/**
* Copyright 2012 Nikita Koksharov
*
* Licensed 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.corundumstudio.socketio.protocol;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.buffer.Unpooled;
import io.netty.handler.codec.base64.Base64;
import io.netty.util.CharsetUtil;
import java.io.IOException;
import java.net.URLDecoder;
import java.util.LinkedList;
import java.util.UUID;
import com.corundumstudio.socketio.AckCallback;
import com.corundumstudio.socketio.ack.AckManager;
import com.corundumstudio.socketio.handler.ClientHead;
public class PacketDecoder {
private final UTF8CharsScanner utf8scanner = new UTF8CharsScanner();
private final ByteBuf QUOTES = Unpooled.copiedBuffer("\"", CharsetUtil.UTF_8);
private final JsonSupport jsonSupport;
private final AckManager ackManager;
public PacketDecoder(JsonSupport jsonSupport, AckManager ackManager) {
this.jsonSupport = jsonSupport;
this.ackManager = ackManager;
}
private boolean isStringPacket(ByteBuf content) {
return content.getByte(content.readerIndex()) == 0x0;
}
// TODO optimize
public ByteBuf preprocessJson(Integer jsonIndex, ByteBuf content) throws IOException {
String packet = URLDecoder.decode(content.toString(CharsetUtil.UTF_8), CharsetUtil.UTF_8.name());
if (jsonIndex != null) {
/**
* double escaping is required for escaped new lines because unescaping of new lines can be done safely on server-side
* (c) socket.io.js
*
* @see https://github.com/Automattic/socket.io-client/blob/1.3.3/socket.io.js#L2682
*/
packet = packet.replace("\\\\n", "\\n");
// skip "d="
packet = packet.substring(2);
}
packet = new String(packet.getBytes(CharsetUtil.ISO_8859_1), CharsetUtil.UTF_8);
return Unpooled.wrappedBuffer(packet.getBytes(CharsetUtil.UTF_8));
}
// fastest way to parse chars to int
private long readLong(ByteBuf chars, int length) {
long result = 0;
for (int i = chars.readerIndex(); i < chars.readerIndex() + length; i++) {
int digit = ((int)chars.getByte(i) & 0xF);
for (int j = 0; j < chars.readerIndex() + length-1-i; j++) {
digit *= 10;
}
result += digit;
}
chars.readerIndex(chars.readerIndex() + length);
return result;
}
private PacketType readType(ByteBuf buffer) {
int typeId = buffer.readByte() & 0xF;
return PacketType.valueOf(typeId);
}
private PacketType readInnerType(ByteBuf buffer) {
int typeId = buffer.readByte() & 0xF;
return PacketType.valueOfInner(typeId);
}
@Deprecated
public Packet decodePacket(String string, UUID uuid) throws IOException {
ByteBuf buf = Unpooled.copiedBuffer(string, CharsetUtil.UTF_8);
try {
return null;
} finally {
buf.release();
}
}
private boolean hasLengthHeader(ByteBuf buffer) {
for (int i = 0; i < Math.min(buffer.readableBytes(), 10); i++) {
byte b = buffer.getByte(buffer.readerIndex() + i);
if (b == (byte)':' && i > 0) {
return true;
}
if (b > 57 || b < 48) {
return false;
}
}
return false;
}
public Packet decodePackets(ByteBuf buffer, ClientHead client) throws IOException {
if (isStringPacket(buffer)) {
// TODO refactor
int maxLength = Math.min(buffer.readableBytes(), 10);
int headEndIndex = buffer.bytesBefore(maxLength, (byte)-1);
if (headEndIndex == -1) {
headEndIndex = buffer.bytesBefore(maxLength, (byte)0x3f);
}
int len = (int) readLong(buffer, headEndIndex);
ByteBuf frame = buffer.slice(buffer.readerIndex() + 1, len);
// skip this frame
buffer.readerIndex(buffer.readerIndex() + 1 + len);
return decode(client, frame);
} else if (hasLengthHeader(buffer)) {
// TODO refactor
int lengthEndIndex = buffer.bytesBefore((byte)':');
int lenHeader = (int) readLong(buffer, lengthEndIndex);
int len = utf8scanner.getActualLength(buffer, lenHeader);
ByteBuf frame = buffer.slice(buffer.readerIndex() + 1, len);
if (lenHeader != len) {
frame = Unpooled.wrappedBuffer(frame.toString(CharsetUtil.UTF_8).getBytes(CharsetUtil.ISO_8859_1));
}
// skip this frame
buffer.readerIndex(buffer.readerIndex() + 1 + len);
return decode(client, frame);
}
return decode(client, buffer);
}
private String readString(ByteBuf frame) {
return readString(frame, frame.readableBytes());
}
private String readString(ByteBuf frame, int size) {
byte[] bytes = new byte[size];
frame.readBytes(bytes);
return new String(bytes, CharsetUtil.UTF_8);
}
private Packet decode(ClientHead head, ByteBuf frame) throws IOException {
if ((frame.getByte(0) == 'b' && frame.getByte(1) == '4')
|| frame.getByte(0) == 4 || frame.getByte(0) == 1) {
return parseBinary(head, frame);
}
PacketType type = readType(frame);
Packet packet = new Packet(type);
if (type == PacketType.PING) {
packet.setData(readString(frame));
return packet;
}
if (!frame.isReadable()) {
return packet;
}
PacketType innerType = readInnerType(frame);
packet.setSubType(innerType);
parseHeader(frame, packet, innerType);
parseBody(head, frame, packet);
return packet;
}
private void parseHeader(ByteBuf frame, Packet packet, PacketType innerType) {
int endIndex = frame.bytesBefore((byte)'[');
if (endIndex <= 0) {
return;
}
int attachmentsDividerIndex = frame.bytesBefore(endIndex, (byte)'-');
boolean hasAttachments = attachmentsDividerIndex != -1;
if (hasAttachments && PacketType.BINARY_EVENT.equals(innerType)) {
int attachments = (int) readLong(frame, attachmentsDividerIndex);
packet.initAttachments(attachments);
frame.readerIndex(frame.readerIndex() + 1);
endIndex -= attachmentsDividerIndex + 1;
}
if (endIndex == 0) {
return;
}
// TODO optimize
boolean hasNsp = frame.bytesBefore(endIndex, (byte)',') != -1;
if (hasNsp) {
String nspAckId = readString(frame, endIndex);
String[] parts = nspAckId.split(",");
String nsp = parts[0];
packet.setNsp(nsp);
if (parts.length > 1) {
String ackId = parts[1];
packet.setAckId(Long.valueOf(ackId));
}
} else {
long ackId = readLong(frame, endIndex);
packet.setAckId(ackId);
}
}
private Packet parseBinary(ClientHead head, ByteBuf frame) throws IOException {
if (frame.getByte(0) == 1) {
frame.readByte();
int headEndIndex = frame.bytesBefore((byte)-1);
int len = (int) readLong(frame, headEndIndex);
ByteBuf oldFrame = frame;
frame = frame.slice(oldFrame.readerIndex() + 1, len);
oldFrame.readerIndex(oldFrame.readerIndex() + 1 + len);
}
if (frame.getByte(0) == 'b' && frame.getByte(1) == '4') {
frame.readShort();
} else if (frame.getByte(0) == 4) {
frame.readByte();
}
Packet binaryPacket = head.getLastBinaryPacket();
if (binaryPacket != null) {
ByteBuf attachBuf;
if (frame.getByte(0) == 'b' && frame.getByte(1) == '4') {
attachBuf = frame;
} else {
attachBuf = Base64.encode(frame);
}
binaryPacket.addAttachment(Unpooled.copiedBuffer(attachBuf));
frame.readerIndex(frame.readerIndex() + frame.readableBytes());
if (binaryPacket.isAttachmentsLoaded()) {
LinkedList<ByteBuf> slices = new LinkedList<ByteBuf>();
ByteBuf source = binaryPacket.getDataSource();
for (int i = 0; i < binaryPacket.getAttachments().size(); i++) {
ByteBuf attachment = binaryPacket.getAttachments().get(i);
ByteBuf scanValue = Unpooled.copiedBuffer("{\"_placeholder\":true,\"num\":" + i + "}", CharsetUtil.UTF_8);
int pos = PacketEncoder.find(source, scanValue);
if (pos == -1) {
scanValue = Unpooled.copiedBuffer("{\"num\":" + i + ",\"_placeholder\":true}", CharsetUtil.UTF_8);
pos = PacketEncoder.find(source, scanValue);
if (pos == -1) {
throw new IllegalStateException("Can't find attachment by index: " + i + " in packet source");
}
}
ByteBuf prefixBuf = source.slice(source.readerIndex(), pos - source.readerIndex());
slices.add(prefixBuf);
slices.add(QUOTES);
slices.add(attachment);
slices.add(QUOTES);
source.readerIndex(pos + scanValue.readableBytes());
}
slices.add(source.slice());
ByteBuf compositeBuf = Unpooled.wrappedBuffer(slices.toArray(new ByteBuf[slices.size()]));
parseBody(head, compositeBuf, binaryPacket);
head.setLastBinaryPacket(null);
return binaryPacket;
}
}
return new Packet(PacketType.MESSAGE);
}
private void parseBody(ClientHead head, ByteBuf frame, Packet packet) throws IOException {
if (packet.getType() == PacketType.MESSAGE) {
if (packet.getSubType() == PacketType.CONNECT
|| packet.getSubType() == PacketType.DISCONNECT) {
packet.setNsp(readString(frame));
}
if (packet.getSubType() == PacketType.ACK) {
ByteBufInputStream in = new ByteBufInputStream(frame);
AckCallback<?> callback = ackManager.getCallback(head.getSessionId(), packet.getAckId());
AckArgs args = jsonSupport.readAckArgs(in, callback);
packet.setData(args.getArgs());
}
if (packet.getSubType() == PacketType.EVENT
|| packet.getSubType() == PacketType.BINARY_EVENT) {
if (packet.hasAttachments() && !packet.isAttachmentsLoaded()) {
packet.setDataSource(Unpooled.copiedBuffer(frame));
frame.readerIndex(frame.readableBytes());
head.setLastBinaryPacket(packet);
} else {
ByteBufInputStream in = new ByteBufInputStream(frame);
Event event = jsonSupport.readValue(packet.getNsp(), in, Event.class);
packet.setName(event.getName());
packet.setData(event.getArgs());
}
}
}
}
}