Add setVarInt method instead of fiddling with writerIndex

SpigotMC · Dec 20, 2024 · 01d8304 · 01d8304
1 parent 220a69c
commit 01d8304
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Showing 2 changed files with 31 additions and 9 deletions.
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
@@ -281,6 +281,30 @@ public static void writeVarInt(int value, ByteBuf output)
             }
         }
     }
+
+    public static void setVarInt(int value, ByteBuf output, int pos, int len) {
+        switch ( len )
+        {
+            case 1:
+                output.setByte( pos, value );
+                break;
+            case 2:
+                output.setShort( pos, ( value & 0x7F | 0x80 ) << 8 | ( value >>> 7 & 0x7F ) );
+                break;
+            case 3:
+                output.setMedium( pos, ( value & 0x7F | 0x80 ) << 16 | ( value >>> 7 & 0x7F | 0x80 ) << 8 | ( value >>> 14 & 0x7F ) );
+                break;
+            case 4:
+                output.setInt( pos, ( value & 0x7F | 0x80 ) << 24 | ( value >>> 7 & 0x7F | 0x80 ) << 16 | ( value >>> 14 & 0x7F | 0x80 ) << 8 | ( value >>> 21 & 0x7F ) );
+                break;
+            case 5:
+                output.setInt( pos, ( value & 0x7F | 0x80 ) << 24 | ( value >>> 7 & 0x7F | 0x80 ) << 16 | ( value >>> 14 & 0x7F | 0x80 ) << 8 | ( value >>> 21 & 0x7F | 0x80 ) );
+                output.setByte( pos + 4, value >>> 28 );
+                break;
+            default:
+                throw new IllegalArgumentException( "Invalid varint len: " + len );
+        }
+    }
 
     public static int readVarShort(ByteBuf buf)
     {

diff --git a/proxy/src/main/java/net/md_5/bungee/netty/LengthPrependerAndCompressor.java b/proxy/src/main/java/net/md_5/bungee/netty/LengthPrependerAndCompressor.java
@@ -85,11 +85,9 @@ protected void encode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out)
                 int compressedLen = writerIndex - MAX_SUPPORTED_VARINT_LENGTH_LEN;
                 byte lengthLen = varintSize( compressedLen );
                 int lengthStart = MAX_SUPPORTED_VARINT_LENGTH_LEN - lengthLen;
-                buf.writerIndex( lengthStart );
-                DefinedPacket.writeVarInt( compressedLen, buf );
+                DefinedPacket.setVarInt( compressedLen, buf, lengthStart, lengthLen );
 
                 buf.readerIndex( lengthStart ); // set start of buffer to ignore potential unused bytes before length
-                buf.writerIndex( writerIndex ); // set end of buffer back to end of compressed data
                 out.add( buf );
             }
         } else
@@ -164,27 +162,27 @@ public void setTwoBuffers(boolean twoBuffers)
         }
     }
 
-    private static byte varintSize(int paramInt)
+    private static byte varintSize(int value)
     {
-        if ( ( paramInt & 0xFFFFFF80 ) == 0 )
+        if ( ( value & 0xFFFFFF80 ) == 0 )
         {
             return 1;
         }
-        if ( ( paramInt & 0xFFFFC000 ) == 0 )
+        if ( ( value & 0xFFFFC000 ) == 0 )
         {
             return 2;
         }
-        if ( ( paramInt & 0xFFE00000 ) == 0 )
+        if ( ( value & 0xFFE00000 ) == 0 )
         {
             return 3;
         }
-        if ( ( paramInt & 0xF0000000 ) == 0 )
+        if ( ( value & 0xF0000000 ) == 0 )
         {
             return 4;
         }
         if ( MAX_SUPPORTED_VARINT_LENGTH_LEN < 5 )
         {
-            throw new IllegalArgumentException( "Packet length " + paramInt + " longer than supported (max. 268435455 for 4 byte varint)" );
+            throw new IllegalArgumentException( "Packet length " + value + " longer than supported (max. 268435455 for 4 byte varint)" );
         }
         return 5;
     }