/*
* 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 java.nio.ByteOrder;
import java.util.Set;
import com.facebook.presto.jdbc.internal.netty.buffer.ChannelBuffer;
import com.facebook.presto.jdbc.internal.netty.buffer.ChannelBuffers;
import static com.facebook.presto.jdbc.internal.netty.handler.codec.spdy.SpdyCodecUtil.*;
public class SpdyHeaderBlockRawEncoder extends SpdyHeaderBlockEncoder {
private final int version;
public SpdyHeaderBlockRawEncoder(int version) {
if (version < SPDY_MIN_VERSION || version > SPDY_MAX_VERSION) {
throw new IllegalArgumentException(
"unknown version: " + version);
}
this.version = version;
}
private void setLengthField(ChannelBuffer buffer, int writerIndex, int length) {
if (version < 3) {
buffer.setShort(writerIndex, length);
} else {
buffer.setInt(writerIndex, length);
}
}
private void writeLengthField(ChannelBuffer buffer, int length) {
if (version < 3) {
buffer.writeShort(length);
} else {
buffer.writeInt(length);
}
}
@Override
public ChannelBuffer encode(SpdyHeadersFrame headerFrame) throws Exception {
Set<String> names = headerFrame.getHeaderNames();
int numHeaders = names.size();
if (numHeaders == 0) {
return ChannelBuffers.EMPTY_BUFFER;
}
if (numHeaders > SPDY_MAX_NV_LENGTH) {
throw new IllegalArgumentException(
"header block contains too many headers");
}
ChannelBuffer headerBlock = ChannelBuffers.dynamicBuffer(
ByteOrder.BIG_ENDIAN, 256);
writeLengthField(headerBlock, numHeaders);
for (String name: names) {
byte[] nameBytes = name.getBytes("UTF-8");
writeLengthField(headerBlock, nameBytes.length);
headerBlock.writeBytes(nameBytes);
int savedIndex = headerBlock.writerIndex();
int valueLength = 0;
writeLengthField(headerBlock, valueLength);
for (String value: headerFrame.getHeaders(name)) {
byte[] valueBytes = value.getBytes("UTF-8");
if (valueBytes.length > 0) {
headerBlock.writeBytes(valueBytes);
headerBlock.writeByte(0);
valueLength += valueBytes.length + 1;
}
}
if (valueLength == 0) {
if (version < 3) {
throw new IllegalArgumentException(
"header value cannot be empty: " + name);
}
} else {
valueLength --;
}
if (valueLength > SPDY_MAX_NV_LENGTH) {
throw new IllegalArgumentException(
"header exceeds allowable length: " + name);
}
if (valueLength > 0) {
setLengthField(headerBlock, savedIndex, valueLength);
headerBlock.writerIndex(headerBlock.writerIndex() - 1);
}
}
return headerBlock;
}
@Override
void end() {
}
}