Reorganize propagation code (shrink PR 381) (#444)

* Rename distributedcontext package to correlation Correlation is the name we agreed upon. * Move trace propagators to api/trace The trace propagators tests had to be moved to a testtrace subpackage to avoid import cycles between api/trace and internal/trace. Needed to shut up golint about stutter in trace.TraceContext - TraceContext is a name of a W3C spec, so this stutter is expected. It's certainly still better than golint's suggestion of having trace.Context. * Rename api/propagators to api/propagation This package will not contain any propagators in the long run, just the interface definitions. Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>
open-telemetry · Jan 28, 2020 · 6b4acf4 · 6b4acf4
1 parent 437d9af
commit 6b4acf4
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Showing 30 changed files with 271 additions and 312 deletions.
diff --git a/api/correlation/context.go b/api/correlation/context.go
@@ -0,0 +1,31 @@
+package correlation
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/api/core"
+)
+
+type correlationsType struct{}
+
+var correlationsKey = &correlationsType{}
+
+// WithMap enters a Map into a new Context.
+func WithMap(ctx context.Context, m Map) context.Context {
+	return context.WithValue(ctx, correlationsKey, m)
+}
+
+// WithMap enters a key:value set into a new Context.
+func NewContext(ctx context.Context, keyvalues ...core.KeyValue) context.Context {
+	return WithMap(ctx, FromContext(ctx).Apply(MapUpdate{
+		MultiKV: keyvalues,
+	}))
+}
+
+// FromContext gets the current Map from a Context.
+func FromContext(ctx context.Context) Map {
+	if m, ok := ctx.Value(correlationsKey).(Map); ok {
+		return m
+	}
+	return NewEmptyMap()
+}
diff --git a/api/distributedcontext/map.go → api/correlation/map.go b/api/distributedcontext/map.go → api/correlation/map.go
@@ -12,12 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package distributedcontext
+package correlation
 
 import (
 	"go.opentelemetry.io/otel/api/core"
 )
 
+// TODO Comments needed! This was formerly known as distributedcontext.Map
+
 type entry struct {
 	value core.Value
 }

diff --git a/api/distributedcontext/map_test.go → api/correlation/map_test.go b/api/distributedcontext/map_test.go → api/correlation/map_test.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package distributedcontext
+package correlation
 
 import (
 	"fmt"

diff --git a/api/distributedcontext/context.go b/api/distributedcontext/context.go
diff --git a/api/propagators/binary_propagator.go → api/propagation/binary_propagator.go b/api/propagators/binary_propagator.go → api/propagation/binary_propagator.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package propagators
+package propagation
 
 import (
 	"go.opentelemetry.io/otel/api/core"

diff --git a/api/propagators/binary_propagator_test.go → api/propagation/binary_propagator_test.go b/api/propagators/binary_propagator_test.go → api/propagation/binary_propagator_test.go
@@ -12,22 +12,22 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package propagators_test
+package propagation_test
 
 import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
 
 	"go.opentelemetry.io/otel/api/core"
-	"go.opentelemetry.io/otel/api/propagators"
+	"go.opentelemetry.io/otel/api/propagation"
 )
 
 func TestExtractSpanContextFromBytes(t *testing.T) {
 	traceID, _ := core.TraceIDFromHex("4bf92f3577b34da6a3ce929d0e0e4736")
 	spanID, _ := core.SpanIDFromHex("00f067aa0ba902b7")
 
-	propagator := propagators.Binary()
+	propagator := propagation.Binary()
 	tests := []struct {
 		name   string
 		bytes  []byte
@@ -123,7 +123,7 @@ func TestConvertSpanContextToBytes(t *testing.T) {
 	traceID, _ := core.TraceIDFromHex("4bf92f3577b34da6a3ce929d0e0e4736")
 	spanID, _ := core.SpanIDFromHex("00f067aa0ba902b7")
 
-	propagator := propagators.Binary()
+	propagator := propagation.Binary()
 	tests := []struct {
 		name  string
 		sc    core.SpanContext

diff --git a/api/distributedcontext/doc.go → api/propagation/doc.go b/api/distributedcontext/doc.go → api/propagation/doc.go
@@ -12,4 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package distributedcontext // import "go.opentelemetry.io/otel/api/distributedcontext"
+// Package propagation contains interface definition for BinaryFormat and
+// TextFormat propagators.
+package propagation // import "go.opentelemetry.io/otel/api/propagation"
diff --git a/api/propagators/text_noop_propagator.go → api/propagation/text_noop_propagator.go b/api/propagators/text_noop_propagator.go → api/propagation/text_noop_propagator.go
@@ -12,13 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package propagators
+package propagation
 
 import (
 	"context"
 
 	"go.opentelemetry.io/otel/api/core"
-	dctx "go.opentelemetry.io/otel/api/distributedcontext"
+	"go.opentelemetry.io/otel/api/correlation"
 )
 
 // NoopTextFormat implements TextFormat that does nothing.
@@ -31,8 +31,8 @@ func (np NoopTextFormat) Inject(ctx context.Context, supplier Supplier) {
 }
 
 // Extract does nothing and returns an empty SpanContext
-func (np NoopTextFormat) Extract(ctx context.Context, supplier Supplier) (core.SpanContext, dctx.Map) {
-	return core.EmptySpanContext(), dctx.NewEmptyMap()
+func (np NoopTextFormat) Extract(ctx context.Context, supplier Supplier) (core.SpanContext, correlation.Map) {
+	return core.EmptySpanContext(), correlation.NewEmptyMap()
 }
 
 // GetAllKeys returns empty list of strings.

diff --git a/api/propagators/text_propagator.go → api/propagation/text_propagator.go b/api/propagators/text_propagator.go → api/propagation/text_propagator.go
@@ -12,13 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package propagators
+package propagation
 
 import (
 	"context"
 
 	"go.opentelemetry.io/otel/api/core"
-	dctx "go.opentelemetry.io/otel/api/distributedcontext"
+	"go.opentelemetry.io/otel/api/correlation"
 )
 
 // TextFormat is an interface that specifies methods to inject and extract SpanContext
@@ -33,10 +33,10 @@ type TextFormat interface {
 	Inject(ctx context.Context, supplier Supplier)
 
 	// Extract method retrieves encoded SpanContext using supplier from the associated carrier.
-	// It decodes the SpanContext and returns it and a dctx of correlated context.
+	// It decodes the SpanContext and returns it and a baggage of correlated context.
 	// If no SpanContext was retrieved OR if the retrieved SpanContext is invalid then
 	// an empty SpanContext is returned.
-	Extract(ctx context.Context, supplier Supplier) (core.SpanContext, dctx.Map)
+	Extract(ctx context.Context, supplier Supplier) (core.SpanContext, correlation.Map)
 
 	// GetAllKeys returns all the keys that this propagator injects/extracts into/from a
 	// carrier. The use cases for this are

diff --git a/api/propagators/doc.go b/api/propagators/doc.go
diff --git a/api/propagators/b3_propagator.go → api/trace/b3_propagator.go b/api/propagators/b3_propagator.go → api/trace/b3_propagator.go
@@ -12,16 +12,16 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package propagators
+package trace
 
 import (
 	"context"
 	"fmt"
 	"strings"
 
 	"go.opentelemetry.io/otel/api/core"
-	dctx "go.opentelemetry.io/otel/api/distributedcontext"
-	"go.opentelemetry.io/otel/api/trace"
+	"go.opentelemetry.io/otel/api/correlation"
+	"go.opentelemetry.io/otel/api/propagation"
 )
 
 const (
@@ -50,10 +50,10 @@ type B3 struct {
 	SingleHeader bool
 }
 
-var _ TextFormat = B3{}
+var _ propagation.TextFormat = B3{}
 
-func (b3 B3) Inject(ctx context.Context, supplier Supplier) {
-	sc := trace.SpanFromContext(ctx).SpanContext()
+func (b3 B3) Inject(ctx context.Context, supplier propagation.Supplier) {
+	sc := SpanFromContext(ctx).SpanContext()
 	if sc.IsValid() {
 		if b3.SingleHeader {
 			sampled := sc.TraceFlags & core.TraceFlagsSampled
@@ -76,11 +76,11 @@ func (b3 B3) Inject(ctx context.Context, supplier Supplier) {
 }
 
 // Extract retrieves B3 Headers from the supplier
-func (b3 B3) Extract(ctx context.Context, supplier Supplier) (core.SpanContext, dctx.Map) {
+func (b3 B3) Extract(ctx context.Context, supplier propagation.Supplier) (core.SpanContext, correlation.Map) {
 	if b3.SingleHeader {
-		return b3.extractSingleHeader(supplier), dctx.NewEmptyMap()
+		return b3.extractSingleHeader(supplier), correlation.NewEmptyMap()
 	}
-	return b3.extract(supplier), dctx.NewEmptyMap()
+	return b3.extract(supplier), correlation.NewEmptyMap()
 }
 
 func (b3 B3) GetAllKeys() []string {
@@ -90,7 +90,7 @@ func (b3 B3) GetAllKeys() []string {
 	return []string{B3TraceIDHeader, B3SpanIDHeader, B3SampledHeader}
 }
 
-func (b3 B3) extract(supplier Supplier) core.SpanContext {
+func (b3 B3) extract(supplier propagation.Supplier) core.SpanContext {
 	tid, err := core.TraceIDFromHex(supplier.Get(B3TraceIDHeader))
 	if err != nil {
 		return core.EmptySpanContext()
@@ -125,7 +125,7 @@ func (b3 B3) extract(supplier Supplier) core.SpanContext {
 	return sc
 }
 
-func (b3 B3) extractSingleHeader(supplier Supplier) core.SpanContext {
+func (b3 B3) extractSingleHeader(supplier propagation.Supplier) core.SpanContext {
 	h := supplier.Get(B3SingleHeader)
 	if h == "" || h == "0" {
 		core.EmptySpanContext()

diff --git a/...opagators/b3_propagator_benchmark_test.go → ...testtrace/b3_propagator_benchmark_test.go b/...opagators/b3_propagator_benchmark_test.go → ...testtrace/b3_propagator_benchmark_test.go
@@ -12,14 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package propagators_test
+package testtrace_test
 
 import (
 	"context"
 	"net/http"
 	"testing"
 
-	"go.opentelemetry.io/otel/api/propagators"
 	"go.opentelemetry.io/otel/api/trace"
 	mocktrace "go.opentelemetry.io/otel/internal/trace"
 )
@@ -53,7 +52,7 @@ func BenchmarkExtractB3(b *testing.B) {
 	}
 
 	for _, tg := range testGroup {
-		propagator := propagators.B3{SingleHeader: tg.singleHeader}
+		propagator := trace.B3{SingleHeader: tg.singleHeader}
 		for _, tt := range tg.tests {
 			traceBenchmark(tg.name+"/"+tt.name, b, func(b *testing.B) {
 				ctx := context.Background()
@@ -97,7 +96,7 @@ func BenchmarkInjectB3(b *testing.B) {
 
 	for _, tg := range testGroup {
 		id = 0
-		propagator := propagators.B3{SingleHeader: tg.singleHeader}
+		propagator := trace.B3{SingleHeader: tg.singleHeader}
 		for _, tt := range tg.tests {
 			traceBenchmark(tg.name+"/"+tt.name, b, func(b *testing.B) {
 				req, _ := http.NewRequest("GET", "http://example.com", nil)