69 lines
1.9 KiB
Go
69 lines
1.9 KiB
Go
// Package metadata is a way of defining message headers
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package metadata
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import (
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"context"
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)
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type mdIncomingKey struct{}
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type mdOutgoingKey struct{}
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type mdKey struct{}
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// FromIncomingContext returns metadata from incoming ctx
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// returned metadata shoud not be modified or race condition happens
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func FromIncomingContext(ctx context.Context) (Metadata, bool) {
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if ctx == nil {
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return nil, false
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}
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md, ok := ctx.Value(mdIncomingKey{}).(Metadata)
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return md, ok
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}
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// FromOutgoingContext returns metadata from outgoing ctx
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// returned metadata shoud not be modified or race condition happens
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func FromOutgoingContext(ctx context.Context) (Metadata, bool) {
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if ctx == nil {
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return nil, false
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}
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md, ok := ctx.Value(mdOutgoingKey{}).(Metadata)
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return md, ok
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}
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// FromContext returns metadata from the given context
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// returned metadata shoud not be modified or race condition happens
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//
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// Deprecated: use FromIncomingContext or FromOutgoingContext
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func FromContext(ctx context.Context) (Metadata, bool) {
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if ctx == nil {
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return nil, false
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}
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md, ok := ctx.Value(mdKey{}).(Metadata)
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return md, ok
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}
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// NewContext creates a new context with the given metadata
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//
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// Deprecated: use NewIncomingContext or NewOutgoingContext
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func NewContext(ctx context.Context, md Metadata) context.Context {
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if ctx == nil {
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ctx = context.Background()
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}
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return context.WithValue(ctx, mdKey{}, md)
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}
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// NewIncomingContext creates a new context with incoming metadata attached
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func NewIncomingContext(ctx context.Context, md Metadata) context.Context {
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if ctx == nil {
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ctx = context.Background()
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}
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return context.WithValue(ctx, mdIncomingKey{}, md)
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}
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// NewOutgoingContext creates a new context with outcoming metadata attached
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func NewOutgoingContext(ctx context.Context, md Metadata) context.Context {
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if ctx == nil {
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ctx = context.Background()
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}
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return context.WithValue(ctx, mdOutgoingKey{}, md)
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}
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