Add sdk/telemetry package

sdk/telemetry/attr.go

@@ -0,0 +1,58 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+// Attr is a key-value pair.
+type Attr struct {
+	Key   string `json:"key,omitempty"`
+	Value Value  `json:"value,omitempty"`
+}
+
+// String returns an Attr for a string value.
+func String(key, value string) Attr {
+	return Attr{key, StringValue(value)}
+}
+
+// Int64 returns an Attr for an int64 value.
+func Int64(key string, value int64) Attr {
+	return Attr{key, Int64Value(value)}
+}
+
+// Int returns an Attr for an int value.
+func Int(key string, value int) Attr {
+	return Int64(key, int64(value))
+}
+
+// Float64 returns an Attr for a float64 value.
+func Float64(key string, value float64) Attr {
+	return Attr{key, Float64Value(value)}
+}
+
+// Bool returns an Attr for a bool value.
+func Bool(key string, value bool) Attr {
+	return Attr{key, BoolValue(value)}
+}
+
+// Bytes returns an Attr for a []byte value.
+// The passed slice must not be changed after it is passed.
+func Bytes(key string, value []byte) Attr {
+	return Attr{key, BytesValue(value)}
+}
+
+// Slice returns an Attr for a []Value value.
+// The passed slice must not be changed after it is passed.
+func Slice(key string, value ...Value) Attr {
+	return Attr{key, SliceValue(value...)}
+}
+
+// Map returns an Attr for a map value.
+// The passed slice must not be changed after it is passed.
+func Map(key string, value ...Attr) Attr {
+	return Attr{key, MapValue(value...)}
+}
+
+// Equal returns if a is equal to b.
+func (a Attr) Equal(b Attr) bool {
+	return a.Key == b.Key && a.Value.Equal(b.Value)
+}

sdk/telemetry/attr_test.go

@@ -0,0 +1,38 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	decoded = []Attr{
+		String("user", "Alice"),
+		Bool("admin", true),
+		Int64("floor", -2),
+		Float64("impact", 0.21362),
+		Slice("reports", StringValue("Bob"), StringValue("Dave")),
+		Map("favorites", String("food", "hot dog"), Int("number", 13)),
+		Bytes("secret", []byte("NUI4RUZGRjc5ODAzODEwM0QyNjlCNjMzODEzRkM2MEM=")),
+	}
+
+	encoded = []byte(`[{"key":"user","value":{"stringValue":"Alice"}},{"key":"admin","value":{"boolValue":true}},{"key":"floor","value":{"intValue":"-2"}},{"key":"impact","value":{"doubleValue":0.21362}},{"key":"reports","value":{"arrayValue":{"values":[{"stringValue":"Bob"},{"stringValue":"Dave"}]}}},{"key":"favorites","value":{"kvlistValue":{"values":[{"key":"food","value":{"stringValue":"hot dog"}},{"key":"number","value":{"intValue":"13"}}]}}},{"key":"secret","value":{"bytesValue":"TlVJNFJVWkdSamM1T0RBek9ERXdNMFF5TmpsQ05qTXpPREV6UmtNMk1FTT0="}}]`)
+)
+
+func TestAttrUnmarshal(t *testing.T) {
+	var got []Attr
+	require.NoError(t, json.Unmarshal(encoded, &got))
+	assert.Equal(t, decoded, got)
+}
+
+func TestAttrMarshal(t *testing.T) {
+	got, err := json.Marshal(decoded)
+	require.NoError(t, err)
+	assert.Equal(t, string(encoded), string(got))
+}

sdk/telemetry/bench_test.go

@@ -0,0 +1,70 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+import (
+	"bytes"
+	"encoding/json"
+	"testing"
+	"time"
+)
+
+var (
+	traceID = [16]byte{0x1}
+
+	spanID1 = [8]byte{0x1}
+	spanID2 = [8]byte{0x2}
+
+	now      = time.Now()
+	nowPlus1 = now.Add(1 * time.Second)
+
+	spanA = &Span{
+		TraceID:      traceID,
+		SpanID:       spanID2,
+		ParentSpanID: spanID1,
+		Flags:        1,
+		Name:         "span-a",
+		StartTime:    now,
+		EndTime:      nowPlus1,
+		Status: &Status{
+			Message: "test status",
+			Code:    StatusCodeOK,
+		},
+	}
+
+	spanB = &Span{}
+
+	scopeSpans = &ScopeSpans{
+		Scope: &Scope{
+			Name:    "TestTracer",
+			Version: "v0.1.0",
+		},
+		SchemaURL: "http://go.opentelemetry.io/test",
+		Spans:     []*Span{spanA, spanB},
+	}
+)
+
+func BenchmarkJSONMarshalUnmarshal(b *testing.B) {
+	var out ScopeSpans
+
+	b.ReportAllocs()
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		var inBuf bytes.Buffer
+		enc := json.NewEncoder(&inBuf)
+		err := enc.Encode(scopeSpans)
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		payload := inBuf.Bytes()
+
+		dec := json.NewDecoder(bytes.NewReader(payload))
+		err = dec.Decode(&out)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+	_ = out
+}

sdk/telemetry/doc.go

@@ -0,0 +1,8 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+/*
+Package telemetry provides a lightweight representations of OpenTelemetry
+telemetry that is compatible with the OTLP JSON protobuf encoding.
+*/
+package telemetry

sdk/telemetry/id.go

@@ -0,0 +1,119 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+import (
+	"encoding/hex"
+	"errors"
+	"fmt"
+)
+
+const (
+	traceIDSize = 16
+	spanIDSize  = 8
+)
+
+// TraceID is a custom data type that is used for all trace IDs.
+type TraceID [traceIDSize]byte
+
+// String returns the hex string representation form of a TraceID.
+func (tid TraceID) String() string {
+	return hex.EncodeToString(tid[:])
+}
+
+// Size returns the size of the data to serialize.
+func (tid TraceID) Size() int {
+	if tid.IsEmpty() {
+		return 0
+	}
+	return traceIDSize
+}
+
+// IsEmpty returns false if id contains at least one non-zero byte.
+func (tid TraceID) IsEmpty() bool {
+	return tid == [traceIDSize]byte{}
+}
+
+// MarshalJSON converts the trace ID into a hex string enclosed in quotes.
+func (tid TraceID) MarshalJSON() ([]byte, error) {
+	if tid.IsEmpty() {
+		return []byte(`""`), nil
+	}
+	return marshalJSON(tid[:])
+}
+
+// UnmarshalJSON inflates the trace ID from hex string, possibly enclosed in
+// quotes.
+func (tid *TraceID) UnmarshalJSON(data []byte) error {
+	*tid = [traceIDSize]byte{}
+	return unmarshalJSON(tid[:], data)
+}
+
+// SpanID is a custom data type that is used for all span IDs.
+type SpanID [spanIDSize]byte
+
+// String returns the hex string representation form of a SpanID.
+func (sid SpanID) String() string {
+	return hex.EncodeToString(sid[:])
+}
+
+// Size returns the size of the data to serialize.
+func (sid SpanID) Size() int {
+	if sid.IsEmpty() {
+		return 0
+	}
+	return spanIDSize
+}
+
+// IsEmpty returns true if the span ID contains at least one non-zero byte.
+func (sid SpanID) IsEmpty() bool {
+	return sid == [spanIDSize]byte{}
+}
+
+// MarshalJSON converts span ID into a hex string enclosed in quotes.
+func (sid SpanID) MarshalJSON() ([]byte, error) {
+	if sid.IsEmpty() {
+		return []byte(`""`), nil
+	}
+	return marshalJSON(sid[:])
+}
+
+// UnmarshalJSON decodes span ID from hex string, possibly enclosed in quotes.
+func (sid *SpanID) UnmarshalJSON(data []byte) error {
+	*sid = [spanIDSize]byte{}
+	return unmarshalJSON(sid[:], data)
+}
+
+// marshalJSON converts id into a hex string enclosed in quotes.
+func marshalJSON(id []byte) ([]byte, error) {
+	// Plus 2 quote chars at the start and end.
+	hexLen := hex.EncodedLen(len(id)) + 2
+
+	b := make([]byte, hexLen)
+	hex.Encode(b[1:hexLen-1], id)
+	b[0], b[hexLen-1] = '"', '"'
+
+	return b, nil
+}
+
+// unmarshalJSON inflates trace id from hex string, possibly enclosed in quotes.
+func unmarshalJSON(dst []byte, src []byte) error {
+	if l := len(src); l >= 2 && src[0] == '"' && src[l-1] == '"' {
+		src = src[1 : l-1]
+	}
+	nLen := len(src)
+	if nLen == 0 {
+		return nil
+	}
+
+	if len(dst) != hex.DecodedLen(nLen) {
+		return errors.New("invalid length for ID")
+	}
+
+	_, err := hex.Decode(dst, src)
+	if err != nil {
+		return fmt.Errorf("cannot unmarshal ID from string '%s': %w", string(src), err)
+	}
+	return nil
+}

sdk/telemetry/number.go

@@ -0,0 +1,67 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+import (
+	"encoding/json"
+	"strconv"
+)
+
+// protoInt64 represents the protobuf encoding of integers which can be either
+// strings or integers.
+type protoInt64 int64
+
+// Int64 returns the protoInt64 as an int64.
+func (i *protoInt64) Int64() int64 { return int64(*i) }
+
+// UnmarshalJSON decodes both strings and integers.
+func (i *protoInt64) UnmarshalJSON(data []byte) error {
+	if data[0] == '"' {
+		var str string
+		if err := json.Unmarshal(data, &str); err != nil {
+			return err
+		}
+		parsedInt, err := strconv.ParseInt(str, 10, 64)
+		if err != nil {
+			return err
+		}
+		*i = protoInt64(parsedInt)
+	} else {
+		var parsedInt int64
+		if err := json.Unmarshal(data, &parsedInt); err != nil {
+			return err
+		}
+		*i = protoInt64(parsedInt)
+	}
+	return nil
+}
+
+// protoUint64 represents the protobuf encoding of integers which can be either
+// strings or integers.
+type protoUint64 uint64
+
+// Int64 returns the protoUint64 as a uint64.
+func (i *protoUint64) Uint64() uint64 { return uint64(*i) }
+
+// UnmarshalJSON decodes both strings and integers.
+func (i *protoUint64) UnmarshalJSON(data []byte) error {
+	if data[0] == '"' {
+		var str string
+		if err := json.Unmarshal(data, &str); err != nil {
+			return err
+		}
+		parsedUint, err := strconv.ParseUint(str, 10, 64)
+		if err != nil {
+			return err
+		}
+		*i = protoUint64(parsedUint)
+	} else {
+		var parsedUint uint64
+		if err := json.Unmarshal(data, &parsedUint); err != nil {
+			return err
+		}
+		*i = protoUint64(parsedUint)
+	}
+	return nil
+}

sdk/telemetry/resource.go

@@ -0,0 +1,15 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+// Resource information.
+type Resource struct {
+	// Attrs are the set of attributes that describe the resource. Attribute
+	// keys MUST be unique (it is not allowed to have more than one attribute
+	// with the same key).
+	Attrs []Attr `json:"attributes"`
+	// DroppedAttrs is the number of dropped attributes. If the value
+	// is 0, then no attributes were dropped.
+	DroppedAttrs uint32 `json:"droppedAttributesCount,omitempty"`
+}

sdk/telemetry/scope.go

@@ -0,0 +1,12 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package telemetry
+
+// Scope is the identifying values of the instrumentation scope.
+type Scope struct {
+	Name         string `json:"name,omitempty"`
+	Version      string `json:"version,omitempty"`
+	Attrs        []Attr `json:"attributes"`
+	DroppedAttrs uint32 `json:"droppedAttributesCount,omitempty"`
+}