Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package expfmt
import (
"bufio"
"bytes"
"fmt"
"io"
"math"
"strconv"
"strings"
"github.com/golang/protobuf/ptypes"
"github.com/prometheus/common/model"
dto "github.com/prometheus/client_model/go"
)
// MetricFamilyToOpenMetrics converts a MetricFamily proto message into the
// OpenMetrics text format and writes the resulting lines to 'out'. It returns
// the number of bytes written and any error encountered. The output will have
// the same order as the input, no further sorting is performed. Furthermore,
// this function assumes the input is already sanitized and does not perform any
// sanity checks. If the input contains duplicate metrics or invalid metric or
// label names, the conversion will result in invalid text format output.
//
// This function fulfills the type 'expfmt.encoder'.
//
// Note that OpenMetrics requires a final `# EOF` line. Since this function acts
// on individual metric families, it is the responsibility of the caller to
// append this line to 'out' once all metric families have been written.
// Conveniently, this can be done by calling FinalizeOpenMetrics.
//
// The output should be fully OpenMetrics compliant. However, there are a few
// missing features and peculiarities to avoid complications when switching from
// Prometheus to OpenMetrics or vice versa:
//
// - Counters are expected to have the `_total` suffix in their metric name. In
// the output, the suffix will be truncated from the `# TYPE` and `# HELP`
// line. A counter with a missing `_total` suffix is not an error. However,
// its type will be set to `unknown` in that case to avoid invalid OpenMetrics
// output.
//
// - No support for the following (optional) features: `# UNIT` line, `_created`
// line, info type, stateset type, gaugehistogram type.
//
// - The size of exemplar labels is not checked (i.e. it's possible to create
// exemplars that are larger than allowed by the OpenMetrics specification).
//
// - The value of Counters is not checked. (OpenMetrics doesn't allow counters
// with a `NaN` value.)
func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int, err error) {
name := in.GetName()
if name == "" {
return 0, fmt.Errorf("MetricFamily has no name: %s", in)
}
// Try the interface upgrade. If it doesn't work, we'll use a
// bufio.Writer from the sync.Pool.
w, ok := out.(enhancedWriter)
if !ok {
b := bufPool.Get().(*bufio.Writer)
b.Reset(out)
w = b
defer func() {
bErr := b.Flush()
if err == nil {
err = bErr
}
bufPool.Put(b)
}()
}
var (
n int
metricType = in.GetType()
shortName = name
)
if metricType == dto.MetricType_COUNTER && strings.HasSuffix(shortName, "_total") {
shortName = name[:len(name)-6]
}
// Comments, first HELP, then TYPE.
if in.Help != nil {
n, err = w.WriteString("# HELP ")
written += n
if err != nil {
return
}
n, err = w.WriteString(shortName)
written += n
if err != nil {
return
}
err = w.WriteByte(' ')
written++
if err != nil {
return
}
n, err = writeEscapedString(w, *in.Help, true)
written += n
if err != nil {
return
}
err = w.WriteByte('\n')
written++
if err != nil {
return
}
}
n, err = w.WriteString("# TYPE ")
written += n
if err != nil {
return
}
n, err = w.WriteString(shortName)
written += n
if err != nil {
return
}
switch metricType {
case dto.MetricType_COUNTER:
if strings.HasSuffix(name, "_total") {
n, err = w.WriteString(" counter\n")
} else {
n, err = w.WriteString(" unknown\n")
}
case dto.MetricType_GAUGE:
n, err = w.WriteString(" gauge\n")
case dto.MetricType_SUMMARY:
n, err = w.WriteString(" summary\n")
case dto.MetricType_UNTYPED:
n, err = w.WriteString(" unknown\n")
case dto.MetricType_HISTOGRAM:
n, err = w.WriteString(" histogram\n")
default:
return written, fmt.Errorf("unknown metric type %s", metricType.String())
}
written += n
if err != nil {
return
}
// Finally the samples, one line for each.
for _, metric := range in.Metric {
switch metricType {
case dto.MetricType_COUNTER:
if metric.Counter == nil {
return written, fmt.Errorf(
"expected counter in metric %s %s", name, metric,
)
}
// Note that we have ensured above that either the name
// ends on `_total` or that the rendered type is
// `unknown`. Therefore, no `_total` must be added here.
n, err = writeOpenMetricsSample(
w, name, "", metric, "", 0,
metric.Counter.GetValue(), 0, false,
metric.Counter.Exemplar,
)
case dto.MetricType_GAUGE:
if metric.Gauge == nil {
return written, fmt.Errorf(
"expected gauge in metric %s %s", name, metric,
)
}
n, err = writeOpenMetricsSample(
w, name, "", metric, "", 0,
metric.Gauge.GetValue(), 0, false,
nil,
)
case dto.MetricType_UNTYPED:
if metric.Untyped == nil {
return written, fmt.Errorf(
"expected untyped in metric %s %s", name, metric,
)
}
n, err = writeOpenMetricsSample(
w, name, "", metric, "", 0,
metric.Untyped.GetValue(), 0, false,
nil,
)
case dto.MetricType_SUMMARY:
if metric.Summary == nil {
return written, fmt.Errorf(
"expected summary in metric %s %s", name, metric,
)
}
for _, q := range metric.Summary.Quantile {
n, err = writeOpenMetricsSample(
w, name, "", metric,
model.QuantileLabel, q.GetQuantile(),
q.GetValue(), 0, false,
nil,
)
written += n
if err != nil {
return
}
}
n, err = writeOpenMetricsSample(
w, name, "_sum", metric, "", 0,
metric.Summary.GetSampleSum(), 0, false,
nil,
)
written += n
if err != nil {
return
}
n, err = writeOpenMetricsSample(
w, name, "_count", metric, "", 0,
0, metric.Summary.GetSampleCount(), true,
nil,
)
case dto.MetricType_HISTOGRAM:
if metric.Histogram == nil {
return written, fmt.Errorf(
"expected histogram in metric %s %s", name, metric,
)
}
infSeen := false
for _, b := range metric.Histogram.Bucket {
n, err = writeOpenMetricsSample(
w, name, "_bucket", metric,
model.BucketLabel, b.GetUpperBound(),
0, b.GetCumulativeCount(), true,
b.Exemplar,
)
written += n
if err != nil {
return
}
if math.IsInf(b.GetUpperBound(), +1) {
infSeen = true
}
}
if !infSeen {
n, err = writeOpenMetricsSample(
w, name, "_bucket", metric,
model.BucketLabel, math.Inf(+1),
0, metric.Histogram.GetSampleCount(), true,
nil,
)
written += n
if err != nil {
return
}
}
n, err = writeOpenMetricsSample(
w, name, "_sum", metric, "", 0,
metric.Histogram.GetSampleSum(), 0, false,
nil,
)
written += n
if err != nil {
return
}
n, err = writeOpenMetricsSample(
w, name, "_count", metric, "", 0,
0, metric.Histogram.GetSampleCount(), true,
nil,
)
default:
return written, fmt.Errorf(
"unexpected type in metric %s %s", name, metric,
)
}
written += n
if err != nil {
return
}
}
return
}
// FinalizeOpenMetrics writes the final `# EOF\n` line required by OpenMetrics.
func FinalizeOpenMetrics(w io.Writer) (written int, err error) {
return w.Write([]byte("# EOF\n"))
}
// writeOpenMetricsSample writes a single sample in OpenMetrics text format to
// w, given the metric name, the metric proto message itself, optionally an
// additional label name with a float64 value (use empty string as label name if
// not required), the value (optionally as float64 or uint64, determined by
// useIntValue), and optionally an exemplar (use nil if not required). The
// function returns the number of bytes written and any error encountered.
func writeOpenMetricsSample(
w enhancedWriter,
name, suffix string,
metric *dto.Metric,
additionalLabelName string, additionalLabelValue float64,
floatValue float64, intValue uint64, useIntValue bool,
exemplar *dto.Exemplar,
) (int, error) {
var written int
n, err := w.WriteString(name)
written += n
if err != nil {
return written, err
}
if suffix != "" {
n, err = w.WriteString(suffix)
written += n
if err != nil {
return written, err
}
}
n, err = writeOpenMetricsLabelPairs(
w, metric.Label, additionalLabelName, additionalLabelValue,
)
written += n
if err != nil {
return written, err
}
err = w.WriteByte(' ')
written++
if err != nil {
return written, err
}
if useIntValue {
n, err = writeUint(w, intValue)
} else {
n, err = writeOpenMetricsFloat(w, floatValue)
}
written += n
if err != nil {
return written, err
}
if metric.TimestampMs != nil {
err = w.WriteByte(' ')
written++
if err != nil {
return written, err
}
// TODO(beorn7): Format this directly without converting to a float first.
n, err = writeOpenMetricsFloat(w, float64(*metric.TimestampMs)/1000)
written += n
if err != nil {
return written, err
}
}
if exemplar != nil {
n, err = writeExemplar(w, exemplar)
written += n
if err != nil {
return written, err
}
}
err = w.WriteByte('\n')
written++
if err != nil {
return written, err
}
return written, nil
}
// writeOpenMetricsLabelPairs works like writeOpenMetrics but formats the float
// in OpenMetrics style.
func writeOpenMetricsLabelPairs(
w enhancedWriter,
in []*dto.LabelPair,
additionalLabelName string, additionalLabelValue float64,
) (int, error) {
if len(in) == 0 && additionalLabelName == "" {
return 0, nil
}
var (
written int
separator byte = '{'
)
for _, lp := range in {
err := w.WriteByte(separator)
written++
if err != nil {
return written, err
}
n, err := w.WriteString(lp.GetName())
written += n
if err != nil {
return written, err
}
n, err = w.WriteString(`="`)
written += n
if err != nil {
return written, err
}
n, err = writeEscapedString(w, lp.GetValue(), true)
written += n
if err != nil {
return written, err
}
err = w.WriteByte('"')
written++
if err != nil {
return written, err
}
separator = ','
}
if additionalLabelName != "" {
err := w.WriteByte(separator)
written++
if err != nil {
return written, err
}
n, err := w.WriteString(additionalLabelName)
written += n
if err != nil {
return written, err
}
n, err = w.WriteString(`="`)
written += n
if err != nil {
return written, err
}
n, err = writeOpenMetricsFloat(w, additionalLabelValue)
written += n
if err != nil {
return written, err
}
err = w.WriteByte('"')
written++
if err != nil {
return written, err
}
}
err := w.WriteByte('}')
written++
if err != nil {
return written, err
}
return written, nil
}
// writeExemplar writes the provided exemplar in OpenMetrics format to w. The
// function returns the number of bytes written and any error encountered.
func writeExemplar(w enhancedWriter, e *dto.Exemplar) (int, error) {
written := 0
n, err := w.WriteString(" # ")
written += n
if err != nil {
return written, err
}
n, err = writeOpenMetricsLabelPairs(w, e.Label, "", 0)
written += n
if err != nil {
return written, err
}
err = w.WriteByte(' ')
written++
if err != nil {
return written, err
}
n, err = writeOpenMetricsFloat(w, e.GetValue())
written += n
if err != nil {
return written, err
}
if e.Timestamp != nil {
err = w.WriteByte(' ')
written++
if err != nil {
return written, err
}
ts, err := ptypes.Timestamp((*e).Timestamp)
if err != nil {
return written, err
}
// TODO(beorn7): Format this directly from components of ts to
// avoid overflow/underflow and precision issues of the float
// conversion.
n, err = writeOpenMetricsFloat(w, float64(ts.UnixNano())/1e9)
written += n
if err != nil {
return written, err
}
}
return written, nil
}
// writeOpenMetricsFloat works like writeFloat but appends ".0" if the resulting
// number would otherwise contain neither a "." nor an "e".
func writeOpenMetricsFloat(w enhancedWriter, f float64) (int, error) {
switch {
case f == 1:
return w.WriteString("1.0")
case f == 0:
return w.WriteString("0.0")
case f == -1:
return w.WriteString("-1.0")
case math.IsNaN(f):
return w.WriteString("NaN")
case math.IsInf(f, +1):
return w.WriteString("+Inf")
case math.IsInf(f, -1):
return w.WriteString("-Inf")
default:
bp := numBufPool.Get().(*[]byte)
*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
if !bytes.ContainsAny(*bp, "e.") {
*bp = append(*bp, '.', '0')
}
written, err := w.Write(*bp)
numBufPool.Put(bp)
return written, err
}
}
// writeUint is like writeInt just for uint64.
func writeUint(w enhancedWriter, u uint64) (int, error) {
bp := numBufPool.Get().(*[]byte)
*bp = strconv.AppendUint((*bp)[:0], u, 10)
written, err := w.Write(*bp)
numBufPool.Put(bp)
return written, err
}
