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.parser; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufAllocator; import io.netty.buffer.ByteBufOutputStream; import java.io.IOException; import java.util.List; import java.util.Queue; import com.corundumstudio.socketio.Configuration; public class Encoder { private final UTF8CharsScanner charsScanner = new UTF8CharsScanner(); private final JsonSupport jsonSupport; private final Configuration configuration; public Encoder(Configuration configuration, JsonSupport jsonSupport) { this.jsonSupport = jsonSupport; this.configuration = configuration; } public void encodeJsonP(String param, String msg, ByteBuf out) throws IOException { String message = "io.j[" + param + "](" + jsonSupport.writeValueAsString(msg) + ");"; out.writeBytes(message.getBytes()); } public ByteBuf allocateBuffer(ByteBufAllocator allocator) { if (configuration.isPreferDirectBuffer()) { return allocator.ioBuffer(); } return allocator.heapBuffer(); } public void encodePackets(Queue<Packet> packets, ByteBuf buffer, ByteBufAllocator allocator) throws IOException { if (packets.size() == 1) { Packet packet = packets.poll(); encodePacket(packet, buffer); } else { int counter = 0; while (true) { Packet packet = packets.poll(); if (packet == null) { break; } counter++; // to prevent infinity out message if (counter == 100) { return; } ByteBuf packetBuffer = allocateBuffer(allocator); try { int len = encodePacket(packet, packetBuffer); byte[] lenBytes = toChars(len); buffer.writeBytes(Packet.DELIMITER_BYTES); buffer.writeBytes(lenBytes); buffer.writeBytes(Packet.DELIMITER_BYTES); buffer.writeBytes(packetBuffer); } finally { packetBuffer.release(); } } } } 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; } } private 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 int encodePacket(Packet packet, ByteBuf buffer) throws IOException { ByteBufOutputStream out = new ByteBufOutputStream(buffer); int start = buffer.writerIndex(); int type = packet.getType().getValue(); buffer.writeByte(toChar(type)); buffer.writeByte(Packet.SEPARATOR); Long id = packet.getId(); String endpoint = packet.getEndpoint(); Object ack = packet.getAck(); if (Packet.ACK_DATA.equals(ack)) { buffer.writeBytes(toChars(id)); buffer.writeByte('+'); } else { if (id != null) { buffer.writeBytes(toChars(id)); } } buffer.writeByte(Packet.SEPARATOR); if (endpoint != null) { buffer.writeBytes(endpoint.getBytes()); } switch (packet.getType()) { case MESSAGE: if (packet.getData() != null) { buffer.writeByte(Packet.SEPARATOR); byte[] data = packet.getData().toString().getBytes(); buffer.writeBytes(data); } break; case EVENT: List<Object> args = packet.getArgs(); if (args.isEmpty()) { args = null; } buffer.writeByte(Packet.SEPARATOR); Event event = new Event(packet.getName(), args); jsonSupport.writeValue(out, event); break; case JSON: buffer.writeByte(Packet.SEPARATOR); jsonSupport.writeValue(out, packet.getData()); break; case CONNECT: if (packet.getQs() != null) { buffer.writeByte(Packet.SEPARATOR); byte[] qsData = packet.getQs().toString().getBytes(); buffer.writeBytes(qsData); } break; case ACK: if (packet.getAckId() != null || !packet.getArgs().isEmpty()) { buffer.writeByte(Packet.SEPARATOR); } if (packet.getAckId() != null) { byte[] ackIdData = toChars(packet.getAckId()); buffer.writeBytes(ackIdData); } if (!packet.getArgs().isEmpty()) { buffer.writeByte('+'); jsonSupport.writeValue(out, packet.getArgs()); } break; case ERROR: if (packet.getReason() != null || packet.getAdvice() != null) { buffer.writeByte(Packet.SEPARATOR); } if (packet.getReason() != null) { int reasonCode = packet.getReason().getValue(); buffer.writeByte(toChar(reasonCode)); } if (packet.getAdvice() != null) { int adviceCode = packet.getAdvice().getValue(); buffer.writeByte('+'); buffer.writeByte(toChar(adviceCode)); } break; } return charsScanner.getLength(buffer, start); } }