Quartz 4

CompressionDecoder.java

4 min read

CompressionDecoder.java

net.minecraft.network.CompressionDecoder

信息

  • 全限定名：net.minecraft.network.CompressionDecoder
  • 类型：public class
  • 包：net.minecraft.network
  • 源码路径：src/main/java/net/minecraft/network/CompressionDecoder.java
  • 起始行号：L12
  • 继承：ByteToMessageDecoder
  • 职责：

    TODO

字段/常量

  • MAXIMUM_COMPRESSED_LENGTH

    • 类型: int
    • 修饰符: public static final
    • 源码定位: L13
    • 说明:

      TODO

  • MAXIMUM_UNCOMPRESSED_LENGTH

    • 类型: int
    • 修饰符: public static final
    • 源码定位: L14
    • 说明:

      TODO

  • inflater

    • 类型: Inflater
    • 修饰符: private final
    • 源码定位: L15
    • 说明:

      TODO

  • threshold

    • 类型: int
    • 修饰符: private
    • 源码定位: L16
    • 说明:

      TODO

  • validateDecompressed

    • 类型: boolean
    • 修饰符: private
    • 源码定位: L17
    • 说明:

      TODO

内部类/嵌套类型

  • 无

构造器

public CompressionDecoder(int threshold, boolean validateDecompressed) @ L19

  • 构造器名：CompressionDecoder
  • 源码定位：L19
  • 修饰符：public

参数:

  • threshold: int
  • validateDecompressed: boolean

说明:

TODO

方法

下面的方法块按源码顺序生成。

protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) @ L25

  • 方法名：decode
  • 源码定位：L25
  • 返回类型：void
  • 修饰符：protected

参数:

  • ctx: ChannelHandlerContext
  • in: ByteBuf
  • out: List

    说明:

    TODO

    private void setupInflaterInput(ByteBuf in) @ L48

    • 方法名：setupInflaterInput
    • 源码定位：L48
    • 返回类型：void
    • 修饰符：private

    参数:

    • in: ByteBuf

    说明:

    TODO

    private ByteBuf inflate(ChannelHandlerContext ctx, int uncompressedLength) @ L62

    • 方法名：inflate
    • 源码定位：L62
    • 返回类型：ByteBuf
    • 修饰符：private

    参数:

    • ctx: ChannelHandlerContext
    • uncompressedLength: int

    说明:

    TODO

    public void setThreshold(int threshold, boolean validateDecompressed) @ L87

    • 方法名：setThreshold
    • 源码定位：L87
    • 返回类型：void
    • 修饰符：public

    参数:

    • threshold: int
    • validateDecompressed: boolean

    说明:

    TODO

    代码

    public class CompressionDecoder extends ByteToMessageDecoder {
    public static final int MAXIMUM_COMPRESSED_LENGTH = 2097152;
    public static final int MAXIMUM_UNCOMPRESSED_LENGTH = 8388608;
    private final Inflater inflater;
    private int threshold;
    private boolean validateDecompressed;
 
    public CompressionDecoder(int threshold, boolean validateDecompressed) {
        this.threshold = threshold;
        this.validateDecompressed = validateDecompressed;
        this.inflater = new Inflater();
    }
 
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        int uncompressedLength = VarInt.read(in);
        if (uncompressedLength == 0) {
            out.add(in.readBytes(in.readableBytes()));
        } else {
            if (this.validateDecompressed) {
                if (uncompressedLength < this.threshold) {
                    throw new DecoderException("Badly compressed packet - size of " + uncompressedLength + " is below server threshold of " + this.threshold);
                }
 
                if (uncompressedLength > 8388608) {
                    throw new DecoderException("Badly compressed packet - size of " + uncompressedLength + " is larger than protocol maximum of 8388608");
                }
            }
 
            this.setupInflaterInput(in);
            ByteBuf output = this.inflate(ctx, uncompressedLength);
            this.inflater.reset();
            out.add(output);
        }
    }
 
    private void setupInflaterInput(ByteBuf in) {
        ByteBuffer input;
        if (in.nioBufferCount() > 0) {
            input = in.nioBuffer();
            in.skipBytes(in.readableBytes());
        } else {
            input = ByteBuffer.allocateDirect(in.readableBytes());
            in.readBytes(input);
            input.flip();
        }
 
        this.inflater.setInput(input);
    }
 
    private ByteBuf inflate(ChannelHandlerContext ctx, int uncompressedLength) throws DataFormatException {
        ByteBuf output = ctx.alloc().directBuffer(uncompressedLength);
 
        try {
            ByteBuffer nioBuffer = output.internalNioBuffer(0, uncompressedLength);
            int pos = nioBuffer.position();
            this.inflater.inflate(nioBuffer);
            int actualUncompressedLength = nioBuffer.position() - pos;
            if (actualUncompressedLength != uncompressedLength) {
                throw new DecoderException(
                    "Badly compressed packet - actual length of uncompressed payload "
                        + actualUncompressedLength
                        + " is does not match declared size "
                        + uncompressedLength
                );
            } else {
                output.writerIndex(output.writerIndex() + actualUncompressedLength);
                return output;
            }
        } catch (Exception var7) {
            output.release();
            throw var7;
        }
    }
 
    public void setThreshold(int threshold, boolean validateDecompressed) {
        this.threshold = threshold;
        this.validateDecompressed = validateDecompressed;
    }
}

    引用的其他类

    • VarInt
      • 引用位置: 方法调用
      • 关联成员: VarInt.read()

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