[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/go_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
new file mode 100644
index 0000000..dc9247f
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
@@ -0,0 +1,396 @@
+// Copyright 2018 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 (
+ "runtime"
+ "runtime/debug"
+ "sync"
+ "time"
+)
+
+type goCollector struct {
+ goroutinesDesc *Desc
+ threadsDesc *Desc
+ gcDesc *Desc
+ goInfoDesc *Desc
+
+ // ms... are memstats related.
+ msLast *runtime.MemStats // Previously collected memstats.
+ msLastTimestamp time.Time
+ msMtx sync.Mutex // Protects msLast and msLastTimestamp.
+ msMetrics memStatsMetrics
+ msRead func(*runtime.MemStats) // For mocking in tests.
+ msMaxWait time.Duration // Wait time for fresh memstats.
+ msMaxAge time.Duration // Maximum allowed age of old memstats.
+}
+
+// NewGoCollector returns a collector that exports metrics about the current Go
+// process. This includes memory stats. To collect those, runtime.ReadMemStats
+// is called. This requires to “stop the world”, which usually only happens for
+// garbage collection (GC). Take the following implications into account when
+// deciding whether to use the Go collector:
+//
+// 1. The performance impact of stopping the world is the more relevant the more
+// frequently metrics are collected. However, with Go1.9 or later the
+// stop-the-world time per metrics collection is very short (~25µs) so that the
+// performance impact will only matter in rare cases. However, with older Go
+// versions, the stop-the-world duration depends on the heap size and can be
+// quite significant (~1.7 ms/GiB as per
+// https://go-review.googlesource.com/c/go/+/34937).
+//
+// 2. During an ongoing GC, nothing else can stop the world. Therefore, if the
+// metrics collection happens to coincide with GC, it will only complete after
+// GC has finished. Usually, GC is fast enough to not cause problems. However,
+// with a very large heap, GC might take multiple seconds, which is enough to
+// cause scrape timeouts in common setups. To avoid this problem, the Go
+// collector will use the memstats from a previous collection if
+// runtime.ReadMemStats takes more than 1s. However, if there are no previously
+// collected memstats, or their collection is more than 5m ago, the collection
+// will block until runtime.ReadMemStats succeeds. (The problem might be solved
+// in Go1.13, see https://github.com/golang/go/issues/19812 for the related Go
+// issue.)
+func NewGoCollector() Collector {
+ return &goCollector{
+ goroutinesDesc: NewDesc(
+ "go_goroutines",
+ "Number of goroutines that currently exist.",
+ nil, nil),
+ threadsDesc: NewDesc(
+ "go_threads",
+ "Number of OS threads created.",
+ nil, nil),
+ gcDesc: NewDesc(
+ "go_gc_duration_seconds",
+ "A summary of the GC invocation durations.",
+ nil, nil),
+ goInfoDesc: NewDesc(
+ "go_info",
+ "Information about the Go environment.",
+ nil, Labels{"version": runtime.Version()}),
+ msLast: &runtime.MemStats{},
+ msRead: runtime.ReadMemStats,
+ msMaxWait: time.Second,
+ msMaxAge: 5 * time.Minute,
+ msMetrics: memStatsMetrics{
+ {
+ desc: NewDesc(
+ memstatNamespace("alloc_bytes"),
+ "Number of bytes allocated and still in use.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("alloc_bytes_total"),
+ "Total number of bytes allocated, even if freed.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
+ valType: CounterValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("sys_bytes"),
+ "Number of bytes obtained from system.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("lookups_total"),
+ "Total number of pointer lookups.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
+ valType: CounterValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("mallocs_total"),
+ "Total number of mallocs.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
+ valType: CounterValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("frees_total"),
+ "Total number of frees.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
+ valType: CounterValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("heap_alloc_bytes"),
+ "Number of heap bytes allocated and still in use.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("heap_sys_bytes"),
+ "Number of heap bytes obtained from system.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("heap_idle_bytes"),
+ "Number of heap bytes waiting to be used.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("heap_inuse_bytes"),
+ "Number of heap bytes that are in use.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("heap_released_bytes"),
+ "Number of heap bytes released to OS.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("heap_objects"),
+ "Number of allocated objects.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("stack_inuse_bytes"),
+ "Number of bytes in use by the stack allocator.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("stack_sys_bytes"),
+ "Number of bytes obtained from system for stack allocator.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("mspan_inuse_bytes"),
+ "Number of bytes in use by mspan structures.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("mspan_sys_bytes"),
+ "Number of bytes used for mspan structures obtained from system.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("mcache_inuse_bytes"),
+ "Number of bytes in use by mcache structures.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("mcache_sys_bytes"),
+ "Number of bytes used for mcache structures obtained from system.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("buck_hash_sys_bytes"),
+ "Number of bytes used by the profiling bucket hash table.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("gc_sys_bytes"),
+ "Number of bytes used for garbage collection system metadata.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("other_sys_bytes"),
+ "Number of bytes used for other system allocations.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("next_gc_bytes"),
+ "Number of heap bytes when next garbage collection will take place.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("last_gc_time_seconds"),
+ "Number of seconds since 1970 of last garbage collection.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
+ valType: GaugeValue,
+ }, {
+ desc: NewDesc(
+ memstatNamespace("gc_cpu_fraction"),
+ "The fraction of this program's available CPU time used by the GC since the program started.",
+ nil, nil,
+ ),
+ eval: func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
+ valType: GaugeValue,
+ },
+ },
+ }
+}
+
+func memstatNamespace(s string) string {
+ return "go_memstats_" + s
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+ ch <- c.goroutinesDesc
+ ch <- c.threadsDesc
+ ch <- c.gcDesc
+ ch <- c.goInfoDesc
+ for _, i := range c.msMetrics {
+ ch <- i.desc
+ }
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+ var (
+ ms = &runtime.MemStats{}
+ done = make(chan struct{})
+ )
+ // Start reading memstats first as it might take a while.
+ go func() {
+ c.msRead(ms)
+ c.msMtx.Lock()
+ c.msLast = ms
+ c.msLastTimestamp = time.Now()
+ c.msMtx.Unlock()
+ close(done)
+ }()
+
+ ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
+ n, _ := runtime.ThreadCreateProfile(nil)
+ ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
+
+ var stats debug.GCStats
+ stats.PauseQuantiles = make([]time.Duration, 5)
+ debug.ReadGCStats(&stats)
+
+ quantiles := make(map[float64]float64)
+ for idx, pq := range stats.PauseQuantiles[1:] {
+ quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
+ }
+ quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
+ ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
+
+ ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+
+ timer := time.NewTimer(c.msMaxWait)
+ select {
+ case <-done: // Our own ReadMemStats succeeded in time. Use it.
+ timer.Stop() // Important for high collection frequencies to not pile up timers.
+ c.msCollect(ch, ms)
+ return
+ case <-timer.C: // Time out, use last memstats if possible. Continue below.
+ }
+ c.msMtx.Lock()
+ if time.Since(c.msLastTimestamp) < c.msMaxAge {
+ // Last memstats are recent enough. Collect from them under the lock.
+ c.msCollect(ch, c.msLast)
+ c.msMtx.Unlock()
+ return
+ }
+ // If we are here, the last memstats are too old or don't exist. We have
+ // to wait until our own ReadMemStats finally completes. For that to
+ // happen, we have to release the lock.
+ c.msMtx.Unlock()
+ <-done
+ c.msCollect(ch, ms)
+}
+
+func (c *goCollector) msCollect(ch chan<- Metric, ms *runtime.MemStats) {
+ for _, i := range c.msMetrics {
+ ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
+ }
+}
+
+// memStatsMetrics provide description, value, and value type for memstat metrics.
+type memStatsMetrics []struct {
+ desc *Desc
+ eval func(*runtime.MemStats) float64
+ valType ValueType
+}
+
+// NewBuildInfoCollector returns a collector collecting a single metric
+// "go_build_info" with the constant value 1 and three labels "path", "version",
+// and "checksum". Their label values contain the main module path, version, and
+// checksum, respectively. The labels will only have meaningful values if the
+// binary is built with Go module support and from source code retrieved from
+// the source repository (rather than the local file system). This is usually
+// accomplished by building from outside of GOPATH, specifying the full address
+// of the main package, e.g. "GO111MODULE=on go run
+// github.com/prometheus/client_golang/examples/random". If built without Go
+// module support, all label values will be "unknown". If built with Go module
+// support but using the source code from the local file system, the "path" will
+// be set appropriately, but "checksum" will be empty and "version" will be
+// "(devel)".
+//
+// This collector uses only the build information for the main module. See
+// https://github.com/povilasv/prommod for an example of a collector for the
+// module dependencies.
+func NewBuildInfoCollector() Collector {
+ path, version, sum := readBuildInfo()
+ c := &selfCollector{MustNewConstMetric(
+ NewDesc(
+ "go_build_info",
+ "Build information about the main Go module.",
+ nil, Labels{"path": path, "version": version, "checksum": sum},
+ ),
+ GaugeValue, 1)}
+ c.init(c.self)
+ return c
+}