From ed8bc523fd0d1a66acf3fa449c453508035efdfc Mon Sep 17 00:00:00 2001 From: Kevin Lyda Date: Sun, 12 Feb 2017 14:38:12 +0000 Subject: Initial pass at prometheus support. (#56) --- .../prometheus/common/expfmt/text_parse.go | 753 +++++++++++++++++++++ 1 file changed, 753 insertions(+) create mode 100644 vendor/github.com/prometheus/common/expfmt/text_parse.go (limited to 'vendor/github.com/prometheus/common/expfmt/text_parse.go') 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 + } +} -- cgit v1.2.3