/*
* Copyright 2013 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:
*
* http://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 com.facebook.presto.jdbc.internal.netty.handler.codec.spdy;
import static com.facebook.presto.jdbc.internal.netty.handler.codec.spdy.SpdyCodecUtil.*;
import java.util.zip.Deflater;
import com.facebook.presto.jdbc.internal.netty.buffer.ChannelBuffer;
import com.facebook.presto.jdbc.internal.netty.buffer.ChannelBuffers;
class SpdyHeaderBlockZlibEncoder extends SpdyHeaderBlockRawEncoder {
private final byte[] out = new byte[8192];
private final Deflater compressor;
private boolean finished;
public SpdyHeaderBlockZlibEncoder(int version, int compressionLevel) {
super(version);
if (compressionLevel < 0 || compressionLevel > 9) {
throw new IllegalArgumentException(
"compressionLevel: " + compressionLevel + " (expected: 0-9)");
}
compressor = new Deflater(compressionLevel);
if (version < 3) {
compressor.setDictionary(SPDY2_DICT);
} else {
compressor.setDictionary(SPDY_DICT);
}
}
private void setInput(ChannelBuffer decompressed) {
byte[] in = new byte[decompressed.readableBytes()];
decompressed.readBytes(in);
compressor.setInput(in);
}
private void encode(ChannelBuffer compressed) {
int numBytes = out.length;
while (numBytes == out.length) {
numBytes = compressor.deflate(out, 0, out.length, Deflater.SYNC_FLUSH);
compressed.writeBytes(out, 0, numBytes);
}
}
@Override
public synchronized ChannelBuffer encode(SpdyHeadersFrame frame) throws Exception {
if (frame == null) {
throw new IllegalArgumentException("frame");
}
if (finished) {
return ChannelBuffers.EMPTY_BUFFER;
}
ChannelBuffer decompressed = super.encode(frame);
if (decompressed.readableBytes() == 0) {
return ChannelBuffers.EMPTY_BUFFER;
}
ChannelBuffer compressed = ChannelBuffers.dynamicBuffer();
setInput(decompressed);
encode(compressed);
return compressed;
}
@Override
public synchronized void end() {
if (finished) {
return;
}
finished = true;
compressor.end();
super.end();
}
}