Add Zipkin example and some new primitives

bdl/primitives.go

@@ -90,4 +90,32 @@ func ReadInt64Fixed(bytes []byte) *int64 {
 
 func WriteInt64Fixed(v int64) []byte {
 	return WriteUint64Fixed(uint64(v))
+}
+
+func ReadBool(bytes []byte) *bool {
+	var value bool
+	switch {
+	case len(bytes) != 1: return nil
+	case bytes[0] == byte(0): value = false
+	case bytes[0] == byte(1): value = true
+	default: return nil
+	}
+	return &value
+}
+
+func WriteBool(v bool) []byte {
+	if v { return []byte{1} }
+	return []byte{0}
+}
+
+func ReadTaint(bytes []byte) *bool {
+	boolValue := ReadBool(bytes)
+	if boolValue == nil { return nil }
+	*boolValue = !*boolValue
+	return boolValue
+}
+
+func WriteTaint(v bool) []byte {
+	if v { return []byte{0} }
+	return []byte{1}
 }
\ No newline at end of file

examples/zipkin.go

+package examples
+
+import (
+	"github.com/tracingplane/tracingplane-go/bdl"
+	"github.com/tracingplane/tracingplane-go/baggageprotocol"
+	"github.com/tracingplane/tracingplane-go/atomlayer"
+	"sort"
+)
+
+// An example of a class that would be generated by BDL for Zipkin
+
+type ZipkinMetadata struct {
+	traceID			*int64				// sfixed64 traceID = 0;
+	spanID			*int64				// sfixed64 spanID = 1;
+	parentSpanID	*int64				// sfixed64 parentSpanID = 2;
+	sampled			*bool				// taint sampled = 3;
+	tags			map[string](string) // map<string, string> tags = 4;
+	overflowed 		bool
+	unknown			[]atomlayer.Atom
+}
+
+
+func (zipkinMetadata *ZipkinMetadata) Read(r *baggageprotocol.Reader) {
+	// traceID
+	if r.EnterIndexed(0) {
+		zipkinMetadata.traceID = bdl.ReadInt64Fixed(r.Next());
+		r.Exit()
+	}
+
+	// spanID
+	if r.EnterIndexed(1) {
+		zipkinMetadata.spanID = bdl.ReadInt64Fixed(r.Next());
+		r.Exit()
+	}
+
+	// parentSpanID
+	if r.EnterIndexed(2) {
+		zipkinMetadata.parentSpanID = bdl.ReadInt64Fixed(r.Next());
+		r.Exit()
+	}
+
+	// sampled
+	if r.EnterIndexed(3) {
+		zipkinMetadata.sampled = bdl.ReadTaint(r.Next())
+		r.Exit()
+	}
+
+	// tags
+	if r.EnterIndexed(4) {
+		zipkinMetadata.tags = make(map[string](string))
+		for {
+			key := r.Enter()
+			if key == nil { break }
+
+			value := r.Next()
+			if value != nil {
+				tagsKey := string(key[1:])
+				tagsValue := string(value)
+				zipkinMetadata.tags[tagsKey] = tagsValue
+			}
+			r.Exit()
+		}
+	}
+
+	// Overflow
+	zipkinMetadata.overflowed = r.Overflowed
+}
+
+func (zipkinMetadata *ZipkinMetadata) Write(w *baggageprotocol.Writer) {
+	// traceID
+	if zipkinMetadata.traceID != nil {
+		w.Enter(0)
+		w.Write(bdl.WriteInt64Fixed(*zipkinMetadata.traceID))
+		w.Exit()
+	}
+
+	// spanID
+	if zipkinMetadata.spanID != nil {
+		w.Enter(1)
+		w.Write(bdl.WriteInt64Fixed(*zipkinMetadata.spanID))
+		w.Exit()
+	}
+
+	// parentSpanID
+	if zipkinMetadata.parentSpanID != nil {
+		w.Enter(2)
+		w.Write(bdl.WriteInt64Fixed(*zipkinMetadata.parentSpanID))
+		w.Exit()
+	}
+
+	// sampled
+	if zipkinMetadata.sampled != nil {
+		w.Enter(3)
+		w.Write(bdl.WriteTaint(*zipkinMetadata.sampled))
+		w.Exit()
+	}
+
+	// tags
+	if len(zipkinMetadata.tags) > 0 {
+		var tagKeys []atomlayer.Atom
+		for tagKey := range(zipkinMetadata.tags) {
+			tagKeys = append(tagKeys, atomlayer.Atom(tagKey))
+		}
+
+		sort.Sort(baggageprotocol.LexicographicAtomSorter(tagKeys))
+
+		for _,tagKey := range(tagKeys) {
+			tagValue := []byte(zipkinMetadata.tags[string(tagKey)])
+			w.EnterKey(tagKey)
+			w.Write(tagValue)
+			w.Exit()
+		}
+	}
+
+	// Overflow
+	if zipkinMetadata.overflowed {
+		w.MarkOverflow()
+	}
+}
+
+func (zipkinMetadata *ZipkinMetadata) SetUnprocessedAtoms(atoms []atomlayer.Atom) {
+	zipkinMetadata.unknown = atoms
+}
+
+func (zipkinMetadata *ZipkinMetadata) GetUnprocessedAtoms() []atomlayer.Atom {
+	return zipkinMetadata.unknown
+}
\ No newline at end of file

examples/zipkin_test.go

+package examples
+
+import (
+	"github.com/stretchr/testify/assert"
+	"github.com/tracingplane/tracingplane-go/tracingplane"
+	"testing"
+	"github.com/tracingplane/tracingplane-go/atomlayer"
+	"fmt"
+)
+
+func TestZipkin(t *testing.T) {
+	var baggage tracingplane.BaggageContext
+	baggage.Atoms = []atomlayer.Atom{
+		{248,2},
+		{240,0},
+		{0,0,0,0,0,0,0,0,55},
+		{240,1},
+		{0,0,0,0,0,0,0,0,70},
+		{240,2},
+		{0,0,0,0,0,0,0,0,10},
+	}
+
+	zmd := ZipkinMetadata{}
+	err := baggage.ReadBag(2, &zmd)
+
+	assert.Nil(t, err)
+	assert.Empty(t, zmd.unknown)
+	assert.False(t, zmd.overflowed)
+	assert.NotNil(t, zmd.traceID)
+	assert.Equal(t, int64(55), *zmd.traceID)
+	assert.NotNil(t, zmd.spanID)
+	assert.Equal(t, int64(70), *zmd.spanID)
+	assert.NotNil(t, zmd.parentSpanID)
+	assert.Equal(t, int64(10), *zmd.parentSpanID)
+
+	var baggage2 tracingplane.BaggageContext
+	baggage2.Set(2, &zmd)
+
+	assert.Equal(t, baggage.Atoms, baggage2.Atoms)
+}
\ No newline at end of file