mirror of
https://github.com/go-gitea/gitea
synced 2024-11-05 05:39:14 +01:00
88 lines
2.3 KiB
Go
88 lines
2.3 KiB
Go
|
// Copyright (c) 2016 Couchbase, 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 registry
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"sync"
|
||
|
|
)
|
||
|
|
|
||
|
|
var ErrAlreadyDefined = fmt.Errorf("item already defined")
|
||
|
|
|
||
|
|
type CacheBuild func(name string, config map[string]interface{}, cache *Cache) (interface{}, error)
|
||
|
|
|
||
|
|
type ConcurrentCache struct {
|
||
|
|
mutex sync.RWMutex
|
||
|
|
data map[string]interface{}
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewConcurrentCache() *ConcurrentCache {
|
||
|
|
return &ConcurrentCache{
|
||
|
|
data: make(map[string]interface{}),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (c *ConcurrentCache) ItemNamed(name string, cache *Cache, build CacheBuild) (interface{}, error) {
|
||
|
|
c.mutex.RLock()
|
||
|
|
item, cached := c.data[name]
|
||
|
|
if cached {
|
||
|
|
c.mutex.RUnlock()
|
||
|
|
return item, nil
|
||
|
|
}
|
||
|
|
// give up read lock
|
||
|
|
c.mutex.RUnlock()
|
||
|
|
// try to build it
|
||
|
|
newItem, err := build(name, nil, cache)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
// acquire write lock
|
||
|
|
c.mutex.Lock()
|
||
|
|
defer c.mutex.Unlock()
|
||
|
|
// check again because it could have been created while trading locks
|
||
|
|
item, cached = c.data[name]
|
||
|
|
if cached {
|
||
|
|
return item, nil
|
||
|
|
}
|
||
|
|
c.data[name] = newItem
|
||
|
|
return newItem, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func (c *ConcurrentCache) DefineItem(name string, typ string, config map[string]interface{}, cache *Cache, build CacheBuild) (interface{}, error) {
|
||
|
|
c.mutex.RLock()
|
||
|
|
_, cached := c.data[name]
|
||
|
|
if cached {
|
||
|
|
c.mutex.RUnlock()
|
||
|
|
return nil, ErrAlreadyDefined
|
||
|
|
}
|
||
|
|
// give up read lock so others lookups can proceed
|
||
|
|
c.mutex.RUnlock()
|
||
|
|
// really not there, try to build it
|
||
|
|
newItem, err := build(typ, config, cache)
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
// now we've built it, acquire lock
|
||
|
|
c.mutex.Lock()
|
||
|
|
defer c.mutex.Unlock()
|
||
|
|
// check again because it could have been created while trading locks
|
||
|
|
_, cached = c.data[name]
|
||
|
|
if cached {
|
||
|
|
return nil, ErrAlreadyDefined
|
||
|
|
}
|
||
|
|
c.data[name] = newItem
|
||
|
|
return newItem, nil
|
||
|
|
}
|