139 lines
5.1 KiB
Java
139 lines
5.1 KiB
Java
/*
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* Copyright 2014 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.handler.codec.http.websocketx.extensions.compression;
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import io.netty.buffer.ByteBuf;
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import io.netty.buffer.CompositeByteBuf;
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import io.netty.buffer.Unpooled;
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import io.netty.channel.ChannelHandlerContext;
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import io.netty.channel.embedded.EmbeddedChannel;
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import io.netty.handler.codec.CodecException;
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import io.netty.handler.codec.compression.ZlibCodecFactory;
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import io.netty.handler.codec.compression.ZlibWrapper;
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import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
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import io.netty.handler.codec.http.websocketx.ContinuationWebSocketFrame;
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import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
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import io.netty.handler.codec.http.websocketx.WebSocketFrame;
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import io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionDecoder;
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import java.util.List;
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/**
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* Deflate implementation of a payload decompressor for
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* <tt>io.netty.handler.codec.http.websocketx.WebSocketFrame</tt>.
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*/
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abstract class DeflateDecoder extends WebSocketExtensionDecoder {
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static final byte[] FRAME_TAIL = new byte[] {0x00, 0x00, (byte) 0xff, (byte) 0xff};
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private final boolean noContext;
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private EmbeddedChannel decoder;
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/**
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* Constructor
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* @param noContext true to disable context takeover.
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*/
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DeflateDecoder(boolean noContext) {
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this.noContext = noContext;
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}
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protected abstract boolean appendFrameTail(WebSocketFrame msg);
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protected abstract int newRsv(WebSocketFrame msg);
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@Override
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protected void decode(ChannelHandlerContext ctx, WebSocketFrame msg, List<Object> out) throws Exception {
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if (decoder == null) {
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if (!(msg instanceof TextWebSocketFrame) && !(msg instanceof BinaryWebSocketFrame)) {
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throw new CodecException("unexpected initial frame type: " + msg.getClass().getName());
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}
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decoder = new EmbeddedChannel(ZlibCodecFactory.newZlibDecoder(ZlibWrapper.NONE));
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}
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boolean readable = msg.content().isReadable();
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decoder.writeInbound(msg.content().retain());
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if (appendFrameTail(msg)) {
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decoder.writeInbound(Unpooled.wrappedBuffer(FRAME_TAIL));
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}
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CompositeByteBuf compositeUncompressedContent = ctx.alloc().compositeBuffer();
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for (;;) {
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ByteBuf partUncompressedContent = decoder.readInbound();
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if (partUncompressedContent == null) {
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break;
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}
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if (!partUncompressedContent.isReadable()) {
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partUncompressedContent.release();
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continue;
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}
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compositeUncompressedContent.addComponent(true, partUncompressedContent);
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}
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// Correctly handle empty frames
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// See https://github.com/netty/netty/issues/4348
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if (readable && compositeUncompressedContent.numComponents() <= 0) {
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compositeUncompressedContent.release();
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throw new CodecException("cannot read uncompressed buffer");
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}
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if (msg.isFinalFragment() && noContext) {
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cleanup();
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}
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WebSocketFrame outMsg;
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if (msg instanceof TextWebSocketFrame) {
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outMsg = new TextWebSocketFrame(msg.isFinalFragment(), newRsv(msg), compositeUncompressedContent);
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} else if (msg instanceof BinaryWebSocketFrame) {
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outMsg = new BinaryWebSocketFrame(msg.isFinalFragment(), newRsv(msg), compositeUncompressedContent);
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} else if (msg instanceof ContinuationWebSocketFrame) {
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outMsg = new ContinuationWebSocketFrame(msg.isFinalFragment(), newRsv(msg),
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compositeUncompressedContent);
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} else {
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throw new CodecException("unexpected frame type: " + msg.getClass().getName());
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}
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out.add(outMsg);
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}
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@Override
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public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
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cleanup();
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super.handlerRemoved(ctx);
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}
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@Override
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public void channelInactive(ChannelHandlerContext ctx) throws Exception {
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cleanup();
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super.channelInactive(ctx);
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}
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private void cleanup() {
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if (decoder != null) {
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// Clean-up the previous encoder if not cleaned up correctly.
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if (decoder.finish()) {
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for (;;) {
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ByteBuf buf = decoder.readOutbound();
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if (buf == null) {
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break;
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}
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// Release the buffer
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buf.release();
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}
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}
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decoder = null;
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}
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}
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}
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