mirror of
https://github.com/containous/traefik.git
synced 2024-12-23 17:34:13 +03:00
1162 lines
30 KiB
Go
1162 lines
30 KiB
Go
package cache
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import (
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"encoding/gob"
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"fmt"
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"io"
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"os"
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"runtime"
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"sync"
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"time"
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)
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type Item struct {
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Object interface{}
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Expiration int64
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}
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// Returns true if the item has expired.
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func (item Item) Expired() bool {
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if item.Expiration == 0 {
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return false
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}
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return time.Now().UnixNano() > item.Expiration
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}
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const (
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// For use with functions that take an expiration time.
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NoExpiration time.Duration = -1
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// For use with functions that take an expiration time. Equivalent to
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// passing in the same expiration duration as was given to New() or
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// NewFrom() when the cache was created (e.g. 5 minutes.)
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DefaultExpiration time.Duration = 0
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)
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type Cache struct {
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*cache
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// If this is confusing, see the comment at the bottom of New()
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}
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type cache struct {
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defaultExpiration time.Duration
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items map[string]Item
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mu sync.RWMutex
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onEvicted func(string, interface{})
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janitor *janitor
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}
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// Add an item to the cache, replacing any existing item. If the duration is 0
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// (DefaultExpiration), the cache's default expiration time is used. If it is -1
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// (NoExpiration), the item never expires.
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func (c *cache) Set(k string, x interface{}, d time.Duration) {
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// "Inlining" of set
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var e int64
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if d == DefaultExpiration {
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d = c.defaultExpiration
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}
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if d > 0 {
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e = time.Now().Add(d).UnixNano()
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}
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c.mu.Lock()
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c.items[k] = Item{
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Object: x,
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Expiration: e,
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}
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// TODO: Calls to mu.Unlock are currently not deferred because defer
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// adds ~200 ns (as of go1.)
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c.mu.Unlock()
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}
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func (c *cache) set(k string, x interface{}, d time.Duration) {
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var e int64
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if d == DefaultExpiration {
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d = c.defaultExpiration
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}
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if d > 0 {
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e = time.Now().Add(d).UnixNano()
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}
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c.items[k] = Item{
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Object: x,
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Expiration: e,
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}
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}
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// Add an item to the cache, replacing any existing item, using the default
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// expiration.
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func (c *cache) SetDefault(k string, x interface{}) {
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c.Set(k, x, DefaultExpiration)
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}
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// Add an item to the cache only if an item doesn't already exist for the given
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// key, or if the existing item has expired. Returns an error otherwise.
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func (c *cache) Add(k string, x interface{}, d time.Duration) error {
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c.mu.Lock()
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_, found := c.get(k)
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if found {
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c.mu.Unlock()
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return fmt.Errorf("Item %s already exists", k)
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}
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c.set(k, x, d)
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c.mu.Unlock()
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return nil
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}
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// Set a new value for the cache key only if it already exists, and the existing
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// item hasn't expired. Returns an error otherwise.
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func (c *cache) Replace(k string, x interface{}, d time.Duration) error {
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c.mu.Lock()
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_, found := c.get(k)
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if !found {
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c.mu.Unlock()
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return fmt.Errorf("Item %s doesn't exist", k)
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}
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c.set(k, x, d)
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c.mu.Unlock()
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return nil
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}
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// Get an item from the cache. Returns the item or nil, and a bool indicating
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// whether the key was found.
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func (c *cache) Get(k string) (interface{}, bool) {
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c.mu.RLock()
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// "Inlining" of get and Expired
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item, found := c.items[k]
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if !found {
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c.mu.RUnlock()
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return nil, false
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}
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if item.Expiration > 0 {
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if time.Now().UnixNano() > item.Expiration {
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c.mu.RUnlock()
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return nil, false
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}
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}
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c.mu.RUnlock()
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return item.Object, true
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}
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// GetWithExpiration returns an item and its expiration time from the cache.
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// It returns the item or nil, the expiration time if one is set (if the item
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// never expires a zero value for time.Time is returned), and a bool indicating
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// whether the key was found.
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func (c *cache) GetWithExpiration(k string) (interface{}, time.Time, bool) {
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c.mu.RLock()
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// "Inlining" of get and Expired
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item, found := c.items[k]
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if !found {
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c.mu.RUnlock()
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return nil, time.Time{}, false
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}
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if item.Expiration > 0 {
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if time.Now().UnixNano() > item.Expiration {
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c.mu.RUnlock()
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return nil, time.Time{}, false
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}
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// Return the item and the expiration time
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c.mu.RUnlock()
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return item.Object, time.Unix(0, item.Expiration), true
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}
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// If expiration <= 0 (i.e. no expiration time set) then return the item
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// and a zeroed time.Time
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c.mu.RUnlock()
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return item.Object, time.Time{}, true
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}
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func (c *cache) get(k string) (interface{}, bool) {
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item, found := c.items[k]
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if !found {
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return nil, false
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}
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// "Inlining" of Expired
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if item.Expiration > 0 {
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if time.Now().UnixNano() > item.Expiration {
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return nil, false
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}
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}
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return item.Object, true
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}
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// Increment an item of type int, int8, int16, int32, int64, uintptr, uint,
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// uint8, uint32, or uint64, float32 or float64 by n. Returns an error if the
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// item's value is not an integer, if it was not found, or if it is not
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// possible to increment it by n. To retrieve the incremented value, use one
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// of the specialized methods, e.g. IncrementInt64.
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func (c *cache) Increment(k string, n int64) error {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return fmt.Errorf("Item %s not found", k)
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}
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switch v.Object.(type) {
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case int:
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v.Object = v.Object.(int) + int(n)
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case int8:
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v.Object = v.Object.(int8) + int8(n)
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case int16:
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v.Object = v.Object.(int16) + int16(n)
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case int32:
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v.Object = v.Object.(int32) + int32(n)
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case int64:
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v.Object = v.Object.(int64) + n
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case uint:
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v.Object = v.Object.(uint) + uint(n)
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case uintptr:
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v.Object = v.Object.(uintptr) + uintptr(n)
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case uint8:
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v.Object = v.Object.(uint8) + uint8(n)
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case uint16:
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v.Object = v.Object.(uint16) + uint16(n)
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case uint32:
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v.Object = v.Object.(uint32) + uint32(n)
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case uint64:
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v.Object = v.Object.(uint64) + uint64(n)
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case float32:
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v.Object = v.Object.(float32) + float32(n)
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case float64:
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v.Object = v.Object.(float64) + float64(n)
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default:
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c.mu.Unlock()
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return fmt.Errorf("The value for %s is not an integer", k)
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}
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c.items[k] = v
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c.mu.Unlock()
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return nil
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}
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// Increment an item of type float32 or float64 by n. Returns an error if the
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// item's value is not floating point, if it was not found, or if it is not
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// possible to increment it by n. Pass a negative number to decrement the
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// value. To retrieve the incremented value, use one of the specialized methods,
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// e.g. IncrementFloat64.
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func (c *cache) IncrementFloat(k string, n float64) error {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return fmt.Errorf("Item %s not found", k)
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}
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switch v.Object.(type) {
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case float32:
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v.Object = v.Object.(float32) + float32(n)
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case float64:
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v.Object = v.Object.(float64) + n
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default:
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c.mu.Unlock()
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return fmt.Errorf("The value for %s does not have type float32 or float64", k)
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}
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c.items[k] = v
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c.mu.Unlock()
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return nil
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}
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// Increment an item of type int by n. Returns an error if the item's value is
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// not an int, or if it was not found. If there is no error, the incremented
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// value is returned.
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func (c *cache) IncrementInt(k string, n int) (int, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(int)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an int", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
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// Increment an item of type int8 by n. Returns an error if the item's value is
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// not an int8, or if it was not found. If there is no error, the incremented
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// value is returned.
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func (c *cache) IncrementInt8(k string, n int8) (int8, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(int8)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an int8", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
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// Increment an item of type int16 by n. Returns an error if the item's value is
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// not an int16, or if it was not found. If there is no error, the incremented
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// value is returned.
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func (c *cache) IncrementInt16(k string, n int16) (int16, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(int16)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an int16", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
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// Increment an item of type int32 by n. Returns an error if the item's value is
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// not an int32, or if it was not found. If there is no error, the incremented
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// value is returned.
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func (c *cache) IncrementInt32(k string, n int32) (int32, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(int32)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an int32", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
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// Increment an item of type int64 by n. Returns an error if the item's value is
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// not an int64, or if it was not found. If there is no error, the incremented
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// value is returned.
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func (c *cache) IncrementInt64(k string, n int64) (int64, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(int64)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an int64", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
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// Increment an item of type uint by n. Returns an error if the item's value is
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// not an uint, or if it was not found. If there is no error, the incremented
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// value is returned.
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func (c *cache) IncrementUint(k string, n uint) (uint, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(uint)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an uint", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
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// Increment an item of type uintptr by n. Returns an error if the item's value
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// is not an uintptr, or if it was not found. If there is no error, the
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// incremented value is returned.
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func (c *cache) IncrementUintptr(k string, n uintptr) (uintptr, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
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rv, ok := v.Object.(uintptr)
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if !ok {
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c.mu.Unlock()
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return 0, fmt.Errorf("The value for %s is not an uintptr", k)
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}
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nv := rv + n
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v.Object = nv
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c.items[k] = v
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c.mu.Unlock()
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return nv, nil
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}
|
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|
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// Increment an item of type uint8 by n. Returns an error if the item's value
|
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// is not an uint8, or if it was not found. If there is no error, the
|
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// incremented value is returned.
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func (c *cache) IncrementUint8(k string, n uint8) (uint8, error) {
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c.mu.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.mu.Unlock()
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return 0, fmt.Errorf("Item %s not found", k)
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}
|
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rv, ok := v.Object.(uint8)
|
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if !ok {
|
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c.mu.Unlock()
|
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return 0, fmt.Errorf("The value for %s is not an uint8", k)
|
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}
|
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nv := rv + n
|
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v.Object = nv
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c.items[k] = v
|
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c.mu.Unlock()
|
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return nv, nil
|
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}
|
|
|
|
// Increment an item of type uint16 by n. Returns an error if the item's value
|
|
// is not an uint16, or if it was not found. If there is no error, the
|
|
// incremented value is returned.
|
|
func (c *cache) IncrementUint16(k string, n uint16) (uint16, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint16)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint16", k)
|
|
}
|
|
nv := rv + n
|
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v.Object = nv
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c.items[k] = v
|
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c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Increment an item of type uint32 by n. Returns an error if the item's value
|
|
// is not an uint32, or if it was not found. If there is no error, the
|
|
// incremented value is returned.
|
|
func (c *cache) IncrementUint32(k string, n uint32) (uint32, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint32)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint32", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Increment an item of type uint64 by n. Returns an error if the item's value
|
|
// is not an uint64, or if it was not found. If there is no error, the
|
|
// incremented value is returned.
|
|
func (c *cache) IncrementUint64(k string, n uint64) (uint64, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint64)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint64", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Increment an item of type float32 by n. Returns an error if the item's value
|
|
// is not an float32, or if it was not found. If there is no error, the
|
|
// incremented value is returned.
|
|
func (c *cache) IncrementFloat32(k string, n float32) (float32, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float32)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float32", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Increment an item of type float64 by n. Returns an error if the item's value
|
|
// is not an float64, or if it was not found. If there is no error, the
|
|
// incremented value is returned.
|
|
func (c *cache) IncrementFloat64(k string, n float64) (float64, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float64)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float64", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type int, int8, int16, int32, int64, uintptr, uint,
|
|
// uint8, uint32, or uint64, float32 or float64 by n. Returns an error if the
|
|
// item's value is not an integer, if it was not found, or if it is not
|
|
// possible to decrement it by n. To retrieve the decremented value, use one
|
|
// of the specialized methods, e.g. DecrementInt64.
|
|
func (c *cache) Decrement(k string, n int64) error {
|
|
// TODO: Implement Increment and Decrement more cleanly.
|
|
// (Cannot do Increment(k, n*-1) for uints.)
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return fmt.Errorf("Item not found")
|
|
}
|
|
switch v.Object.(type) {
|
|
case int:
|
|
v.Object = v.Object.(int) - int(n)
|
|
case int8:
|
|
v.Object = v.Object.(int8) - int8(n)
|
|
case int16:
|
|
v.Object = v.Object.(int16) - int16(n)
|
|
case int32:
|
|
v.Object = v.Object.(int32) - int32(n)
|
|
case int64:
|
|
v.Object = v.Object.(int64) - n
|
|
case uint:
|
|
v.Object = v.Object.(uint) - uint(n)
|
|
case uintptr:
|
|
v.Object = v.Object.(uintptr) - uintptr(n)
|
|
case uint8:
|
|
v.Object = v.Object.(uint8) - uint8(n)
|
|
case uint16:
|
|
v.Object = v.Object.(uint16) - uint16(n)
|
|
case uint32:
|
|
v.Object = v.Object.(uint32) - uint32(n)
|
|
case uint64:
|
|
v.Object = v.Object.(uint64) - uint64(n)
|
|
case float32:
|
|
v.Object = v.Object.(float32) - float32(n)
|
|
case float64:
|
|
v.Object = v.Object.(float64) - float64(n)
|
|
default:
|
|
c.mu.Unlock()
|
|
return fmt.Errorf("The value for %s is not an integer", k)
|
|
}
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nil
|
|
}
|
|
|
|
// Decrement an item of type float32 or float64 by n. Returns an error if the
|
|
// item's value is not floating point, if it was not found, or if it is not
|
|
// possible to decrement it by n. Pass a negative number to decrement the
|
|
// value. To retrieve the decremented value, use one of the specialized methods,
|
|
// e.g. DecrementFloat64.
|
|
func (c *cache) DecrementFloat(k string, n float64) error {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return fmt.Errorf("Item %s not found", k)
|
|
}
|
|
switch v.Object.(type) {
|
|
case float32:
|
|
v.Object = v.Object.(float32) - float32(n)
|
|
case float64:
|
|
v.Object = v.Object.(float64) - n
|
|
default:
|
|
c.mu.Unlock()
|
|
return fmt.Errorf("The value for %s does not have type float32 or float64", k)
|
|
}
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nil
|
|
}
|
|
|
|
// Decrement an item of type int by n. Returns an error if the item's value is
|
|
// not an int, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementInt(k string, n int) (int, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type int8 by n. Returns an error if the item's value is
|
|
// not an int8, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementInt8(k string, n int8) (int8, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int8)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int8", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type int16 by n. Returns an error if the item's value is
|
|
// not an int16, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementInt16(k string, n int16) (int16, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int16)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int16", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type int32 by n. Returns an error if the item's value is
|
|
// not an int32, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementInt32(k string, n int32) (int32, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int32)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int32", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type int64 by n. Returns an error if the item's value is
|
|
// not an int64, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementInt64(k string, n int64) (int64, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int64)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int64", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type uint by n. Returns an error if the item's value is
|
|
// not an uint, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementUint(k string, n uint) (uint, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type uintptr by n. Returns an error if the item's value
|
|
// is not an uintptr, or if it was not found. If there is no error, the
|
|
// decremented value is returned.
|
|
func (c *cache) DecrementUintptr(k string, n uintptr) (uintptr, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uintptr)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uintptr", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type uint8 by n. Returns an error if the item's value is
|
|
// not an uint8, or if it was not found. If there is no error, the decremented
|
|
// value is returned.
|
|
func (c *cache) DecrementUint8(k string, n uint8) (uint8, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint8)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint8", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type uint16 by n. Returns an error if the item's value
|
|
// is not an uint16, or if it was not found. If there is no error, the
|
|
// decremented value is returned.
|
|
func (c *cache) DecrementUint16(k string, n uint16) (uint16, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint16)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint16", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type uint32 by n. Returns an error if the item's value
|
|
// is not an uint32, or if it was not found. If there is no error, the
|
|
// decremented value is returned.
|
|
func (c *cache) DecrementUint32(k string, n uint32) (uint32, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint32)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint32", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type uint64 by n. Returns an error if the item's value
|
|
// is not an uint64, or if it was not found. If there is no error, the
|
|
// decremented value is returned.
|
|
func (c *cache) DecrementUint64(k string, n uint64) (uint64, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint64)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint64", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type float32 by n. Returns an error if the item's value
|
|
// is not an float32, or if it was not found. If there is no error, the
|
|
// decremented value is returned.
|
|
func (c *cache) DecrementFloat32(k string, n float32) (float32, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float32)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float32", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Decrement an item of type float64 by n. Returns an error if the item's value
|
|
// is not an float64, or if it was not found. If there is no error, the
|
|
// decremented value is returned.
|
|
func (c *cache) DecrementFloat64(k string, n float64) (float64, error) {
|
|
c.mu.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float64)
|
|
if !ok {
|
|
c.mu.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float64", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.items[k] = v
|
|
c.mu.Unlock()
|
|
return nv, nil
|
|
}
|
|
|
|
// Delete an item from the cache. Does nothing if the key is not in the cache.
|
|
func (c *cache) Delete(k string) {
|
|
c.mu.Lock()
|
|
v, evicted := c.delete(k)
|
|
c.mu.Unlock()
|
|
if evicted {
|
|
c.onEvicted(k, v)
|
|
}
|
|
}
|
|
|
|
func (c *cache) delete(k string) (interface{}, bool) {
|
|
if c.onEvicted != nil {
|
|
if v, found := c.items[k]; found {
|
|
delete(c.items, k)
|
|
return v.Object, true
|
|
}
|
|
}
|
|
delete(c.items, k)
|
|
return nil, false
|
|
}
|
|
|
|
type keyAndValue struct {
|
|
key string
|
|
value interface{}
|
|
}
|
|
|
|
// Delete all expired items from the cache.
|
|
func (c *cache) DeleteExpired() {
|
|
var evictedItems []keyAndValue
|
|
now := time.Now().UnixNano()
|
|
c.mu.Lock()
|
|
for k, v := range c.items {
|
|
// "Inlining" of expired
|
|
if v.Expiration > 0 && now > v.Expiration {
|
|
ov, evicted := c.delete(k)
|
|
if evicted {
|
|
evictedItems = append(evictedItems, keyAndValue{k, ov})
|
|
}
|
|
}
|
|
}
|
|
c.mu.Unlock()
|
|
for _, v := range evictedItems {
|
|
c.onEvicted(v.key, v.value)
|
|
}
|
|
}
|
|
|
|
// Sets an (optional) function that is called with the key and value when an
|
|
// item is evicted from the cache. (Including when it is deleted manually, but
|
|
// not when it is overwritten.) Set to nil to disable.
|
|
func (c *cache) OnEvicted(f func(string, interface{})) {
|
|
c.mu.Lock()
|
|
c.onEvicted = f
|
|
c.mu.Unlock()
|
|
}
|
|
|
|
// Write the cache's items (using Gob) to an io.Writer.
|
|
//
|
|
// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
|
|
// documentation for NewFrom().)
|
|
func (c *cache) Save(w io.Writer) (err error) {
|
|
enc := gob.NewEncoder(w)
|
|
defer func() {
|
|
if x := recover(); x != nil {
|
|
err = fmt.Errorf("Error registering item types with Gob library")
|
|
}
|
|
}()
|
|
c.mu.RLock()
|
|
defer c.mu.RUnlock()
|
|
for _, v := range c.items {
|
|
gob.Register(v.Object)
|
|
}
|
|
err = enc.Encode(&c.items)
|
|
return
|
|
}
|
|
|
|
// Save the cache's items to the given filename, creating the file if it
|
|
// doesn't exist, and overwriting it if it does.
|
|
//
|
|
// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
|
|
// documentation for NewFrom().)
|
|
func (c *cache) SaveFile(fname string) error {
|
|
fp, err := os.Create(fname)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = c.Save(fp)
|
|
if err != nil {
|
|
fp.Close()
|
|
return err
|
|
}
|
|
return fp.Close()
|
|
}
|
|
|
|
// Add (Gob-serialized) cache items from an io.Reader, excluding any items with
|
|
// keys that already exist (and haven't expired) in the current cache.
|
|
//
|
|
// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
|
|
// documentation for NewFrom().)
|
|
func (c *cache) Load(r io.Reader) error {
|
|
dec := gob.NewDecoder(r)
|
|
items := map[string]Item{}
|
|
err := dec.Decode(&items)
|
|
if err == nil {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
for k, v := range items {
|
|
ov, found := c.items[k]
|
|
if !found || ov.Expired() {
|
|
c.items[k] = v
|
|
}
|
|
}
|
|
}
|
|
return err
|
|
}
|
|
|
|
// Load and add cache items from the given filename, excluding any items with
|
|
// keys that already exist in the current cache.
|
|
//
|
|
// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
|
|
// documentation for NewFrom().)
|
|
func (c *cache) LoadFile(fname string) error {
|
|
fp, err := os.Open(fname)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = c.Load(fp)
|
|
if err != nil {
|
|
fp.Close()
|
|
return err
|
|
}
|
|
return fp.Close()
|
|
}
|
|
|
|
// Copies all unexpired items in the cache into a new map and returns it.
|
|
func (c *cache) Items() map[string]Item {
|
|
c.mu.RLock()
|
|
defer c.mu.RUnlock()
|
|
m := make(map[string]Item, len(c.items))
|
|
now := time.Now().UnixNano()
|
|
for k, v := range c.items {
|
|
// "Inlining" of Expired
|
|
if v.Expiration > 0 {
|
|
if now > v.Expiration {
|
|
continue
|
|
}
|
|
}
|
|
m[k] = v
|
|
}
|
|
return m
|
|
}
|
|
|
|
// Returns the number of items in the cache. This may include items that have
|
|
// expired, but have not yet been cleaned up.
|
|
func (c *cache) ItemCount() int {
|
|
c.mu.RLock()
|
|
n := len(c.items)
|
|
c.mu.RUnlock()
|
|
return n
|
|
}
|
|
|
|
// Delete all items from the cache.
|
|
func (c *cache) Flush() {
|
|
c.mu.Lock()
|
|
c.items = map[string]Item{}
|
|
c.mu.Unlock()
|
|
}
|
|
|
|
type janitor struct {
|
|
Interval time.Duration
|
|
stop chan bool
|
|
}
|
|
|
|
func (j *janitor) Run(c *cache) {
|
|
ticker := time.NewTicker(j.Interval)
|
|
for {
|
|
select {
|
|
case <-ticker.C:
|
|
c.DeleteExpired()
|
|
case <-j.stop:
|
|
ticker.Stop()
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
func stopJanitor(c *Cache) {
|
|
c.janitor.stop <- true
|
|
}
|
|
|
|
func runJanitor(c *cache, ci time.Duration) {
|
|
j := &janitor{
|
|
Interval: ci,
|
|
stop: make(chan bool),
|
|
}
|
|
c.janitor = j
|
|
go j.Run(c)
|
|
}
|
|
|
|
func newCache(de time.Duration, m map[string]Item) *cache {
|
|
if de == 0 {
|
|
de = -1
|
|
}
|
|
c := &cache{
|
|
defaultExpiration: de,
|
|
items: m,
|
|
}
|
|
return c
|
|
}
|
|
|
|
func newCacheWithJanitor(de time.Duration, ci time.Duration, m map[string]Item) *Cache {
|
|
c := newCache(de, m)
|
|
// This trick ensures that the janitor goroutine (which--granted it
|
|
// was enabled--is running DeleteExpired on c forever) does not keep
|
|
// the returned C object from being garbage collected. When it is
|
|
// garbage collected, the finalizer stops the janitor goroutine, after
|
|
// which c can be collected.
|
|
C := &Cache{c}
|
|
if ci > 0 {
|
|
runJanitor(c, ci)
|
|
runtime.SetFinalizer(C, stopJanitor)
|
|
}
|
|
return C
|
|
}
|
|
|
|
// Return a new cache with a given default expiration duration and cleanup
|
|
// interval. If the expiration duration is less than one (or NoExpiration),
|
|
// the items in the cache never expire (by default), and must be deleted
|
|
// manually. If the cleanup interval is less than one, expired items are not
|
|
// deleted from the cache before calling c.DeleteExpired().
|
|
func New(defaultExpiration, cleanupInterval time.Duration) *Cache {
|
|
items := make(map[string]Item)
|
|
return newCacheWithJanitor(defaultExpiration, cleanupInterval, items)
|
|
}
|
|
|
|
// Return a new cache with a given default expiration duration and cleanup
|
|
// interval. If the expiration duration is less than one (or NoExpiration),
|
|
// the items in the cache never expire (by default), and must be deleted
|
|
// manually. If the cleanup interval is less than one, expired items are not
|
|
// deleted from the cache before calling c.DeleteExpired().
|
|
//
|
|
// NewFrom() also accepts an items map which will serve as the underlying map
|
|
// for the cache. This is useful for starting from a deserialized cache
|
|
// (serialized using e.g. gob.Encode() on c.Items()), or passing in e.g.
|
|
// make(map[string]Item, 500) to improve startup performance when the cache
|
|
// is expected to reach a certain minimum size.
|
|
//
|
|
// Only the cache's methods synchronize access to this map, so it is not
|
|
// recommended to keep any references to the map around after creating a cache.
|
|
// If need be, the map can be accessed at a later point using c.Items() (subject
|
|
// to the same caveat.)
|
|
//
|
|
// Note regarding serialization: When using e.g. gob, make sure to
|
|
// gob.Register() the individual types stored in the cache before encoding a
|
|
// map retrieved with c.Items(), and to register those same types before
|
|
// decoding a blob containing an items map.
|
|
func NewFrom(defaultExpiration, cleanupInterval time.Duration, items map[string]Item) *Cache {
|
|
return newCacheWithJanitor(defaultExpiration, cleanupInterval, items)
|
|
}
|