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Diffstat (limited to 'vendor/github.com/prometheus/common/expfmt/expfmt.go')
| -rw-r--r-- | vendor/github.com/prometheus/common/expfmt/expfmt.go | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/expfmt/expfmt.go b/vendor/github.com/prometheus/common/expfmt/expfmt.go new file mode 100644 index 0000000..b268865 --- /dev/null +++ b/vendor/github.com/prometheus/common/expfmt/expfmt.go @@ -0,0 +1,207 @@ +// Copyright 2015 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 contains tools for reading and writing Prometheus metrics. +package expfmt + +import ( + "errors" + "strings" + + "github.com/prometheus/common/model" +) + +// Format specifies the HTTP content type of the different wire protocols. +type Format string + +// Constants to assemble the Content-Type values for the different wire +// protocols. The Content-Type strings here are all for the legacy exposition +// formats, where valid characters for metric names and label names are limited. +// Support for arbitrary UTF-8 characters in those names is already partially +// implemented in this module (see model.ValidationScheme), but to actually use +// it on the wire, new content-type strings will have to be agreed upon and +// added here. +const ( + TextVersion = "0.0.4" + ProtoType = `application/vnd.google.protobuf` + ProtoProtocol = `io.prometheus.client.MetricFamily` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoCompact) instead. + ProtoFmt = ProtoType + "; proto=" + ProtoProtocol + ";" + OpenMetricsType = `application/openmetrics-text` + OpenMetricsVersion_0_0_1 = "0.0.1" + OpenMetricsVersion_1_0_0 = "1.0.0" + + // The Content-Type values for the different wire protocols. Do not do direct + // comparisons to these constants, instead use the comparison functions. + // Deprecated: Use expfmt.NewFormat(expfmt.TypeUnknown) instead. + FmtUnknown Format = `<unknown>` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeTextPlain) instead. + FmtText Format = `text/plain; version=` + TextVersion + `; charset=utf-8` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoDelim) instead. + FmtProtoDelim Format = ProtoFmt + ` encoding=delimited` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoText) instead. + FmtProtoText Format = ProtoFmt + ` encoding=text` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoCompact) instead. + FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeOpenMetrics) instead. + FmtOpenMetrics_1_0_0 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_1_0_0 + `; charset=utf-8` + // Deprecated: Use expfmt.NewFormat(expfmt.TypeOpenMetrics) instead. + FmtOpenMetrics_0_0_1 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_0_0_1 + `; charset=utf-8` +) + +const ( + hdrContentType = "Content-Type" + hdrAccept = "Accept" +) + +// FormatType is a Go enum representing the overall category for the given +// Format. As the number of Format permutations increases, doing basic string +// comparisons are not feasible, so this enum captures the most useful +// high-level attribute of the Format string. +type FormatType int + +const ( + TypeUnknown FormatType = iota + TypeProtoCompact + TypeProtoDelim + TypeProtoText + TypeTextPlain + TypeOpenMetrics +) + +// NewFormat generates a new Format from the type provided. Mostly used for +// tests, most Formats should be generated as part of content negotiation in +// encode.go. If a type has more than one version, the latest version will be +// returned. +func NewFormat(t FormatType) Format { + switch t { + case TypeProtoCompact: + return FmtProtoCompact + case TypeProtoDelim: + return FmtProtoDelim + case TypeProtoText: + return FmtProtoText + case TypeTextPlain: + return FmtText + case TypeOpenMetrics: + return FmtOpenMetrics_1_0_0 + default: + return FmtUnknown + } +} + +// NewOpenMetricsFormat generates a new OpenMetrics format matching the +// specified version number. +func NewOpenMetricsFormat(version string) (Format, error) { + if version == OpenMetricsVersion_0_0_1 { + return FmtOpenMetrics_0_0_1, nil + } + if version == OpenMetricsVersion_1_0_0 { + return FmtOpenMetrics_1_0_0, nil + } + return FmtUnknown, errors.New("unknown open metrics version string") +} + +// WithEscapingScheme returns a copy of Format with the specified escaping +// scheme appended to the end. If an escaping scheme already exists it is +// removed. +func (f Format) WithEscapingScheme(s model.EscapingScheme) Format { + var terms []string + for _, p := range strings.Split(string(f), ";") { + toks := strings.Split(p, "=") + if len(toks) != 2 { + trimmed := strings.TrimSpace(p) + if len(trimmed) > 0 { + terms = append(terms, trimmed) + } + continue + } + key := strings.TrimSpace(toks[0]) + if key != model.EscapingKey { + terms = append(terms, strings.TrimSpace(p)) + } + } + terms = append(terms, model.EscapingKey+"="+s.String()) + return Format(strings.Join(terms, "; ")) +} + +// FormatType deduces an overall FormatType for the given format. +func (f Format) FormatType() FormatType { + toks := strings.Split(string(f), ";") + params := make(map[string]string) + for i, t := range toks { + if i == 0 { + continue + } + args := strings.Split(t, "=") + if len(args) != 2 { + continue + } + params[strings.TrimSpace(args[0])] = strings.TrimSpace(args[1]) + } + + switch strings.TrimSpace(toks[0]) { + case ProtoType: + if params["proto"] != ProtoProtocol { + return TypeUnknown + } + switch params["encoding"] { + case "delimited": + return TypeProtoDelim + case "text": + return TypeProtoText + case "compact-text": + return TypeProtoCompact + default: + return TypeUnknown + } + case OpenMetricsType: + if params["charset"] != "utf-8" { + return TypeUnknown + } + return TypeOpenMetrics + case "text/plain": + v, ok := params["version"] + if !ok { + return TypeTextPlain + } + if v == TextVersion { + return TypeTextPlain + } + return TypeUnknown + default: + return TypeUnknown + } +} + +// ToEscapingScheme returns an EscapingScheme depending on the Format. Iff the +// Format contains a escaping=allow-utf-8 term, it will select NoEscaping. If a valid +// "escaping" term exists, that will be used. Otherwise, the global default will +// be returned. +func (format Format) ToEscapingScheme() model.EscapingScheme { + for _, p := range strings.Split(string(format), ";") { + toks := strings.Split(p, "=") + if len(toks) != 2 { + continue + } + key, value := strings.TrimSpace(toks[0]), strings.TrimSpace(toks[1]) + if key == model.EscapingKey { + scheme, err := model.ToEscapingScheme(value) + if err != nil { + return model.NameEscapingScheme + } + return scheme + } + } + return model.NameEscapingScheme +} |
