    }
+}
diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/BadPacketException.java b/protocol/src/main/java/net/md_5/bungee/protocol/BadPacketException.java
index 6c0ef4df..f20104a2 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/BadPacketException.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/BadPacketException.java
@@ -2,6 +2,7 @@ package net.md_5.bungee.protocol;
 
 public class BadPacketException extends RuntimeException
 {
+    private static final boolean PROCESS_TRACES = Boolean.getBoolean("waterfall.bad-packet-traces");
 
     public BadPacketException(String message)
     {
@@ -12,4 +13,24 @@ public class BadPacketException extends RuntimeException
     {
         super( message, cause );
     }
+
+    // Waterfall start
+    @Override
+    public Throwable initCause(Throwable cause)
+    {
+        if (PROCESS_TRACES) {
+            return super.initCause(cause);
+        }
+        return this;
+    }
+
+    @Override
+    public Throwable fillInStackTrace()
+    {
+        if (PROCESS_TRACES) {
+            return super.fillInStackTrace();
+        }
+        return this;
+    }
+    // Waterfall end
 }
diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/DefinedPacket.java b/protocol/src/main/java/net/md_5/bungee/protocol/DefinedPacket.java
index 9951c1f9..68c716b9 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/DefinedPacket.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/DefinedPacket.java
@@ -11,6 +11,9 @@ import lombok.RequiredArgsConstructor;
 public abstract class DefinedPacket
 {
 
+    private static final boolean PROCESS_TRACES = Boolean.getBoolean("waterfall.bad-packet-traces");
+    private static final BadPacketException OVERSIZED_VAR_INT_EXCEPTION = new BadPacketException( "VarInt too big" );
+    private static final BadPacketException NO_MORE_BYTES_EXCEPTION = new BadPacketException("No more bytes reading varint");
     public static void writeString(String s, ByteBuf buf)
     {
         if ( s.length() > Short.MAX_VALUE )
@@ -145,13 +148,18 @@ public abstract class DefinedPacket
         byte in;
         while ( true )
         {
+            // Waterfall start
+            if (input.readableBytes() == 0) {
+                throw PROCESS_TRACES ? new BadPacketException("No more bytes reading varint") : NO_MORE_BYTES_EXCEPTION;
+            }
+            // Waterfall end
             in = input.readByte();
 
             out |= ( in & 0x7F ) << ( bytes++ * 7 );
 
             if ( bytes > maxBytes )
             {
-                throw new RuntimeException( "VarInt too big" );
+                throw PROCESS_TRACES ? new BadPacketException( "VarInt too big" ) : OVERSIZED_VAR_INT_EXCEPTION;
             }
 
             if ( ( in & 0x80 ) != 0x80 )
diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/FastDecoderException.java b/protocol/src/main/java/net/md_5/bungee/protocol/FastDecoderException.java
new file mode 100644
index 00000000..2583aa2c
--- /dev/null
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/FastDecoderException.java
@@ -0,0 +1,26 @@
+package net.md_5.bungee.protocol;
+
+import io.netty.handler.codec.DecoderException;
+
+public class FastDecoderException extends DecoderException {
+
+    public FastDecoderException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public FastDecoderException(String message) {
+        super(message);
+    }
+
+    @Override
+    public Throwable initCause(Throwable cause)
+    {
+        return this;
+    }
+
+    @Override
+    public Throwable fillInStackTrace()
+    {
+        return this;
+    }
+}
diff --git a/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java b/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java
index a2c72c9b..1a647f2b 100644
--- a/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java
+++ b/protocol/src/main/java/net/md_5/bungee/protocol/MinecraftDecoder.java
@@ -78,7 +78,7 @@ public class MinecraftDecoder extends MessageToMessageDecoder<ByteBuf>
             } else {
                 packetTypeStr = "unknown";
             }
-            throw new DecoderException("Error decoding packet " + packetTypeStr + " with contents:\n" + ByteBufUtil.prettyHexDump(slice), e);
+            throw new FastDecoderException("Error decoding packet " + packetTypeStr + " with contents:\n" + ByteBufUtil.prettyHexDump(slice), e); // Waterfall
         } finally
         {
             if ( slice != null )
diff --git a/query/src/main/java/net/md_5/bungee/query/QueryHandler.java b/query/src/main/java/net/md_5/bungee/query/QueryHandler.java
index ac99d02c..0c1ecfb8 100644
--- a/query/src/main/java/net/md_5/bungee/query/QueryHandler.java
+++ b/query/src/main/java/net/md_5/bungee/query/QueryHandler.java
@@ -32,6 +32,7 @@ public class QueryHandler extends SimpleChannelInboundHandler<DatagramPacket>
     /*========================================================================*/
     private final Random random = new Random();
     private final Cache<InetAddress, QuerySession> sessions = CacheBuilder.newBuilder().expireAfterWrite( 30, TimeUnit.SECONDS ).build();
+    private static io.github.waterfallmc.waterfall.utils.FastException cachedNoSessionException = new io.github.waterfallmc.waterfall.utils.FastException("No Session!");
 
     private void writeShort(ByteBuf buf, int s)
     {
@@ -96,7 +97,7 @@ public class QueryHandler extends SimpleChannelInboundHandler<DatagramPacket>
             QuerySession session = sessions.getIfPresent( msg.sender().getAddress() );
             if ( session == null || session.getToken() != challengeToken )
             {
-                throw new IllegalStateException( "No session!" );
+                throw cachedNoSessionException; // Waterfall
             }
 
             // Waterfall start
-- 
2.25.1