reader: intial developer data fields support

Updates #21.

Partially based on code provided by @beyoung:
#59

README.md

@@ -21,25 +21,21 @@ are required for running the full test suite and benchmarks.
 
 _Note:_ 0.6.0 contains a breaking change, see #46.
 
-### FIT SDK Version Support
+### Version Support
 
-**Current supported FIT SDK version:** 21.67
+The current supported FIT SDK version is **21.67**.
 
-**Warning:** Data Developers Fields are not yet supported (#21).
+Developer data fields are currently only _partially_ supported.
+At the moment the decoder parses Developer Data Field Descriptions, Developer Data ID Messages and Field Description Messages.
+The decoder currently discards developer data fields found in records. 
 
-Older supported profile versions:
+The encoder will currently (silently) ignore anything related to Developer data fields,
+This also means that encoding will not fail if protocol version 2 is specified for a file header.
 
-* 21.60
-* 21.40
-* 21.38
-* 21.32
-* 20.90
-* 20.43
-* 20.27
-* 20.14
-* 16.20
-
-Other profile versions may work, but have not been tested.
+Developer data fields support is tracked by
+[#21](https://github.com/tormoder/fit/issues/21)
+and
+[#64](https://github.com/tormoder/fit/issues/64).
 
 ### Features
 
@@ -79,3 +75,4 @@ $ go get github.com/tormoder/fit
 - [colinrgodsey](https://github.com/colinrgodsey)
 - [bpg](https://github.com/bpg)
 - [pieterclaerhout](https://github.com/pieterclaerhout)
+- [beyoung](https://github.com/beyoung)

consts.go

@@ -53,6 +53,7 @@ const (
 	compressedLocalMesgNumMask byte = 0x60
 
 	mesgDefinitionMask byte = 0x40
+	devDataMask        byte = 0x20
 	mesgHeaderMask     byte = 0x00
 	localMesgNumMask   byte = 0x0F
 

file.go

@@ -20,6 +20,10 @@ type File struct {
 	FileCreator          *FileCreatorMsg
 	TimestampCorrelation *TimestampCorrelationMsg
 
+	// Developer data fields.
+	fieldDescriptionMsgs []*FieldDescriptionMsg
+	developerDataIdMsgs  []*DeveloperDataIdMsg
+
 	// UnknownMessages is a slice of unknown messages encountered during
 	// decoding. It is sorted by message number.
 	UnknownMessages []UnknownMessage
@@ -73,6 +77,10 @@ func (f *File) add(msg reflect.Value) {
 		f.FileCreator = &tmp
 	case TimestampCorrelationMsg:
 		f.TimestampCorrelation = &tmp
+	case FieldDescriptionMsg:
+		f.fieldDescriptionMsgs = append(f.fieldDescriptionMsgs, &tmp)
+	case DeveloperDataIdMsg:
+		f.developerDataIdMsgs = append(f.developerDataIdMsgs, &tmp)
 	default:
 		f.msgAdder.add(msg)
 	}

reader.go

@@ -315,17 +315,18 @@ func (d *decoder) readFull(p []byte) error {
 }
 
 type defmsg struct {
-	localMsgType uint8
-	arch         binary.ByteOrder
-	globalMsgNum MesgNum
-	fields       byte
-	fieldDefs    []fieldDef
+	localMsgType      uint8
+	arch              binary.ByteOrder
+	globalMsgNum      MesgNum
+	fields            byte
+	fieldDefs         []fieldDef
+	devDataFieldDescs []devDataFieldDesc
 }
 
 func (dm defmsg) String() string {
 	return fmt.Sprintf(
-		"local: %d | global: %v | arch: %v | fields: %d",
-		dm.localMsgType, dm.globalMsgNum, dm.arch, dm.fields,
+		"local: %d | global: %v | arch: %v | fields: %d | data dev fields: %d",
+		dm.localMsgType, dm.globalMsgNum, dm.arch, dm.fields, len(dm.devDataFieldDescs),
 	)
 }
 
@@ -339,6 +340,16 @@ func (fd fieldDef) String() string {
 	return fmt.Sprintf("num: %d | size: %d | btype: %v", fd.num, fd.size, fd.btype)
 }
 
+type devDataFieldDesc struct {
+	fieldNum     byte
+	size         byte
+	devDataIndex byte
+}
+
+func (ddfd devDataFieldDesc) String() string {
+	return fmt.Sprintf("field number: %d | size: %d | developer data index: %d", ddfd.fieldNum, ddfd.size, ddfd.devDataIndex)
+}
+
 func (d *decoder) parseFileIdMsg() error {
 	b, err := d.readByte()
 	if err != nil {
@@ -452,6 +463,26 @@ func (d *decoder) parseDefinitionMessage(recordHeader byte) (*defmsg, error) {
 		dm.fieldDefs[i] = fd
 	}
 
+	if recordHeader&devDataMask == devDataMask {
+		numDevFields, err := d.readByte()
+		if err != nil {
+			return nil, fmt.Errorf("error reading number of developer data fields: %w", err)
+		}
+
+		if err = d.readFull(d.tmp[0 : 3*uint16(numDevFields)]); err != nil {
+			return nil, fmt.Errorf("error reading developer data field description data: %w", err)
+		}
+
+		dm.devDataFieldDescs = make([]devDataFieldDesc, numDevFields)
+		for i, ddfd := range dm.devDataFieldDescs {
+			ddfd.fieldNum = d.tmp[i*3]
+			ddfd.size = d.tmp[(i*3)+1]
+			ddfd.devDataIndex = d.tmp[(i*3)+2]
+			dm.devDataFieldDescs[i] = ddfd
+		}
+
+	}
+
 	if d.debug {
 		d.opts.logger.Println("definition message parsed:", dm)
 	}
@@ -669,6 +700,13 @@ func (d *decoder) parseDataFields(dm *defmsg, knownMsg bool, msgv reflect.Value)
 		}
 	}
 
+	for i, ddfd := range dm.devDataFieldDescs {
+		err := d.readFull(d.tmp[0:int(ddfd.size)])
+		if err != nil {
+			return reflect.Value{}, fmt.Errorf("error parsing data developer message: %v (field %d [%v] for [%v])", err, i, ddfd, dm)
+		}
+	}
+
 	if knownMsg && !msgv.IsValid() {
 		panic("internal decoder error: parse data fields: known message, but not (reflect) valid")
 	}

reader_files_test.go

@@ -17,7 +17,7 @@ var decodeTestFiles = [...]struct {
 		"me",
 		"activity-small-fenix2-run.fit",
 		false,
-		4159419868942230381,
+		16272604713108132935,
 		true,
 		tdoAllWithDiscardLogger,
 		true,
@@ -27,7 +27,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"Activity.fit",
 		false,
-		17200987073157828903,
+		5393063379197673570,
 		true,
 		tdoNone,
 		false,
@@ -37,7 +37,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"MonitoringFile.fit",
 		false,
-		17438554766263628503,
+		11936585269915402423,
 		true,
 		tdoNone,
 		true,
@@ -47,7 +47,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"Settings.fit",
 		false,
-		13777716833885766673,
+		18422634047426156243,
 		true,
 		tdoNone,
 		false,
@@ -57,7 +57,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"WeightScaleMultiUser.fit",
 		false,
-		5002902390457186100,
+		15668939108214135507,
 		true,
 		tdoNone,
 		false,
@@ -67,7 +67,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"WorkoutCustomTargetValues.fit",
 		false,
-		1795447305759253807,
+		14786462533817802322,
 		true,
 		tdoNone,
 		false,
@@ -77,7 +77,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"WorkoutIndividualSteps.fit",
 		false,
-		13432157117047365566,
+		5594723163894392697,
 		true,
 		tdoNone,
 		false,
@@ -87,7 +87,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"WorkoutRepeatGreaterThanStep.fit",
 		false,
-		10036597401811670605,
+		17460594330644784595,
 		true,
 		tdoNone,
 		false,
@@ -97,7 +97,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"WorkoutRepeatSteps.fit",
 		false,
-		2000919626000542509,
+		4256650519608265147,
 		true,
 		tdoNone,
 		false,
@@ -107,7 +107,7 @@ var decodeTestFiles = [...]struct {
 		"fitsdk",
 		"WeightScaleSingleUser.fit",
 		false,
-		170466418772016754,
+		16394851171432919279,
 		true,
 		tdoNone,
 		false,
@@ -117,7 +117,7 @@ var decodeTestFiles = [...]struct {
 		"python-fitparse",
 		"garmin-edge-500-activitiy.fit",
 		false,
-		6593572577964555599,
+		17514013668470756651,
 		true,
 		tdoNone,
 		false,
@@ -127,7 +127,7 @@ var decodeTestFiles = [...]struct {
 		"python-fitparse",
 		"sample-activity-indoor-trainer.fit",
 		false,
-		16971736118512546826,
+		945649812206588852,
 		true,
 		tdoNone,
 		true,
@@ -147,7 +147,7 @@ var decodeTestFiles = [...]struct {
 		"python-fitparse",
 		"antfs-dump.63.fit",
 		false,
-		17636932664957499573,
+		6282273622209975218,
 		true,
 		tdoNone,
 		true,
@@ -157,7 +157,7 @@ var decodeTestFiles = [...]struct {
 		"sram",
 		"Settings.fit",
 		false,
-		15334527618026463003,
+		5866657363356029809,
 		true,
 		tdoNone,
 		true,
@@ -167,7 +167,7 @@ var decodeTestFiles = [...]struct {
 		"sram",
 		"Settings2.fit",
 		false,
-		3203160144706376883,
+		15709312684722569429,
 		true,
 		tdoNone,
 		true,
@@ -177,7 +177,7 @@ var decodeTestFiles = [...]struct {
 		"dcrainmaker",
 		"Edge810-Vector-2013-08-16-15-35-10.fit",
 		false,
-		7445399672663916413,
+		12420128971150793206,
 		true,
 		tdoNone,
 		true,
@@ -187,7 +187,7 @@ var decodeTestFiles = [...]struct {
 		"misc",
 		"2013-02-06-12-11-14.fit",
 		false,
-		13418237519260555178,
+		11959686082894445424,
 		true,
 		tdoNone,
 		false,
@@ -197,7 +197,7 @@ var decodeTestFiles = [...]struct {
 		"misc",
 		"2015-10-13-08-43-15.fit",
 		false,
-		9824244170689694008,
+		16776362073923423348,
 		true,
 		tdoNone,
 		false,
@@ -207,7 +207,7 @@ var decodeTestFiles = [...]struct {
 		"bpg",
 		"garmin.fit",
 		false,
-		8578045933883478770,
+		11468599866908951097,
 		true,
 		tdoNone,
 		false,
@@ -217,7 +217,7 @@ var decodeTestFiles = [...]struct {
 		"corrupt",
 		"activity-filecrc.fit",
 		true,
-		1128179132232601357,
+		13015127050946751954,
 		true,
 		tdoNone,
 		false,
@@ -227,10 +227,40 @@ var decodeTestFiles = [...]struct {
 		"corrupt",
 		"activity-unexpected-eof.fit",
 		true,
-		3268441259118371812,
+		5112456444205297678,
 		true,
 		tdoNone,
 		false,
 		"",
 	},
+	{
+		"misc",
+		"0134902991.fit",
+		false,
+		1269717752691992296,
+		true,
+		tdoNone,
+		true,
+		"Contains developer data fields",
+	},
+	{
+		"misc",
+		"mornindew-broken.fit",
+		false,
+		864390381975294256,
+		true,
+		tdoNone,
+		true,
+		"Contains developer data fields",
+	},
+	{
+		"fitsdk",
+		"DeveloperData.fit",
+		false,
+		7735802126653373100,
+		true,
+		tdoNone,
+		true,
+		"Contains developer data fields",
+	},
 }