diff options
Diffstat (limited to 'vendor/github.com/prometheus/common/expfmt/text_create.go')
| -rw-r--r-- | vendor/github.com/prometheus/common/expfmt/text_create.go | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/expfmt/text_create.go b/vendor/github.com/prometheus/common/expfmt/text_create.go new file mode 100644 index 0000000..f11321c --- /dev/null +++ b/vendor/github.com/prometheus/common/expfmt/text_create.go @@ -0,0 +1,303 @@ +// 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 ( + "fmt" + "io" + "math" + "strings" + + dto "github.com/prometheus/client_model/go" + "github.com/prometheus/common/model" +) + +// MetricFamilyToText converts a MetricFamily proto message into text format and +// writes the resulting lines to 'out'. It returns the number of bytes written +// and any error encountered. The output will have the same order as the input, +// no further sorting is performed. Furthermore, this function assumes the input +// is already sanitized and does not perform any sanity checks. If the input +// contains duplicate metrics or invalid metric or label names, the conversion +// will result in invalid text format output. +// +// This method fulfills the type 'prometheus.encoder'. +func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) { + var written int + + // Fail-fast checks. + if len(in.Metric) == 0 { + return written, fmt.Errorf("MetricFamily has no metrics: %s", in) + } + name := in.GetName() + if name == "" { + return written, fmt.Errorf("MetricFamily has no name: %s", in) + } + + // Comments, first HELP, then TYPE. + if in.Help != nil { + n, err := fmt.Fprintf( + out, "# HELP %s %s\n", + name, escapeString(*in.Help, false), + ) + written += n + if err != nil { + return written, err + } + } + metricType := in.GetType() + n, err := fmt.Fprintf( + out, "# TYPE %s %s\n", + name, strings.ToLower(metricType.String()), + ) + written += n + if err != nil { + return written, err + } + + // Finally the samples, one line for each. + for _, metric := range in.Metric { + switch metricType { + case dto.MetricType_COUNTER: + if metric.Counter == nil { + return written, fmt.Errorf( + "expected counter in metric %s %s", name, metric, + ) + } + n, err = writeSample( + name, metric, "", "", + metric.Counter.GetValue(), + out, + ) + case dto.MetricType_GAUGE: + if metric.Gauge == nil { + return written, fmt.Errorf( + "expected gauge in metric %s %s", name, metric, + ) + } + n, err = writeSample( + name, metric, "", "", + metric.Gauge.GetValue(), + out, + ) + case dto.MetricType_UNTYPED: + if metric.Untyped == nil { + return written, fmt.Errorf( + "expected untyped in metric %s %s", name, metric, + ) + } + n, err = writeSample( + name, metric, "", "", + metric.Untyped.GetValue(), + out, + ) + case dto.MetricType_SUMMARY: + if metric.Summary == nil { + return written, fmt.Errorf( + "expected summary in metric %s %s", name, metric, + ) + } + for _, q := range metric.Summary.Quantile { + n, err = writeSample( + name, metric, + model.QuantileLabel, fmt.Sprint(q.GetQuantile()), + q.GetValue(), + out, + ) + written += n + if err != nil { + return written, err + } + } + n, err = writeSample( + name+"_sum", metric, "", "", + metric.Summary.GetSampleSum(), + out, + ) + if err != nil { + return written, err + } + written += n + n, err = writeSample( + name+"_count", metric, "", "", + float64(metric.Summary.GetSampleCount()), + out, + ) + case dto.MetricType_HISTOGRAM: + if metric.Histogram == nil { + return written, fmt.Errorf( + "expected histogram in metric %s %s", name, metric, + ) + } + infSeen := false + for _, q := range metric.Histogram.Bucket { + n, err = writeSample( + name+"_bucket", metric, + model.BucketLabel, fmt.Sprint(q.GetUpperBound()), + float64(q.GetCumulativeCount()), + out, + ) + written += n + if err != nil { + return written, err + } + if math.IsInf(q.GetUpperBound(), +1) { + infSeen = true + } + } + if !infSeen { + n, err = writeSample( + name+"_bucket", metric, + model.BucketLabel, "+Inf", + float64(metric.Histogram.GetSampleCount()), + out, + ) + if err != nil { + return written, err + } + written += n + } + n, err = writeSample( + name+"_sum", metric, "", "", + metric.Histogram.GetSampleSum(), + out, + ) + if err != nil { + return written, err + } + written += n + n, err = writeSample( + name+"_count", metric, "", "", + float64(metric.Histogram.GetSampleCount()), + out, + ) + default: + return written, fmt.Errorf( + "unexpected type in metric %s %s", name, metric, + ) + } + written += n + if err != nil { + return written, err + } + } + return written, nil +} + +// writeSample writes a single sample in text format to out, given the metric +// name, the metric proto message itself, optionally an additional label name +// and value (use empty strings if not required), and the value. The function +// returns the number of bytes written and any error encountered. +func writeSample( + name string, + metric *dto.Metric, + additionalLabelName, additionalLabelValue string, + value float64, + out io.Writer, +) (int, error) { + var written int + n, err := fmt.Fprint(out, name) + written += n + if err != nil { + return written, err + } + n, err = labelPairsToText( + metric.Label, + additionalLabelName, additionalLabelValue, + out, + ) + written += n + if err != nil { + return written, err + } + n, err = fmt.Fprintf(out, " %v", value) + written += n + if err != nil { + return written, err + } + if metric.TimestampMs != nil { + n, err = fmt.Fprintf(out, " %v", *metric.TimestampMs) + written += n + if err != nil { + return written, err + } + } + n, err = out.Write([]byte{'\n'}) + written += n + if err != nil { + return written, err + } + return written, nil +} + +// labelPairsToText converts a slice of LabelPair proto messages plus the +// explicitly given additional label pair into text formatted as required by the +// text format and writes it to 'out'. An empty slice in combination with an +// empty string 'additionalLabelName' results in nothing being +// written. Otherwise, the label pairs are written, escaped as required by the +// text format, and enclosed in '{...}'. The function returns the number of +// bytes written and any error encountered. +func labelPairsToText( + in []*dto.LabelPair, + additionalLabelName, additionalLabelValue string, + out io.Writer, +) (int, error) { + if len(in) == 0 && additionalLabelName == "" { + return 0, nil + } + var written int + separator := '{' + for _, lp := range in { + n, err := fmt.Fprintf( + out, `%c%s="%s"`, + separator, lp.GetName(), escapeString(lp.GetValue(), true), + ) + written += n + if err != nil { + return written, err + } + separator = ',' + } + if additionalLabelName != "" { + n, err := fmt.Fprintf( + out, `%c%s="%s"`, + separator, additionalLabelName, + escapeString(additionalLabelValue, true), + ) + written += n + if err != nil { + return written, err + } + } + n, err := out.Write([]byte{'}'}) + written += n + if err != nil { + return written, err + } + return written, nil +} + +var ( + escape = strings.NewReplacer("\\", `\\`, "\n", `\n`) + escapeWithDoubleQuote = strings.NewReplacer("\\", `\\`, "\n", `\n`, "\"", `\"`) +) + +// escapeString replaces '\' by '\\', new line character by '\n', and - if +// includeDoubleQuote is true - '"' by '\"'. +func escapeString(v string, includeDoubleQuote bool) string { + if includeDoubleQuote { + return escapeWithDoubleQuote.Replace(v) + } + + return escape.Replace(v) +} |