mctx: refactor to no longer have parent/child logic
This commit is contained in:
Brian Picciano
parent
c98f154992
commit
467bcbe52d
113
mctx/annotate.go
113
mctx/annotate.go
@ -4,15 +4,12 @@ import (
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"context"
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"fmt"
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"sort"
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"strings"
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)
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// Annotation describes the annotation of a key/value pair made on a Context via
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// the Annotate call. The Path field is the Path of the Context on which the
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// call was made.
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// the Annotate call.
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type Annotation struct {
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Key, Value interface{}
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Path []string
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}
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type annotation struct {
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@ -23,11 +20,7 @@ type annotation struct {
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type annotationKey int
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// Annotate takes in one or more key/value pairs (kvs' length must be even) and
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// returns a Context carrying them. Annotations only exist on the local level,
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// i.e. a child and parent share different annotation namespaces.
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//
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// NOTE that annotations are preserved across NewChild calls, but are keyed
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// based on the passed in key _and_ the Context's Path.
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// returns a Context carrying them.
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func Annotate(ctx context.Context, kvs ...interface{}) context.Context {
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if len(kvs)%2 > 0 {
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panic("kvs being passed to mctx.Annotate must have an even number of elements")
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@ -43,13 +36,9 @@ func Annotate(ctx context.Context, kvs ...interface{}) context.Context {
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if prev != nil {
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root = prev.root
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}
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path := Path(ctx)
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for i := 0; i < len(kvs); i += 2 {
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curr = &annotation{
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Annotation: Annotation{
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Key: kvs[i], Value: kvs[i+1],
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Path: path,
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},
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Annotation: Annotation{Key: kvs[i], Value: kvs[i+1]},
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prev: prev,
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}
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if root == nil {
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@ -81,11 +70,7 @@ func Annotations(ctx context.Context) AnnotationSet {
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if a == nil {
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return nil
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}
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type mKey struct {
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pathHash string
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key interface{}
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}
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m := map[mKey]bool{}
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m := map[interface{}]bool{}
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var aa AnnotationSet
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for {
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@ -93,33 +78,29 @@ func Annotations(ctx context.Context) AnnotationSet {
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break
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}
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k := mKey{pathHash: pathHash(a.Path), key: a.Key}
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if m[k] {
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if m[a.Key] {
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a = a.prev
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continue
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}
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aa = append(aa, a.Annotation)
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m[k] = true
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m[a.Key] = true
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a = a.prev
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}
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return aa
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}
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// StringMapByPath is similar to StringMap, but it first maps each annotation
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// datum by its path.
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func (aa AnnotationSet) StringMapByPath() map[string]map[string]string {
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// StringMap formats each of the Annotations into strings using fmt.Sprint. If
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// any two keys format to the same string, then type information will be
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// prefaced to each one.
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func (aa AnnotationSet) StringMap() map[string]string {
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type mKey struct {
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str string
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path string
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typ string
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}
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m := map[mKey][]Annotation{}
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for _, a := range aa {
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k := mKey{
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str: fmt.Sprint(a.Key),
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path: "/" + strings.Join(a.Path, "/"),
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}
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k := mKey{str: fmt.Sprint(a.Key)}
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m[k] = append(m[k], a)
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}
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@ -150,75 +131,12 @@ func (aa AnnotationSet) StringMapByPath() map[string]map[string]string {
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}
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}
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outM := map[string]map[string]string{}
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for k, annotations := range m {
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a := annotations[0]
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if outM[k.path] == nil {
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outM[k.path] = map[string]string{}
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}
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kStr := k.str
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if k.typ != "" {
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kStr += "(" + k.typ + ")"
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}
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outM[k.path][kStr] = fmt.Sprint(a.Value)
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}
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return outM
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}
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// StringMap formats each of the Annotations into strings using fmt.Sprint. If
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// any two keys format to the same string, then path information will be
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// prefaced to each one. If they still format to the same string, then type
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// information will be prefaced to each one.
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func (aa AnnotationSet) StringMap() map[string]string {
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type mKey struct {
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str string
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path string
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typ string
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}
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m := map[mKey][]Annotation{}
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for _, a := range aa {
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k := mKey{str: fmt.Sprint(a.Key)}
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m[k] = append(m[k], a)
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}
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nextK := func(k mKey, a Annotation) mKey {
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if k.path == "" {
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k.path = "/" + strings.Join(a.Path, "/")
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} else if k.typ == "" {
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k.typ = fmt.Sprintf("%T", a.Key)
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} else {
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panic(fmt.Sprintf("mKey %#v is somehow conflicting with another", k))
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}
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return k
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}
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for {
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var any bool
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for k, annotations := range m {
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if len(annotations) == 1 {
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continue
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}
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any = true
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for _, a := range annotations {
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k2 := nextK(k, a)
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m[k2] = append(m[k2], a)
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}
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delete(m, k)
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}
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if !any {
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break
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}
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}
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outM := map[string]string{}
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for k, annotations := range m {
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a := annotations[0]
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kStr := k.str
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if k.path != "" {
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kStr += "(" + k.path + ")"
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}
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if k.typ != "" {
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kStr += "(" + k.typ + ")"
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kStr = k.typ + "(" + kStr + ")"
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}
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outM[kStr] = fmt.Sprint(a.Value)
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}
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@ -277,10 +195,9 @@ func mergeAnnotations(ctxA, ctxB context.Context) context.Context {
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// MergeAnnotations sequentially merges the annotation data of the passed in
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// Contexts into the first passed in one. Data from a Context overwrites
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// overlapping data on all passed in Contexts to the left of it (keeping in mind
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// that two Annotations must share the same Key _and_ Path to overlap). All
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// other aspects of the first Context remain the same, and that Context is
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// returned with the new set of Annotation data.
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// overlapping data on all passed in Contexts to the left of it. All other
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// aspects of the first Context remain the same, and that Context is returned
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// with the new set of Annotation data.
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//
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// NOTE this will panic if no Contexts are passed in.
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func MergeAnnotations(ctxs ...context.Context) context.Context {
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@ -8,30 +8,16 @@ import (
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)
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func TestAnnotate(t *T) {
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parent := context.Background()
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parent = Annotate(parent, "a", "foo")
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parent = Annotate(parent, "b", "bar")
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ctx := context.Background()
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ctx = Annotate(ctx, "a", "foo")
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ctx = Annotate(ctx, "b", "bar")
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ctx = Annotate(ctx, "b", "BAR")
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child := NewChild(parent, "child")
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child = Annotate(child, "a", "Foo")
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child = Annotate(child, "a", "FOO")
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child = Annotate(child, "c", "BAZ")
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parent = WithChild(parent, child)
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parentAnnotations := Annotations(parent)
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childAnnotations := Annotations(child)
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annotations := Annotations(ctx)
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massert.Require(t,
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massert.Length(parentAnnotations, 2),
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massert.HasValue(parentAnnotations, Annotation{Key: "a", Value: "foo"}),
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massert.HasValue(parentAnnotations, Annotation{Key: "b", Value: "bar"}),
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massert.Length(childAnnotations, 4),
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massert.HasValue(childAnnotations, Annotation{Key: "a", Value: "foo"}),
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massert.HasValue(childAnnotations, Annotation{Key: "b", Value: "bar"}),
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massert.HasValue(childAnnotations,
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Annotation{Key: "a", Path: []string{"child"}, Value: "FOO"}),
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massert.HasValue(childAnnotations,
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Annotation{Key: "c", Path: []string{"child"}, Value: "BAZ"}),
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massert.Length(annotations, 2),
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massert.HasValue(annotations, Annotation{Key: "a", Value: "foo"}),
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massert.HasValue(annotations, Annotation{Key: "b", Value: "BAR"}),
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)
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}
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@ -39,32 +25,19 @@ func TestAnnotationsStringMap(t *T) {
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type A int
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type B int
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aa := AnnotationSet{
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{Key: 0, Path: nil, Value: "zero"},
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{Key: 1, Path: nil, Value: "one"},
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{Key: 1, Path: []string{"foo"}, Value: "ONE"},
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{Key: A(2), Path: []string{"foo"}, Value: "two"},
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{Key: B(2), Path: []string{"foo"}, Value: "TWO"},
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{Key: 0, Value: "zero"},
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{Key: 1, Value: "one"},
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{Key: A(2), Value: "two"},
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{Key: B(2), Value: "TWO"},
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}
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massert.Require(t,
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massert.Equal(map[string]string{
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"0": "zero",
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"1(/)": "one",
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"1(/foo)": "ONE",
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"2(/foo)(mctx.A)": "two",
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"2(/foo)(mctx.B)": "TWO",
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}, aa.StringMap()),
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massert.Equal(map[string]map[string]string{
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"/": {
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"0": "zero",
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"1": "one",
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},
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"/foo": {
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"1": "ONE",
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"2(mctx.A)": "two",
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"2(mctx.B)": "TWO",
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},
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}, aa.StringMapByPath()),
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"mctx.A(2)": "two",
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"mctx.B(2)": "TWO",
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}, aa.StringMap()),
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)
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}
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298
mctx/ctx.go
298
mctx/ctx.go
@ -1,298 +0,0 @@
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// Package mctx extends the builtin context package to organize Contexts into a
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// hierarchy.
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//
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// All functions and methods in this package are thread-safe unless otherwise
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// noted.
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//
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// Parents and children
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//
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// Each node in the hierarchy is given a name and is aware of all of its
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// ancestors. The sequence of ancestor's names, ending in the node's name, is
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// called its "path". For example:
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//
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// ctx := context.Background()
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// ctxA := mctx.NewChild(ctx, "A")
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// ctxB := mctx.NewChild(ctx, "B")
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// fmt.Printf("ctx:%#v\n", mctx.Path(ctx)) // prints "ctx:[]string(nil)"
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// fmt.Printf("ctxA:%#v\n", mctx.Path(ctxA)) // prints "ctxA:[]string{"A"}
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// fmt.Printf("ctxB:%#v\n", mctx.Path(ctxB)) // prints "ctxA:[]string{"A", "B"}
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//
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// WithChild can be used to incorporate a child into its parent, making the
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// parent's children iterable on it:
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//
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// ctx := context.Background()
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// ctxA1 := mctx.NewChild(ctx, "A1")
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// ctxA2 := mctx.NewChild(ctx, "A2")
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// ctx = mctx.WithChild(ctx, ctxA1)
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// ctx = mctx.WithChild(ctx, ctxA2)
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// for _, childCtx := range mctx.Children(ctx) {
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// fmt.Printf("%q\n", mctx.Name(childCtx)) // prints "A1" then "A2"
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// }
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//
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// Key/Value
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//
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// The context's key/value namespace is split into two: a space local to a node,
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// not inherited from its parent or inheritable by its children
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// (WithLocalValue), and the original one which comes with the builtin context
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// package (context.WithValue):
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//
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// ctx := context.Background()
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// ctx = context.WithValue(ctx, "inheritableKey", "foo")
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// ctx = mctx.WithLocalValue(ctx, "localKey", "bar")
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// childCtx := mctx.NewChild(ctx, "child")
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//
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// // ctx.Value("inheritableKey") == "foo"
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// // child.Value("inheritableKey") == "foo"
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// // mctx.LocalValue(ctx, "localKey") == "bar"
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// // mctx.LocalValue(child, "localKey") == nil
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//
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// Annotations
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//
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// Annotations are a special case of local key/values, where the data being
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// stored is specifically runtime metadata which would be useful for logging,
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// error output, etc... Annotation data might include an IP address of a
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// connected client, a userID the client has authenticated as, the primary key
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// of a row in a database being queried, etc...
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//
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// Annotations are always tied to the path of the node they were set on, so that
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// even when the annotations of two contexts are merged the annotation data will
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// not overlap unless the contexts have the same path.
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package mctx
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import (
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"context"
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"crypto/sha256"
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"encoding/hex"
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"fmt"
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)
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////////////////////////////////////////////////////////////////////////////////
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type ancestryKey int // 0 -> children, 1 -> parent, 2 -> path
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const (
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ancestryKeyChildren ancestryKey = iota
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ancestryKeyChildrenMap
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ancestryKeyParent
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ancestryKeyPath
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)
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// Child returns the Context of the given name which was added to parent via
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// WithChild, or nil if no Context of that name was ever added.
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func Child(parent context.Context, name string) context.Context {
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childrenMap, _ := parent.Value(ancestryKeyChildrenMap).(map[string]int)
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if len(childrenMap) == 0 {
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return nil
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}
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i, ok := childrenMap[name]
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if !ok {
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return nil
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}
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return parent.Value(ancestryKeyChildren).([]context.Context)[i]
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}
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// Children returns all children of this Context which have been added by
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// WithChild, in the order they were added. If this Context wasn't produced by
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// WithChild then this returns nil.
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func Children(parent context.Context) []context.Context {
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children, _ := parent.Value(ancestryKeyChildren).([]context.Context)
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return children
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}
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func childrenCP(parent context.Context) ([]context.Context, map[string]int) {
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children := Children(parent)
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// plus 1 because this is most commonly used in WithChild, which will append
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// to it. At any rate it doesn't hurt anything.
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outChildren := make([]context.Context, len(children), len(children)+1)
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copy(outChildren, children)
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childrenMap, _ := parent.Value(ancestryKeyChildrenMap).(map[string]int)
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outChildrenMap := make(map[string]int, len(childrenMap)+1)
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for name, i := range childrenMap {
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outChildrenMap[name] = i
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}
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return outChildren, outChildrenMap
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}
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// parentOf returns the Context from which this one was generated via NewChild.
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// Returns nil if this Context was not generated via NewChild.
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//
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// This is kept private because the behavior is a bit confusing. This will
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// return the Context which was passed into NewChild, but users would probably
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// expect it to return the one from WithChild if they were to call this.
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func parentOf(ctx context.Context) context.Context {
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parent, _ := ctx.Value(ancestryKeyParent).(context.Context)
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return parent
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}
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// Path returns the sequence of names which were used to produce this Context
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// via the NewChild function. If this Context wasn't produced by NewChild then
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// this returns nil.
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func Path(ctx context.Context) []string {
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path, _ := ctx.Value(ancestryKeyPath).([]string)
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return path
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}
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func pathCP(ctx context.Context) []string {
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path := Path(ctx)
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// plus 1 because this is most commonly used in NewChild, which will append
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// to it. At any rate it doesn't hurt anything.
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outPath := make([]string, len(path), len(path)+1)
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copy(outPath, path)
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return outPath
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}
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func pathHash(path []string) string {
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pathHash := sha256.New()
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for _, pathEl := range path {
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fmt.Fprintf(pathHash, "%q.", pathEl)
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}
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return hex.EncodeToString(pathHash.Sum(nil))
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}
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// Name returns the name this Context was created with via NewChild, or false if
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// this Context was not created via NewChild.
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func Name(ctx context.Context) (string, bool) {
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path := Path(ctx)
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if len(path) == 0 {
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return "", false
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}
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return path[len(path)-1], true
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}
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// NewChild creates and returns a new Context based off of the parent one. The
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// child will have a path which is the parent's path appended with the given
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// name. In order for the parent to "see" the child (via the Child or Children
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// functions) the WithChild function must be used.
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//
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// If the parent already has a child of the given name this function panics.
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func NewChild(parent context.Context, name string) context.Context {
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if Child(parent, name) != nil {
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panic(fmt.Sprintf("child with name %q already exists on parent", name))
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}
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childPath := append(pathCP(parent), name)
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child := withoutLocalValues(parent)
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child = context.WithValue(child, ancestryKeyChildren, nil) // unset children
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child = context.WithValue(child, ancestryKeyChildrenMap, nil) // unset children
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child = context.WithValue(child, ancestryKeyParent, parent)
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child = context.WithValue(child, ancestryKeyPath, childPath)
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return child
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}
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func isChild(parent, child context.Context) bool {
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parentPath, childPath := Path(parent), Path(child)
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if len(parentPath) != len(childPath)-1 {
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return false
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}
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for i := range parentPath {
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if parentPath[i] != childPath[i] {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// WithChild returns a modified parent which holds a reference to child in its
|
||||
// Children list. If the child's name is already taken in the parent then this
|
||||
// function panics.
|
||||
func WithChild(parent, child context.Context) context.Context {
|
||||
if !isChild(parent, child) {
|
||||
panic(fmt.Sprintf("child cannot be kept by Context which is not its parent"))
|
||||
}
|
||||
|
||||
name, _ := Name(child)
|
||||
children, childrenMap := childrenCP(parent)
|
||||
if _, ok := childrenMap[name]; ok {
|
||||
panic(fmt.Sprintf("child with name %q already exists on parent", name))
|
||||
}
|
||||
children = append(children, child)
|
||||
childrenMap[name] = len(children) - 1
|
||||
|
||||
parent = context.WithValue(parent, ancestryKeyChildren, children)
|
||||
parent = context.WithValue(parent, ancestryKeyChildrenMap, childrenMap)
|
||||
return parent
|
||||
}
|
||||
|
||||
// BreadthFirstVisit visits this Context and all of its children, and their
|
||||
// children, etc... in a breadth-first order. If the callback returns false then
|
||||
// the function returns without visiting any more Contexts.
|
||||
func BreadthFirstVisit(ctx context.Context, callback func(context.Context) bool) {
|
||||
queue := []context.Context{ctx}
|
||||
for len(queue) > 0 {
|
||||
if !callback(queue[0]) {
|
||||
return
|
||||
}
|
||||
for _, child := range Children(queue[0]) {
|
||||
queue = append(queue, child)
|
||||
}
|
||||
queue = queue[1:]
|
||||
}
|
||||
}
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
// local value stuff
|
||||
|
||||
type localValsKey int
|
||||
|
||||
type localVal struct {
|
||||
prev *localVal
|
||||
key, val interface{}
|
||||
}
|
||||
|
||||
// WithLocalValue is like context.WithValue, but the stored value will not be
|
||||
// present on any children created via NewChild. Local values must be retrieved
|
||||
// with the LocalValue function in this package. Local values share a different
|
||||
// namespace than the normal WithValue/Value values (i.e. they do not overlap).
|
||||
func WithLocalValue(ctx context.Context, key, val interface{}) context.Context {
|
||||
prev, _ := ctx.Value(localValsKey(0)).(*localVal)
|
||||
return context.WithValue(ctx, localValsKey(0), &localVal{
|
||||
prev: prev,
|
||||
key: key, val: val,
|
||||
})
|
||||
}
|
||||
|
||||
func withoutLocalValues(ctx context.Context) context.Context {
|
||||
return context.WithValue(ctx, localValsKey(0), nil)
|
||||
}
|
||||
|
||||
// LocalValue returns the value for the given key which was set by a call to
|
||||
// WithLocalValue, or nil if no value was set for the given key.
|
||||
func LocalValue(ctx context.Context, key interface{}) interface{} {
|
||||
lv, _ := ctx.Value(localValsKey(0)).(*localVal)
|
||||
for {
|
||||
if lv == nil {
|
||||
return nil
|
||||
} else if lv.key == key {
|
||||
return lv.val
|
||||
}
|
||||
lv = lv.prev
|
||||
}
|
||||
}
|
||||
|
||||
func localValuesIter(ctx context.Context, callback func(key, val interface{})) {
|
||||
m := map[interface{}]struct{}{}
|
||||
lv, _ := ctx.Value(localValsKey(0)).(*localVal)
|
||||
for {
|
||||
if lv == nil {
|
||||
return
|
||||
} else if _, ok := m[lv.key]; !ok {
|
||||
callback(lv.key, lv.val)
|
||||
m[lv.key] = struct{}{}
|
||||
}
|
||||
lv = lv.prev
|
||||
}
|
||||
}
|
||||
|
||||
// LocalValues returns all key/value pairs which have been set on the Context
|
||||
// via WithLocalValue.
|
||||
func LocalValues(ctx context.Context) map[interface{}]interface{} {
|
||||
m := map[interface{}]interface{}{}
|
||||
localValuesIter(ctx, func(key, val interface{}) {
|
||||
m[key] = val
|
||||
})
|
||||
return m
|
||||
}
|
||||
156
mctx/ctx_test.go
156
mctx/ctx_test.go
@ -1,156 +0,0 @@
|
||||
package mctx
|
||||
|
||||
import (
|
||||
"context"
|
||||
. "testing"
|
||||
|
||||
"github.com/mediocregopher/mediocre-go-lib/mtest/massert"
|
||||
)
|
||||
|
||||
func TestInheritance(t *T) {
|
||||
ctx := context.Background()
|
||||
ctx1 := NewChild(ctx, "1")
|
||||
ctx1a := NewChild(ctx1, "a")
|
||||
ctx1b := NewChild(ctx1, "b")
|
||||
ctx1 = WithChild(ctx1, ctx1a)
|
||||
ctx1 = WithChild(ctx1, ctx1b)
|
||||
ctx2 := NewChild(ctx, "2")
|
||||
ctx = WithChild(ctx, ctx1)
|
||||
ctx = WithChild(ctx, ctx2)
|
||||
|
||||
massert.Require(t,
|
||||
massert.Length(Path(ctx), 0),
|
||||
massert.Equal(Path(ctx1), []string{"1"}),
|
||||
massert.Equal(Path(ctx1a), []string{"1", "a"}),
|
||||
massert.Equal(Path(ctx1b), []string{"1", "b"}),
|
||||
massert.Equal(Path(ctx2), []string{"2"}),
|
||||
)
|
||||
|
||||
massert.Require(t,
|
||||
massert.Equal([]context.Context{ctx1, ctx2}, Children(ctx)),
|
||||
massert.Equal([]context.Context{ctx1a, ctx1b}, Children(ctx1)),
|
||||
massert.Length(Children(ctx2), 0),
|
||||
)
|
||||
}
|
||||
|
||||
func TestBreadFirstVisit(t *T) {
|
||||
ctx := context.Background()
|
||||
ctx1 := NewChild(ctx, "1")
|
||||
ctx1a := NewChild(ctx1, "a")
|
||||
ctx1b := NewChild(ctx1, "b")
|
||||
ctx1 = WithChild(ctx1, ctx1a)
|
||||
ctx1 = WithChild(ctx1, ctx1b)
|
||||
ctx2 := NewChild(ctx, "2")
|
||||
ctx = WithChild(ctx, ctx1)
|
||||
ctx = WithChild(ctx, ctx2)
|
||||
|
||||
{
|
||||
got := make([]context.Context, 0, 5)
|
||||
BreadthFirstVisit(ctx, func(ctx context.Context) bool {
|
||||
got = append(got, ctx)
|
||||
return true
|
||||
})
|
||||
massert.Require(t,
|
||||
massert.Equal([]context.Context{ctx, ctx1, ctx2, ctx1a, ctx1b}, got),
|
||||
)
|
||||
}
|
||||
|
||||
{
|
||||
got := make([]context.Context, 0, 3)
|
||||
BreadthFirstVisit(ctx, func(ctx context.Context) bool {
|
||||
if len(Path(ctx)) > 1 {
|
||||
return false
|
||||
}
|
||||
got = append(got, ctx)
|
||||
return true
|
||||
})
|
||||
massert.Require(t,
|
||||
massert.Equal([]context.Context{ctx, ctx1, ctx2}, got),
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
func TestLocalValues(t *T) {
|
||||
|
||||
// test with no value set
|
||||
ctx := context.Background()
|
||||
massert.Require(t,
|
||||
massert.Nil(LocalValue(ctx, "foo")),
|
||||
massert.Length(LocalValues(ctx), 0),
|
||||
)
|
||||
|
||||
// test basic value retrieval
|
||||
ctx = WithLocalValue(ctx, "foo", "bar")
|
||||
massert.Require(t,
|
||||
massert.Equal("bar", LocalValue(ctx, "foo")),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "bar"},
|
||||
LocalValues(ctx),
|
||||
),
|
||||
)
|
||||
|
||||
// test that doesn't conflict with WithValue
|
||||
ctx = context.WithValue(ctx, "foo", "WithValue bar")
|
||||
massert.Require(t,
|
||||
massert.Equal("bar", LocalValue(ctx, "foo")),
|
||||
massert.Equal("WithValue bar", ctx.Value("foo")),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "bar"},
|
||||
LocalValues(ctx),
|
||||
),
|
||||
)
|
||||
|
||||
// test that child doesn't get values
|
||||
child := NewChild(ctx, "child")
|
||||
massert.Require(t,
|
||||
massert.Equal("bar", LocalValue(ctx, "foo")),
|
||||
massert.Nil(LocalValue(child, "foo")),
|
||||
massert.Length(LocalValues(child), 0),
|
||||
)
|
||||
|
||||
// test that values on child don't affect parent values
|
||||
child = WithLocalValue(child, "foo", "child bar")
|
||||
ctx = WithChild(ctx, child)
|
||||
massert.Require(t,
|
||||
massert.Equal("bar", LocalValue(ctx, "foo")),
|
||||
massert.Equal("child bar", LocalValue(child, "foo")),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "bar"},
|
||||
LocalValues(ctx),
|
||||
),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "child bar"},
|
||||
LocalValues(child),
|
||||
),
|
||||
)
|
||||
|
||||
// test that two With calls on the same context generate distinct contexts
|
||||
childA := WithLocalValue(child, "foo2", "baz")
|
||||
childB := WithLocalValue(child, "foo2", "buz")
|
||||
massert.Require(t,
|
||||
massert.Equal("bar", LocalValue(ctx, "foo")),
|
||||
massert.Equal("child bar", LocalValue(child, "foo")),
|
||||
massert.Nil(LocalValue(child, "foo2")),
|
||||
massert.Equal("baz", LocalValue(childA, "foo2")),
|
||||
massert.Equal("buz", LocalValue(childB, "foo2")),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "child bar", "foo2": "baz"},
|
||||
LocalValues(childA),
|
||||
),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "child bar", "foo2": "buz"},
|
||||
LocalValues(childB),
|
||||
),
|
||||
)
|
||||
|
||||
// if a value overwrites a previous one the newer one should show in
|
||||
// LocalValues
|
||||
ctx = WithLocalValue(ctx, "foo", "barbar")
|
||||
massert.Require(t,
|
||||
massert.Equal("barbar", LocalValue(ctx, "foo")),
|
||||
massert.Equal(
|
||||
map[interface{}]interface{}{"foo": "barbar"},
|
||||
LocalValues(ctx),
|
||||
),
|
||||
)
|
||||
}
|
||||
15
mctx/mctx.go
Normal file
15
mctx/mctx.go
Normal file
@ -0,0 +1,15 @@
|
||||
// Package mctx extends the builtin context package to add easy-to-use
|
||||
// annotation functionality, which is useful for logging and errors.
|
||||
//
|
||||
// All functions and methods in this package are thread-safe unless otherwise
|
||||
// noted.
|
||||
//
|
||||
// Annotations
|
||||
//
|
||||
// Annotations are a special case of key/values, where the data being
|
||||
// stored is specifically runtime metadata which would be useful for logging,
|
||||
// error output, etc... Annotation data might include an IP address of a
|
||||
// connected client, a userID the client has authenticated as, the primary key
|
||||
// of a row in a database being queried, etc...
|
||||
//
|
||||
package mctx
|
||||
Loading…
Reference in New Issue
Block a user