66 lines
1.7 KiB
Go
66 lines
1.7 KiB
Go
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//
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// Copyright (c) 2019 Ted Unangst <tedu@tedunangst.com>
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//
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// Permission to use, copy, modify, and distribute this software for any
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// purpose with or without fee is hereby granted, provided that the above
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// copyright notice and this permission notice appear in all copies.
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//
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// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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package main
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import (
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"reflect"
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"sync"
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)
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type cacheFiller func(key interface{}) (interface{}, bool)
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type Cache struct {
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cache map[interface{}]interface{}
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filler cacheFiller
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lock sync.Mutex
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}
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func cacheNew(filler cacheFiller) *Cache {
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c := new(Cache)
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c.cache = make(map[interface{}]interface{})
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c.filler = filler
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return c
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}
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func (cache *Cache) Get(key interface{}, value interface{}) bool {
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cache.lock.Lock()
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defer cache.lock.Unlock()
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v, ok := cache.cache[key]
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if !ok {
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v, ok = cache.filler(key)
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if ok {
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cache.cache[key] = v
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}
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}
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if ok {
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ptr := reflect.ValueOf(v)
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reflect.ValueOf(value).Elem().Set(ptr)
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}
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return ok
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}
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func (cache *Cache) Clear(key interface{}) {
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cache.lock.Lock()
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defer cache.lock.Unlock()
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delete(cache.cache, key)
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}
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func (cache *Cache) Flush() {
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cache.lock.Lock()
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defer cache.lock.Unlock()
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cache.cache = make(map[interface{}]interface{})
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}
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