Method generateContinuousChanges

rest/changes_api.go:472–483

This is the core functionality of both the HTTP and WebSocket-based continuous change feed. It defers to a callback function 'send()' to actually send the changes to the client. It will call send(nil) to notify that it's caught up and waiting for new changes, or as a periodic heartbeat while waiting

(inChannels base.Set, options db.ChangesOptions, send func([]*db.ChangeEntry) error)

// It will call send(nil) to notify that it's caught up and waiting for new changes, or as
// a periodic heartbeat while waiting.
func (h *handler) generateContinuousChanges(inChannels base.Set, options db.ChangesOptions, send func([]*db.ChangeEntry) error) (error, bool) {
	// Ensure continuous is set, since generateChanges now supports both continuous and one-shot
	options.Continuous = true
	err, forceClose := db.GenerateChanges(h.ctx(), h.collection, inChannels, options, nil, send)
	if sendErr, ok := err.(*db.ChangesSendErr); ok {
		h.logStatus(http.StatusOK, fmt.Sprintf("Write error: %v", sendErr))
		return nil, forceClose // error is probably because the client closed the connection
	} else {
		h.logStatus(http.StatusOK, "OK (continuous feed closed)")
	}
	return err, forceClose
}

func (h *handler) sendContinuousChangesByHTTP(inChannels base.Set, options db.ChangesOptions) (error, bool) {
	// Setting a non-default content type will keep the client HTTP framework from trying to sniff