[VOL-2235] Mocks and interfaces for rw-core
This update consists of mocks that are used by the rw-core
during unit testing. It also includes interfaces used for unit
tests.
Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go
new file mode 100644
index 0000000..9db2438
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go
@@ -0,0 +1,447 @@
+// Copyright 2017 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 promhttp
+
+import (
+ "errors"
+ "net/http"
+ "strconv"
+ "strings"
+ "time"
+
+ dto "github.com/prometheus/client_model/go"
+
+ "github.com/prometheus/client_golang/prometheus"
+)
+
+// magicString is used for the hacky label test in checkLabels. Remove once fixed.
+const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
+
+// InstrumentHandlerInFlight is a middleware that wraps the provided
+// http.Handler. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.Handler.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ g.Inc()
+ defer g.Dec()
+ next.ServeHTTP(w, r)
+ })
+}
+
+// InstrumentHandlerDuration is a middleware that wraps the provided
+// http.Handler to observe the request duration with the provided ObserverVec.
+// The ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request duration in seconds. Partitioning happens by HTTP
+// status code and/or HTTP method if the respective instance label names are
+// present in the ObserverVec. For unpartitioned observations, use an
+// ObserverVec with zero labels. Note that partitioning of Histograms is
+// expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(obs)
+
+ if code {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+
+ obs.With(labels(code, method, r.Method, d.Status())).Observe(time.Since(now).Seconds())
+ })
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+ next.ServeHTTP(w, r)
+ obs.With(labels(code, method, r.Method, 0)).Observe(time.Since(now).Seconds())
+ })
+}
+
+// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
+// to observe the request result with the provided CounterVec. The CounterVec
+// must have zero, one, or two non-const non-curried labels. For those, the only
+// allowed label names are "code" and "method". The function panics
+// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or
+// HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, the Counter is not incremented.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(counter)
+
+ if code {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+ counter.With(labels(code, method, r.Method, d.Status())).Inc()
+ })
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ next.ServeHTTP(w, r)
+ counter.With(labels(code, method, r.Method, 0)).Inc()
+ })
+}
+
+// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
+// http.Handler to observe with the provided ObserverVec the request duration
+// until the response headers are written. The ObserverVec must have zero, one,
+// or two non-const non-curried labels. For those, the only allowed label names
+// are "code" and "method". The function panics otherwise. The Observe method of
+// the Observer in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler panics before calling WriteHeader, no value is
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(obs)
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+ d := newDelegator(w, func(status int) {
+ obs.With(labels(code, method, r.Method, status)).Observe(time.Since(now).Seconds())
+ })
+ next.ServeHTTP(d, r)
+ })
+}
+
+// InstrumentHandlerRequestSize is a middleware that wraps the provided
+// http.Handler to observe the request size with the provided ObserverVec. The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(obs)
+
+ if code {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+ size := computeApproximateRequestSize(r)
+ obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(size))
+ })
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ next.ServeHTTP(w, r)
+ size := computeApproximateRequestSize(r)
+ obs.With(labels(code, method, r.Method, 0)).Observe(float64(size))
+ })
+}
+
+// InstrumentHandlerResponseSize is a middleware that wraps the provided
+// http.Handler to observe the response size with the provided ObserverVec. The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the response size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler) http.Handler {
+ code, method := checkLabels(obs)
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+ obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(d.Written()))
+ })
+}
+
+func checkLabels(c prometheus.Collector) (code bool, method bool) {
+ // TODO(beorn7): Remove this hacky way to check for instance labels
+ // once Descriptors can have their dimensionality queried.
+ var (
+ desc *prometheus.Desc
+ m prometheus.Metric
+ pm dto.Metric
+ lvs []string
+ )
+
+ // Get the Desc from the Collector.
+ descc := make(chan *prometheus.Desc, 1)
+ c.Describe(descc)
+
+ select {
+ case desc = <-descc:
+ default:
+ panic("no description provided by collector")
+ }
+ select {
+ case <-descc:
+ panic("more than one description provided by collector")
+ default:
+ }
+
+ close(descc)
+
+ // Create a ConstMetric with the Desc. Since we don't know how many
+ // variable labels there are, try for as long as it needs.
+ for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
+ m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
+ }
+
+ // Write out the metric into a proto message and look at the labels.
+ // If the value is not the magicString, it is a constLabel, which doesn't interest us.
+ // If the label is curried, it doesn't interest us.
+ // In all other cases, only "code" or "method" is allowed.
+ if err := m.Write(&pm); err != nil {
+ panic("error checking metric for labels")
+ }
+ for _, label := range pm.Label {
+ name, value := label.GetName(), label.GetValue()
+ if value != magicString || isLabelCurried(c, name) {
+ continue
+ }
+ switch name {
+ case "code":
+ code = true
+ case "method":
+ method = true
+ default:
+ panic("metric partitioned with non-supported labels")
+ }
+ }
+ return
+}
+
+func isLabelCurried(c prometheus.Collector, label string) bool {
+ // This is even hackier than the label test above.
+ // We essentially try to curry again and see if it works.
+ // But for that, we need to type-convert to the two
+ // types we use here, ObserverVec or *CounterVec.
+ switch v := c.(type) {
+ case *prometheus.CounterVec:
+ if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+ return false
+ }
+ case prometheus.ObserverVec:
+ if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+ return false
+ }
+ default:
+ panic("unsupported metric vec type")
+ }
+ return true
+}
+
+// emptyLabels is a one-time allocation for non-partitioned metrics to avoid
+// unnecessary allocations on each request.
+var emptyLabels = prometheus.Labels{}
+
+func labels(code, method bool, reqMethod string, status int) prometheus.Labels {
+ if !(code || method) {
+ return emptyLabels
+ }
+ labels := prometheus.Labels{}
+
+ if code {
+ labels["code"] = sanitizeCode(status)
+ }
+ if method {
+ labels["method"] = sanitizeMethod(reqMethod)
+ }
+
+ return labels
+}
+
+func computeApproximateRequestSize(r *http.Request) int {
+ s := 0
+ if r.URL != nil {
+ s += len(r.URL.String())
+ }
+
+ 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)
+ }
+ return s
+}
+
+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)
+ }
+}
+
+// If the wrapped http.Handler has not set a status code, i.e. the value is
+// currently 0, santizeCode will return 200, for consistency with behavior in
+// the stdlib.
+func sanitizeCode(s int) string {
+ switch s {
+ case 100:
+ return "100"
+ case 101:
+ return "101"
+
+ case 200, 0:
+ 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)
+ }
+}