1143 lines
29 KiB
Go
1143 lines
29 KiB
Go
package cache
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import (
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"encoding/binary"
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"encoding/gob"
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"fmt"
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"hash/fnv"
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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 unexportedInterface interface {
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Set(string, interface{}, time.Duration)
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Add(string, interface{}, time.Duration) error
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Replace(string, interface{}, time.Duration) error
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Get(string) (interface{}, bool)
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Increment(string, int64) error
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IncrementInt(string, int) (int, error)
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IncrementInt8(string, int8) (int8, error)
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IncrementInt16(string, int16) (int16, error)
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IncrementInt32(string, int32) (int32, error)
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IncrementInt64(string, int64) (int64, error)
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IncrementUint(string, uint) (uint, error)
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IncrementUintptr(string, uintptr) (uintptr, error)
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IncrementUint8(string, uint8) (uint8, error)
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IncrementUint16(string, uint16) (uint16, error)
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IncrementUint32(string, uint32) (uint32, error)
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IncrementUint64(string, uint64) (uint64, error)
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IncrementFloat(string, float64) error
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IncrementFloat32(string, float32) (float32, error)
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IncrementFloat64(string, float64) (float64, error)
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Decrement(string, int64) error
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DecrementInt(string, int) (int, error)
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DecrementInt8(string, int8) (int8, error)
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DecrementInt16(string, int16) (int16, error)
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DecrementInt32(string, int32) (int32, error)
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DecrementInt64(string, int64) (int64, error)
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DecrementUint(string, uint) (uint, error)
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DecrementUintptr(string, uintptr) (uintptr, error)
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DecrementUint8(string, uint8) (uint8, error)
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DecrementUint16(string, uint16) (uint16, error)
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DecrementUint32(string, uint32) (uint32, error)
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DecrementUint64(string, uint64) (uint64, error)
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DecrementFloat(string, float64) error
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DecrementFloat32(string, float32) (float32, error)
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DecrementFloat64(string, float64) (float64, error)
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Delete(string)
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DeleteExpired()
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Items() map[string]*Item
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ItemCount() int
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Flush()
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Save(io.Writer) error
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SaveFile(string) error
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Load(io.Reader) error
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LoadFile(io.Reader) error
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}
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type Item struct {
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Object interface{}
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Expiration *time.Time
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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 == nil {
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return false
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}
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return item.Expiration.Before(time.Now())
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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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sync.RWMutex
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defaultExpiration time.Duration
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items map[string]*Item
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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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// the cache's default expiration time is used. If it is -1, the item never
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// expires.
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func (c *cache) Set(k string, x interface{}, d time.Duration) {
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c.Lock()
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c.set(k, x, d)
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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.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 *time.Time
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if d == 0 {
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d = c.defaultExpiration
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}
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if d > 0 {
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t := time.Now().Add(d)
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e = &t
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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 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.Lock()
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_, found := c.get(k)
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if found {
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c.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.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.Lock()
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_, found := c.get(k)
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if !found {
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c.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.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.RLock()
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x, found := c.get(k)
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c.RUnlock()
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return x, found
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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 || item.Expired() {
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return nil, false
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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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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 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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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 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
|
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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.Lock()
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v, found := c.items[k]
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if !found || v.Expired() {
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c.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.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.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
|
|
// 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.Lock()
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v, found := c.items[k]
|
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if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
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}
|
|
rv, ok := v.Object.(uint8)
|
|
if !ok {
|
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c.Unlock()
|
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return 0, fmt.Errorf("The value for %s is not an uint8", k)
|
|
}
|
|
nv := rv + n
|
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v.Object = nv
|
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c.Unlock()
|
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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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint16)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint16", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint32)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint32", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint64)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint64", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float32)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float32", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float64)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float64", k)
|
|
}
|
|
nv := rv + n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.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.Unlock()
|
|
return fmt.Errorf("The value for %s is not an integer", k)
|
|
}
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.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.Unlock()
|
|
return fmt.Errorf("The value for %s does not have type float32 or float64", k)
|
|
}
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int8)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int8", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int16)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int16", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int32)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int32", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(int64)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an int64", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uintptr)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uintptr", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint8)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint8", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint16)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint16", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint32)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint32", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(uint64)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an uint64", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float32)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float32", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
v, found := c.items[k]
|
|
if !found || v.Expired() {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("Item %s not found", k)
|
|
}
|
|
rv, ok := v.Object.(float64)
|
|
if !ok {
|
|
c.Unlock()
|
|
return 0, fmt.Errorf("The value for %s is not an float64", k)
|
|
}
|
|
nv := rv - n
|
|
v.Object = nv
|
|
c.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.Lock()
|
|
c.delete(k)
|
|
c.Unlock()
|
|
}
|
|
|
|
func (c *cache) delete(k string) {
|
|
delete(c.items, k)
|
|
}
|
|
|
|
// Delete all expired items from the cache.
|
|
func (c *cache) DeleteExpired() {
|
|
c.Lock()
|
|
for k, v := range c.items {
|
|
if v.Expired() {
|
|
c.delete(k)
|
|
}
|
|
}
|
|
c.Unlock()
|
|
}
|
|
|
|
// Write the cache's items (using Gob) to an io.Writer.
|
|
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.RLock()
|
|
defer c.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.
|
|
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.
|
|
func (c *cache) Load(r io.Reader) error {
|
|
dec := gob.NewDecoder(r)
|
|
items := map[string]*Item{}
|
|
err := dec.Decode(&items)
|
|
if err == nil {
|
|
c.Lock()
|
|
defer c.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.
|
|
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()
|
|
}
|
|
|
|
// Returns the items in the cache. This may include items that have expired,
|
|
// but have not yet been cleaned up. If this is significant, the Expiration
|
|
// fields of the items should be checked. Note that explicit synchronization
|
|
// is needed to use a cache and its corresponding Items() return value at
|
|
// the same time, as the map is shared.
|
|
func (c *cache) Items() map[string]*Item {
|
|
c.RLock()
|
|
defer c.RUnlock()
|
|
return c.items
|
|
}
|
|
|
|
// Returns the number of items in the cache. This may include items that have
|
|
// expired, but have not yet been cleaned up. Equivalent to len(c.Items()).
|
|
func (c *cache) ItemCount() int {
|
|
c.RLock()
|
|
n := len(c.items)
|
|
c.RUnlock()
|
|
return n
|
|
}
|
|
|
|
// Delete all items from the cache.
|
|
func (c *cache) Flush() {
|
|
c.Lock()
|
|
c.items = map[string]*Item{}
|
|
c.Unlock()
|
|
}
|
|
|
|
type janitor struct {
|
|
Interval time.Duration
|
|
stop chan bool
|
|
}
|
|
|
|
func (j *janitor) Run(c *cache) {
|
|
j.stop = make(chan bool)
|
|
tick := time.Tick(j.Interval)
|
|
for {
|
|
select {
|
|
case <-tick:
|
|
c.DeleteExpired()
|
|
case <-j.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) *cache {
|
|
if de == 0 {
|
|
de = -1
|
|
}
|
|
c := &cache{
|
|
defaultExpiration: de,
|
|
items: map[string]*Item{},
|
|
}
|
|
return c
|
|
}
|
|
|
|
// Return a new cache with a given default expiration duration and cleanup
|
|
// interval. If the expiration duration is less than 1, 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 DeleteExpired.
|
|
func New(defaultExpiration, cleanupInterval time.Duration) *Cache {
|
|
c := newCache(defaultExpiration)
|
|
// 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 cleanupInterval > 0 {
|
|
runJanitor(c, cleanupInterval)
|
|
runtime.SetFinalizer(C, stopJanitor)
|
|
}
|
|
return C
|
|
}
|
|
|
|
type unexportedShardedCache struct {
|
|
*shardedCache
|
|
}
|
|
|
|
type shardedCache struct {
|
|
m uint32
|
|
cs []*cache
|
|
janitor *shardedJanitor
|
|
}
|
|
|
|
func (sc *shardedCache) bucket(k string) *cache {
|
|
h := fnv.New32()
|
|
h.Write([]byte(k))
|
|
n := binary.BigEndian.Uint32(h.Sum(nil))
|
|
return sc.cs[n%sc.m]
|
|
}
|
|
|
|
func (sc *shardedCache) Set(k string, x interface{}, d time.Duration) {
|
|
sc.bucket(k).Set(k, x, d)
|
|
}
|
|
|
|
func (sc *shardedCache) Add(k string, x interface{}, d time.Duration) error {
|
|
return sc.bucket(k).Add(k, x, d)
|
|
}
|
|
|
|
func (sc *shardedCache) Replace(k string, x interface{}, d time.Duration) error {
|
|
return sc.bucket(k).Replace(k, x, d)
|
|
}
|
|
|
|
func (sc *shardedCache) Get(k string) (interface{}, bool) {
|
|
return sc.bucket(k).Get(k)
|
|
}
|
|
|
|
func (sc *shardedCache) Increment(k string, n int64) error {
|
|
return sc.bucket(k).Increment(k, n)
|
|
}
|
|
|
|
func (sc *shardedCache) IncrementFloat(k string, n float64) error {
|
|
return sc.bucket(k).IncrementFloat(k, n)
|
|
}
|
|
|
|
func (sc *shardedCache) Decrement(k string, n int64) error {
|
|
return sc.bucket(k).Decrement(k, n)
|
|
}
|
|
|
|
func (sc *shardedCache) Delete(k string) {
|
|
sc.bucket(k).Delete(k)
|
|
}
|
|
|
|
func (sc *shardedCache) DeleteExpired() {
|
|
for _, v := range sc.cs {
|
|
v.DeleteExpired()
|
|
}
|
|
}
|
|
|
|
func (sc *shardedCache) Flush() {
|
|
for _, v := range sc.cs {
|
|
v.Flush()
|
|
}
|
|
}
|
|
|
|
type shardedJanitor struct {
|
|
Interval time.Duration
|
|
stop chan bool
|
|
}
|
|
|
|
func (j *shardedJanitor) Run(sc *shardedCache) {
|
|
j.stop = make(chan bool)
|
|
tick := time.Tick(j.Interval)
|
|
for {
|
|
select {
|
|
case <-tick:
|
|
sc.DeleteExpired()
|
|
case <-j.stop:
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
func stopShardedJanitor(sc *unexportedShardedCache) {
|
|
sc.janitor.stop <- true
|
|
}
|
|
|
|
func runShardedJanitor(sc *shardedCache, ci time.Duration) {
|
|
j := &shardedJanitor{
|
|
Interval: ci,
|
|
}
|
|
sc.janitor = j
|
|
go j.Run(sc)
|
|
}
|
|
|
|
func newShardedCache(n int, de time.Duration) *shardedCache {
|
|
sc := &shardedCache{
|
|
m: uint32(n - 1),
|
|
cs: make([]*cache, n),
|
|
}
|
|
for i := 0; i < n; i++ {
|
|
c := &cache{
|
|
defaultExpiration: de,
|
|
items: map[string]*Item{},
|
|
}
|
|
sc.cs[i] = c
|
|
}
|
|
return sc
|
|
}
|
|
|
|
func unexportedNewSharded(shards int, defaultExpiration, cleanupInterval time.Duration) *unexportedShardedCache {
|
|
if defaultExpiration == 0 {
|
|
defaultExpiration = -1
|
|
}
|
|
sc := newShardedCache(shards, defaultExpiration)
|
|
SC := &unexportedShardedCache{sc}
|
|
if cleanupInterval > 0 {
|
|
runShardedJanitor(sc, cleanupInterval)
|
|
runtime.SetFinalizer(SC, stopShardedJanitor)
|
|
}
|
|
return SC
|
|
}
|