mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-27 06:06:38 +00:00
5e871e81a8
* otel to 1.24 * prometheus exporter to 0.46 * bunotel to 1.1.17 Also: * Use schemaless URL for metrics * Add software version to tracing schema
95 lines
2.7 KiB
Go
95 lines
2.7 KiB
Go
// 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.
|
|
|
|
package metric // import "go.opentelemetry.io/otel/sdk/metric"
|
|
|
|
import (
|
|
"sync"
|
|
)
|
|
|
|
// cache is a locking storage used to quickly return already computed values.
|
|
//
|
|
// The zero value of a cache is empty and ready to use.
|
|
//
|
|
// A cache must not be copied after first use.
|
|
//
|
|
// All methods of a cache are safe to call concurrently.
|
|
type cache[K comparable, V any] struct {
|
|
sync.Mutex
|
|
data map[K]V
|
|
}
|
|
|
|
// Lookup returns the value stored in the cache with the associated key if it
|
|
// exists. Otherwise, f is called and its returned value is set in the cache
|
|
// for key and returned.
|
|
//
|
|
// Lookup is safe to call concurrently. It will hold the cache lock, so f
|
|
// should not block excessively.
|
|
func (c *cache[K, V]) Lookup(key K, f func() V) V {
|
|
c.Lock()
|
|
defer c.Unlock()
|
|
|
|
if c.data == nil {
|
|
val := f()
|
|
c.data = map[K]V{key: val}
|
|
return val
|
|
}
|
|
if v, ok := c.data[key]; ok {
|
|
return v
|
|
}
|
|
val := f()
|
|
c.data[key] = val
|
|
return val
|
|
}
|
|
|
|
// HasKey returns true if Lookup has previously been called with that key
|
|
//
|
|
// HasKey is safe to call concurrently.
|
|
func (c *cache[K, V]) HasKey(key K) bool {
|
|
c.Lock()
|
|
defer c.Unlock()
|
|
_, ok := c.data[key]
|
|
return ok
|
|
}
|
|
|
|
// cacheWithErr is a locking storage used to quickly return already computed values and an error.
|
|
//
|
|
// The zero value of a cacheWithErr is empty and ready to use.
|
|
//
|
|
// A cacheWithErr must not be copied after first use.
|
|
//
|
|
// All methods of a cacheWithErr are safe to call concurrently.
|
|
type cacheWithErr[K comparable, V any] struct {
|
|
cache[K, valAndErr[V]]
|
|
}
|
|
|
|
type valAndErr[V any] struct {
|
|
val V
|
|
err error
|
|
}
|
|
|
|
// Lookup returns the value stored in the cacheWithErr with the associated key
|
|
// if it exists. Otherwise, f is called and its returned value is set in the
|
|
// cacheWithErr for key and returned.
|
|
//
|
|
// Lookup is safe to call concurrently. It will hold the cacheWithErr lock, so f
|
|
// should not block excessively.
|
|
func (c *cacheWithErr[K, V]) Lookup(key K, f func() (V, error)) (V, error) {
|
|
combined := c.cache.Lookup(key, func() valAndErr[V] {
|
|
val, err := f()
|
|
return valAndErr[V]{val: val, err: err}
|
|
})
|
|
return combined.val, combined.err
|
|
}
|