43 lines
1.0 KiB
Go
43 lines
1.0 KiB
Go
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package otgrpc
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import (
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"strings"
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opentracing "github.com/opentracing/opentracing-go"
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"github.com/opentracing/opentracing-go/ext"
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"google.golang.org/grpc/metadata"
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)
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var (
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// Morally a const:
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gRPCComponentTag = opentracing.Tag{string(ext.Component), "gRPC"}
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)
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// metadataReaderWriter satisfies both the opentracing.TextMapReader and
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// opentracing.TextMapWriter interfaces.
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type metadataReaderWriter struct {
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metadata.MD
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}
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func (w metadataReaderWriter) Set(key, val string) {
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// The GRPC HPACK implementation rejects any uppercase keys here.
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//
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// As such, since the HTTP_HEADERS format is case-insensitive anyway, we
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// blindly lowercase the key (which is guaranteed to work in the
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// Inject/Extract sense per the OpenTracing spec).
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key = strings.ToLower(key)
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w.MD[key] = append(w.MD[key], val)
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}
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func (w metadataReaderWriter) ForeachKey(handler func(key, val string) error) error {
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for k, vals := range w.MD {
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for _, v := range vals {
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if err := handler(k, v); err != nil {
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return err
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}
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}
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}
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return nil
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}
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