Merge branch 'arnavi4_remarks'

2 files changed, 39 insertions, 35 deletions

diff --git a/src/org/traccar/protocol/Arnavi4FrameDecoder.java b/src/org/traccar/protocol/Arnavi4FrameDecoder.java
index bb130e6bb..ee4aee32a 100644
--- a/src/org/traccar/protocol/Arnavi4FrameDecoder.java
+++ b/src/org/traccar/protocol/Arnavi4FrameDecoder.java
@@ -22,17 +22,18 @@ import org.jboss.netty.handler.codec.frame.FrameDecoder;
 
 public class Arnavi4FrameDecoder extends FrameDecoder {
 
-    static final int PACKET_MIN_LENGTH = 4;
+    private static final int PACKET_MINIMUM_LENGTH = 4;
+    private static final int RECORD_MINIMUM_LENGTH = 8;
 
-    static final byte HEADER_START_SIGN = (byte) 0xFF;
+    static final byte HEADER_START_SIGN = (byte) 0xff;
     static final byte HEADER_VERSION_1 = 0x22;
     static final byte HEADER_VERSION_2 = 0x23;
-    static final int HEADER_LENGTH = 10;
+    private static final int HEADER_LENGTH = 10;
 
-    static final byte PACKAGE_START_SIGN = 0x5B;
-    static final byte PACKAGE_END_SIGN = 0x5D;
-    static final int PACKAGE_MIN_PARCEL_NUMBER = 0x01;
-    static final int PACKAGE_MAX_PARCEL_NUMBER = 0xFB;
+    private static final byte PACKAGE_START_SIGN = 0x5b;
+    private static final byte PACKAGE_END_SIGN = 0x5d;
+    private static final int PACKAGE_MIN_PARCEL_NUMBER = 0x01;
+    private static final int PACKAGE_MAX_PARCEL_NUMBER = 0xfb;
 
     @Override
     protected Object decode(
@@ -40,31 +41,37 @@ public class Arnavi4FrameDecoder extends FrameDecoder {
             Channel channel,
             ChannelBuffer buf) throws Exception {
 
-        if (buf.readableBytes() < PACKET_MIN_LENGTH) {
+        if (buf.readableBytes() < PACKET_MINIMUM_LENGTH) {
             return null;
         }
 
         if (buf.getByte(0) == HEADER_START_SIGN
                 && buf.readableBytes() == HEADER_LENGTH
                 && (buf.getByte(1) == HEADER_VERSION_1 || buf.getByte(1) == HEADER_VERSION_2)) {
+
             return buf.readBytes(HEADER_LENGTH);
         }
 
-        int index = buf.getByte(1) & 0xFF; // parcel number
+        int index = buf.getUnsignedByte(1); // parcel number
         if (buf.getByte(0) == PACKAGE_START_SIGN
                 && index >= PACKAGE_MIN_PARCEL_NUMBER && index <= PACKAGE_MAX_PARCEL_NUMBER) {
 
-            // package: 1 byte start sign, 1 byte parcel number, packets, 1 byte end sign
-            int packetStartIndex = 2;
-            while (packetStartIndex + 8 < buf.readableBytes() && buf.getByte(packetStartIndex) != PACKAGE_END_SIGN) {
-                // packet: 1 byte type, 2 bytes length, 4 bytes unixtime, length-bytes data, 1 byte crc
-                packetStartIndex += buf.getUnsignedShort(packetStartIndex + 1) + 8;
+            int bufferPosition = 2; // start sign + parcel number
+            while (bufferPosition + RECORD_MINIMUM_LENGTH < buf.readableBytes()
+                    && buf.getByte(bufferPosition) != PACKAGE_END_SIGN) {
+
+                int dataLength = buf.getUnsignedShort(bufferPosition + 1);
+                bufferPosition += RECORD_MINIMUM_LENGTH + dataLength; // type + data length + unixtime + data + crc
             }
 
-            return buf.readBytes(packetStartIndex + 1);
+            if (bufferPosition < buf.readableBytes()
+                    && buf.getByte(bufferPosition) == PACKAGE_END_SIGN) {
+
+                return buf.readBytes(bufferPosition + 1); // end sign
+            }
         }
 
         return null;
     }
 
-}
+}
\ No newline at end of file
diff --git a/src/org/traccar/protocol/Arnavi4ProtocolDecoder.java b/src/org/traccar/protocol/Arnavi4ProtocolDecoder.java
index a1a9d2ea1..4ab929cf7 100644
--- a/src/org/traccar/protocol/Arnavi4ProtocolDecoder.java
+++ b/src/org/traccar/protocol/Arnavi4ProtocolDecoder.java
@@ -50,34 +50,31 @@ public class Arnavi4ProtocolDecoder extends BaseProtocolDecoder {
         super(protocol);
     }
 
-    private void sendHeaderResponse(Channel channel, byte version) {
+    private void sendResponse(Channel channel, byte version, int index) {
         if (channel != null) {
             final ChannelBuffer response;
             if (version == HEADER_VERSION_1) {
                 response = ChannelBuffers.dynamicBuffer(ByteOrder.LITTLE_ENDIAN, 4);
-                response.writeBytes(new byte[]{0x7B, 0x00, 0x00, 0x7D});
+                response.writeByte(0x7b);
+                response.writeByte(0x00);
+                response.writeByte((byte) index);
+                response.writeByte(0x7d);
             } else if (version == HEADER_VERSION_2) {
                 response = ChannelBuffers.dynamicBuffer(ByteOrder.LITTLE_ENDIAN, 9);
-                response.writeBytes(new byte[]{0x7B, 0x04, 0x00});
+                response.writeByte(0x7b);
+                response.writeByte(0x04);
+                response.writeByte(0x00);
                 byte[] timeBytes = ByteBuffer.allocate(4).putInt((int) (System.currentTimeMillis() / 1000)).array();
                 response.writeByte(Checksum.modulo256(timeBytes));
                 response.writeBytes(timeBytes);
-                response.writeByte(0x7D);
+                response.writeByte(0x7d);
             } else {
-                return; // Ignore unsupported versions of header
+                return; // Ignore unsupported header's versions
             }
             channel.write(response);
         }
     }
-
-    private void sendPackageResponse(Channel channel, int index) {
-        if (channel != null) {
-            final ChannelBuffer response = ChannelBuffers.dynamicBuffer(ByteOrder.LITTLE_ENDIAN, 4);
-            response.writeBytes(new byte[]{0x7B, 0x00, (byte) index, 0x7D});
-            channel.write(response);
-        }
-    }
-
+    
     private Position decodePosition(DeviceSession deviceSession, ChannelBuffer buf, int length, Date time) {
 
         final Position position = new Position();
@@ -135,7 +132,7 @@ public class Arnavi4ProtocolDecoder extends BaseProtocolDecoder {
             DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, imei);
 
             if (deviceSession != null) {
-                sendHeaderResponse(channel, version);
+                sendResponse(channel, version, 0);
             }
 
             return null;
@@ -164,20 +161,20 @@ public class Arnavi4ProtocolDecoder extends BaseProtocolDecoder {
                     if (recordType == RECORD_DATA) {
                         positions.add(decodePosition(deviceSession, buf, length, time));
                     } else {
-                        buf.readBytes(length); // Skip other records
+                        buf.readBytes(length); // Skip other types of record
                     }
 
                     buf.readUnsignedByte(); // crc
                     break;
 
                 default:
-                    return null; // Ignore unsupported types of package
+                    return null; // Ignore unsupported types of record
             }
 
-            recordType = buf.readByte(); // The last byte in package is end sign
+            recordType = buf.readByte();
         }
 
-        sendPackageResponse(channel, index);
+        sendResponse(channel, HEADER_VERSION_1, index);
 
         return positions;
     }