78 lines
1.6 KiB
Go
78 lines
1.6 KiB
Go
package cache
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import (
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"context"
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"errors"
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"fmt"
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"sync"
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"time"
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)
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type MapCache[K comparable, V any] struct {
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data map[K]V
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mutex *sync.Mutex
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setCacheFunc func(...any) (V, error)
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expireTime time.Duration
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setTime time.Time
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incr int
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}
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func NewMapCache[K comparable, V any](fun func(...any) (V, error), duration time.Duration) *MapCache[K, V] {
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return &MapCache[K, V]{
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mutex: &sync.Mutex{},
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setCacheFunc: fun,
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expireTime: duration,
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data: make(map[K]V),
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}
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}
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func (c *MapCache[K, V]) FlushCache(k any) {
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c.mutex.Lock()
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defer c.mutex.Unlock()
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key := k.(K)
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delete(c.data, key)
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}
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func (c *MapCache[K, V]) GetCache(ctx context.Context, key K, timeout time.Duration, params ...any) (V, error) {
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_, ok := c.data[key]
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var err error
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expired := time.Duration(c.setTime.Unix())+c.expireTime/time.Second < time.Duration(time.Now().Unix())
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//todo 这里应该判断下取出的值是否为零值，不过怎么操作呢？
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if !ok || (c.expireTime >= 0 && expired) {
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t := c.incr
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call := func() {
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c.mutex.Lock()
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defer c.mutex.Unlock()
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if c.incr > t {
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return
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}
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r, er := c.setCacheFunc(params...)
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if err != nil {
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err = er
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return
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}
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c.setTime = time.Now()
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c.data[key] = r
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c.incr++
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}
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if timeout > 0 {
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ctx, cancel := context.WithTimeout(ctx, timeout)
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defer cancel()
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done := make(chan struct{})
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go func() {
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call()
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done <- struct{}{}
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}()
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select {
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case <-ctx.Done():
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err = errors.New(fmt.Sprintf("get cache %v %s", key, ctx.Err().Error()))
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case <-done:
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}
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} else {
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call()
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}
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}
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return c.data[key], err
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}
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