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@@ -0,0 +1,1466 @@
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+package cache
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+
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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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+
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+type Item struct {
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+ Object interface{}
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+ Expiration int64
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+ Accessed int64
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+}
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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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+
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+// Return the time at which this item was last accessed.
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+func (item Item) LastAccessed() time.Time {
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+ return time.Unix(0, item.Accessed)
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+}
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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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+
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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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+
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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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+ maxItems int
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+}
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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 (
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+ now time.Time
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+ e int64
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+ )
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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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+ now = time.Now()
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+ e = now.Add(d).UnixNano()
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+ }
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+ if c.maxItems > 0 {
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+ if d <= 0 {
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+ // d <= 0 means we didn't set now above
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+ now = time.Now()
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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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+ Accessed: now.UnixNano(),
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+ }
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+ // TODO: Calls to mu.Unlock are currently not deferred because
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+ // defer adds ~200 ns (as of go1.)
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+ c.mu.Unlock()
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+ } else {
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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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+ c.mu.Unlock()
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+ }
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+}
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+
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+func (c *cache) set(k string, x interface{}, d time.Duration) {
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+ var (
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+ now time.Time
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+ e int64
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+ )
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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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+ now = time.Now()
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+ e = now.Add(d).UnixNano()
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+ }
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+ if c.maxItems > 0 {
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+ if d <= 0 {
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+ // d <= 0 means we didn't set now above
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+ now = time.Now()
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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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+ Accessed: now.UnixNano(),
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+ }
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+ } else {
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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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+}
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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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+
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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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+
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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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+
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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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+ if c.maxItems > 0 {
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+ // LRU enabled; Get implies write
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+ c.mu.Lock()
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+ } else {
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+ // LRU not enabled; Get is read-only
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+ c.mu.RLock()
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+ }
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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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+ if c.maxItems > 0 {
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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+ }
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+ return nil, false
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+ }
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+ var now int64
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+ if item.Expiration > 0 {
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+ now = time.Now().UnixNano()
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+ if now > item.Expiration {
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+ if c.maxItems > 0 {
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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+ }
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+ return nil, false
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+ }
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+ }
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+ if c.maxItems > 0 {
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+ if now == 0 {
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+ now = time.Now().UnixNano()
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+ }
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+ item.Accessed = now
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+ c.items[k] = item
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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+ }
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+ return item.Object, true
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+}
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+
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+// If LRU functionality is being used (and get implies updating item.Accessed,)
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+// this function must be write-locked.
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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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+ var now int64
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+ if item.Expiration > 0 {
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+ now = time.Now().UnixNano()
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+ if now > item.Expiration {
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+ return nil, false
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+ }
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+ }
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+ if c.maxItems > 0 {
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+ if now == 0 {
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+ now = time.Now().UnixNano()
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+ }
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+ item.Accessed = now
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+ c.items[k] = item
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+ }
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+ return item.Object, true
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+}
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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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+ if c.maxItems > 0 {
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+ // LRU enabled; GetWithExpiration implies write
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+ c.mu.Lock()
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+ } else {
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+ // LRU not enabled; GetWithExpiration is read-only
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+ c.mu.RLock()
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+ }
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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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+ if c.maxItems > 0 {
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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+ }
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+ return nil, time.Time{}, false
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+ }
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+ var now int64
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+ if item.Expiration > 0 {
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+ now = time.Now().UnixNano()
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+ if now > item.Expiration {
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+ if c.maxItems > 0 {
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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+ }
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+ return nil, time.Time{}, false
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+ }
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+ if c.maxItems > 0 {
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+ if now == 0 {
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+ now = time.Now().UnixNano()
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+ }
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+ item.Accessed = now
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+ c.items[k] = item
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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+ }
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+ return item.Object, time.Unix(0, item.Expiration), true
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+ }
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+ if c.maxItems > 0 {
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+ if now == 0 {
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+ now = time.Now().UnixNano()
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+ }
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+ item.Accessed = now
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+ c.items[k] = item
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+ c.mu.Unlock()
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+ } else {
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+ c.mu.RUnlock()
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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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+ return item.Object, time.Time{}, true
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+}
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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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+ if c.maxItems > 0 {
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+ v.Accessed = time.Now().UnixNano()
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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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+
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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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+ if c.maxItems > 0 {
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+ v.Accessed = time.Now().UnixNano()
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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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+
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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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+ if c.maxItems > 0 {
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+ v.Accessed = time.Now().UnixNano()
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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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+
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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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+ if c.maxItems > 0 {
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+ v.Accessed = time.Now().UnixNano()
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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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+
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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() {
|
|
|
+ c.mu.Unlock()
|
|
|
+ return 0, fmt.Errorf("Item %s not found", k)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// Increment 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 incremented
|
|
|
+// value is returned.
|
|
|
+func (c *cache) IncrementInt32(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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// Increment 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 incremented
|
|
|
+// value is returned.
|
|
|
+func (c *cache) IncrementInt64(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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// Increment 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 incremented
|
|
|
+// value is returned.
|
|
|
+func (c *cache) IncrementUint(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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// Increment 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
|
|
|
+// incremented value is returned.
|
|
|
+func (c *cache) IncrementUintptr(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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// Increment 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
|
|
|
+// incremented value is returned.
|
|
|
+func (c *cache) IncrementUint8(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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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
|
|
|
+}
|
|
|
+
|
|
|
+// 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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")
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ }
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ v.Accessed = time.Now().UnixNano()
|
|
|
+ }
|
|
|
+ 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)
|
|
|
+ evictFunc := c.onEvicted
|
|
|
+ c.mu.Unlock()
|
|
|
+ if evicted {
|
|
|
+ evictFunc(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()
|
|
|
+ evictFunc := c.onEvicted
|
|
|
+ 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 {
|
|
|
+ evictFunc(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()
|
|
|
+}
|
|
|
+
|
|
|
+// Delete some of the oldest items in the cache if the soft size limit has been
|
|
|
+// exceeded.
|
|
|
+func (c *cache) DeleteLRU() {
|
|
|
+ c.mu.Lock()
|
|
|
+ var (
|
|
|
+ overCount = c.itemCount() - c.maxItems
|
|
|
+ evictFunc = c.onEvicted
|
|
|
+ )
|
|
|
+ evicted := c.deleteLRUAmount(overCount)
|
|
|
+ c.mu.Unlock()
|
|
|
+ for _, v := range evicted {
|
|
|
+ evictFunc(v.key, v.value)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// Delete a number of the oldest items from the cache.
|
|
|
+func (c *cache) DeleteLRUAmount(numItems int) {
|
|
|
+ c.mu.Lock()
|
|
|
+ evictFunc := c.onEvicted
|
|
|
+ evicted := c.deleteLRUAmount(numItems)
|
|
|
+ c.mu.Unlock()
|
|
|
+ for _, v := range evicted {
|
|
|
+ evictFunc(v.key, v.value)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+func (c *cache) deleteLRUAmount(numItems int) []keyAndValue {
|
|
|
+ if numItems <= 0 {
|
|
|
+ return nil
|
|
|
+ }
|
|
|
+ var (
|
|
|
+ lastTime int64 = 0
|
|
|
+ lastItems = make([]string, numItems) // Ring buffer
|
|
|
+ liCount = 0
|
|
|
+ full = false
|
|
|
+ evictedItems []keyAndValue
|
|
|
+ now = time.Now().UnixNano()
|
|
|
+ )
|
|
|
+ if c.onEvicted != nil {
|
|
|
+ evictedItems = make([]keyAndValue, 0, numItems)
|
|
|
+ }
|
|
|
+ for k, v := range c.items {
|
|
|
+ // "Inlining" of !Expired
|
|
|
+ if v.Expiration == 0 || now <= v.Expiration {
|
|
|
+ if full == false || v.Accessed < lastTime {
|
|
|
+ // We found a least-recently-used item, or our
|
|
|
+ // purge buffer isn't full yet
|
|
|
+ lastTime = v.Accessed
|
|
|
+ // Append it to the buffer, or start overwriting
|
|
|
+ // it
|
|
|
+ if liCount < numItems {
|
|
|
+ lastItems[liCount] = k
|
|
|
+ liCount++
|
|
|
+ } else {
|
|
|
+ lastItems[0] = k
|
|
|
+ liCount = 1
|
|
|
+ full = true
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ if lastTime > 0 {
|
|
|
+ for _, v := range lastItems {
|
|
|
+ if v != "" {
|
|
|
+ ov, evicted := c.delete(v)
|
|
|
+ if evicted {
|
|
|
+ evictedItems = append(evictedItems, keyAndValue{v, ov})
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return evictedItems
|
|
|
+}
|
|
|
+
|
|
|
+// 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
|
|
|
+}
|
|
|
+
|
|
|
+// Returns the number of items in the cache without locking. This may include
|
|
|
+// items that have expired, but have not yet been cleaned up. Equivalent to
|
|
|
+// len(c.Items()).
|
|
|
+func (c *cache) itemCount() int {
|
|
|
+ n := len(c.items)
|
|
|
+ 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) {
|
|
|
+ j.stop = make(chan bool)
|
|
|
+ ticker := time.NewTicker(j.Interval)
|
|
|
+ for {
|
|
|
+ select {
|
|
|
+ case <-ticker.C:
|
|
|
+ c.DeleteExpired()
|
|
|
+ if c.maxItems > 0 {
|
|
|
+ c.DeleteLRU()
|
|
|
+ }
|
|
|
+ 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,
|
|
|
+ }
|
|
|
+ c.janitor = j
|
|
|
+ go j.Run(c)
|
|
|
+}
|
|
|
+
|
|
|
+func newCache(de time.Duration, m map[string]Item, mi int) *cache {
|
|
|
+ if de == 0 {
|
|
|
+ de = -1
|
|
|
+ }
|
|
|
+ c := &cache{
|
|
|
+ defaultExpiration: de,
|
|
|
+ maxItems: mi,
|
|
|
+ items: m,
|
|
|
+ }
|
|
|
+ return c
|
|
|
+}
|
|
|
+
|
|
|
+func newCacheWithJanitor(de time.Duration, ci time.Duration, m map[string]Item, mi int) *Cache {
|
|
|
+ c := newCache(de, m, mi)
|
|
|
+ // 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, 0)
|
|
|
+}
|
|
|
+
|
|
|
+// Return a new cache with a given default expiration duration, cleanup
|
|
|
+// interval, and maximum-ish number of items. 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(), c.DeleteLRU(), or c.DeleteLRUAmount(). If maxItems
|
|
|
+// is not greater than zero, then there will be no soft cap on the number of
|
|
|
+// items in the cache.
|
|
|
+//
|
|
|
+// Using the LRU functionality makes Get() a slower, write-locked operation.
|
|
|
+func NewWithLRU(defaultExpiration, cleanupInterval time.Duration, maxItems int) *Cache {
|
|
|
+ items := make(map[string]Item)
|
|
|
+ return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, maxItems)
|
|
|
+}
|
|
|
+
|
|
|
+// 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, 0)
|
|
|
+}
|
|
|
+
|
|
|
+// Similar to NewFrom, but creates a cache with LRU functionality enabled.
|
|
|
+func NewFromWithLRU(defaultExpiration, cleanupInterval time.Duration, items map[string]Item, maxItems int) *Cache {
|
|
|
+ return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, maxItems)
|
|
|
+}
|
Rod Hynes