Struct FloatHistogram

model/histogram/float_histogram.go:33–62

FloatHistogram is similar to Histogram but uses float64 for all counts. Additionally, bucket counts are absolute and not deltas. A FloatHistogram is needed by PromQL to handle operations that might result in fractional counts. Since the counts in a histogram are unlikely to be too large to be repre

// used to represent a histogram with integer counts and thus serves as a more
// generalized representation.
type FloatHistogram struct {
	// Counter reset information.
	CounterResetHint CounterResetHint
	// Currently valid schema numbers are -4 <= n <= 8 for exponential buckets.
	// They are all for base-2 bucket schemas, where 1 is a bucket boundary in
	// each case, and then each power of two is divided into 2^n logarithmic buckets.
	// Or in other words, each bucket boundary is the previous boundary times
	// 2^(2^-n). Another valid schema number is -53 for custom buckets, defined by
	// the CustomValues field.
	Schema int32
	// Width of the zero bucket.
	ZeroThreshold float64
	// Observations falling into the zero bucket. Must be zero or positive.
	ZeroCount float64
	// Total number of observations. Must be zero or positive.
	Count float64
	// Sum of observations. This is also used as the stale marker.
	Sum float64
	// Spans for positive and negative buckets (see Span below).
	PositiveSpans, NegativeSpans []Span
	// Observation counts in buckets. Each represents an absolute count and
	// must be zero or positive.
	PositiveBuckets, NegativeBuckets []float64
	// Holds the custom (usually upper) bounds for bucket definitions, otherwise nil.
	// This slice is interned, to be treated as immutable and copied by reference.
	// These numbers should be strictly increasing. This field is only used when the
	// schema is for custom buckets, and the ZeroThreshold, ZeroCount, NegativeSpans
	// and NegativeBuckets fields are not used in that case.
	CustomValues []float64
}

func (h *FloatHistogram) UsesCustomBuckets() bool {
	return IsCustomBucketsSchema(h.Schema)