Interface Filter

api.go:86–100

Filter represents a data filter; a filter is a function that processes records. A filter can discard, transform, forward and even create records.

// Filter represents a data filter; a filter is a function that processes
// records. A filter can discard, transform, forward and even create records.
type Filter interface {
	// Process processes a single Record, and then optionally sends it to
	// next filter in the chain.
	// Process might mutate the Record, adding/modifying/removing fields,
	// and might decide to throw it away, or pass it to next filter in chain
	// by calling the next() function. In some cases, a filter might generate
	// multiple Record in output, by calling next() multiple times.
	// next() is guaranteed to be non-nil; for the last filter of the chain,
	// it points to a function that wraps up the filtering chain and sends
	// the Record to the output.
	Process(l Record, next func(Record))

	// Stats returns stats about the filter
	Stats() FilterStats
}

// Output is the final end of a topology, it process the records that have
// reached the end of the filter chain and performs the final action (storing,