diff options
Diffstat (limited to 'src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/patrickmn/go-cache/cache.go')
| -rw-r--r-- | src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/patrickmn/go-cache/cache.go | 1118 |
1 files changed, 0 insertions, 1118 deletions
diff --git a/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/patrickmn/go-cache/cache.go b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/patrickmn/go-cache/cache.go deleted file mode 100644 index 35625430c94..00000000000 --- a/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/github.com/patrickmn/go-cache/cache.go +++ /dev/null @@ -1,1118 +0,0 @@ -package cache - -import ( - "encoding/gob" - "fmt" - "io" - "os" - "runtime" - "sync" - "time" -) - -type Item struct { - Object interface{} - Expiration int64 -} - -// Returns true if the item has expired. -func (item Item) Expired() bool { - if item.Expiration == 0 { - return false - } - return time.Now().UnixNano() > item.Expiration -} - -const ( - // For use with functions that take an expiration time. - NoExpiration time.Duration = -1 - // For use with functions that take an expiration time. Equivalent to - // passing in the same expiration duration as was given to New() or - // NewFrom() when the cache was created (e.g. 5 minutes.) - DefaultExpiration time.Duration = 0 -) - -type Cache struct { - *cache - // If this is confusing, see the comment at the bottom of New() -} - -type cache struct { - defaultExpiration time.Duration - items map[string]Item - mu sync.RWMutex - onEvicted func(string, interface{}) - janitor *janitor -} - -// Add an item to the cache, replacing any existing item. If the duration is 0 -// (DefaultExpiration), the cache's default expiration time is used. If it is -1 -// (NoExpiration), the item never expires. -func (c *cache) Set(k string, x interface{}, d time.Duration) { - // "Inlining" of set - var e int64 - if d == DefaultExpiration { - d = c.defaultExpiration - } - if d > 0 { - e = time.Now().Add(d).UnixNano() - } - c.mu.Lock() - c.items[k] = Item{ - Object: x, - Expiration: e, - } - // TODO: Calls to mu.Unlock are currently not deferred because defer - // adds ~200 ns (as of go1.) - c.mu.Unlock() -} - -func (c *cache) set(k string, x interface{}, d time.Duration) { - var e int64 - if d == DefaultExpiration { - d = c.defaultExpiration - } - if d > 0 { - e = time.Now().Add(d).UnixNano() - } - c.items[k] = Item{ - Object: x, - Expiration: e, - } -} - -// Add an item to the cache only if an item doesn't already exist for the given -// key, or if the existing item has expired. Returns an error otherwise. -func (c *cache) Add(k string, x interface{}, d time.Duration) error { - c.mu.Lock() - _, found := c.get(k) - if found { - c.mu.Unlock() - return fmt.Errorf("Item %s already exists", k) - } - c.set(k, x, d) - c.mu.Unlock() - return nil -} - -// Set a new value for the cache key only if it already exists, and the existing -// item hasn't expired. Returns an error otherwise. -func (c *cache) Replace(k string, x interface{}, d time.Duration) error { - c.mu.Lock() - _, found := c.get(k) - if !found { - c.mu.Unlock() - return fmt.Errorf("Item %s doesn't exist", k) - } - c.set(k, x, d) - c.mu.Unlock() - return nil -} - -// Get an item from the cache. Returns the item or nil, and a bool indicating -// whether the key was found. -func (c *cache) Get(k string) (interface{}, bool) { - c.mu.RLock() - // "Inlining" of get and Expired - item, found := c.items[k] - if !found { - c.mu.RUnlock() - return nil, false - } - if item.Expiration > 0 { - if time.Now().UnixNano() > item.Expiration { - c.mu.RUnlock() - return nil, false - } - } - c.mu.RUnlock() - return item.Object, true -} - -func (c *cache) get(k string) (interface{}, bool) { - item, found := c.items[k] - if !found { - return nil, false - } - // "Inlining" of Expired - if item.Expiration > 0 { - if time.Now().UnixNano() > item.Expiration { - return nil, false - } - } - return item.Object, true -} - -// Increment 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 increment it by n. To retrieve the incremented value, use one -// of the specialized methods, e.g. IncrementInt64. -func (c *cache) Increment(k string, n int64) error { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return fmt.Errorf("Item %s not found", k) - } - switch v.Object.(type) { - case 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 -} - -// Increment 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 increment it by n. Pass a negative number to decrement the -// value. To retrieve the incremented value, use one of the specialized methods, -// e.g. IncrementFloat64. -func (c *cache) IncrementFloat(k string, n float64) error { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return fmt.Errorf("Item %s not found", k) - } - switch v.Object.(type) { - case float32: - v.Object = v.Object.(float32) + float32(n) - case float64: - v.Object = v.Object.(float64) + n - default: - c.mu.Unlock() - return fmt.Errorf("The value for %s does not have type float32 or float64", k) - } - c.items[k] = v - c.mu.Unlock() - return nil -} - -// Increment 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 incremented -// value is returned. -func (c *cache) IncrementInt(k string, n int) (int, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Increment 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 incremented -// value is returned. -func (c *cache) IncrementInt8(k string, n int8) (int8, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int8) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int8", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Increment 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 incremented -// value is returned. -func (c *cache) IncrementInt16(k string, n int16) (int16, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int16) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int16", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// 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) - } - 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) - } - 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) - } - 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) - } - 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) - } - 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) - } - 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) - } - rv, ok := v.Object.(uint32) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint32", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Increment an item of type uint64 by n. Returns an error if the item's value -// is not an uint64, or if it was not found. If there is no error, the -// incremented value is returned. -func (c *cache) IncrementUint64(k string, n uint64) (uint64, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uint64) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint64", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Increment an item of type float32 by n. Returns an error if the item's value -// is not an float32, or if it was not found. If there is no error, the -// incremented value is returned. -func (c *cache) IncrementFloat32(k string, n float32) (float32, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(float32) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an float32", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Increment an item of type float64 by n. Returns an error if the item's value -// is not an float64, or if it was not found. If there is no error, the -// incremented value is returned. -func (c *cache) IncrementFloat64(k string, n float64) (float64, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(float64) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an float64", k) - } - nv := rv + n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type int, int8, int16, int32, int64, uintptr, uint, -// uint8, uint32, or uint64, float32 or float64 by n. Returns an error if the -// item's value is not an integer, if it was not found, or if it is not -// possible to decrement it by n. To retrieve the decremented value, use one -// of the specialized methods, e.g. DecrementInt64. -func (c *cache) Decrement(k string, n int64) error { - // TODO: Implement Increment and Decrement more cleanly. - // (Cannot do Increment(k, n*-1) for uints.) - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return fmt.Errorf("Item not found") - } - switch v.Object.(type) { - case int: - v.Object = v.Object.(int) - int(n) - case int8: - v.Object = v.Object.(int8) - int8(n) - case int16: - v.Object = v.Object.(int16) - int16(n) - case int32: - v.Object = v.Object.(int32) - int32(n) - case int64: - v.Object = v.Object.(int64) - n - case uint: - v.Object = v.Object.(uint) - uint(n) - case uintptr: - v.Object = v.Object.(uintptr) - uintptr(n) - case uint8: - v.Object = v.Object.(uint8) - uint8(n) - case uint16: - v.Object = v.Object.(uint16) - uint16(n) - case uint32: - v.Object = v.Object.(uint32) - uint32(n) - case uint64: - v.Object = v.Object.(uint64) - uint64(n) - case float32: - v.Object = v.Object.(float32) - float32(n) - case float64: - v.Object = v.Object.(float64) - float64(n) - default: - c.mu.Unlock() - return fmt.Errorf("The value for %s is not an integer", k) - } - c.items[k] = v - c.mu.Unlock() - return nil -} - -// Decrement an item of type float32 or float64 by n. Returns an error if the -// item's value is not floating point, if it was not found, or if it is not -// possible to decrement it by n. Pass a negative number to decrement the -// value. To retrieve the decremented value, use one of the specialized methods, -// e.g. DecrementFloat64. -func (c *cache) DecrementFloat(k string, n float64) error { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return fmt.Errorf("Item %s not found", k) - } - switch v.Object.(type) { - case float32: - v.Object = v.Object.(float32) - float32(n) - case float64: - v.Object = v.Object.(float64) - n - default: - c.mu.Unlock() - return fmt.Errorf("The value for %s does not have type float32 or float64", k) - } - c.items[k] = v - c.mu.Unlock() - return nil -} - -// Decrement an item of type int by n. Returns an error if the item's value is -// not an int, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementInt(k string, n int) (int, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type int8 by n. Returns an error if the item's value is -// not an int8, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementInt8(k string, n int8) (int8, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int8) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int8", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type int16 by n. Returns an error if the item's value is -// not an int16, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementInt16(k string, n int16) (int16, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int16) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int16", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type int32 by n. Returns an error if the item's value is -// not an int32, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementInt32(k string, n int32) (int32, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int32) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int32", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type int64 by n. Returns an error if the item's value is -// not an int64, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementInt64(k string, n int64) (int64, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(int64) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an int64", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type uint by n. Returns an error if the item's value is -// not an uint, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementUint(k string, n uint) (uint, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uint) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type uintptr by n. Returns an error if the item's value -// is not an uintptr, or if it was not found. If there is no error, the -// decremented value is returned. -func (c *cache) DecrementUintptr(k string, n uintptr) (uintptr, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uintptr) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uintptr", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type uint8 by n. Returns an error if the item's value is -// not an uint8, or if it was not found. If there is no error, the decremented -// value is returned. -func (c *cache) DecrementUint8(k string, n uint8) (uint8, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uint8) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint8", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type uint16 by n. Returns an error if the item's value -// is not an uint16, or if it was not found. If there is no error, the -// decremented value is returned. -func (c *cache) DecrementUint16(k string, n uint16) (uint16, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uint16) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint16", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type uint32 by n. Returns an error if the item's value -// is not an uint32, or if it was not found. If there is no error, the -// decremented value is returned. -func (c *cache) DecrementUint32(k string, n uint32) (uint32, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uint32) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint32", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type uint64 by n. Returns an error if the item's value -// is not an uint64, or if it was not found. If there is no error, the -// decremented value is returned. -func (c *cache) DecrementUint64(k string, n uint64) (uint64, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(uint64) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an uint64", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type float32 by n. Returns an error if the item's value -// is not an float32, or if it was not found. If there is no error, the -// decremented value is returned. -func (c *cache) DecrementFloat32(k string, n float32) (float32, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(float32) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an float32", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Decrement an item of type float64 by n. Returns an error if the item's value -// is not an float64, or if it was not found. If there is no error, the -// decremented value is returned. -func (c *cache) DecrementFloat64(k string, n float64) (float64, error) { - c.mu.Lock() - v, found := c.items[k] - if !found || v.Expired() { - c.mu.Unlock() - return 0, fmt.Errorf("Item %s not found", k) - } - rv, ok := v.Object.(float64) - if !ok { - c.mu.Unlock() - return 0, fmt.Errorf("The value for %s is not an float64", k) - } - nv := rv - n - v.Object = nv - c.items[k] = v - c.mu.Unlock() - return nv, nil -} - -// Delete an item from the cache. Does nothing if the key is not in the cache. -func (c *cache) Delete(k string) { - c.mu.Lock() - v, evicted := c.delete(k) - c.mu.Unlock() - if evicted { - c.onEvicted(k, v) - } -} - -func (c *cache) delete(k string) (interface{}, bool) { - if c.onEvicted != nil { - if v, found := c.items[k]; found { - delete(c.items, k) - return v.Object, true - } - } - delete(c.items, k) - return nil, false -} - -type keyAndValue struct { - key string - value interface{} -} - -// Delete all expired items from the cache. -func (c *cache) DeleteExpired() { - var evictedItems []keyAndValue - now := time.Now().UnixNano() - c.mu.Lock() - for k, v := range c.items { - // "Inlining" of expired - if v.Expiration > 0 && now > v.Expiration { - ov, evicted := c.delete(k) - if evicted { - evictedItems = append(evictedItems, keyAndValue{k, ov}) - } - } - } - c.mu.Unlock() - for _, v := range evictedItems { - c.onEvicted(v.key, v.value) - } -} - -// Sets an (optional) function that is called with the key and value when an -// item is evicted from the cache. (Including when it is deleted manually, but -// not when it is overwritten.) Set to nil to disable. -func (c *cache) OnEvicted(f func(string, interface{})) { - c.mu.Lock() - c.onEvicted = f - c.mu.Unlock() -} - -// Write the cache's items (using Gob) to an io.Writer. -// -// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the -// documentation for NewFrom().) -func (c *cache) Save(w io.Writer) (err error) { - enc := gob.NewEncoder(w) - defer func() { - if x := recover(); x != nil { - err = fmt.Errorf("Error registering item types with Gob library") - } - }() - c.mu.RLock() - defer c.mu.RUnlock() - for _, v := range c.items { - gob.Register(v.Object) - } - err = enc.Encode(&c.items) - return -} - -// Save the cache's items to the given filename, creating the file if it -// doesn't exist, and overwriting it if it does. -// -// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the -// documentation for NewFrom().) -func (c *cache) SaveFile(fname string) error { - fp, err := os.Create(fname) - if err != nil { - return err - } - err = c.Save(fp) - if err != nil { - fp.Close() - return err - } - return fp.Close() -} - -// Add (Gob-serialized) cache items from an io.Reader, excluding any items with -// keys that already exist (and haven't expired) in the current cache. -// -// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the -// documentation for NewFrom().) -func (c *cache) Load(r io.Reader) error { - dec := gob.NewDecoder(r) - items := map[string]Item{} - err := dec.Decode(&items) - if err == nil { - c.mu.Lock() - defer c.mu.Unlock() - for k, v := range items { - ov, found := c.items[k] - if !found || ov.Expired() { - c.items[k] = v - } - } - } - return err -} - -// Load and add cache items from the given filename, excluding any items with -// keys that already exist in the current cache. -// -// NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the -// documentation for NewFrom().) -func (c *cache) LoadFile(fname string) error { - fp, err := os.Open(fname) - if err != nil { - return err - } - err = c.Load(fp) - if err != nil { - fp.Close() - return err - } - return fp.Close() -} - -// 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.mu.RLock() - defer c.mu.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.mu.RLock() - n := len(c.items) - c.mu.RUnlock() - return n -} - -// Delete all items from the cache. -func (c *cache) Flush() { - c.mu.Lock() - c.items = map[string]Item{} - c.mu.Unlock() -} - -type janitor struct { - Interval time.Duration - stop chan bool -} - -func (j *janitor) Run(c *cache) { - j.stop = make(chan bool) - ticker := time.NewTicker(j.Interval) - for { - select { - case <-ticker.C: - c.DeleteExpired() - case <-j.stop: - ticker.Stop() - return - } - } -} - -func stopJanitor(c *Cache) { - c.janitor.stop <- true -} - -func runJanitor(c *cache, ci time.Duration) { - j := &janitor{ - Interval: ci, - } - c.janitor = j - go j.Run(c) -} - -func newCache(de time.Duration, m map[string]Item) *cache { - if de == 0 { - de = -1 - } - c := &cache{ - defaultExpiration: de, - items: m, - } - return c -} - -func newCacheWithJanitor(de time.Duration, ci time.Duration, m map[string]Item) *Cache { - c := newCache(de, m) - // This trick ensures that the janitor goroutine (which--granted it - // was enabled--is running DeleteExpired on c forever) does not keep - // the returned C object from being garbage collected. When it is - // garbage collected, the finalizer stops the janitor goroutine, after - // which c can be collected. - C := &Cache{c} - if ci > 0 { - runJanitor(c, ci) - runtime.SetFinalizer(C, stopJanitor) - } - return C -} - -// Return a new cache with a given default expiration duration and cleanup -// interval. If the expiration duration is less than one (or NoExpiration), -// the items in the cache never expire (by default), and must be deleted -// manually. If the cleanup interval is less than one, expired items are not -// deleted from the cache before calling c.DeleteExpired(). -func New(defaultExpiration, cleanupInterval time.Duration) *Cache { - items := make(map[string]Item) - return newCacheWithJanitor(defaultExpiration, cleanupInterval, items) -} - -// Return a new cache with a given default expiration duration and cleanup -// interval. If the expiration duration is less than one (or NoExpiration), -// the items in the cache never expire (by default), and must be deleted -// manually. If the cleanup interval is less than one, expired items are not -// deleted from the cache before calling c.DeleteExpired(). -// -// NewFrom() also accepts an items map which will serve as the underlying map -// for the cache. This is useful for starting from a deserialized cache -// (serialized using e.g. gob.Encode() on c.Items()), or passing in e.g. -// make(map[string]Item, 500) to improve startup performance when the cache -// is expected to reach a certain minimum size. -// -// Only the cache's methods synchronize access to this map, so it is not -// recommended to keep any references to the map around after creating a cache. -// If need be, the map can be accessed at a later point using c.Items() (subject -// to the same caveat.) -// -// Note regarding serialization: When using e.g. gob, make sure to -// gob.Register() the individual types stored in the cache before encoding a -// map retrieved with c.Items(), and to register those same types before -// decoding a blob containing an items map. -func NewFrom(defaultExpiration, cleanupInterval time.Duration, items map[string]Item) *Cache { - return newCacheWithJanitor(defaultExpiration, cleanupInterval, items) -} |