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-rw-r--r--src/kube2msb/vendor/github.com/prometheus/client_golang/prometheus/http.go361
1 files changed, 361 insertions, 0 deletions
diff --git a/src/kube2msb/vendor/github.com/prometheus/client_golang/prometheus/http.go b/src/kube2msb/vendor/github.com/prometheus/client_golang/prometheus/http.go
new file mode 100644
index 0000000..eabe602
--- /dev/null
+++ b/src/kube2msb/vendor/github.com/prometheus/client_golang/prometheus/http.go
@@ -0,0 +1,361 @@
+// 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 prometheus
+
+import (
+ "bufio"
+ "io"
+ "net"
+ "net/http"
+ "strconv"
+ "strings"
+ "time"
+)
+
+var instLabels = []string{"method", "code"}
+
+type nower interface {
+ Now() time.Time
+}
+
+type nowFunc func() time.Time
+
+func (n nowFunc) Now() time.Time {
+ return n()
+}
+
+var now nower = nowFunc(func() time.Time {
+ return time.Now()
+})
+
+func nowSeries(t ...time.Time) nower {
+ return nowFunc(func() time.Time {
+ defer func() {
+ t = t[1:]
+ }()
+
+ return t[0]
+ })
+}
+
+// InstrumentHandler wraps the given HTTP handler for instrumentation. It
+// registers four metric collectors (if not already done) and reports HTTP
+// metrics to the (newly or already) registered collectors: http_requests_total
+// (CounterVec), http_request_duration_microseconds (Summary),
+// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
+// has a constant label named "handler" with the provided handlerName as
+// value. http_requests_total is a metric vector partitioned by HTTP method
+// (label name "method") and HTTP status code (label name "code").
+func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
+ return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFunc wraps the given function for instrumentation. It
+// otherwise works in the same way as InstrumentHandler.
+func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+ return InstrumentHandlerFuncWithOpts(
+ SummaryOpts{
+ Subsystem: "http",
+ ConstLabels: Labels{"handler": handlerName},
+ },
+ handlerFunc,
+ )
+}
+
+// InstrumentHandlerWithOpts works like InstrumentHandler but provides more
+// flexibility (at the cost of a more complex call syntax). As
+// InstrumentHandler, this function registers four metric collectors, but it
+// uses the provided SummaryOpts to create them. However, the fields "Name" and
+// "Help" in the SummaryOpts are ignored. "Name" is replaced by
+// "requests_total", "request_duration_microseconds", "request_size_bytes", and
+// "response_size_bytes", respectively. "Help" is replaced by an appropriate
+// help string. The names of the variable labels of the http_requests_total
+// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
+//
+// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
+// behavior of InstrumentHandler:
+//
+// prometheus.InstrumentHandlerWithOpts(
+// prometheus.SummaryOpts{
+// Subsystem: "http",
+// ConstLabels: prometheus.Labels{"handler": handlerName},
+// },
+// handler,
+// )
+//
+// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
+// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
+// and all its fields are set to the equally named fields in the provided
+// SummaryOpts.
+func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
+ return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc but provides
+// more flexibility (at the cost of a more complex call syntax). See
+// InstrumentHandlerWithOpts for details how the provided SummaryOpts are used.
+func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+ reqCnt := NewCounterVec(
+ CounterOpts{
+ Namespace: opts.Namespace,
+ Subsystem: opts.Subsystem,
+ Name: "requests_total",
+ Help: "Total number of HTTP requests made.",
+ ConstLabels: opts.ConstLabels,
+ },
+ instLabels,
+ )
+
+ opts.Name = "request_duration_microseconds"
+ opts.Help = "The HTTP request latencies in microseconds."
+ reqDur := NewSummary(opts)
+
+ opts.Name = "request_size_bytes"
+ opts.Help = "The HTTP request sizes in bytes."
+ reqSz := NewSummary(opts)
+
+ opts.Name = "response_size_bytes"
+ opts.Help = "The HTTP response sizes in bytes."
+ resSz := NewSummary(opts)
+
+ regReqCnt := MustRegisterOrGet(reqCnt).(*CounterVec)
+ regReqDur := MustRegisterOrGet(reqDur).(Summary)
+ regReqSz := MustRegisterOrGet(reqSz).(Summary)
+ regResSz := MustRegisterOrGet(resSz).(Summary)
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+
+ delegate := &responseWriterDelegator{ResponseWriter: w}
+ out := make(chan int)
+ urlLen := 0
+ if r.URL != nil {
+ urlLen = len(r.URL.String())
+ }
+ go computeApproximateRequestSize(r, out, urlLen)
+
+ _, cn := w.(http.CloseNotifier)
+ _, fl := w.(http.Flusher)
+ _, hj := w.(http.Hijacker)
+ _, rf := w.(io.ReaderFrom)
+ var rw http.ResponseWriter
+ if cn && fl && hj && rf {
+ rw = &fancyResponseWriterDelegator{delegate}
+ } else {
+ rw = delegate
+ }
+ handlerFunc(rw, r)
+
+ elapsed := float64(time.Since(now)) / float64(time.Microsecond)
+
+ method := sanitizeMethod(r.Method)
+ code := sanitizeCode(delegate.status)
+ regReqCnt.WithLabelValues(method, code).Inc()
+ regReqDur.Observe(elapsed)
+ regResSz.Observe(float64(delegate.written))
+ regReqSz.Observe(float64(<-out))
+ })
+}
+
+func computeApproximateRequestSize(r *http.Request, out chan int, s int) {
+ s += len(r.Method)
+ s += len(r.Proto)
+ for name, values := range r.Header {
+ s += len(name)
+ for _, value := range values {
+ s += len(value)
+ }
+ }
+ s += len(r.Host)
+
+ // N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+
+ if r.ContentLength != -1 {
+ s += int(r.ContentLength)
+ }
+ out <- s
+}
+
+type responseWriterDelegator struct {
+ http.ResponseWriter
+
+ handler, method string
+ status int
+ written int64
+ wroteHeader bool
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+ r.status = code
+ r.wroteHeader = true
+ r.ResponseWriter.WriteHeader(code)
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+ if !r.wroteHeader {
+ r.WriteHeader(http.StatusOK)
+ }
+ n, err := r.ResponseWriter.Write(b)
+ r.written += int64(n)
+ return n, err
+}
+
+type fancyResponseWriterDelegator struct {
+ *responseWriterDelegator
+}
+
+func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
+ return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+func (f *fancyResponseWriterDelegator) Flush() {
+ f.ResponseWriter.(http.Flusher).Flush()
+}
+
+func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+ return f.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
+ if !f.wroteHeader {
+ f.WriteHeader(http.StatusOK)
+ }
+ n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
+ f.written += n
+ return n, err
+}
+
+func sanitizeMethod(m string) string {
+ switch m {
+ case "GET", "get":
+ return "get"
+ case "PUT", "put":
+ return "put"
+ case "HEAD", "head":
+ return "head"
+ case "POST", "post":
+ return "post"
+ case "DELETE", "delete":
+ return "delete"
+ case "CONNECT", "connect":
+ return "connect"
+ case "OPTIONS", "options":
+ return "options"
+ case "NOTIFY", "notify":
+ return "notify"
+ default:
+ return strings.ToLower(m)
+ }
+}
+
+func sanitizeCode(s int) string {
+ switch s {
+ case 100:
+ return "100"
+ case 101:
+ return "101"
+
+ case 200:
+ return "200"
+ case 201:
+ return "201"
+ case 202:
+ return "202"
+ case 203:
+ return "203"
+ case 204:
+ return "204"
+ case 205:
+ return "205"
+ case 206:
+ return "206"
+
+ case 300:
+ return "300"
+ case 301:
+ return "301"
+ case 302:
+ return "302"
+ case 304:
+ return "304"
+ case 305:
+ return "305"
+ case 307:
+ return "307"
+
+ case 400:
+ return "400"
+ case 401:
+ return "401"
+ case 402:
+ return "402"
+ case 403:
+ return "403"
+ case 404:
+ return "404"
+ case 405:
+ return "405"
+ case 406:
+ return "406"
+ case 407:
+ return "407"
+ case 408:
+ return "408"
+ case 409:
+ return "409"
+ case 410:
+ return "410"
+ case 411:
+ return "411"
+ case 412:
+ return "412"
+ case 413:
+ return "413"
+ case 414:
+ return "414"
+ case 415:
+ return "415"
+ case 416:
+ return "416"
+ case 417:
+ return "417"
+ case 418:
+ return "418"
+
+ case 500:
+ return "500"
+ case 501:
+ return "501"
+ case 502:
+ return "502"
+ case 503:
+ return "503"
+ case 504:
+ return "504"
+ case 505:
+ return "505"
+
+ case 428:
+ return "428"
+ case 429:
+ return "429"
+ case 431:
+ return "431"
+ case 511:
+ return "511"
+
+ default:
+ return strconv.Itoa(s)
+ }
+}