mts: got rid of LocationStrBytes func

stream/mts/psi/helpers.go

@@ -99,14 +99,6 @@ func LocationFrom(p []byte) (g string, err error) {
 	return g, nil
 }
 
-// LocationStrBytes take a string of location data and converts to a 32 byte slice -
-// easy update of slice representation of a pmt with location descriptor
-func LocationStrBytes(s string) []byte {
-	var b [LocationDataSize]byte
-	copy(b[:], s)
-	return b[:]
-}
-
 // UpdateLocation takes a byte slice representation of a psi-pmt containing a location
 // descriptor and attempts to update the location data value with the passed string.
 // If the psi does not contain a location descriptor, and error is returned.
@@ -114,8 +106,15 @@ func UpdateLocation(d []byte, s string) error {
 	if !HasLocation(d) {
 		return errors.New("pmt does not location descriptor, cannot update")
 	}
-	gb := LocationStrBytes(s)
-	copy(d[LocationDataIndx:LocationDataIndx+LocationDataSize], gb)
+	sb := []byte(s)
+	locBytes := d[LocationDataIndx : LocationDataIndx+LocationDataSize]
+	for i, _ := range locBytes {
+		if i < len(sb) {
+			locBytes[i] = sb[i]
+		} else {
+			locBytes[i] = 0x00
+		}
+	}
 	updateCrc(d)
 	return nil
 }

stream/mts/psi/psi_test.go

@@ -123,9 +123,20 @@ const (
 
 // GPS string for testing
 // TODO: make these realistic
-const (
-	locationTstStr1 = "$GPGGA,123519,4807.038,N,01131.0"
-	locationTstStr2 = "$GPGGA,183710,4902.048,N,02171.0"
+var (
+	locationTstStr1 = [LocationDataSize]byte{
+		0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+		0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+		0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+		0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+	}
+
+	locationTstStr2 = [LocationDataSize]byte{
+		0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
+		0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
+		0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
+		0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01,
+	}
 )
 
 // err message
@@ -175,10 +186,10 @@ var (
 	}
 
 	// Bytes representing pmt with time1 and location1
-	pmtTimeLocationBytes1 = buildPmtTimeLocationBytes(locationTstStr1)
+	pmtTimeLocationBytes1 = buildPmtTimeLocationBytes(locationTstStr1[:])
 
 	// bytes representing pmt with with time1 and location 2
-	pmtTimeLocationBytes2 = buildPmtTimeLocationBytes(locationTstStr2)
+	pmtTimeLocationBytes2 = buildPmtTimeLocationBytes(locationTstStr2[:])
 )
 
 // bytesTests contains data for testing the Bytes() funcs for the PSI data struct
@@ -262,7 +273,7 @@ var bytesTests = []struct {
 						{
 							Dt: LocationDescTag,
 							Dl: LocationDataSize,
-							Dd: LocationStrBytes(locationTstStr1),
+							Dd: locationTstStr1[:],
 						},
 					},
 					Essd: &ESSD{
@@ -273,7 +284,7 @@ var bytesTests = []struct {
 				},
 			},
 		},
-		want: buildPmtTimeLocationBytes(locationTstStr1),
+		want: buildPmtTimeLocationBytes(locationTstStr1[:]),
 	},
 }
 
@@ -326,7 +337,7 @@ func TestTimeGet(t *testing.T) {
 // TestLocationGet checks that we can correctly get location data from a pmt table
 func TestLocationGet(t *testing.T) {
 	pb := standardPmtTimeLocation.Bytes()
-	err := UpdateLocation(pb, locationTstStr1)
+	err := UpdateLocation(pb, string(locationTstStr1[:]))
 	if err != nil {
 		t.Errorf("Error for TestLocationGet UpdateLocation(pb, locationTstStr1): %v", err)
 	}
@@ -334,7 +345,7 @@ func TestLocationGet(t *testing.T) {
 	if err != nil {
 		t.Errorf("Error for TestLocationGet LocationOf(pb): %v", err)
 	}
-	if g != locationTstStr1 {
+	if g != string(locationTstStr1[:]) {
 		t.Errorf(errCmp, "TestLocationGet", locationTstStr1, g)
 	}
 }
@@ -344,7 +355,7 @@ func TestLocationUpdate(t *testing.T) {
 	cpy := make([]byte, len(pmtTimeLocationBytes1))
 	copy(cpy, pmtTimeLocationBytes1)
 	cpy = addCrc(cpy)
-	err := UpdateLocation(cpy, locationTstStr2)
+	err := UpdateLocation(cpy, string(locationTstStr2[:]))
 	cpy = cpy[:len(cpy)-4]
 	if err != nil {
 		t.Errorf("Update time returned err: %v", err)
@@ -366,7 +377,7 @@ func TestTrim(t *testing.T) {
 // buildPmtTimeLocationBytes is a helper function to help construct the byte slices
 // for pmts with time and location, as the location data field is 32 bytes, i.e. quite large
 // to type out
-func buildPmtTimeLocationBytes(tstStr string) []byte {
+func buildPmtTimeLocationBytes(tstStr []byte) []byte {
 	return append(append(append(make([]byte, 0), pmtTimeLocationBytesPart1...),
-		LocationStrBytes(tstStr)...), pmtTimeLocationBytesPart2...)
+		tstStr...), pmtTimeLocationBytesPart2...)
 }