lastIndexOf() — netty Function Reference

Architecture documentation for the lastIndexOf() function in ByteBufUtil.java from the netty codebase.

Function java Buffer Allocators calls 2

Entity Profile

Buffer→ Allocators→ lastIndexOf() — netty Function Reference

Dependency Diagram

graph TD
  e9312b0e_c5cc_d3d1_73a9_ba37fd8c6bb4["lastIndexOf()"]
  920454f6_25f6_4a9b_3d32_9684c3e11f6c["ByteBufUtil"]
  e9312b0e_c5cc_d3d1_73a9_ba37fd8c6bb4 -->|defined in| 920454f6_25f6_4a9b_3d32_9684c3e11f6c
  d11f1706_dd2f_a5f2_9233_cb78ffafb90a["linearLastIndexOf()"]
  e9312b0e_c5cc_d3d1_73a9_ba37fd8c6bb4 -->|calls| d11f1706_dd2f_a5f2_9233_cb78ffafb90a
  eec154fb_8b13_48f3_3735_b609819320b4["unrolledLastIndexOf()"]
  e9312b0e_c5cc_d3d1_73a9_ba37fd8c6bb4 -->|calls| eec154fb_8b13_48f3_3735_b609819320b4
  style e9312b0e_c5cc_d3d1_73a9_ba37fd8c6bb4 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

buffer/src/main/java/io/netty/buffer/ByteBufUtil.java lines 723–752

    static int lastIndexOf(final AbstractByteBuf buffer, int fromIndex, final int toIndex, final byte value) {
        assert fromIndex > toIndex;
        final int capacity = buffer.capacity();
        fromIndex = Math.min(fromIndex, capacity);
        if (fromIndex <= 0) { // fromIndex is the exclusive upper bound.
            return -1;
        }
        final int length = fromIndex - toIndex;
        buffer.checkIndex(toIndex, length);
        if (!PlatformDependent.isUnaligned()) {
            return linearLastIndexOf(buffer, fromIndex, toIndex, value);
        }
        final int longCount = length >>> 3;
        if (longCount > 0) {
            final ByteOrder nativeOrder = ByteOrder.nativeOrder();
            final boolean isNative = nativeOrder == buffer.order();
            final boolean useLE = nativeOrder == ByteOrder.LITTLE_ENDIAN;
            final long pattern = SWARUtil.compilePattern(value);
            for (int i = 0, offset = fromIndex - Long.BYTES; i < longCount; i++, offset -= Long.BYTES) {
                // use the faster available getLong
                final long word = useLE? buffer._getLongLE(offset) : buffer._getLong(offset);
                final long result = SWARUtil.applyPattern(word, pattern);
                if (result != 0) {
                    // used the oppoiste endianness since we are looking for the last index.
                    return offset + Long.BYTES - 1 - SWARUtil.getIndex(result, !isNative);
                }
            }
        }
        return unrolledLastIndexOf(buffer, fromIndex - (longCount << 3), length & 7, value);
    }