gotosocial/vendor/codeberg.org/gruf/go-cache/v3/simple/cache.go

455 lines
8 KiB
Go

package simple
import (
"sync"
"codeberg.org/gruf/go-maps"
)
// Entry represents an item in the cache.
type Entry struct {
Key any
Value any
}
// Cache is the underlying Cache implementation, providing both the base Cache interface and unsafe access to underlying map to allow flexibility in building your own.
type Cache[Key comparable, Value any] struct {
// Evict is the hook that is called when an item is evicted from the cache.
Evict func(Key, Value)
// Invalid is the hook that is called when an item's data in the cache is invalidated, includes Add/Set.
Invalid func(Key, Value)
// Cache is the underlying hashmap used for this cache.
Cache maps.LRUMap[Key, *Entry]
// Embedded mutex.
sync.Mutex
}
// New returns a new initialized Cache with given initial length, maximum capacity and item TTL.
func New[K comparable, V any](len, cap int) *Cache[K, V] {
c := new(Cache[K, V])
c.Init(len, cap)
return c
}
// Init will initialize this cache with given initial length, maximum capacity and item TTL.
func (c *Cache[K, V]) Init(len, cap int) {
c.SetEvictionCallback(nil)
c.SetInvalidateCallback(nil)
c.Cache.Init(len, cap)
}
// SetEvictionCallback: implements cache.Cache's SetEvictionCallback().
func (c *Cache[K, V]) SetEvictionCallback(hook func(K, V)) {
c.locked(func() { c.Evict = hook })
}
// SetInvalidateCallback: implements cache.Cache's SetInvalidateCallback().
func (c *Cache[K, V]) SetInvalidateCallback(hook func(K, V)) {
c.locked(func() { c.Invalid = hook })
}
// Get: implements cache.Cache's Get().
func (c *Cache[K, V]) Get(key K) (V, bool) {
var (
// did exist in cache?
ok bool
// cached value.
v V
)
c.locked(func() {
var item *Entry
// Check for item in cache
item, ok = c.Cache.Get(key)
if !ok {
return
}
// Set item value.
v = item.Value.(V)
})
return v, ok
}
// Add: implements cache.Cache's Add().
func (c *Cache[K, V]) Add(key K, value V) bool {
var (
// did exist in cache?
ok bool
// was entry evicted?
ev bool
// evicted key values.
evcK K
evcV V
// hook func ptrs.
evict func(K, V)
)
c.locked(func() {
// Check if in cache.
ok = c.Cache.Has(key)
if ok {
return
}
// Alloc new entry.
new := GetEntry()
new.Key = key
new.Value = value
// Add new entry to cache and catched any evicted item.
c.Cache.SetWithHook(key, new, func(_ K, item *Entry) {
evcK = item.Key.(K)
evcV = item.Value.(V)
ev = true
PutEntry(item)
})
// Set hook func ptr.
evict = c.Evict
})
if ev && evict != nil {
// Pass to eviction hook.
evict(evcK, evcV)
}
return !ok
}
// Set: implements cache.Cache's Set().
func (c *Cache[K, V]) Set(key K, value V) {
var (
// did exist in cache?
ok bool
// was entry evicted?
ev bool
// old value.
oldV V
// evicted key values.
evcK K
evcV V
// hook func ptrs.
invalid func(K, V)
evict func(K, V)
)
c.locked(func() {
var item *Entry
// Check for item in cache
item, ok = c.Cache.Get(key)
if ok {
// Set old value.
oldV = item.Value.(V)
// Update the existing item.
item.Value = value
} else {
// Alloc new entry.
new := GetEntry()
new.Key = key
new.Value = value
// Add new entry to cache and catched any evicted item.
c.Cache.SetWithHook(key, new, func(_ K, item *Entry) {
evcK = item.Key.(K)
evcV = item.Value.(V)
ev = true
PutEntry(item)
})
}
// Set hook func ptrs.
invalid = c.Invalid
evict = c.Evict
})
if ok && invalid != nil {
// Pass to invalidate hook.
invalid(key, oldV)
}
if ev && evict != nil {
// Pass to eviction hook.
evict(evcK, evcV)
}
}
// CAS: implements cache.Cache's CAS().
func (c *Cache[K, V]) CAS(key K, old V, new V, cmp func(V, V) bool) bool {
var (
// did exist in cache?
ok bool
// swapped value.
oldV V
// hook func ptrs.
invalid func(K, V)
)
c.locked(func() {
var item *Entry
// Check for item in cache
item, ok = c.Cache.Get(key)
if !ok {
return
}
// Set old value.
oldV = item.Value.(V)
// Perform the comparison
if !cmp(old, oldV) {
var zero V
oldV = zero
return
}
// Update value.
item.Value = new
// Set hook func ptr.
invalid = c.Invalid
})
if ok && invalid != nil {
// Pass to invalidate hook.
invalid(key, oldV)
}
return ok
}
// Swap: implements cache.Cache's Swap().
func (c *Cache[K, V]) Swap(key K, swp V) V {
var (
// did exist in cache?
ok bool
// swapped value.
oldV V
// hook func ptrs.
invalid func(K, V)
)
c.locked(func() {
var item *Entry
// Check for item in cache
item, ok = c.Cache.Get(key)
if !ok {
return
}
// Set old value.
oldV = item.Value.(V)
// Update value.
item.Value = swp
// Set hook func ptr.
invalid = c.Invalid
})
if ok && invalid != nil {
// Pass to invalidate hook.
invalid(key, oldV)
}
return oldV
}
// Has: implements cache.Cache's Has().
func (c *Cache[K, V]) Has(key K) (ok bool) {
c.locked(func() {
ok = c.Cache.Has(key)
})
return
}
// Invalidate: implements cache.Cache's Invalidate().
func (c *Cache[K, V]) Invalidate(key K) (ok bool) {
var (
// old value.
oldV V
// hook func ptrs.
invalid func(K, V)
)
c.locked(func() {
var item *Entry
// Check for item in cache
item, ok = c.Cache.Get(key)
if !ok {
return
}
// Set old value.
oldV = item.Value.(V)
// Remove from cache map
_ = c.Cache.Delete(key)
// Free entry
PutEntry(item)
// Set hook func ptrs.
invalid = c.Invalid
})
if ok && invalid != nil {
// Pass to invalidate hook.
invalid(key, oldV)
}
return
}
// InvalidateAll: implements cache.Cache's InvalidateAll().
func (c *Cache[K, V]) InvalidateAll(keys ...K) (ok bool) {
var (
// deleted items.
items []*Entry
// hook func ptrs.
invalid func(K, V)
)
// Allocate a slice for invalidated.
items = make([]*Entry, 0, len(keys))
c.locked(func() {
for x := range keys {
var item *Entry
// Check for item in cache
item, ok = c.Cache.Get(keys[x])
if !ok {
continue
}
// Append this old value.
items = append(items, item)
// Remove from cache map
_ = c.Cache.Delete(keys[x])
}
// Set hook func ptrs.
invalid = c.Invalid
})
if invalid != nil {
for x := range items {
// Pass to invalidate hook.
k := items[x].Key.(K)
v := items[x].Value.(V)
invalid(k, v)
// Free this entry.
PutEntry(items[x])
}
}
return
}
// Clear: implements cache.Cache's Clear().
func (c *Cache[K, V]) Clear() { c.Trim(100) }
// Trim will truncate the cache to ensure it stays within given percentage of total capacity.
func (c *Cache[K, V]) Trim(perc float64) {
var (
// deleted items
items []*Entry
// hook func ptrs.
invalid func(K, V)
)
c.locked(func() {
// Calculate number of cache items to truncate.
max := (perc / 100) * float64(c.Cache.Cap())
diff := c.Cache.Len() - int(max)
if diff <= 0 {
return
}
// Set hook func ptr.
invalid = c.Invalid
// Truncate by calculated length.
items = c.truncate(diff, invalid)
})
if invalid != nil {
for x := range items {
// Pass to invalidate hook.
k := items[x].Key.(K)
v := items[x].Value.(V)
invalid(k, v)
// Free this entry.
PutEntry(items[x])
}
}
}
// Len: implements cache.Cache's Len().
func (c *Cache[K, V]) Len() (l int) {
c.locked(func() { l = c.Cache.Len() })
return
}
// Cap: implements cache.Cache's Cap().
func (c *Cache[K, V]) Cap() (l int) {
c.locked(func() { l = c.Cache.Cap() })
return
}
// locked performs given function within mutex lock (NOTE: UNLOCK IS NOT DEFERRED).
func (c *Cache[K, V]) locked(fn func()) {
c.Lock()
fn()
c.Unlock()
}
// truncate will truncate the cache by given size, returning deleted items.
func (c *Cache[K, V]) truncate(sz int, hook func(K, V)) []*Entry {
if hook == nil {
// No hook to execute, simply release all truncated entries.
c.Cache.Truncate(sz, func(_ K, item *Entry) { PutEntry(item) })
return nil
}
// Allocate a slice for deleted.
deleted := make([]*Entry, 0, sz)
// Truncate and catch all deleted k-v pairs.
c.Cache.Truncate(sz, func(_ K, item *Entry) {
deleted = append(deleted, item)
})
return deleted
}