109 lines
3.1 KiB
Go
109 lines
3.1 KiB
Go
package gocache
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import (
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"fmt"
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"time"
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"unsafe"
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)
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// Entry is a cache entry
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type Entry struct {
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// Key is the name of the cache entry
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Key string
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// Value is the value of the cache entry
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Value interface{}
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// RelevantTimestamp is the variable used to store either:
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// - creation timestamp, if the Cache's EvictionPolicy is FirstInFirstOut
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// - last access timestamp, if the Cache's EvictionPolicy is LeastRecentlyUsed
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//
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// Note that updating an existing entry will also update this value
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RelevantTimestamp time.Time
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// Expiration is the unix time in nanoseconds at which the entry will expire (-1 means no expiration)
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Expiration int64
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next *Entry
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previous *Entry
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}
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// Accessed updates the Entry's RelevantTimestamp to now
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func (entry *Entry) Accessed() {
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entry.RelevantTimestamp = time.Now()
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}
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// Expired returns whether the Entry has expired
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func (entry Entry) Expired() bool {
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if entry.Expiration > 0 {
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if time.Now().UnixNano() > entry.Expiration {
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return true
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}
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}
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return false
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}
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// SizeInBytes returns the size of an entry in bytes, approximately.
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func (entry *Entry) SizeInBytes() int {
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return toBytes(entry.Key) + toBytes(entry.Value) + 32
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}
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func toBytes(value interface{}) int {
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switch value.(type) {
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case string:
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return int(unsafe.Sizeof(value)) + len(value.(string))
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case int8, uint8, bool:
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return int(unsafe.Sizeof(value)) + 1
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case int16, uint16:
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return int(unsafe.Sizeof(value)) + 2
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case int32, uint32, float32, complex64:
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return int(unsafe.Sizeof(value)) + 4
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case int64, uint64, int, uint, float64, complex128:
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return int(unsafe.Sizeof(value)) + 8
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case []interface{}:
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size := 0
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for _, v := range value.([]interface{}) {
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size += toBytes(v)
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}
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return int(unsafe.Sizeof(value)) + size
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case []string:
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size := 0
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for _, v := range value.([]string) {
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size += toBytes(v)
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}
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return int(unsafe.Sizeof(value)) + size
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case []int8:
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return int(unsafe.Sizeof(value)) + len(value.([]int8))
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case []uint8:
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return int(unsafe.Sizeof(value)) + len(value.([]uint8))
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case []bool:
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return int(unsafe.Sizeof(value)) + len(value.([]bool))
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case []int16:
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return int(unsafe.Sizeof(value)) + (len(value.([]int16)) * 2)
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case []uint16:
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return int(unsafe.Sizeof(value)) + (len(value.([]uint16)) * 2)
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case []int32:
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return int(unsafe.Sizeof(value)) + (len(value.([]int32)) * 4)
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case []uint32:
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return int(unsafe.Sizeof(value)) + (len(value.([]uint32)) * 4)
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case []float32:
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return int(unsafe.Sizeof(value)) + (len(value.([]float32)) * 4)
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case []complex64:
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return int(unsafe.Sizeof(value)) + (len(value.([]complex64)) * 4)
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case []int64:
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return int(unsafe.Sizeof(value)) + (len(value.([]int64)) * 8)
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case []uint64:
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return int(unsafe.Sizeof(value)) + (len(value.([]uint64)) * 8)
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case []int:
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return int(unsafe.Sizeof(value)) + (len(value.([]int)) * 8)
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case []uint:
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return int(unsafe.Sizeof(value)) + (len(value.([]uint)) * 8)
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case []float64:
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return int(unsafe.Sizeof(value)) + (len(value.([]float64)) * 8)
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case []complex128:
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return int(unsafe.Sizeof(value)) + (len(value.([]complex128)) * 8)
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default:
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return int(unsafe.Sizeof(value)) + len(fmt.Sprintf("%v", value))
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}
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}
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