senders

type Centroid struct {
	Value float64
	Count int
}

type DirectConfiguration struct {
	Server string // Wavefront URL of the form https://<INSTANCE>.wavefront.com
	Token  string // Wavefront API token with direct data ingestion permission

	// max batch of data sent per flush interval. defaults to 10,000. recommended not to exceed 40,000.
	BatchSize int

	// size of internal buffer beyond which received data is dropped.
	// helps with handling brief increases in data and buffering on errors.
	// separate buffers are maintained per data type (metrics, spans and distributions)
	// buffers are not pre-allocated to max size and vary based on actual usage.
	// defaults to 50,000. higher values could use more memory.
	MaxBufferSize int

	// interval (in seconds) at which to flush data to Wavefront. defaults to 1 Second.
	// together with batch size controls the max theoretical throughput of the sender.
	FlushIntervalSeconds int
}

type DistributionSender interface {
	// Sends a distribution of metrics to Wavefront with optional timestamp and tags.
	// Each centroid is a 2-dimensional entity with the first dimension the mean value
	// and the second dimension the count of points in the centroid.
	// The granularity informs the set of intervals (minute, hour, and/or day) by which the
	// histogram data should be aggregated.
	SendDistribution(name string, centroids []Centroid, hgs map[HistogramGranularity]bool, ts int64, source string, tags map[string]string) error
}

type EventSender interface {
	// Sends an event to Wavefront with optional tags
	SendEvent(name string, startMillis, endMillis int64, source string, tags map[string]string) error
}

type HistogramGranularity int8

type MetricSender interface {
	// Sends a single metric to Wavefront with optional timestamp and tags.
	SendMetric(name string, value float64, ts int64, source string, tags map[string]string) error

	// Sends a delta counter (counter aggregated at the Wavefront service) to Wavefront.
	// the timestamp for a delta counter is assigned at the server side.
	SendDeltaCounter(name string, value float64, source string, tags map[string]string) error
}

type ProxyConfiguration struct {
	Host string // the hostname of the Wavefront proxy

	MetricsPort      int // metrics port on which the proxy is listening on, typically 2878.
	DistributionPort int // distribution port on which the proxy is listening on, typically 40000.
	TracingPort      int // tracing port on which the proxy is listening on.

	FlushIntervalSeconds int // defaults to 1 second
}

type Sender interface {
	MetricSender
	DistributionSender
	SpanSender
	internal.Flusher
	Close()
}

type SpanLog struct {
	Timestamp int64
	Fields    map[string]string
}

type SpanSender interface {
	// Sends a tracing span to Wavefront.
	// traceId, spanId, parentIds and preceding spanIds are expected to be UUID strings.
	// parents and preceding spans can be empty for a root span.
	// span tag keys can be repeated (example: "user"="foo" and "user"="bar")
	// span logs are currently omitted
	SendSpan(name string, startMillis, durationMillis int64, source, traceId, spanId string, parents, followsFrom []string, tags []SpanTag, spanLogs []SpanLog) error
}

type SpanTag struct {
	Key   string
	Value string
}