74 lines
1.3 KiB
Go
74 lines
1.3 KiB
Go
package kvmemcache
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import (
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"container/list"
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"sync"
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"time"
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"git.crumpington.com/public/toolbox/keyedmutex"
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)
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type Cache struct {
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updateLock keyedmutex.KeyedMutex
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src func(string) (interface{}, error)
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ttl time.Duration
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maxSize int
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// Lock protects cache, ll, and stats.
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lock sync.Mutex
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cache map[string]*list.Element
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ll *list.List
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stats Stats
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}
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type lruItem struct {
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key string
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createdAt time.Time
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value interface{}
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err error
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}
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type Config struct {
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MaxSize int
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TTL time.Duration // Zero to ignore.
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Src func(string) (interface{}, error)
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}
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type Stats struct {
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Hits uint64
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Misses uint64
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Expired uint64
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}
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func New(conf Config) *Cache {
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return &Cache{
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lock: sync.Mutex{},
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updateLock: keyedmutex.New(),
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src: conf.Src,
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ttl: conf.TTL,
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maxSize: conf.MaxSize,
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cache: make(map[string]*list.Element),
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ll: list.New(),
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}
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}
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func (c *Cache) Get(key string) (interface{}, error) {
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item := c.getItem(key)
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if item == nil {
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item = c.loadItemFromSource(key)
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}
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return item.value, item.err
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}
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func (c *Cache) Evict(key string) {
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c.lock.Lock()
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defer c.lock.Unlock()
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c.evictKey(key)
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}
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func (c Cache) Stats() Stats {
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c.lock.Lock()
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defer c.lock.Unlock()
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return c.stats
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}
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