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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 2021 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.aayushatharva.brotli4j.decoder.DecoderJNI;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.util.internal.ObjectUtil;

import java.nio.ByteBuffer;
import java.util.List;

/**
 * Decompresses a {@link ByteBuf} encoded with the brotli format.
 *
 * See brotli.
 */
public final class BrotliDecoder extends ByteToMessageDecoder {

    private enum State {
        DONE, NEEDS_MORE_INPUT, ERROR
    }

    static {
        try {
            Brotli.ensureAvailability();
        } catch (Throwable throwable) {
            throw new ExceptionInInitializerError(throwable);
        }
    }

    private final int inputBufferSize;
    private DecoderJNI.Wrapper decoder;
    private boolean destroyed;

    /**
     * Creates a new BrotliDecoder with a default 8kB input buffer
     */
    public BrotliDecoder() {
        this(8 * 1024);
    }

    /**
     * Creates a new BrotliDecoder
     * @param inputBufferSize desired size of the input buffer in bytes
     */
    public BrotliDecoder(int inputBufferSize) {
        this.inputBufferSize = ObjectUtil.checkPositive(inputBufferSize, "inputBufferSize");
    }

    private ByteBuf pull(ByteBufAllocator alloc) {
        ByteBuffer nativeBuffer = decoder.pull();
        // nativeBuffer actually wraps brotli's internal buffer so we need to copy its content
        ByteBuf copy = alloc.buffer(nativeBuffer.remaining());
        copy.writeBytes(nativeBuffer);
        return copy;
    }

    private State decompress(ByteBuf input, List output, ByteBufAllocator alloc) {
        for (;;) {
            switch (decoder.getStatus()) {
                case DONE:
                    return State.DONE;

                case OK:
                    decoder.push(0);
                    break;

                case NEEDS_MORE_INPUT:
                    if (decoder.hasOutput()) {
                        output.add(pull(alloc));
                    }

                    if (!input.isReadable()) {
                        return State.NEEDS_MORE_INPUT;
                    }

                    ByteBuffer decoderInputBuffer = decoder.getInputBuffer();
                    decoderInputBuffer.clear();
                    int readBytes = readBytes(input, decoderInputBuffer);
                    decoder.push(readBytes);
                    break;

                case NEEDS_MORE_OUTPUT:
                    output.add(pull(alloc));
                    break;

                default:
                    return State.ERROR;
            }
        }
    }

    private static int readBytes(ByteBuf in, ByteBuffer dest) {
        int limit = Math.min(in.readableBytes(), dest.remaining());
        ByteBuffer slice = dest.slice();
        slice.limit(limit);
        in.readBytes(slice);
        dest.position(dest.position() + limit);
        return limit;
    }

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        decoder = new DecoderJNI.Wrapper(inputBufferSize);
    }

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List out) throws Exception {
        if (destroyed) {
            // Skip data received after finished.
            in.skipBytes(in.readableBytes());
            return;
        }

        if (!in.isReadable()) {
            return;
        }

        try {
            State state = decompress(in, out, ctx.alloc());
            if (state == State.DONE) {
                destroy();
            } else if (state == State.ERROR) {
                throw new DecompressionException("Brotli stream corrupted");
            }
        } catch (Exception e) {
            destroy();
            throw e;
        }
    }

    private void destroy() {
        if (!destroyed) {
            destroyed = true;
            decoder.destroy();
        }
    }

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

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        try {
            destroy();
        } finally {
            super.channelInactive(ctx);
        }
    }
}