1 files changed, 59 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/TotemFrameDecoder.java b/src/main/java/org/traccar/protocol/TotemFrameDecoder.java
new file mode 100644
index 000000000..3fa5abc7a
--- /dev/null
+++ b/src/main/java/org/traccar/protocol/TotemFrameDecoder.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2013 - 2018 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 io.netty.buffer.ByteBuf;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+
+import java.nio.charset.StandardCharsets;
+
+import org.traccar.BaseFrameDecoder;
+import org.traccar.helper.BufferUtil;
+
+public class TotemFrameDecoder extends BaseFrameDecoder {
+
+    @Override
+    protected Object decode(
+            ChannelHandlerContext ctx, Channel channel, ByteBuf buf) throws Exception {
+
+        if (buf.readableBytes() < 10) {
+            return null;
+        }
+
+        int beginIndex = BufferUtil.indexOf("$$", buf);
+        if (beginIndex == -1) {
+            return null;
+        } else if (beginIndex > buf.readerIndex()) {
+            buf.readerIndex(beginIndex);
+        }
+
+        int length;
+
+        if (buf.getByte(buf.readerIndex() + 2) == (byte) '0') {
+            length = Integer.parseInt(buf.toString(buf.readerIndex() + 2, 4, StandardCharsets.US_ASCII));
+        } else {
+            length = Integer.parseInt(buf.toString(buf.readerIndex() + 2, 2, StandardCharsets.US_ASCII), 16);
+        }
+
+        if (length <= buf.readableBytes()) {
+            return buf.readRetainedSlice(length);
+        }
+
+        return null;
+    }
+
+}