Java tutorial
/** * Copyright 2016 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 org.redisson.client.handler; import java.util.HashMap; import java.util.List; import java.util.Map; import org.redisson.client.codec.StringCodec; import org.redisson.client.protocol.CommandData; import org.redisson.client.protocol.DefaultParamsEncoder; import org.redisson.client.protocol.Encoder; import org.redisson.client.protocol.RedisCommand.ValueType; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelPromise; import io.netty.channel.ChannelHandler.Sharable; import io.netty.handler.codec.MessageToByteEncoder; import io.netty.util.CharsetUtil; /** * Redis protocol command encoder * * Code parts from Sam Pullara * * @author Nikita Koksharov * */ @Sharable public class CommandEncoder extends MessageToByteEncoder<CommandData<?, ?>> { public static final CommandEncoder INSTANCE = new CommandEncoder(); private final Logger log = LoggerFactory.getLogger(getClass()); private final Encoder paramsEncoder = new DefaultParamsEncoder(); private static final char ARGS_PREFIX = '*'; private static final char BYTES_PREFIX = '$'; private static final byte[] CRLF = "\r\n".getBytes(); private static final Map<Long, byte[]> longCache = new HashMap<Long, byte[]>(); @Override public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception { try { super.write(ctx, msg, promise); } catch (Exception e) { promise.tryFailure(e); throw e; } } @Override protected void encode(ChannelHandlerContext ctx, CommandData<?, ?> msg, ByteBuf out) throws Exception { try { out.writeByte(ARGS_PREFIX); int len = 1 + msg.getParams().length; if (msg.getCommand().getSubName() != null) { len++; } out.writeBytes(convert(len)); out.writeBytes(CRLF); writeArgument(out, msg.getCommand().getName().getBytes("UTF-8")); if (msg.getCommand().getSubName() != null) { writeArgument(out, msg.getCommand().getSubName().getBytes("UTF-8")); } int i = 1; for (Object param : msg.getParams()) { Encoder encoder = paramsEncoder; if (msg.getCommand().getInParamType().size() == 1) { if (msg.getCommand().getInParamIndex() == i && msg.getCommand().getInParamType().get(0) == ValueType.OBJECT) { encoder = msg.getCodec().getValueEncoder(); } else if (msg.getCommand().getInParamIndex() <= i && msg.getCommand().getInParamType().get(0) != ValueType.OBJECT) { encoder = selectEncoder(msg, i - msg.getCommand().getInParamIndex()); } } else { if (msg.getCommand().getInParamIndex() <= i) { int paramNum = i - msg.getCommand().getInParamIndex(); encoder = selectEncoder(msg, paramNum); } } writeArgument(out, encoder.encode(param)); i++; } if (log.isTraceEnabled()) { log.trace("channel: {} message: {}", ctx.channel(), out.toString(CharsetUtil.UTF_8)); } } catch (Exception e) { msg.getPromise().tryFailure(e); throw e; } } private Encoder selectEncoder(CommandData<?, ?> msg, int param) { int typeIndex = 0; List<ValueType> inParamType = msg.getCommand().getInParamType(); if (inParamType.size() > 1) { typeIndex = param; } if (inParamType.get(typeIndex) == ValueType.MAP) { if (param % 2 != 0) { return msg.getCodec().getMapValueEncoder(); } else { return msg.getCodec().getMapKeyEncoder(); } } if (inParamType.get(typeIndex) == ValueType.MAP_KEY) { return msg.getCodec().getMapKeyEncoder(); } if (inParamType.get(typeIndex) == ValueType.MAP_VALUE) { return msg.getCodec().getMapValueEncoder(); } if (inParamType.get(typeIndex) == ValueType.OBJECTS) { return msg.getCodec().getValueEncoder(); } if (inParamType.get(typeIndex) == ValueType.OBJECT) { return msg.getCodec().getValueEncoder(); } if (inParamType.get(typeIndex) == ValueType.STRING) { return StringCodec.INSTANCE.getValueEncoder(); } throw new IllegalStateException(); } private void writeArgument(ByteBuf out, byte[] arg) { out.writeByte(BYTES_PREFIX); out.writeBytes(convert(arg.length)); out.writeBytes(CRLF); out.writeBytes(arg); out.writeBytes(CRLF); } static final 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', }; static final 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', }; static final 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' }; static final 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[] convert(long i) { if (i >= 0 && i <= 255) { return longCache.get(i); } return toChars(i); } 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; } static { for (long i = 0; i < 256; i++) { byte[] value = toChars(i); longCache.put(i, value); } } }