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// 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
}
// Check for duplicate label names.
labels := make(map[string]struct{})
for _, l := range p.currentMetric.Label {
lName := l.GetName()
if _, exists := labels[lName]; !exists {
labels[lName] = struct{}{}
} else {
p.parseError(fmt.Sprintf("duplicate label names for metric %q", p.currentMF.GetName()))
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)
}
