parent
d42dd38b07
commit
a768269e5d
@ -1,94 +0,0 @@
|
||||
//
|
||||
// Copyright (c) 2019 Ted Unangst <tedu@tedunangst.com>
|
||||
//
|
||||
// Permission to use, copy, modify, and distribute this software for any
|
||||
// purpose with or without fee is hereby granted, provided that the above
|
||||
// copyright notice and this permission notice appear in all copies.
|
||||
//
|
||||
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
||||
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
||||
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
||||
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
||||
// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
||||
// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
||||
// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
||||
|
||||
package main
|
||||
|
||||
import (
|
||||
"reflect"
|
||||
"sync"
|
||||
"time"
|
||||
)
|
||||
|
||||
type cacheFiller func(key interface{}) (interface{}, bool)
|
||||
|
||||
type cacheOptions struct {
|
||||
Filler interface{}
|
||||
Duration time.Duration
|
||||
}
|
||||
|
||||
type Cache struct {
|
||||
cache map[interface{}]interface{}
|
||||
filler cacheFiller
|
||||
lock sync.Mutex
|
||||
stale time.Time
|
||||
duration time.Duration
|
||||
}
|
||||
|
||||
func cacheNew(options cacheOptions) *Cache {
|
||||
c := new(Cache)
|
||||
c.cache = make(map[interface{}]interface{})
|
||||
fillfn := options.Filler
|
||||
ftype := reflect.TypeOf(fillfn)
|
||||
if ftype.Kind() != reflect.Func {
|
||||
panic("cache filler is not function")
|
||||
}
|
||||
if ftype.NumIn() != 1 || ftype.NumOut() != 2 {
|
||||
panic("cache filler has wrong argument count")
|
||||
}
|
||||
c.filler = func(key interface{}) (interface{}, bool) {
|
||||
vfn := reflect.ValueOf(fillfn)
|
||||
args := []reflect.Value{reflect.ValueOf(key)}
|
||||
rv := vfn.Call(args)
|
||||
return rv[0].Interface(), rv[1].Bool()
|
||||
}
|
||||
if options.Duration != 0 {
|
||||
c.duration = options.Duration
|
||||
c.stale = time.Now().Add(c.duration)
|
||||
}
|
||||
return c
|
||||
}
|
||||
|
||||
func (cache *Cache) Get(key interface{}, value interface{}) bool {
|
||||
cache.lock.Lock()
|
||||
defer cache.lock.Unlock()
|
||||
if !cache.stale.IsZero() && cache.stale.Before(time.Now()) {
|
||||
cache.stale = time.Now().Add(cache.duration)
|
||||
cache.cache = make(map[interface{}]interface{})
|
||||
}
|
||||
v, ok := cache.cache[key]
|
||||
if !ok {
|
||||
v, ok = cache.filler(key)
|
||||
if ok {
|
||||
cache.cache[key] = v
|
||||
}
|
||||
}
|
||||
if ok {
|
||||
ptr := reflect.ValueOf(v)
|
||||
reflect.ValueOf(value).Elem().Set(ptr)
|
||||
}
|
||||
return ok
|
||||
}
|
||||
|
||||
func (cache *Cache) Clear(key interface{}) {
|
||||
cache.lock.Lock()
|
||||
defer cache.lock.Unlock()
|
||||
delete(cache.cache, key)
|
||||
}
|
||||
|
||||
func (cache *Cache) Flush() {
|
||||
cache.lock.Lock()
|
||||
defer cache.lock.Unlock()
|
||||
cache.cache = make(map[interface{}]interface{})
|
||||
}
|
Loading…
Reference in new issue