diff options
Diffstat (limited to 'src/org/traccar/protocol/Tk103FrameDecoder.java')
-rw-r--r-- | src/org/traccar/protocol/Tk103FrameDecoder.java | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/src/org/traccar/protocol/Tk103FrameDecoder.java b/src/org/traccar/protocol/Tk103FrameDecoder.java new file mode 100644 index 000000000..390e38906 --- /dev/null +++ b/src/org/traccar/protocol/Tk103FrameDecoder.java @@ -0,0 +1,75 @@ +/* + * Copyright 2017 Valerii Vyshniak (val@val.one) + * Copyright 2017 Anton Tananaev (anton@traccar.org) + * + * 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.traccar.protocol; + +import org.jboss.netty.buffer.ChannelBuffer; +import org.jboss.netty.channel.Channel; +import org.jboss.netty.channel.ChannelHandlerContext; +import org.jboss.netty.handler.codec.frame.FrameDecoder; + +public class Tk103FrameDecoder extends FrameDecoder { + + @Override + protected Object decode( + ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception { + + if (buf.readableBytes() < 2) { + return null; + } + + int frameStartIndex = buf.indexOf(buf.readerIndex(), buf.writerIndex(), (byte) '('); + if (frameStartIndex == -1) { + buf.clear(); + return null; + } + + int frameEndIndex, freeTextSymbolCounter; + for (frameEndIndex = frameStartIndex, freeTextSymbolCounter = 0;; frameEndIndex++) { + int freeTextIndex = frameEndIndex; + frameEndIndex = buf.indexOf(frameEndIndex, buf.writerIndex(), (byte) ')'); + if (frameEndIndex == -1) { + break; + } + for (;; freeTextIndex++, freeTextSymbolCounter++) { + freeTextIndex = buf.indexOf(freeTextIndex, frameEndIndex, (byte) '$'); + if (freeTextIndex == -1 || freeTextIndex >= frameEndIndex) { + break; + } + } + if (freeTextSymbolCounter % 2 == 0) { + break; + } + } + + if (frameEndIndex == -1) { + while (buf.readableBytes() > 1024) { + int discardUntilIndex = buf.indexOf(buf.readerIndex() + 1, buf.writerIndex(), (byte) '('); + if (discardUntilIndex == -1) { + buf.clear(); + } else { + buf.readerIndex(discardUntilIndex); + } + } + return null; + } + + buf.readerIndex(frameStartIndex); + + return buf.readBytes(frameEndIndex + 1 - frameStartIndex); + } + +} |