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lrucacheuint64tohash.go
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lrucacheuint64tohash.go
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package lrucacheuint64tohash
import "github.com/BTCGhostdag/BTCD/domain/consensus/model/externalapi"
// LRUCache is a least-recently-used cache from
// uint64 to DomainHash
type LRUCache struct {
cache map[uint64]*externalapi.DomainHash
capacity int
}
// New creates a new LRUCache
func New(capacity int, preallocate bool) *LRUCache {
var cache map[uint64]*externalapi.DomainHash
if preallocate {
cache = make(map[uint64]*externalapi.DomainHash, capacity+1)
} else {
cache = make(map[uint64]*externalapi.DomainHash)
}
return &LRUCache{
cache: cache,
capacity: capacity,
}
}
// Add adds an entry to the LRUCache
func (c *LRUCache) Add(key uint64, value *externalapi.DomainHash) {
c.cache[key] = value
if len(c.cache) > c.capacity {
c.evictRandom()
}
}
// Get returns the entry for the given key, or (nil, false) otherwise
func (c *LRUCache) Get(key uint64) (*externalapi.DomainHash, bool) {
value, ok := c.cache[key]
if !ok {
return nil, false
}
return value, true
}
// Has returns whether the LRUCache contains the given key
func (c *LRUCache) Has(key uint64) bool {
_, ok := c.cache[key]
return ok
}
// Remove removes the entry for the the given key. Does nothing if
// the entry does not exist
func (c *LRUCache) Remove(key uint64) {
delete(c.cache, key)
}
func (c *LRUCache) evictRandom() {
var keyToEvict uint64
for key := range c.cache {
keyToEvict = key
break
}
c.Remove(keyToEvict)
}