io.netty.handler.codec.spdy.SpdyHeaderBlockZlibDecoder Maven / Gradle / Ivy
/*
* Copyright 2014 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.spdy;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;
import static io.netty.handler.codec.spdy.SpdyCodecUtil.*;
final class SpdyHeaderBlockZlibDecoder extends SpdyHeaderBlockRawDecoder {
private static final int DEFAULT_BUFFER_CAPACITY = 4096;
private static final SpdyProtocolException INVALID_HEADER_BLOCK =
new SpdyProtocolException("Invalid Header Block");
private final Inflater decompressor = new Inflater();
private ByteBuf decompressed;
SpdyHeaderBlockZlibDecoder(SpdyVersion spdyVersion, int maxHeaderSize) {
super(spdyVersion, maxHeaderSize);
}
@Override
void decode(ByteBufAllocator alloc, ByteBuf headerBlock, SpdyHeadersFrame frame) throws Exception {
int len = setInput(headerBlock);
int numBytes;
do {
numBytes = decompress(alloc, frame);
} while (numBytes > 0);
// z_stream has an internal 64-bit hold buffer
// it is always capable of consuming the entire input
if (decompressor.getRemaining() != 0) {
// we reached the end of the deflate stream
throw INVALID_HEADER_BLOCK;
}
headerBlock.skipBytes(len);
}
private int setInput(ByteBuf compressed) {
int len = compressed.readableBytes();
if (compressed.hasArray()) {
decompressor.setInput(compressed.array(), compressed.arrayOffset() + compressed.readerIndex(), len);
} else {
byte[] in = new byte[len];
compressed.getBytes(compressed.readerIndex(), in);
decompressor.setInput(in, 0, in.length);
}
return len;
}
private int decompress(ByteBufAllocator alloc, SpdyHeadersFrame frame) throws Exception {
ensureBuffer(alloc);
byte[] out = decompressed.array();
int off = decompressed.arrayOffset() + decompressed.writerIndex();
try {
int numBytes = decompressor.inflate(out, off, decompressed.writableBytes());
if (numBytes == 0 && decompressor.needsDictionary()) {
try {
decompressor.setDictionary(SPDY_DICT);
} catch (IllegalArgumentException ignored) {
throw INVALID_HEADER_BLOCK;
}
numBytes = decompressor.inflate(out, off, decompressed.writableBytes());
}
if (frame != null) {
decompressed.writerIndex(decompressed.writerIndex() + numBytes);
decodeHeaderBlock(decompressed, frame);
decompressed.discardReadBytes();
}
return numBytes;
} catch (DataFormatException e) {
throw new SpdyProtocolException("Received invalid header block", e);
}
}
private void ensureBuffer(ByteBufAllocator alloc) {
if (decompressed == null) {
decompressed = alloc.heapBuffer(DEFAULT_BUFFER_CAPACITY);
}
decompressed.ensureWritable(1);
}
@Override
void endHeaderBlock(SpdyHeadersFrame frame) throws Exception {
super.endHeaderBlock(frame);
releaseBuffer();
}
@Override
public void end() {
super.end();
releaseBuffer();
decompressor.end();
}
private void releaseBuffer() {
if (decompressed != null) {
decompressed.release();
decompressed = null;
}
}
}
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