Merge cb596f1105 into d5f5ae0dc4

protocol/src/main/java/org/geysermc/mcprotocollib/network/codec/BasePacketCodecHelper.java

@@ -9,135 +9,58 @@ public class BasePacketCodecHelper implements PacketCodecHelper {
 
     @Override
     public void writeVarInt(ByteBuf buf, int value) {
-        this.writeVarLong(buf, value & 0xFFFFFFFFL);
+        while ((value & ~0x7F) != 0) {
+            buf.writeByte(value & 0x7F | 0x80);
+            value >>>= 7;
+        }
+
+        buf.writeByte(value);
     }
 
     @Override
     public int readVarInt(ByteBuf buf) {
         int value = 0;
         int size = 0;
-        int b;
+
-        while (((b = buf.readByte()) & 0x80) == 0x80) {
+        byte b;
-            value |= (b & 0x7F) << (size++ * 7);
+        do {
-            if (size > 5) {
+            if (size >= 35) {
-                throw new IllegalArgumentException("VarInt too long (length must be <= 5)");
+                throw new RuntimeException("VarInt wider than 5 bytes");
             }
+            b = buf.readByte();
+            value |= (b & 0x7F) << size;
+            size += 7;
+        } while ((b & 0x80) == 0x80);
+
+        return value;
     }
 
-        return value | ((b & 0x7F) << (size * 7));
-    }
-
-    // Based off of Andrew Steinborn's blog post:
-    // https://steinborn.me/posts/performance/how-fast-can-you-write-a-varint/
     @Override
     public void writeVarLong(ByteBuf buf, long value) {
-        // Peel the one and two byte count cases explicitly as they are the most common VarInt sizes
+        while ((value & ~0x7FL) != 0) {
-        // that the server will write, to improve inlining.
+            buf.writeByte((int) (value & 0x7F | 0x80));
-        if ((value & ~0x7FL) == 0) {
+            value >>>= 7;
-            buf.writeByte((byte) value);
-        } else if ((value & ~0x3FFFL) == 0) {
-            int w = (int) ((value & 0x7FL | 0x80L) << 8 |
-                    (value >>> 7));
-            buf.writeShort(w);
-        } else {
-            writeVarLongFull(buf, value);
-        }
         }
 
-    private static void writeVarLongFull(ByteBuf buf, long value) {
+        buf.writeByte((int) value);
-        if ((value & ~0x7FL) == 0) {
-            buf.writeByte((byte) value);
-        } else if ((value & ~0x3FFFL) == 0) {
-            int w = (int) ((value & 0x7FL | 0x80L) << 8 |
-                    (value >>> 7));
-            buf.writeShort(w);
-        } else if ((value & ~0x1FFFFFL) == 0) {
-            int w = (int) ((value & 0x7FL | 0x80L) << 16 |
-                    ((value >>> 7) & 0x7FL | 0x80L) << 8 |
-                    (value >>> 14));
-            buf.writeMedium(w);
-        } else if ((value & ~0xFFFFFFFL) == 0) {
-            int w = (int) ((value & 0x7F | 0x80) << 24 |
-                    (((value >>> 7) & 0x7F | 0x80) << 16) |
-                    ((value >>> 14) & 0x7F | 0x80) << 8 |
-                    (value >>> 21));
-            buf.writeInt(w);
-        } else if ((value & ~0x7FFFFFFFFL) == 0) {
-            int w = (int) ((value & 0x7F | 0x80) << 24 |
-                    ((value >>> 7) & 0x7F | 0x80) << 16 |
-                    ((value >>> 14) & 0x7F | 0x80) << 8 |
-                    ((value >>> 21) & 0x7F | 0x80));
-            buf.writeInt(w);
-            buf.writeByte((int) (value >>> 28));
-        } else if ((value & ~0x3FFFFFFFFFFL) == 0) {
-            int w = (int) ((value & 0x7F | 0x80) << 24 |
-                    ((value >>> 7) & 0x7F | 0x80) << 16 |
-                    ((value >>> 14) & 0x7F | 0x80) << 8 |
-                    ((value >>> 21) & 0x7F | 0x80));
-            int w2 = (int) (((value >>> 28) & 0x7FL | 0x80L) << 8 |
-                    (value >>> 35));
-            buf.writeInt(w);
-            buf.writeShort(w2);
-        } else if ((value & ~0x1FFFFFFFFFFFFL) == 0) {
-            int w = (int) ((value & 0x7F | 0x80) << 24 |
-                    ((value >>> 7) & 0x7F | 0x80) << 16 |
-                    ((value >>> 14) & 0x7F | 0x80) << 8 |
-                    ((value >>> 21) & 0x7F | 0x80));
-            int w2 = (int) ((((value >>> 28) & 0x7FL | 0x80L) << 16 |
-                    ((value >>> 35) & 0x7FL | 0x80L) << 8) |
-                    (value >>> 42));
-            buf.writeInt(w);
-            buf.writeMedium(w2);
-        } else if ((value & ~0xFFFFFFFFFFFFFFL) == 0) {
-            long w = (value & 0x7F | 0x80) << 56 |
-                    ((value >>> 7) & 0x7F | 0x80) << 48 |
-                    ((value >>> 14) & 0x7F | 0x80) << 40 |
-                    ((value >>> 21) & 0x7F | 0x80) << 32 |
-                    ((value >>> 28) & 0x7FL | 0x80L) << 24 |
-                    ((value >>> 35) & 0x7FL | 0x80L) << 16 |
-                    ((value >>> 42) & 0x7FL | 0x80L) << 8 |
-                    (value >>> 49);
-            buf.writeLong(w);
-        } else if ((value & ~0x7FFFFFFFFFFFFFFFL) == 0) {
-            long w = (value & 0x7F | 0x80) << 56 |
-                    ((value >>> 7) & 0x7F | 0x80) << 48 |
-                    ((value >>> 14) & 0x7F | 0x80) << 40 |
-                    ((value >>> 21) & 0x7F | 0x80) << 32 |
-                    ((value >>> 28) & 0x7FL | 0x80L) << 24 |
-                    ((value >>> 35) & 0x7FL | 0x80L) << 16 |
-                    ((value >>> 42) & 0x7FL | 0x80L) << 8 |
-                    (value >>> 49);
-            buf.writeLong(w);
-            buf.writeByte((byte) (value >>> 56));
-        } else {
-            long w = (value & 0x7F | 0x80) << 56 |
-                    ((value >>> 7) & 0x7F | 0x80) << 48 |
-                    ((value >>> 14) & 0x7F | 0x80) << 40 |
-                    ((value >>> 21) & 0x7F | 0x80) << 32 |
-                    ((value >>> 28) & 0x7FL | 0x80L) << 24 |
-                    ((value >>> 35) & 0x7FL | 0x80L) << 16 |
-                    ((value >>> 42) & 0x7FL | 0x80L) << 8 |
-                    (value >>> 49);
-            int w2 = (int) (((value >>> 56) & 0x7FL | 0x80L) << 8 |
-                    (value >>> 63));
-            buf.writeLong(w);
-            buf.writeShort(w2);
-        }
     }
 
     @Override
     public long readVarLong(ByteBuf buf) {
-        int value = 0;
+        long value = 0;
         int size = 0;
-        int b;
-        while (((b = buf.readByte()) & 0x80) == 0x80) {
-            value |= (b & 0x7F) << (size++ * 7);
-            if (size > 10) {
-                throw new IllegalArgumentException("VarLong too long (length must be <= 10)");
-            }
-        }
 
-        return value | ((b & 0x7FL) << (size * 7));
+        byte b;
+        do {
+            if (size >= 70) {
+                throw new RuntimeException("VarLong wider than 10 bytes");
+            }
+            b = buf.readByte();
+            value |= (b & 0x7FL) << size;
+            size += 7;
+        } while ((b & 0x80) == 0x80);
+
+        return value;
     }
 
     @Override

protocol/src/test/java/org/geysermc/mcprotocollib/protocol/codec/BasePacketCodecHelperTest.java

@@ -0,0 +1,50 @@
+package org.geysermc.mcprotocollib.protocol.codec;
+
+import io.netty.buffer.Unpooled;
+import org.geysermc.mcprotocollib.network.codec.BasePacketCodecHelper;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class BasePacketCodecHelperTest {
+    private static final BasePacketCodecHelper codecHelper = new BasePacketCodecHelper();
+
+    @Test
+    public void readVarInt() {
+        assertEquals(0x80808080, codecHelper.readVarInt(Unpooled.wrappedBuffer(new byte[]{
+            (byte) 0x80, (byte) 0x81, (byte) 0x82, (byte) 0x84, (byte) 0x08
+        })));
+    }
+
+    @Test
+    public void readVarIntTooLong() {
+        try {
+            // VarInt too long error should take precedence over IndexOutOfBoundsException
+            codecHelper.readVarInt(Unpooled.wrappedBuffer(new byte[]{
+                (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80
+            }));
+        } catch (RuntimeException ex) {
+            // (assertThrow doesn't work as IndexOutOfBoundsException is also a RuntimeException)
+            assertEquals("VarInt wider than 5 bytes", ex.getMessage());
+        }
+    }
+
+    @Test
+    public void readVarLong() {
+        assertEquals(0x8080808080808080L, codecHelper.readVarLong(Unpooled.wrappedBuffer(new byte[]{
+            (byte) 0x80, (byte) 0x81, (byte) 0x82, (byte) 0x84, (byte) 0x88, (byte) 0x90, (byte) 0xa0, (byte) 0xc0, (byte) 0x80, (byte) 0x01
+        })));
+    }
+
+    @Test
+    public void readVarLongTooLong() {
+        try {
+            // VarLong too long error should take precedence over IndexOutOfBoundsException
+            codecHelper.readVarLong(Unpooled.wrappedBuffer(new byte[]{
+                (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80, (byte) 0x80
+            }));
+        } catch (RuntimeException ex) {
+            assertEquals("VarLong wider than 10 bytes", ex.getMessage());
+        }
+    }
+}