diff options
Diffstat (limited to 'vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go')
| -rw-r--r-- | vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go | 48 |
1 files changed, 22 insertions, 26 deletions
diff --git a/vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go b/vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go index 7f9fda5b4..199a2608f 100644 --- a/vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go +++ b/vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go @@ -1,16 +1,5 @@ // Copyright The OpenTelemetry 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. +// SPDX-License-Identifier: Apache-2.0 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar" @@ -18,17 +7,21 @@ import ( "context" "math" "math/rand" + "sync" "time" "go.opentelemetry.io/otel/attribute" - "go.opentelemetry.io/otel/sdk/metric/metricdata" ) -// rng is used to make sampling decisions. -// -// Do not use crypto/rand. There is no reason for the decrease in performance -// given this is not a security sensitive decision. -var rng = rand.New(rand.NewSource(time.Now().UnixNano())) +var ( + // rng is used to make sampling decisions. + // + // Do not use crypto/rand. There is no reason for the decrease in performance + // given this is not a security sensitive decision. + rng = rand.New(rand.NewSource(time.Now().UnixNano())) + // Ensure concurrent safe accecess to rng and its underlying source. + rngMu sync.Mutex +) // random returns, as a float64, a uniform pseudo-random number in the open // interval (0.0,1.0). @@ -50,6 +43,9 @@ func random() float64 { // // There are likely many other methods to explore here as well. + rngMu.Lock() + defer rngMu.Unlock() + f := rng.Float64() for f == 0 { f = rng.Float64() @@ -61,14 +57,14 @@ func random() float64 { // are k or less measurements made, the Reservoir will sample each one. If // there are more than k, the Reservoir will then randomly sample all // additional measurement with a decreasing probability. -func FixedSize[N int64 | float64](k int) Reservoir[N] { - r := &randRes[N]{storage: newStorage[N](k)} +func FixedSize(k int) Reservoir { + r := &randRes{storage: newStorage(k)} r.reset() return r } -type randRes[N int64 | float64] struct { - *storage[N] +type randRes struct { + *storage // count is the number of measurement seen. count int64 @@ -80,7 +76,7 @@ type randRes[N int64 | float64] struct { w float64 } -func (r *randRes[N]) Offer(ctx context.Context, t time.Time, n N, a []attribute.KeyValue) { +func (r *randRes) Offer(ctx context.Context, t time.Time, n Value, a []attribute.KeyValue) { // The following algorithm is "Algorithm L" from Li, Kim-Hung (4 December // 1994). "Reservoir-Sampling Algorithms of Time Complexity // O(n(1+log(N/n)))". ACM Transactions on Mathematical Software. 20 (4): @@ -136,7 +132,7 @@ func (r *randRes[N]) Offer(ctx context.Context, t time.Time, n N, a []attribute. } // reset resets r to the initial state. -func (r *randRes[N]) reset() { +func (r *randRes) reset() { // This resets the number of exemplars known. r.count = 0 // Random index inserts should only happen after the storage is full. @@ -158,7 +154,7 @@ func (r *randRes[N]) reset() { // advance updates the count at which the offered measurement will overwrite an // existing exemplar. -func (r *randRes[N]) advance() { +func (r *randRes) advance() { // Calculate the next value in the random number series. // // The current value of r.w is based on the max of a distribution of random @@ -185,7 +181,7 @@ func (r *randRes[N]) advance() { r.next += int64(math.Log(random())/math.Log(1-r.w)) + 1 } -func (r *randRes[N]) Collect(dest *[]metricdata.Exemplar[N]) { +func (r *randRes) Collect(dest *[]Exemplar) { r.storage.Collect(dest) // Call reset here even though it will reset r.count and restart the random // number series. This will persist any old exemplars as long as no new |