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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * Copyright 2024 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.compression;

import com.github.luben.zstd.ZstdInputStreamNoFinalizer;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * Decompresses a compressed block {@link ByteBuf} using the Zstandard algorithm.
 * See Zstandard.
 */
public final class ZstdDecoder extends ByteToMessageDecoder {
    // Don't use static here as we want to still allow to load the classes.
    {
        try {
            Zstd.ensureAvailability();
        } catch (Throwable throwable) {
            throw new ExceptionInInitializerError(throwable);
        }
    }

    private final MutableByteBufInputStream inputStream = new MutableByteBufInputStream();
    private ZstdInputStreamNoFinalizer zstdIs;

    private State currentState = State.DECOMPRESS_DATA;

    /**
     * Current state of stream.
     */
    private enum State {
        DECOMPRESS_DATA,
        CORRUPTED
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) throws Exception {
        try {
            if (currentState == State.CORRUPTED) {
                in.skipBytes(in.readableBytes());
                return;
            }
            final int compressedLength = in.readableBytes();

            inputStream.current = in;

            ByteBuf outBuffer = null;
            try {
                int w;
                do {
                    if (outBuffer == null) {
                        // Let's start with the compressedLength * 2 as often we will not have everything
                        // we need in the in buffer and don't want to reserve too much memory.
                        outBuffer = ctx.alloc().heapBuffer(compressedLength * 2);
                    }
                    do {
                        w = outBuffer.writeBytes(zstdIs, outBuffer.writableBytes());
                    } while (w != -1 && outBuffer.isWritable());
                    if (outBuffer.isReadable()) {
                        out.add(outBuffer);
                        outBuffer = null;
                    }
                } while (w != -1);
            } finally {
                if (outBuffer != null) {
                    outBuffer.release();
                }
            }
        } catch (Exception e) {
            currentState = State.CORRUPTED;
            throw new DecompressionException(e);
        } finally {
            inputStream.current = null;
        }
    }

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        super.handlerAdded(ctx);
        zstdIs = new ZstdInputStreamNoFinalizer(inputStream);
        zstdIs.setContinuous(true);
    }

    @Override
    protected void handlerRemoved0(ChannelHandlerContext ctx) throws Exception {
        try {
            closeSilently(zstdIs);
        } finally {
            super.handlerRemoved0(ctx);
        }
    }

    private static void closeSilently(Closeable closeable) {
        if (closeable != null) {
            try {
                closeable.close();
            } catch (IOException ignore) {
                // ignore
            }
        }
    }

    private static final class MutableByteBufInputStream extends InputStream {
        ByteBuf current;

        @Override
        public int read() {
            if (current == null || !current.isReadable()) {
                return -1;
            }
            return current.readByte() & 0xff;
        }

        @Override
        public int read(byte[] b, int off, int len) {
            int available = available();
            if (available == 0) {
                return -1;
            }

            len = Math.min(available, len);
            current.readBytes(b, off, len);
            return len;
        }

        @Override
        public int available() {
            return current == null ? 0 : current.readableBytes();
        }
    }
}
    

    

    

            

    

            



    
    






    
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