mirror of
https://github.com/prometheus/prometheus.git
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807fd33ecc
- Update read path to use labels.Labels. - Fix the tests. - Remove pack. - Remove unused function. - Fix race in tests. Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
91 lines
1.7 KiB
Go
91 lines
1.7 KiB
Go
// Copyright 2019 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Inspired / copied / modified from https://gitlab.com/cznic/strutil/blob/master/strutil.go,
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// which is MIT licensed, so:
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//
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// Copyright (c) 2014 The strutil Authors. All rights reserved.
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package remote
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import (
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"sync"
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"sync/atomic"
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)
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var interner = newPool()
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type pool struct {
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mtx sync.RWMutex
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pool map[string]*entry
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}
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type entry struct {
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s string
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refs int64
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}
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func newPool() *pool {
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return &pool{
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pool: map[string]*entry{},
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}
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}
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func (p *pool) intern(s string) string {
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if s == "" {
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return ""
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}
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p.mtx.RLock()
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interned, ok := p.pool[s]
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p.mtx.RUnlock()
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if ok {
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atomic.AddInt64(&interned.refs, 1)
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return interned.s
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}
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p.mtx.Lock()
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defer p.mtx.Unlock()
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if interned, ok := p.pool[s]; ok {
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atomic.AddInt64(&interned.refs, 1)
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return interned.s
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}
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p.pool[s] = &entry{
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s: s,
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refs: 1,
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}
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return s
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}
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func (p *pool) release(s string) {
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p.mtx.RLock()
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interned, ok := p.pool[s]
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p.mtx.RUnlock()
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if !ok {
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panic("released unknown string")
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}
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refs := atomic.AddInt64(&interned.refs, -1)
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if refs > 0 {
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return
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}
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p.mtx.Lock()
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defer p.mtx.Unlock()
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if atomic.LoadInt64(&interned.refs) != 0 {
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return
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}
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delete(p.pool, s)
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}
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