[VOL-4638] Initial commit
Change-Id: I5e785d017e1d27783b24591b52f20f442895e602
diff --git a/vendor/github.com/uber/jaeger-lib/metrics/metrics.go b/vendor/github.com/uber/jaeger-lib/metrics/metrics.go
new file mode 100644
index 0000000..0df0c66
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-lib/metrics/metrics.go
@@ -0,0 +1,137 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// 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 metrics
+
+import (
+ "fmt"
+ "reflect"
+ "strconv"
+ "strings"
+)
+
+// MustInit initializes the passed in metrics and initializes its fields using the passed in factory.
+//
+// It uses reflection to initialize a struct containing metrics fields
+// by assigning new Counter/Gauge/Timer values with the metric name retrieved
+// from the `metric` tag and stats tags retrieved from the `tags` tag.
+//
+// Note: all fields of the struct must be exported, have a `metric` tag, and be
+// of type Counter or Gauge or Timer.
+//
+// Errors during Init lead to a panic.
+func MustInit(metrics interface{}, factory Factory, globalTags map[string]string) {
+ if err := Init(metrics, factory, globalTags); err != nil {
+ panic(err.Error())
+ }
+}
+
+// Init does the same as MustInit, but returns an error instead of
+// panicking.
+func Init(m interface{}, factory Factory, globalTags map[string]string) error {
+ // Allow user to opt out of reporting metrics by passing in nil.
+ if factory == nil {
+ factory = NullFactory
+ }
+
+ counterPtrType := reflect.TypeOf((*Counter)(nil)).Elem()
+ gaugePtrType := reflect.TypeOf((*Gauge)(nil)).Elem()
+ timerPtrType := reflect.TypeOf((*Timer)(nil)).Elem()
+ histogramPtrType := reflect.TypeOf((*Histogram)(nil)).Elem()
+
+ v := reflect.ValueOf(m).Elem()
+ t := v.Type()
+ for i := 0; i < t.NumField(); i++ {
+ tags := make(map[string]string)
+ for k, v := range globalTags {
+ tags[k] = v
+ }
+ var buckets []float64
+ field := t.Field(i)
+ metric := field.Tag.Get("metric")
+ if metric == "" {
+ return fmt.Errorf("Field %s is missing a tag 'metric'", field.Name)
+ }
+ if tagString := field.Tag.Get("tags"); tagString != "" {
+ tagPairs := strings.Split(tagString, ",")
+ for _, tagPair := range tagPairs {
+ tag := strings.Split(tagPair, "=")
+ if len(tag) != 2 {
+ return fmt.Errorf(
+ "Field [%s]: Tag [%s] is not of the form key=value in 'tags' string [%s]",
+ field.Name, tagPair, tagString)
+ }
+ tags[tag[0]] = tag[1]
+ }
+ }
+ if bucketString := field.Tag.Get("buckets"); bucketString != "" {
+ if field.Type.AssignableTo(timerPtrType) {
+ // TODO: Parse timer duration buckets
+ return fmt.Errorf(
+ "Field [%s]: Buckets are not currently initialized for timer metrics",
+ field.Name)
+ } else if field.Type.AssignableTo(histogramPtrType) {
+ bucketValues := strings.Split(bucketString, ",")
+ for _, bucket := range bucketValues {
+ b, err := strconv.ParseFloat(bucket, 64)
+ if err != nil {
+ return fmt.Errorf(
+ "Field [%s]: Bucket [%s] could not be converted to float64 in 'buckets' string [%s]",
+ field.Name, bucket, bucketString)
+ }
+ buckets = append(buckets, b)
+ }
+ } else {
+ return fmt.Errorf(
+ "Field [%s]: Buckets should only be defined for Timer and Histogram metric types",
+ field.Name)
+ }
+ }
+ help := field.Tag.Get("help")
+ var obj interface{}
+ if field.Type.AssignableTo(counterPtrType) {
+ obj = factory.Counter(Options{
+ Name: metric,
+ Tags: tags,
+ Help: help,
+ })
+ } else if field.Type.AssignableTo(gaugePtrType) {
+ obj = factory.Gauge(Options{
+ Name: metric,
+ Tags: tags,
+ Help: help,
+ })
+ } else if field.Type.AssignableTo(timerPtrType) {
+ // TODO: Add buckets once parsed (see TODO above)
+ obj = factory.Timer(TimerOptions{
+ Name: metric,
+ Tags: tags,
+ Help: help,
+ })
+ } else if field.Type.AssignableTo(histogramPtrType) {
+ obj = factory.Histogram(HistogramOptions{
+ Name: metric,
+ Tags: tags,
+ Help: help,
+ Buckets: buckets,
+ })
+ } else {
+ return fmt.Errorf(
+ "Field %s is not a pointer to timer, gauge, or counter",
+ field.Name)
+ }
+ v.Field(i).Set(reflect.ValueOf(obj))
+ }
+ return nil
+}