Unify signed magnitude int decoding

7 files changed, 24 insertions, 32 deletions

diff --git a/src/main/java/org/traccar/helper/BitUtil.java b/src/main/java/org/traccar/helper/BitUtil.java
index b6108edff..829ddebc9 100644
--- a/src/main/java/org/traccar/helper/BitUtil.java
+++ b/src/main/java/org/traccar/helper/BitUtil.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ * Copyright 2015 - 2022 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.
@@ -21,7 +21,7 @@ public final class BitUtil {
     }
 
     public static boolean check(long number, int index) {
-        return (number & (1 << index)) != 0;
+        return (number & (1L << index)) != 0;
     }
 
     public static int between(int number, int from, int to) {
diff --git a/src/main/java/org/traccar/helper/BufferUtil.java b/src/main/java/org/traccar/helper/BufferUtil.java
index 1e1a687fa..0dbe0a4ad 100644
--- a/src/main/java/org/traccar/helper/BufferUtil.java
+++ b/src/main/java/org/traccar/helper/BufferUtil.java
@@ -27,6 +27,12 @@ public final class BufferUtil {
     private BufferUtil() {
     }
 
+    public static int readSignedMagnitudeInt(ByteBuf buffer) {
+        long value = buffer.readUnsignedInt();
+        int result = (int) BitUtil.to(value, 31);
+        return BitUtil.check(value, 31) ? -result : result;
+    }
+
     public static int indexOf(ByteBuf buffer, int fromIndex, int toIndex, byte value, int count) {
         int startIndex = fromIndex;
         for (int i = 0; i < count; i++) {
diff --git a/src/main/java/org/traccar/protocol/NiotProtocolDecoder.java b/src/main/java/org/traccar/protocol/NiotProtocolDecoder.java
index 16d992938..35614ccca 100644
--- a/src/main/java/org/traccar/protocol/NiotProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/NiotProtocolDecoder.java
@@ -20,6 +20,7 @@ import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.helper.BufferUtil;
 import org.traccar.session.DeviceSession;
 import org.traccar.NetworkMessage;
 import org.traccar.Protocol;
@@ -57,12 +58,6 @@ public class NiotProtocolDecoder extends BaseProtocolDecoder {
         }
     }
 
-    private double readCoordinate(ByteBuf buf) {
-        long value = buf.readUnsignedInt();
-        double result = BitUtil.to(value, 31) / 1800000.0;
-        return BitUtil.check(value, 31) ? -result : result;
-    }
-
     @Override
     protected Object decode(
             Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {
@@ -96,8 +91,8 @@ public class NiotProtocolDecoder extends BaseProtocolDecoder {
                     .setSecond(BcdUtil.readInteger(buf, 2));
             position.setTime(dateBuilder.getDate());
 
-            position.setLatitude(readCoordinate(buf));
-            position.setLongitude(readCoordinate(buf));
+            position.setLatitude(BufferUtil.readSignedMagnitudeInt(buf) / 1800000.0);
+            position.setLongitude(BufferUtil.readSignedMagnitudeInt(buf) / 1800000.0);
             BcdUtil.readInteger(buf, 4); // reserved
             position.setCourse(BcdUtil.readInteger(buf, 4));
 
diff --git a/src/main/java/org/traccar/protocol/SigfoxProtocolDecoder.java b/src/main/java/org/traccar/protocol/SigfoxProtocolDecoder.java
index bbb8bc1cc..4ed2bb51d 100644
--- a/src/main/java/org/traccar/protocol/SigfoxProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/SigfoxProtocolDecoder.java
@@ -22,6 +22,7 @@ import io.netty.channel.Channel;
 import io.netty.handler.codec.http.FullHttpRequest;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import org.traccar.BaseHttpProtocolDecoder;
+import org.traccar.helper.BufferUtil;
 import org.traccar.session.DeviceSession;
 import org.traccar.Protocol;
 import org.traccar.helper.BitUtil;
@@ -159,18 +160,8 @@ public class SigfoxProtocolDecoder extends BaseHttpProtocolDecoder {
                 if (event == 0x0f || event == 0x1f) {
 
                     position.setValid(event >> 4 > 0);
-
-                    long value;
-                    value = buf.readUnsignedInt();
-                    position.setLatitude(BitUtil.to(value, 31) * 0.000001);
-                    if (BitUtil.check(value, 31)) {
-                        position.setLatitude(-position.getLatitude());
-                    }
-                    value = buf.readUnsignedInt();
-                    position.setLongitude(BitUtil.to(value, 31) * 0.000001);
-                    if (BitUtil.check(value, 31)) {
-                        position.setLongitude(-position.getLongitude());
-                    }
+                    position.setLatitude(BufferUtil.readSignedMagnitudeInt(buf) * 0.000001);
+                    position.setLongitude(BufferUtil.readSignedMagnitudeInt(buf) * 0.000001);
 
                     position.set(Position.KEY_BATTERY, (int) buf.readUnsignedByte());
 
diff --git a/src/main/java/org/traccar/protocol/SuntechProtocolDecoder.java b/src/main/java/org/traccar/protocol/SuntechProtocolDecoder.java
index 67a82a688..938d290c0 100644
--- a/src/main/java/org/traccar/protocol/SuntechProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/SuntechProtocolDecoder.java
@@ -21,6 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
 import org.traccar.config.Keys;
+import org.traccar.helper.BufferUtil;
 import org.traccar.helper.model.AttributeUtil;
 import org.traccar.session.DeviceSession;
 import org.traccar.Protocol;
@@ -673,19 +674,11 @@ public class SuntechProtocolDecoder extends BaseProtocolDecoder {
         }
 
         if (BitUtil.check(mask, 11)) {
-            long value = buf.readUnsignedInt();
-            if (BitUtil.check(value, 31)) {
-                value = -BitUtil.to(value, 31);
-            }
-            position.setLatitude(value / 1000000.0);
+            position.setLatitude(BufferUtil.readSignedMagnitudeInt(buf) / 1000000.0);
         }
 
         if (BitUtil.check(mask, 12)) {
-            long value = buf.readUnsignedInt();
-            if (BitUtil.check(value, 31)) {
-                value = -BitUtil.to(value, 31);
-            }
-            position.setLongitude(value / 1000000.0);
+            position.setLongitude(BufferUtil.readSignedMagnitudeInt(buf) / 1000000.0);
         }
 
         if (BitUtil.check(mask, 13)) {
diff --git a/src/main/java/org/traccar/protocol/ThinkPowerProtocolDecoder.java b/src/main/java/org/traccar/protocol/ThinkPowerProtocolDecoder.java
index 085ce4c91..26d60daba 100644
--- a/src/main/java/org/traccar/protocol/ThinkPowerProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/ThinkPowerProtocolDecoder.java
@@ -19,6 +19,7 @@ import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import org.traccar.BaseProtocolDecoder;
+import org.traccar.helper.BitUtil;
 import org.traccar.session.DeviceSession;
 import org.traccar.NetworkMessage;
 import org.traccar.Protocol;
diff --git a/src/test/java/org/traccar/helper/BufferUtilTest.java b/src/test/java/org/traccar/helper/BufferUtilTest.java
index b539b5b28..0196cef9d 100644
--- a/src/test/java/org/traccar/helper/BufferUtilTest.java
+++ b/src/test/java/org/traccar/helper/BufferUtilTest.java
@@ -11,6 +11,12 @@ import static org.junit.Assert.assertEquals;
 public class BufferUtilTest {
 
     @Test
+    public void testReadSignedMagnitudeInt() {
+        ByteBuf buf = Unpooled.wrappedBuffer(DataConverter.parseHex("80000001"));
+        assertEquals(-1, BufferUtil.readSignedMagnitudeInt(buf));
+    }
+
+    @Test
     public void test1() {
         ByteBuf buf = Unpooled.copiedBuffer("abcdef", StandardCharsets.US_ASCII);
         assertEquals(2, BufferUtil.indexOf("cd", buf));