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-rw-r--r--vendor/github.com/prometheus/common/expfmt/text_parse.go753
1 files changed, 753 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/expfmt/text_parse.go b/vendor/github.com/prometheus/common/expfmt/text_parse.go
new file mode 100644
index 0000000..ef9a150
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/text_parse.go
@@ -0,0 +1,753 @@
+// 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
+ }
+ 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 = strconv.ParseFloat(p.currentLabelPair.GetValue(), 64); 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 = strconv.ParseFloat(p.currentLabelPair.GetValue(), 64); 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.Value))
+ 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 := strconv.ParseFloat(p.currentToken.String(), 64)
+ 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: '\\' tranlates 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
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 17:17:40 +0000