/*
 * 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:
 *
 *   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 io.netty.handler.codec.spdy;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;

import java.nio.ByteOrder;
import java.util.Set;

import static io.netty.handler.codec.spdy.SpdyCodecUtil.*;

Encodes a SPDY Frame into a ByteBuf.
/** * Encodes a SPDY Frame into a {@link ByteBuf}. */
public class SpdyFrameEncoder { private final int version;
Creates a new instance with the specified spdyVersion.
/** * Creates a new instance with the specified {@code spdyVersion}. */
public SpdyFrameEncoder(SpdyVersion spdyVersion) { if (spdyVersion == null) { throw new NullPointerException("spdyVersion"); } version = spdyVersion.getVersion(); } private void writeControlFrameHeader(ByteBuf buffer, int type, byte flags, int length) { buffer.writeShort(version | 0x8000); buffer.writeShort(type); buffer.writeByte(flags); buffer.writeMedium(length); } public ByteBuf encodeDataFrame(ByteBufAllocator allocator, int streamId, boolean last, ByteBuf data) { byte flags = last ? SPDY_DATA_FLAG_FIN : 0; int length = data.readableBytes(); ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); frame.writeInt(streamId & 0x7FFFFFFF); frame.writeByte(flags); frame.writeMedium(length); frame.writeBytes(data, data.readerIndex(), length); return frame; } public ByteBuf encodeSynStreamFrame(ByteBufAllocator allocator, int streamId, int associatedToStreamId, byte priority, boolean last, boolean unidirectional, ByteBuf headerBlock) { int headerBlockLength = headerBlock.readableBytes(); byte flags = last ? SPDY_FLAG_FIN : 0; if (unidirectional) { flags |= SPDY_FLAG_UNIDIRECTIONAL; } int length = 10 + headerBlockLength; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_SYN_STREAM_FRAME, flags, length); frame.writeInt(streamId); frame.writeInt(associatedToStreamId); frame.writeShort((priority & 0xFF) << 13); frame.writeBytes(headerBlock, headerBlock.readerIndex(), headerBlockLength); return frame; } public ByteBuf encodeSynReplyFrame(ByteBufAllocator allocator, int streamId, boolean last, ByteBuf headerBlock) { int headerBlockLength = headerBlock.readableBytes(); byte flags = last ? SPDY_FLAG_FIN : 0; int length = 4 + headerBlockLength; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_SYN_REPLY_FRAME, flags, length); frame.writeInt(streamId); frame.writeBytes(headerBlock, headerBlock.readerIndex(), headerBlockLength); return frame; } public ByteBuf encodeRstStreamFrame(ByteBufAllocator allocator, int streamId, int statusCode) { byte flags = 0; int length = 8; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_RST_STREAM_FRAME, flags, length); frame.writeInt(streamId); frame.writeInt(statusCode); return frame; } public ByteBuf encodeSettingsFrame(ByteBufAllocator allocator, SpdySettingsFrame spdySettingsFrame) { Set<Integer> ids = spdySettingsFrame.ids(); int numSettings = ids.size(); byte flags = spdySettingsFrame.clearPreviouslyPersistedSettings() ? SPDY_SETTINGS_CLEAR : 0; int length = 4 + 8 * numSettings; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_SETTINGS_FRAME, flags, length); frame.writeInt(numSettings); for (Integer id : ids) { flags = 0; if (spdySettingsFrame.isPersistValue(id)) { flags |= SPDY_SETTINGS_PERSIST_VALUE; } if (spdySettingsFrame.isPersisted(id)) { flags |= SPDY_SETTINGS_PERSISTED; } frame.writeByte(flags); frame.writeMedium(id); frame.writeInt(spdySettingsFrame.getValue(id)); } return frame; } public ByteBuf encodePingFrame(ByteBufAllocator allocator, int id) { byte flags = 0; int length = 4; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_PING_FRAME, flags, length); frame.writeInt(id); return frame; } public ByteBuf encodeGoAwayFrame(ByteBufAllocator allocator, int lastGoodStreamId, int statusCode) { byte flags = 0; int length = 8; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_GOAWAY_FRAME, flags, length); frame.writeInt(lastGoodStreamId); frame.writeInt(statusCode); return frame; } public ByteBuf encodeHeadersFrame(ByteBufAllocator allocator, int streamId, boolean last, ByteBuf headerBlock) { int headerBlockLength = headerBlock.readableBytes(); byte flags = last ? SPDY_FLAG_FIN : 0; int length = 4 + headerBlockLength; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_HEADERS_FRAME, flags, length); frame.writeInt(streamId); frame.writeBytes(headerBlock, headerBlock.readerIndex(), headerBlockLength); return frame; } public ByteBuf encodeWindowUpdateFrame(ByteBufAllocator allocator, int streamId, int deltaWindowSize) { byte flags = 0; int length = 8; ByteBuf frame = allocator.ioBuffer(SPDY_HEADER_SIZE + length).order(ByteOrder.BIG_ENDIAN); writeControlFrameHeader(frame, SPDY_WINDOW_UPDATE_FRAME, flags, length); frame.writeInt(streamId); frame.writeInt(deltaWindowSize); return frame; } }