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-rw-r--r--vendor/go.opencensus.io/tag/map.go197
1 files changed, 197 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/tag/map.go b/vendor/go.opencensus.io/tag/map.go
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+++ b/vendor/go.opencensus.io/tag/map.go
@@ -0,0 +1,197 @@
+// Copyright 2017, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package tag
+
+import (
+ "bytes"
+ "context"
+ "fmt"
+ "sort"
+)
+
+// Tag is a key value pair that can be propagated on wire.
+type Tag struct {
+ Key Key
+ Value string
+}
+
+// Map is a map of tags. Use New to create a context containing
+// a new Map.
+type Map struct {
+ m map[Key]string
+}
+
+// Value returns the value for the key if a value for the key exists.
+func (m *Map) Value(k Key) (string, bool) {
+ if m == nil {
+ return "", false
+ }
+ v, ok := m.m[k]
+ return v, ok
+}
+
+func (m *Map) String() string {
+ if m == nil {
+ return "nil"
+ }
+ keys := make([]Key, 0, len(m.m))
+ for k := range m.m {
+ keys = append(keys, k)
+ }
+ sort.Slice(keys, func(i, j int) bool { return keys[i].Name() < keys[j].Name() })
+
+ var buffer bytes.Buffer
+ buffer.WriteString("{ ")
+ for _, k := range keys {
+ buffer.WriteString(fmt.Sprintf("{%v %v}", k.name, m.m[k]))
+ }
+ buffer.WriteString(" }")
+ return buffer.String()
+}
+
+func (m *Map) insert(k Key, v string) {
+ if _, ok := m.m[k]; ok {
+ return
+ }
+ m.m[k] = v
+}
+
+func (m *Map) update(k Key, v string) {
+ if _, ok := m.m[k]; ok {
+ m.m[k] = v
+ }
+}
+
+func (m *Map) upsert(k Key, v string) {
+ m.m[k] = v
+}
+
+func (m *Map) delete(k Key) {
+ delete(m.m, k)
+}
+
+func newMap() *Map {
+ return &Map{m: make(map[Key]string)}
+}
+
+// Mutator modifies a tag map.
+type Mutator interface {
+ Mutate(t *Map) (*Map, error)
+}
+
+// Insert returns a mutator that inserts a
+// value associated with k. If k already exists in the tag map,
+// mutator doesn't update the value.
+func Insert(k Key, v string) Mutator {
+ return &mutator{
+ fn: func(m *Map) (*Map, error) {
+ if !checkValue(v) {
+ return nil, errInvalidValue
+ }
+ m.insert(k, v)
+ return m, nil
+ },
+ }
+}
+
+// Update returns a mutator that updates the
+// value of the tag associated with k with v. If k doesn't
+// exists in the tag map, the mutator doesn't insert the value.
+func Update(k Key, v string) Mutator {
+ return &mutator{
+ fn: func(m *Map) (*Map, error) {
+ if !checkValue(v) {
+ return nil, errInvalidValue
+ }
+ m.update(k, v)
+ return m, nil
+ },
+ }
+}
+
+// Upsert returns a mutator that upserts the
+// value of the tag associated with k with v. It inserts the
+// value if k doesn't exist already. It mutates the value
+// if k already exists.
+func Upsert(k Key, v string) Mutator {
+ return &mutator{
+ fn: func(m *Map) (*Map, error) {
+ if !checkValue(v) {
+ return nil, errInvalidValue
+ }
+ m.upsert(k, v)
+ return m, nil
+ },
+ }
+}
+
+// Delete returns a mutator that deletes
+// the value associated with k.
+func Delete(k Key) Mutator {
+ return &mutator{
+ fn: func(m *Map) (*Map, error) {
+ m.delete(k)
+ return m, nil
+ },
+ }
+}
+
+// New returns a new context that contains a tag map
+// originated from the incoming context and modified
+// with the provided mutators.
+func New(ctx context.Context, mutator ...Mutator) (context.Context, error) {
+ m := newMap()
+ orig := FromContext(ctx)
+ if orig != nil {
+ for k, v := range orig.m {
+ if !checkKeyName(k.Name()) {
+ return ctx, fmt.Errorf("key:%q: %v", k, errInvalidKeyName)
+ }
+ if !checkValue(v) {
+ return ctx, fmt.Errorf("key:%q value:%q: %v", k.Name(), v, errInvalidValue)
+ }
+ m.insert(k, v)
+ }
+ }
+ var err error
+ for _, mod := range mutator {
+ m, err = mod.Mutate(m)
+ if err != nil {
+ return ctx, err
+ }
+ }
+ return NewContext(ctx, m), nil
+}
+
+// Do is similar to pprof.Do: a convenience for installing the tags
+// from the context as Go profiler labels. This allows you to
+// correlated runtime profiling with stats.
+//
+// It converts the key/values from the given map to Go profiler labels
+// and calls pprof.Do.
+//
+// Do is going to do nothing if your Go version is below 1.9.
+func Do(ctx context.Context, f func(ctx context.Context)) {
+ do(ctx, f)
+}
+
+type mutator struct {
+ fn func(t *Map) (*Map, error)
+}
+
+func (m *mutator) Mutate(t *Map) (*Map, error) {
+ return m.fn(t)
+}