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author | Niall Sheridan <nsheridan@gmail.com> | 2018-06-20 22:39:07 +0100 |
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committer | Niall Sheridan <nsheridan@gmail.com> | 2018-06-20 22:39:07 +0100 |
commit | de6d2c524430287c699aaa898c1325da6afea539 (patch) | |
tree | f78eb841208d667668a7bc92a9290d693cc7103b /vendor/go.opencensus.io/tag/context.go | |
parent | eb99016e1629e690e55633de6fc63a14c53e7ea2 (diff) |
Update dependencies
Diffstat (limited to 'vendor/go.opencensus.io/tag/context.go')
-rw-r--r-- | vendor/go.opencensus.io/tag/context.go | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/tag/context.go b/vendor/go.opencensus.io/tag/context.go new file mode 100644 index 0000000..ed528bc --- /dev/null +++ b/vendor/go.opencensus.io/tag/context.go @@ -0,0 +1,41 @@ +// 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 "context" + +// FromContext returns the tag map stored in the context. +func FromContext(ctx context.Context) *Map { + // The returned tag map shouldn't be mutated. + ts := ctx.Value(mapCtxKey) + if ts == nil { + return nil + } + return ts.(*Map) +} + +// NewContext creates a new context with the given tag map. +// To propagate a tag map to downstream methods and downstream RPCs, add a tag map +// to the current context. NewContext will return a copy of the current context, +// and put the tag map into the returned one. +// If there is already a tag map in the current context, it will be replaced with m. +func NewContext(ctx context.Context, m *Map) context.Context { + return context.WithValue(ctx, mapCtxKey, m) +} + +type ctxKey struct{} + +var mapCtxKey = ctxKey{} |