62 lines
1.8 KiB
Go
62 lines
1.8 KiB
Go
package lcw
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import "fmt"
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// Value type wraps interface{}
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type Value interface{}
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// Sizer allows to perform size-based restrictions, optional.
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// If not defined both maxValueSize and maxCacheSize checks will be ignored
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type Sizer interface {
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Size() int
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}
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// LoadingCache defines guava-like cache with Get method returning cached value ao retriving it if not in cache
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type LoadingCache interface {
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Get(key string, fn func() (Value, error)) (val Value, err error) // load or get from cache
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Peek(key string) (Value, bool) // get from cache by key
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Invalidate(fn func(key string) bool) // invalidate items for func(key) == true
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Purge() // clear cache
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Stat() CacheStat // cache stats
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}
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// CacheStat represent stats values
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type CacheStat struct {
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Hits int64
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Misses int64
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Keys int
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Size int64
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Errors int64
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}
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// String fromats cache stats
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func (s *CacheStat) String() string {
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return fmt.Sprintf("{hits:%d, misses:%d, ratio:%.1f%%, keys:%d, size:%d, errors:%d}",
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s.Hits, s.Misses, 100*(float64(s.Hits)/float64(s.Hits+s.Misses)), s.Keys, s.Size, s.Errors)
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}
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// Nop is do-nothing implementation of LoadingCache
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type Nop struct{}
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// NewNopCache makes new do-nothing cache
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func NewNopCache() *Nop {
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return &Nop{}
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}
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// Get calls fn without any caching
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func (n *Nop) Get(key string, fn func() (Value, error)) (Value, error) { return fn() }
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// Peek does nothing and always returns false
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func (n *Nop) Peek(key string) (Value, bool) { return nil, false }
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// Invalidate does nothing for nop cache
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func (n *Nop) Invalidate(fn func(key string) bool) {}
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// Purge does nothing for nop cache
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func (n *Nop) Purge() {}
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// Stat always 0s for nop cache
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func (n *Nop) Stat() CacheStat {
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return CacheStat{}
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}
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