diff options
Diffstat (limited to 'vendor/go.opentelemetry.io/otel/internal/baggage/context.go')
-rw-r--r-- | vendor/go.opentelemetry.io/otel/internal/baggage/context.go | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/internal/baggage/context.go b/vendor/go.opentelemetry.io/otel/internal/baggage/context.go new file mode 100644 index 000000000..4469700d9 --- /dev/null +++ b/vendor/go.opentelemetry.io/otel/internal/baggage/context.go @@ -0,0 +1,92 @@ +// Copyright The OpenTelemetry 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 baggage // import "go.opentelemetry.io/otel/internal/baggage" + +import "context" + +type baggageContextKeyType int + +const baggageKey baggageContextKeyType = iota + +// SetHookFunc is a callback called when storing baggage in the context. +type SetHookFunc func(context.Context, List) context.Context + +// GetHookFunc is a callback called when getting baggage from the context. +type GetHookFunc func(context.Context, List) List + +type baggageState struct { + list List + + setHook SetHookFunc + getHook GetHookFunc +} + +// ContextWithSetHook returns a copy of parent with hook configured to be +// invoked every time ContextWithBaggage is called. +// +// Passing nil SetHookFunc creates a context with no set hook to call. +func ContextWithSetHook(parent context.Context, hook SetHookFunc) context.Context { + var s baggageState + if v, ok := parent.Value(baggageKey).(baggageState); ok { + s = v + } + + s.setHook = hook + return context.WithValue(parent, baggageKey, s) +} + +// ContextWithGetHook returns a copy of parent with hook configured to be +// invoked every time FromContext is called. +// +// Passing nil GetHookFunc creates a context with no get hook to call. +func ContextWithGetHook(parent context.Context, hook GetHookFunc) context.Context { + var s baggageState + if v, ok := parent.Value(baggageKey).(baggageState); ok { + s = v + } + + s.getHook = hook + return context.WithValue(parent, baggageKey, s) +} + +// ContextWithList returns a copy of parent with baggage. Passing nil list +// returns a context without any baggage. +func ContextWithList(parent context.Context, list List) context.Context { + var s baggageState + if v, ok := parent.Value(baggageKey).(baggageState); ok { + s = v + } + + s.list = list + ctx := context.WithValue(parent, baggageKey, s) + if s.setHook != nil { + ctx = s.setHook(ctx, list) + } + + return ctx +} + +// ListFromContext returns the baggage contained in ctx. +func ListFromContext(ctx context.Context) List { + switch v := ctx.Value(baggageKey).(type) { + case baggageState: + if v.getHook != nil { + return v.getHook(ctx, v.list) + } + return v.list + default: + return nil + } +} |