wp-go/cache/map.go
2022-09-20 16:11:20 +08:00

76 lines
1.5 KiB
Go

package cache
import (
"context"
"errors"
"fmt"
"sync"
"time"
)
type MapCache[K comparable, V any] struct {
data map[K]V
mutex *sync.Mutex
setCacheFunc func(...any) (V, error)
expireTime time.Duration
setTime time.Time
incr int
}
func NewMapCache[K comparable, V any](fun func(...any) (V, error), duration time.Duration) *MapCache[K, V] {
return &MapCache[K, V]{
mutex: &sync.Mutex{},
setCacheFunc: fun,
expireTime: duration,
}
}
func (c *MapCache[K, V]) FlushCache(k any) {
c.mutex.Lock()
defer c.mutex.Unlock()
key := k.(K)
delete(c.data, key)
}
func (c *MapCache[K, V]) GetCache(ctx context.Context, key K, timeout time.Duration, params ...any) (V, error) {
l := len(c.data)
var err error
expired := time.Duration(c.setTime.Unix())+c.expireTime/time.Second < time.Duration(time.Now().Unix())
if l < 1 || (l > 0 && c.expireTime >= 0 && expired) {
t := c.incr
call := func() {
c.mutex.Lock()
defer c.mutex.Unlock()
if c.incr > t {
return
}
r, er := c.setCacheFunc(params...)
if err != nil {
err = er
return
}
c.setTime = time.Now()
c.data[key] = r
c.incr++
}
if timeout > 0 {
ctx, cancel := context.WithTimeout(ctx, timeout)
defer cancel()
done := make(chan struct{})
go func() {
call()
done <- struct{}{}
}()
select {
case <-ctx.Done():
err = errors.New(fmt.Sprintf("get cache %v %s", key, ctx.Err().Error()))
case <-done:
}
} else {
call()
}
}
return c.data[key], err
}