open-nomad/vendor/github.com/prometheus/common/expfmt/text_parse.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

765 lines
25 KiB
Go

// Copyright 2014 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"
dto "github.com/prometheus/client_model/go"
"github.com/golang/protobuf/proto"
"github.com/prometheus/common/model"
)
// A stateFn is a function that represents a state in a state machine. By
// executing it, the state is progressed to the next state. The stateFn returns
// another stateFn, which represents the new state. The end state is represented
// by nil.
type stateFn func() stateFn
// ParseError signals errors while parsing the simple and flat text-based
// exchange format.
type ParseError struct {
Line int
Msg string
}
// Error implements the error interface.
func (e ParseError) Error() string {
return fmt.Sprintf("text format parsing error in line %d: %s", e.Line, e.Msg)
}
// TextParser is used to parse the simple and flat text-based exchange format. Its
// zero value is ready to use.
type TextParser struct {
metricFamiliesByName map[string]*dto.MetricFamily
buf *bufio.Reader // Where the parsed input is read through.
err error // Most recent error.
lineCount int // Tracks the line count for error messages.
currentByte byte // The most recent byte read.
currentToken bytes.Buffer // Re-used each time a token has to be gathered from multiple bytes.
currentMF *dto.MetricFamily
currentMetric *dto.Metric
currentLabelPair *dto.LabelPair
// The remaining member variables are only used for summaries/histograms.
currentLabels map[string]string // All labels including '__name__' but excluding 'quantile'/'le'
// Summary specific.
summaries map[uint64]*dto.Metric // Key is created with LabelsToSignature.
currentQuantile float64
// Histogram specific.
histograms map[uint64]*dto.Metric // Key is created with LabelsToSignature.
currentBucket float64
// These tell us if the currently processed line ends on '_count' or
// '_sum' respectively and belong to a summary/histogram, representing the sample
// count and sum of that summary/histogram.
currentIsSummaryCount, currentIsSummarySum bool
currentIsHistogramCount, currentIsHistogramSum bool
}
// TextToMetricFamilies reads 'in' as the simple and flat text-based exchange
// format and creates MetricFamily proto messages. It returns the MetricFamily
// proto messages in a map where the metric names are the keys, along with any
// error encountered.
//
// If the input contains duplicate metrics (i.e. lines with the same metric name
// and exactly the same label set), the resulting MetricFamily will contain
// duplicate Metric proto messages. Similar is true for duplicate label
// names. Checks for duplicates have to be performed separately, if required.
// Also note that neither the metrics within each MetricFamily are sorted nor
// the label pairs within each Metric. Sorting is not required for the most
// frequent use of this method, which is sample ingestion in the Prometheus
// server. However, for presentation purposes, you might want to sort the
// metrics, and in some cases, you must sort the labels, e.g. for consumption by
// the metric family injection hook of the Prometheus registry.
//
// Summaries and histograms are rather special beasts. You would probably not
// use them in the simple text format anyway. This method can deal with
// summaries and histograms if they are presented in exactly the way the
// text.Create function creates them.
//
// This method must not be called concurrently. If you want to parse different
// input concurrently, instantiate a separate Parser for each goroutine.
func (p *TextParser) TextToMetricFamilies(in io.Reader) (map[string]*dto.MetricFamily, error) {
p.reset(in)
for nextState := p.startOfLine; nextState != nil; nextState = nextState() {
// Magic happens here...
}
// Get rid of empty metric families.
for k, mf := range p.metricFamiliesByName {
if len(mf.GetMetric()) == 0 {
delete(p.metricFamiliesByName, k)
}
}
// If p.err is io.EOF now, we have run into a premature end of the input
// stream. Turn this error into something nicer and more
// meaningful. (io.EOF is often used as a signal for the legitimate end
// of an input stream.)
if p.err == io.EOF {
p.parseError("unexpected end of input stream")
}
return p.metricFamiliesByName, p.err
}
func (p *TextParser) reset(in io.Reader) {
p.metricFamiliesByName = map[string]*dto.MetricFamily{}
if p.buf == nil {
p.buf = bufio.NewReader(in)
} else {
p.buf.Reset(in)
}
p.err = nil
p.lineCount = 0
if p.summaries == nil || len(p.summaries) > 0 {
p.summaries = map[uint64]*dto.Metric{}
}
if p.histograms == nil || len(p.histograms) > 0 {
p.histograms = map[uint64]*dto.Metric{}
}
p.currentQuantile = math.NaN()
p.currentBucket = math.NaN()
}
// startOfLine represents the state where the next byte read from p.buf is the
// start of a line (or whitespace leading up to it).
func (p *TextParser) startOfLine() stateFn {
p.lineCount++
if p.skipBlankTab(); p.err != nil {
// End of input reached. This is the only case where
// that is not an error but a signal that we are done.
p.err = nil
return nil
}
switch p.currentByte {
case '#':
return p.startComment
case '\n':
return p.startOfLine // Empty line, start the next one.
}
return p.readingMetricName
}
// startComment represents the state where the next byte read from p.buf is the
// start of a comment (or whitespace leading up to it).
func (p *TextParser) startComment() stateFn {
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentByte == '\n' {
return p.startOfLine
}
if p.readTokenUntilWhitespace(); p.err != nil {
return nil // Unexpected end of input.
}
// If we have hit the end of line already, there is nothing left
// to do. This is not considered a syntax error.
if p.currentByte == '\n' {
return p.startOfLine
}
keyword := p.currentToken.String()
if keyword != "HELP" && keyword != "TYPE" {
// Generic comment, ignore by fast forwarding to end of line.
for p.currentByte != '\n' {
if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil {
return nil // Unexpected end of input.
}
}
return p.startOfLine
}
// There is something. Next has to be a metric name.
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.readTokenAsMetricName(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentByte == '\n' {
// At the end of the line already.
// Again, this is not considered a syntax error.
return p.startOfLine
}
if !isBlankOrTab(p.currentByte) {
p.parseError("invalid metric name in comment")
return nil
}
p.setOrCreateCurrentMF()
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentByte == '\n' {
// At the end of the line already.
// Again, this is not considered a syntax error.
return p.startOfLine
}
switch keyword {
case "HELP":
return p.readingHelp
case "TYPE":
return p.readingType
}
panic(fmt.Sprintf("code error: unexpected keyword %q", keyword))
}
// readingMetricName represents the state where the last byte read (now in
// p.currentByte) is the first byte of a metric name.
func (p *TextParser) readingMetricName() stateFn {
if p.readTokenAsMetricName(); p.err != nil {
return nil
}
if p.currentToken.Len() == 0 {
p.parseError("invalid metric name")
return nil
}
p.setOrCreateCurrentMF()
// Now is the time to fix the type if it hasn't happened yet.
if p.currentMF.Type == nil {
p.currentMF.Type = dto.MetricType_UNTYPED.Enum()
}
p.currentMetric = &dto.Metric{}
// Do not append the newly created currentMetric to
// currentMF.Metric right now. First wait if this is a summary,
// and the metric exists already, which we can only know after
// having read all the labels.
if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
return p.readingLabels
}
// readingLabels represents the state where the last byte read (now in
// p.currentByte) is either the first byte of the label set (i.e. a '{'), or the
// first byte of the value (otherwise).
func (p *TextParser) readingLabels() stateFn {
// Summaries/histograms are special. We have to reset the
// currentLabels map, currentQuantile and currentBucket before starting to
// read labels.
if p.currentMF.GetType() == dto.MetricType_SUMMARY || p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
p.currentLabels = map[string]string{}
p.currentLabels[string(model.MetricNameLabel)] = p.currentMF.GetName()
p.currentQuantile = math.NaN()
p.currentBucket = math.NaN()
}
if p.currentByte != '{' {
return p.readingValue
}
return p.startLabelName
}
// startLabelName represents the state where the next byte read from p.buf is
// the start of a label name (or whitespace leading up to it).
func (p *TextParser) startLabelName() stateFn {
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentByte == '}' {
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
return p.readingValue
}
if p.readTokenAsLabelName(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentToken.Len() == 0 {
p.parseError(fmt.Sprintf("invalid label name for metric %q", p.currentMF.GetName()))
return nil
}
p.currentLabelPair = &dto.LabelPair{Name: proto.String(p.currentToken.String())}
if p.currentLabelPair.GetName() == string(model.MetricNameLabel) {
p.parseError(fmt.Sprintf("label name %q is reserved", model.MetricNameLabel))
return nil
}
// Special summary/histogram treatment. Don't add 'quantile' and 'le'
// labels to 'real' labels.
if !(p.currentMF.GetType() == dto.MetricType_SUMMARY && p.currentLabelPair.GetName() == model.QuantileLabel) &&
!(p.currentMF.GetType() == dto.MetricType_HISTOGRAM && p.currentLabelPair.GetName() == model.BucketLabel) {
p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPair)
}
if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentByte != '=' {
p.parseError(fmt.Sprintf("expected '=' after label name, found %q", p.currentByte))
return nil
}
return p.startLabelValue
}
// startLabelValue represents the state where the next byte read from p.buf is
// the start of a (quoted) label value (or whitespace leading up to it).
func (p *TextParser) startLabelValue() stateFn {
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentByte != '"' {
p.parseError(fmt.Sprintf("expected '\"' at start of label value, found %q", p.currentByte))
return nil
}
if p.readTokenAsLabelValue(); p.err != nil {
return nil
}
if !model.LabelValue(p.currentToken.String()).IsValid() {
p.parseError(fmt.Sprintf("invalid label value %q", p.currentToken.String()))
return nil
}
p.currentLabelPair.Value = proto.String(p.currentToken.String())
// Special treatment of summaries:
// - Quantile labels are special, will result in dto.Quantile later.
// - Other labels have to be added to currentLabels for signature calculation.
if p.currentMF.GetType() == dto.MetricType_SUMMARY {
if p.currentLabelPair.GetName() == model.QuantileLabel {
if p.currentQuantile, p.err = parseFloat(p.currentLabelPair.GetValue()); p.err != nil {
// Create a more helpful error message.
p.parseError(fmt.Sprintf("expected float as value for 'quantile' label, got %q", p.currentLabelPair.GetValue()))
return nil
}
} else {
p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
}
}
// Similar special treatment of histograms.
if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
if p.currentLabelPair.GetName() == model.BucketLabel {
if p.currentBucket, p.err = parseFloat(p.currentLabelPair.GetValue()); p.err != nil {
// Create a more helpful error message.
p.parseError(fmt.Sprintf("expected float as value for 'le' label, got %q", p.currentLabelPair.GetValue()))
return nil
}
} else {
p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
}
}
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
switch p.currentByte {
case ',':
return p.startLabelName
case '}':
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
return p.readingValue
default:
p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.GetValue()))
return nil
}
}
// readingValue represents the state where the last byte read (now in
// p.currentByte) is the first byte of the sample value (i.e. a float).
func (p *TextParser) readingValue() stateFn {
// When we are here, we have read all the labels, so for the
// special case of a summary/histogram, we can finally find out
// if the metric already exists.
if p.currentMF.GetType() == dto.MetricType_SUMMARY {
signature := model.LabelsToSignature(p.currentLabels)
if summary := p.summaries[signature]; summary != nil {
p.currentMetric = summary
} else {
p.summaries[signature] = p.currentMetric
p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
}
} else if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
signature := model.LabelsToSignature(p.currentLabels)
if histogram := p.histograms[signature]; histogram != nil {
p.currentMetric = histogram
} else {
p.histograms[signature] = p.currentMetric
p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
}
} else {
p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
}
if p.readTokenUntilWhitespace(); p.err != nil {
return nil // Unexpected end of input.
}
value, err := parseFloat(p.currentToken.String())
if err != nil {
// Create a more helpful error message.
p.parseError(fmt.Sprintf("expected float as value, got %q", p.currentToken.String()))
return nil
}
switch p.currentMF.GetType() {
case dto.MetricType_COUNTER:
p.currentMetric.Counter = &dto.Counter{Value: proto.Float64(value)}
case dto.MetricType_GAUGE:
p.currentMetric.Gauge = &dto.Gauge{Value: proto.Float64(value)}
case dto.MetricType_UNTYPED:
p.currentMetric.Untyped = &dto.Untyped{Value: proto.Float64(value)}
case dto.MetricType_SUMMARY:
// *sigh*
if p.currentMetric.Summary == nil {
p.currentMetric.Summary = &dto.Summary{}
}
switch {
case p.currentIsSummaryCount:
p.currentMetric.Summary.SampleCount = proto.Uint64(uint64(value))
case p.currentIsSummarySum:
p.currentMetric.Summary.SampleSum = proto.Float64(value)
case !math.IsNaN(p.currentQuantile):
p.currentMetric.Summary.Quantile = append(
p.currentMetric.Summary.Quantile,
&dto.Quantile{
Quantile: proto.Float64(p.currentQuantile),
Value: proto.Float64(value),
},
)
}
case dto.MetricType_HISTOGRAM:
// *sigh*
if p.currentMetric.Histogram == nil {
p.currentMetric.Histogram = &dto.Histogram{}
}
switch {
case p.currentIsHistogramCount:
p.currentMetric.Histogram.SampleCount = proto.Uint64(uint64(value))
case p.currentIsHistogramSum:
p.currentMetric.Histogram.SampleSum = proto.Float64(value)
case !math.IsNaN(p.currentBucket):
p.currentMetric.Histogram.Bucket = append(
p.currentMetric.Histogram.Bucket,
&dto.Bucket{
UpperBound: proto.Float64(p.currentBucket),
CumulativeCount: proto.Uint64(uint64(value)),
},
)
}
default:
p.err = fmt.Errorf("unexpected type for metric name %q", p.currentMF.GetName())
}
if p.currentByte == '\n' {
return p.startOfLine
}
return p.startTimestamp
}
// startTimestamp represents the state where the next byte read from p.buf is
// the start of the timestamp (or whitespace leading up to it).
func (p *TextParser) startTimestamp() stateFn {
if p.skipBlankTab(); p.err != nil {
return nil // Unexpected end of input.
}
if p.readTokenUntilWhitespace(); p.err != nil {
return nil // Unexpected end of input.
}
timestamp, err := strconv.ParseInt(p.currentToken.String(), 10, 64)
if err != nil {
// Create a more helpful error message.
p.parseError(fmt.Sprintf("expected integer as timestamp, got %q", p.currentToken.String()))
return nil
}
p.currentMetric.TimestampMs = proto.Int64(timestamp)
if p.readTokenUntilNewline(false); p.err != nil {
return nil // Unexpected end of input.
}
if p.currentToken.Len() > 0 {
p.parseError(fmt.Sprintf("spurious string after timestamp: %q", p.currentToken.String()))
return nil
}
return p.startOfLine
}
// readingHelp represents the state where the last byte read (now in
// p.currentByte) is the first byte of the docstring after 'HELP'.
func (p *TextParser) readingHelp() stateFn {
if p.currentMF.Help != nil {
p.parseError(fmt.Sprintf("second HELP line for metric name %q", p.currentMF.GetName()))
return nil
}
// Rest of line is the docstring.
if p.readTokenUntilNewline(true); p.err != nil {
return nil // Unexpected end of input.
}
p.currentMF.Help = proto.String(p.currentToken.String())
return p.startOfLine
}
// readingType represents the state where the last byte read (now in
// p.currentByte) is the first byte of the type hint after 'HELP'.
func (p *TextParser) readingType() stateFn {
if p.currentMF.Type != nil {
p.parseError(fmt.Sprintf("second TYPE line for metric name %q, or TYPE reported after samples", p.currentMF.GetName()))
return nil
}
// Rest of line is the type.
if p.readTokenUntilNewline(false); p.err != nil {
return nil // Unexpected end of input.
}
metricType, ok := dto.MetricType_value[strings.ToUpper(p.currentToken.String())]
if !ok {
p.parseError(fmt.Sprintf("unknown metric type %q", p.currentToken.String()))
return nil
}
p.currentMF.Type = dto.MetricType(metricType).Enum()
return p.startOfLine
}
// parseError sets p.err to a ParseError at the current line with the given
// message.
func (p *TextParser) parseError(msg string) {
p.err = ParseError{
Line: p.lineCount,
Msg: msg,
}
}
// skipBlankTab reads (and discards) bytes from p.buf until it encounters a byte
// that is neither ' ' nor '\t'. That byte is left in p.currentByte.
func (p *TextParser) skipBlankTab() {
for {
if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil || !isBlankOrTab(p.currentByte) {
return
}
}
}
// skipBlankTabIfCurrentBlankTab works exactly as skipBlankTab but doesn't do
// anything if p.currentByte is neither ' ' nor '\t'.
func (p *TextParser) skipBlankTabIfCurrentBlankTab() {
if isBlankOrTab(p.currentByte) {
p.skipBlankTab()
}
}
// readTokenUntilWhitespace copies bytes from p.buf into p.currentToken. The
// first byte considered is the byte already read (now in p.currentByte). The
// first whitespace byte encountered is still copied into p.currentByte, but not
// into p.currentToken.
func (p *TextParser) readTokenUntilWhitespace() {
p.currentToken.Reset()
for p.err == nil && !isBlankOrTab(p.currentByte) && p.currentByte != '\n' {
p.currentToken.WriteByte(p.currentByte)
p.currentByte, p.err = p.buf.ReadByte()
}
}
// readTokenUntilNewline copies bytes from p.buf into p.currentToken. The first
// byte considered is the byte already read (now in p.currentByte). The first
// newline byte encountered is still copied into p.currentByte, but not into
// p.currentToken. If recognizeEscapeSequence is true, two escape sequences are
// recognized: '\\' translates into '\', and '\n' into a line-feed character.
// All other escape sequences are invalid and cause an error.
func (p *TextParser) readTokenUntilNewline(recognizeEscapeSequence bool) {
p.currentToken.Reset()
escaped := false
for p.err == nil {
if recognizeEscapeSequence && escaped {
switch p.currentByte {
case '\\':
p.currentToken.WriteByte(p.currentByte)
case 'n':
p.currentToken.WriteByte('\n')
default:
p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
return
}
escaped = false
} else {
switch p.currentByte {
case '\n':
return
case '\\':
escaped = true
default:
p.currentToken.WriteByte(p.currentByte)
}
}
p.currentByte, p.err = p.buf.ReadByte()
}
}
// readTokenAsMetricName copies a metric name from p.buf into p.currentToken.
// The first byte considered is the byte already read (now in p.currentByte).
// The first byte not part of a metric name is still copied into p.currentByte,
// but not into p.currentToken.
func (p *TextParser) readTokenAsMetricName() {
p.currentToken.Reset()
if !isValidMetricNameStart(p.currentByte) {
return
}
for {
p.currentToken.WriteByte(p.currentByte)
p.currentByte, p.err = p.buf.ReadByte()
if p.err != nil || !isValidMetricNameContinuation(p.currentByte) {
return
}
}
}
// readTokenAsLabelName copies a label name from p.buf into p.currentToken.
// The first byte considered is the byte already read (now in p.currentByte).
// The first byte not part of a label name is still copied into p.currentByte,
// but not into p.currentToken.
func (p *TextParser) readTokenAsLabelName() {
p.currentToken.Reset()
if !isValidLabelNameStart(p.currentByte) {
return
}
for {
p.currentToken.WriteByte(p.currentByte)
p.currentByte, p.err = p.buf.ReadByte()
if p.err != nil || !isValidLabelNameContinuation(p.currentByte) {
return
}
}
}
// readTokenAsLabelValue copies a label value from p.buf into p.currentToken.
// In contrast to the other 'readTokenAs...' functions, which start with the
// last read byte in p.currentByte, this method ignores p.currentByte and starts
// with reading a new byte from p.buf. The first byte not part of a label value
// is still copied into p.currentByte, but not into p.currentToken.
func (p *TextParser) readTokenAsLabelValue() {
p.currentToken.Reset()
escaped := false
for {
if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil {
return
}
if escaped {
switch p.currentByte {
case '"', '\\':
p.currentToken.WriteByte(p.currentByte)
case 'n':
p.currentToken.WriteByte('\n')
default:
p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
return
}
escaped = false
continue
}
switch p.currentByte {
case '"':
return
case '\n':
p.parseError(fmt.Sprintf("label value %q contains unescaped new-line", p.currentToken.String()))
return
case '\\':
escaped = true
default:
p.currentToken.WriteByte(p.currentByte)
}
}
}
func (p *TextParser) setOrCreateCurrentMF() {
p.currentIsSummaryCount = false
p.currentIsSummarySum = false
p.currentIsHistogramCount = false
p.currentIsHistogramSum = false
name := p.currentToken.String()
if p.currentMF = p.metricFamiliesByName[name]; p.currentMF != nil {
return
}
// Try out if this is a _sum or _count for a summary/histogram.
summaryName := summaryMetricName(name)
if p.currentMF = p.metricFamiliesByName[summaryName]; p.currentMF != nil {
if p.currentMF.GetType() == dto.MetricType_SUMMARY {
if isCount(name) {
p.currentIsSummaryCount = true
}
if isSum(name) {
p.currentIsSummarySum = true
}
return
}
}
histogramName := histogramMetricName(name)
if p.currentMF = p.metricFamiliesByName[histogramName]; p.currentMF != nil {
if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
if isCount(name) {
p.currentIsHistogramCount = true
}
if isSum(name) {
p.currentIsHistogramSum = true
}
return
}
}
p.currentMF = &dto.MetricFamily{Name: proto.String(name)}
p.metricFamiliesByName[name] = p.currentMF
}
func isValidLabelNameStart(b byte) bool {
return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_'
}
func isValidLabelNameContinuation(b byte) bool {
return isValidLabelNameStart(b) || (b >= '0' && b <= '9')
}
func isValidMetricNameStart(b byte) bool {
return isValidLabelNameStart(b) || b == ':'
}
func isValidMetricNameContinuation(b byte) bool {
return isValidLabelNameContinuation(b) || b == ':'
}
func isBlankOrTab(b byte) bool {
return b == ' ' || b == '\t'
}
func isCount(name string) bool {
return len(name) > 6 && name[len(name)-6:] == "_count"
}
func isSum(name string) bool {
return len(name) > 4 && name[len(name)-4:] == "_sum"
}
func isBucket(name string) bool {
return len(name) > 7 && name[len(name)-7:] == "_bucket"
}
func summaryMetricName(name string) string {
switch {
case isCount(name):
return name[:len(name)-6]
case isSum(name):
return name[:len(name)-4]
default:
return name
}
}
func histogramMetricName(name string) string {
switch {
case isCount(name):
return name[:len(name)-6]
case isSum(name):
return name[:len(name)-4]
case isBucket(name):
return name[:len(name)-7]
default:
return name
}
}
func parseFloat(s string) (float64, error) {
if strings.ContainsAny(s, "pP_") {
return 0, fmt.Errorf("unsupported character in float")
}
return strconv.ParseFloat(s, 64)
}