Java tutorial
/** * 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.ByteBufAllocator; import io.netty.buffer.ByteBufOutputStream; import io.netty.buffer.Unpooled; import io.netty.handler.codec.base64.Base64; import io.netty.handler.codec.base64.Base64Dialect; import io.netty.util.CharsetUtil; import java.io.IOException; import java.util.ArrayList; import java.util.List; import java.util.Queue; import com.corundumstudio.socketio.Configuration; public class PacketEncoder { private static final byte[] BINARY_HEADER = "b4".getBytes(CharsetUtil.UTF_8); private static final byte[] B64_DELIMITER = new byte[] { ':' }; private static final byte[] JSONP_HEAD = "___eio[".getBytes(CharsetUtil.UTF_8); private static final byte[] JSONP_START = "]('".getBytes(CharsetUtil.UTF_8); private static final byte[] JSONP_END = "');".getBytes(CharsetUtil.UTF_8); private final JsonSupport jsonSupport; private final Configuration configuration; public PacketEncoder(Configuration configuration, JsonSupport jsonSupport) { this.jsonSupport = jsonSupport; this.configuration = configuration; } public ByteBuf allocateBuffer(ByteBufAllocator allocator) { if (configuration.isPreferDirectBuffer()) { return allocator.ioBuffer(); } return allocator.heapBuffer(); } public void encodeJsonP(Integer jsonpIndex, Queue<Packet> packets, ByteBuf out, ByteBufAllocator allocator, int limit) throws IOException { boolean jsonpMode = jsonpIndex != null; ByteBuf buf = allocateBuffer(allocator); int i = 0; while (true) { Packet packet = packets.poll(); if (packet == null || i == limit) { break; } ByteBuf packetBuf = allocateBuffer(allocator); encodePacket(packet, packetBuf, allocator, true); int packetSize = packetBuf.writerIndex(); buf.writeBytes(toChars(packetSize)); buf.writeBytes(B64_DELIMITER); buf.writeBytes(packetBuf); packetBuf.release(); i++; for (ByteBuf attachment : packet.getAttachments()) { ByteBuf encodedBuf = Base64.encode(attachment, Base64Dialect.URL_SAFE); buf.writeBytes(toChars(encodedBuf.readableBytes() + 2)); buf.writeBytes(B64_DELIMITER); buf.writeBytes(BINARY_HEADER); buf.writeBytes(encodedBuf); } } if (jsonpMode) { out.writeBytes(JSONP_HEAD); out.writeBytes(toChars(jsonpIndex)); out.writeBytes(JSONP_START); } processUtf8(buf, out, jsonpMode); buf.release(); if (jsonpMode) { out.writeBytes(JSONP_END); } } private void processUtf8(ByteBuf in, ByteBuf out, boolean jsonpMode) { while (in.isReadable()) { short value = (short) (in.readByte() & 0xFF); if (value >>> 7 == 0) { if (jsonpMode && (value == '\\' || value == '\'')) { out.writeByte('\\'); } out.writeByte(value); } else { out.writeByte(((value >>> 6) | 0xC0)); out.writeByte(((value & 0x3F) | 0x80)); } } } public void encodePackets(Queue<Packet> packets, ByteBuf buffer, ByteBufAllocator allocator, int limit) throws IOException { int i = 0; while (true) { Packet packet = packets.poll(); if (packet == null || i == limit) { break; } encodePacket(packet, buffer, allocator, false); i++; for (ByteBuf attachment : packet.getAttachments()) { buffer.writeByte(1); buffer.writeBytes(longToBytes(attachment.readableBytes() + 1)); buffer.writeByte(0xff); buffer.writeByte(4); buffer.writeBytes(attachment); } } } private byte toChar(int number) { return (byte) (number ^ 0x30); } final static char[] DigitTens = { '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '1', '1', '1', '1', '1', '1', '1', '1', '1', '1', '2', '2', '2', '2', '2', '2', '2', '2', '2', '2', '3', '3', '3', '3', '3', '3', '3', '3', '3', '3', '4', '4', '4', '4', '4', '4', '4', '4', '4', '4', '5', '5', '5', '5', '5', '5', '5', '5', '5', '5', '6', '6', '6', '6', '6', '6', '6', '6', '6', '6', '7', '7', '7', '7', '7', '7', '7', '7', '7', '7', '8', '8', '8', '8', '8', '8', '8', '8', '8', '8', '9', '9', '9', '9', '9', '9', '9', '9', '9', '9', }; final static char[] DigitOnes = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', }; final static char[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' }; final static int[] sizeTable = { 9, 99, 999, 9999, 99999, 999999, 9999999, 99999999, 999999999, Integer.MAX_VALUE }; // Requires positive x static int stringSize(long x) { for (int i = 0;; i++) if (x <= sizeTable[i]) return i + 1; } static void getChars(long i, int index, byte[] buf) { long q, r; int charPos = index; byte sign = 0; if (i < 0) { sign = '-'; i = -i; } // Generate two digits per iteration while (i >= 65536) { q = i / 100; // really: r = i - (q * 100); r = i - ((q << 6) + (q << 5) + (q << 2)); i = q; buf[--charPos] = (byte) DigitOnes[(int) r]; buf[--charPos] = (byte) DigitTens[(int) r]; } // Fall thru to fast mode for smaller numbers // assert(i <= 65536, i); for (;;) { q = (i * 52429) >>> (16 + 3); r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ... buf[--charPos] = (byte) digits[(int) r]; i = q; if (i == 0) break; } if (sign != 0) { buf[--charPos] = sign; } } public static byte[] toChars(long i) { int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i); byte[] buf = new byte[size]; getChars(i, size, buf); return buf; } public static byte[] longToBytes(long number) { // TODO optimize int length = (int) (Math.log10(number) + 1); byte[] res = new byte[length]; int i = length; while (number > 0) { res[--i] = (byte) (number % 10); number = number / 10; } return res; } public void encodePacket(Packet packet, ByteBuf buffer, ByteBufAllocator allocator, boolean binary) throws IOException { ByteBuf buf = buffer; if (!binary) { buf = allocateBuffer(allocator); } byte type = toChar(packet.getType().getValue()); buf.writeByte(type); try { switch (packet.getType()) { case PONG: { buf.writeBytes(packet.getData().toString().getBytes(CharsetUtil.UTF_8)); break; } case OPEN: { ByteBufOutputStream out = new ByteBufOutputStream(buf); jsonSupport.writeValue(out, packet.getData()); break; } case MESSAGE: { ByteBuf encBuf = null; if (packet.getSubType() == PacketType.ERROR) { encBuf = allocateBuffer(allocator); ByteBufOutputStream out = new ByteBufOutputStream(encBuf); jsonSupport.writeValue(out, packet.getData()); } if (packet.getSubType() == PacketType.EVENT || packet.getSubType() == PacketType.ACK) { List<Object> values = new ArrayList<Object>(); if (packet.getSubType() == PacketType.EVENT) { values.add(packet.getName()); } encBuf = allocateBuffer(allocator); List<Object> args = packet.getData(); values.addAll(args); ByteBufOutputStream out = new ByteBufOutputStream(encBuf); jsonSupport.writeValue(out, values); if (!jsonSupport.getArrays().isEmpty()) { packet.initAttachments(jsonSupport.getArrays().size()); for (byte[] array : jsonSupport.getArrays()) { packet.addAttachment(Unpooled.wrappedBuffer(array)); } packet.setSubType(PacketType.BINARY_EVENT); } } byte subType = toChar(packet.getSubType().getValue()); buf.writeByte(subType); if (packet.hasAttachments()) { byte[] ackId = toChars(packet.getAttachments().size()); buf.writeBytes(ackId); buf.writeByte('-'); } if (packet.getSubType() == PacketType.CONNECT) { if (!packet.getNsp().isEmpty()) { buf.writeBytes(packet.getNsp().getBytes(CharsetUtil.UTF_8)); } } else { if (!packet.getNsp().isEmpty()) { buf.writeBytes(packet.getNsp().getBytes(CharsetUtil.UTF_8)); buf.writeByte(','); } } if (packet.getAckId() != null) { byte[] ackId = toChars(packet.getAckId()); buf.writeBytes(ackId); } if (encBuf != null) { buf.writeBytes(encBuf); encBuf.release(); } break; } } } finally { // we need to write a buffer in any case if (!binary) { buffer.writeByte(0); int length = buf.writerIndex(); buffer.writeBytes(longToBytes(length)); buffer.writeByte(0xff); buffer.writeBytes(buf); buf.release(); } } } public static int find(ByteBuf buffer, ByteBuf searchValue) { for (int i = buffer.readerIndex(); i < buffer.readerIndex() + buffer.readableBytes(); i++) { if (isValueFound(buffer, i, searchValue)) { return i; } } return -1; } private static boolean isValueFound(ByteBuf buffer, int index, ByteBuf search) { for (int i = 0; i < search.readableBytes(); i++) { if (buffer.getByte(index + i) != search.getByte(i)) { return false; } } return true; } }