Method floatHistogramSamplesV1

tsdb/record/record.go:1234–1267

(histograms []RefFloatHistogramSample, b []byte)

}

func (*Encoder) floatHistogramSamplesV1(histograms []RefFloatHistogramSample, b []byte) ([]byte, []RefFloatHistogramSample) {
	buf := encoding.Encbuf{B: b}
	buf.PutByte(byte(FloatHistogramSamples))

	if len(histograms) == 0 {
		return buf.Get(), nil
	}

	var customBucketsFloatHistograms []RefFloatHistogramSample

	// Store base timestamp and base reference number of first histogram.
	// All histograms encode their timestamp and ref as delta to those.
	first := histograms[0]
	buf.PutBE64(uint64(first.Ref))
	buf.PutBE64int64(first.T)

	for _, h := range histograms {
		if h.FH.UsesCustomBuckets() {
			customBucketsFloatHistograms = append(customBucketsFloatHistograms, h)
			continue
		}
		buf.PutVarint64(int64(h.Ref) - int64(first.Ref))
		buf.PutVarint64(h.T - first.T)

		EncodeFloatHistogram(&buf, h.FH)
	}

	// Reset buffer if only custom bucket histograms existed in list of histogram samples
	if len(histograms) == len(customBucketsFloatHistograms) {
		buf.Reset()
	}

	return buf.Get(), customBucketsFloatHistograms
}

// floatHistogramSamplesV2 encodes exponential float histogram samples and
// splits off custom-bucket float histogram samples to be encoded later.