[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/procfs/proc_psi.go b/vendor/github.com/prometheus/procfs/proc_psi.go
new file mode 100644
index 0000000..46fe266
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc_psi.go
@@ -0,0 +1,101 @@
+// Copyright 2019 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 procfs
+
+// The PSI / pressure interface is described at
+// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/accounting/psi.txt
+// Each resource (cpu, io, memory, ...) is exposed as a single file.
+// Each file may contain up to two lines, one for "some" pressure and one for "full" pressure.
+// Each line contains several averages (over n seconds) and a total in µs.
+//
+// Example io pressure file:
+// > some avg10=0.06 avg60=0.21 avg300=0.99 total=8537362
+// > full avg10=0.00 avg60=0.13 avg300=0.96 total=8183134
+
+import (
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "strings"
+)
+
+const lineFormat = "avg10=%f avg60=%f avg300=%f total=%d"
+
+// PSILine is a single line of values as returned by /proc/pressure/*
+// The Avg entries are averages over n seconds, as a percentage
+// The Total line is in microseconds
+type PSILine struct {
+ Avg10 float64
+ Avg60 float64
+ Avg300 float64
+ Total uint64
+}
+
+// PSIStats represent pressure stall information from /proc/pressure/*
+// Some indicates the share of time in which at least some tasks are stalled
+// Full indicates the share of time in which all non-idle tasks are stalled simultaneously
+type PSIStats struct {
+ Some *PSILine
+ Full *PSILine
+}
+
+// PSIStatsForResource reads pressure stall information for the specified
+// resource from /proc/pressure/<resource>. At time of writing this can be
+// either "cpu", "memory" or "io".
+func (fs FS) PSIStatsForResource(resource string) (PSIStats, error) {
+ file, err := os.Open(fs.proc.Path(fmt.Sprintf("%s/%s", "pressure", resource)))
+ if err != nil {
+ return PSIStats{}, fmt.Errorf("psi_stats: unavailable for %s", resource)
+ }
+
+ defer file.Close()
+ return parsePSIStats(resource, file)
+}
+
+// parsePSIStats parses the specified file for pressure stall information
+func parsePSIStats(resource string, file io.Reader) (PSIStats, error) {
+ psiStats := PSIStats{}
+ stats, err := ioutil.ReadAll(file)
+ if err != nil {
+ return psiStats, fmt.Errorf("psi_stats: unable to read data for %s", resource)
+ }
+
+ for _, l := range strings.Split(string(stats), "\n") {
+ prefix := strings.Split(l, " ")[0]
+ switch prefix {
+ case "some":
+ psi := PSILine{}
+ _, err := fmt.Sscanf(l, fmt.Sprintf("some %s", lineFormat), &psi.Avg10, &psi.Avg60, &psi.Avg300, &psi.Total)
+ if err != nil {
+ return PSIStats{}, err
+ }
+ psiStats.Some = &psi
+ case "full":
+ psi := PSILine{}
+ _, err := fmt.Sscanf(l, fmt.Sprintf("full %s", lineFormat), &psi.Avg10, &psi.Avg60, &psi.Avg300, &psi.Total)
+ if err != nil {
+ return PSIStats{}, err
+ }
+ psiStats.Full = &psi
+ default:
+ // If we encounter a line with an unknown prefix, ignore it and move on
+ // Should new measurement types be added in the future we'll simply ignore them instead
+ // of erroring on retrieval
+ continue
+ }
+ }
+
+ return psiStats, nil
+}