mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-14 23:17:27 +01:00
107 lines
2.2 KiB
Go
107 lines
2.2 KiB
Go
// Copyright 2024 The Ebitengine Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package text
|
|
|
|
import (
|
|
"math"
|
|
"sync"
|
|
"sync/atomic"
|
|
|
|
"github.com/hajimehoshi/ebiten/v2/internal/hook"
|
|
)
|
|
|
|
var monotonicClock atomic.Int64
|
|
|
|
const infTime = math.MaxInt64
|
|
|
|
func init() {
|
|
hook.AppendHookOnBeforeUpdate(func() error {
|
|
monotonicClock.Add(1)
|
|
return nil
|
|
})
|
|
}
|
|
|
|
type cacheValue[Value any] struct {
|
|
value Value
|
|
|
|
// atime is the last time when the value was accessed.
|
|
atime int64
|
|
}
|
|
|
|
type cache[Key comparable, Value any] struct {
|
|
// softLimit indicates the soft limit of the number of values in the cache.
|
|
softLimit int
|
|
|
|
values map[Key]*cacheValue[Value]
|
|
|
|
// atime is the last time when the cache was accessed.
|
|
atime int64
|
|
|
|
m sync.Mutex
|
|
}
|
|
|
|
func newCache[Key comparable, Value any](softLimit int) *cache[Key, Value] {
|
|
return &cache[Key, Value]{
|
|
softLimit: softLimit,
|
|
}
|
|
}
|
|
|
|
func (c *cache[Key, Value]) getOrCreate(key Key, create func() (Value, bool)) Value {
|
|
n := monotonicClock.Load()
|
|
|
|
c.m.Lock()
|
|
defer c.m.Unlock()
|
|
|
|
e, ok := c.values[key]
|
|
if ok {
|
|
e.atime = n
|
|
return e.value
|
|
}
|
|
|
|
if c.values == nil {
|
|
c.values = map[Key]*cacheValue[Value]{}
|
|
}
|
|
|
|
ent, canExpire := create()
|
|
e = &cacheValue[Value]{
|
|
value: ent,
|
|
atime: infTime,
|
|
}
|
|
if canExpire {
|
|
e.atime = n
|
|
}
|
|
c.values[key] = e
|
|
|
|
// Clean up old entries.
|
|
if c.atime < n {
|
|
// If the number of values exceeds the soft limits, old values are removed.
|
|
// Even after cleaning up the cache, the number of values might still exceed the soft limit,
|
|
// but this is fine.
|
|
if len(c.values) > c.softLimit {
|
|
for key, e := range c.values {
|
|
// 60 is an arbitrary number.
|
|
if e.atime >= n-60 {
|
|
continue
|
|
}
|
|
delete(c.values, key)
|
|
}
|
|
}
|
|
}
|
|
|
|
c.atime = n
|
|
|
|
return e.value
|
|
}
|