datastreams

type Pathway ¶

type Pathway interface {
	// GetHash returns the hash of the pathway, representing the upstream path of the data.
	GetHash() uint64
}

func PathwayFromContext(ctx context.Context) (Pathway, bool)

type TextMapReader ¶

type TextMapReader interface {
	// ForeachKey iterates over all keys that exist in the underlying
	// carrier. It takes a callback function which will be called
	// using all key/value pairs as arguments. ForeachKey will return
	// the first error returned by the handler.
	ForeachKey(handler func(key, val string) error) error
}

TextMapReader allows iterating over sets of key/value pairs. Carriers implementing TextMapReader are compatible to be used with Datadog's TextMapPropagator.

type TextMapReaderByKey ¶

type TextMapReaderByKey interface {
	// Get returns the value for key, and whether it was present.
	Get(key string) (val string, ok bool)
}

TextMapReaderByKey is an optional interface a carrier can implement to return a single key directly. Extraction only needs the pathway key (PropagationKeyBase64), but the generic ForeachKey contract forces the carrier to produce a string value for every entry it holds. Carriers backed by many/large entries (e.g. Kafka message headers) should implement this to avoid converting every entry's value to a string on the consume hot path when only the pathway key is used.

type TextMapWriter ¶

type TextMapWriter interface {
	// Set sets the given key/value pair.
	Set(key, val string)
}

TextMapWriter allows setting key/value pairs of strings on the underlying data structure. Carriers implementing TextMapWriter are compatible to be used with Datadog's TextMapPropagator.