sm/cache
1
0
Fork 0
Code

Various fixes for upstream acceptance, and formatting

Browse Source 
Removes the ctime tracking and access. Reverts NewFrom() changes from
upstream, and adds NewFromWithLRU() in place of it.
This commit is contained in:
M 2017-04-18 12:40:40 -04:00
parent 378662d53f
commit d8d9d6491e
1 changed files with 179 additions and 125 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

304
cache.go
View File

@ -13,7 +13,6 @@ import (
type Item struct { type Item struct {
Object interface{} Object interface{}
Expiration *time.Time Expiration *time.Time
Ctime *time.Time
Atime *time.Time Atime *time.Time
} }
@ -30,16 +29,12 @@ func (item *Item) LastAccessed() *time.Time {
return item.Atime return item.Atime
} }
// Set the Atime
func (item *Item) Accessed() { func (item *Item) Accessed() {
now := time.Now() now := time.Now()
item.Atime = &now item.Atime = &now
} }
// Return the Ctime
func (item *Item) Created() *time.Time {
return item.Ctime
}
const ( const (
// For use with functions that take an expiration time. // For use with functions that take an expiration time.
NoExpiration time.Duration = -1 NoExpiration time.Duration = -1
@ -75,29 +70,23 @@ func (c *cache) Set(k string, x interface{}, d time.Duration) {
func (c *cache) set(k string, x interface{}, d time.Duration) { func (c *cache) set(k string, x interface{}, d time.Duration) {
var e *time.Time var e *time.Time
t := time.Now()
at := &t
ct := &t
if d == DefaultExpiration { if d == DefaultExpiration {
d = c.defaultExpiration d = c.defaultExpiration
} }
if d > 0 { if d > 0 {
t = time.Now().Add(d) t := time.Now().Add(d)
e = &t e = &t
} }
if c.maxItems > 0 { if c.maxItems > 0 {
// We don't want to hit the expiration if we're updating. // Using maxItems (LRU)
_, found := c.get(k) now := time.Now()
if found { at := &now
// Update means change the Ctime
ct = c.items[k].Created()
}
c.items[k] = &Item{ c.items[k] = &Item{
Object: x, Object: x,
Expiration: e, Expiration: e,
Ctime: ct,
Atime: at, Atime: at,
} }
} else { } else {
@ -151,9 +140,11 @@ func (c *cache) get(k string) (interface{}, bool) {
if !found || item.Expired() { if !found || item.Expired() {
return nil, false return nil, false
} }
if c.maxItems > 0 { item.Accessed() } if c.maxItems > 0 {
item.Accessed()
}
return item.Object, true return item.Object, true
} }
@ -169,9 +160,11 @@ func (c *cache) Increment(k string, n int64) error {
c.Unlock() c.Unlock()
return fmt.Errorf("Item %s not found", k) return fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) { switch v.Object.(type) {
case int: case int:
v.Object = v.Object.(int) + int(n) v.Object = v.Object.(int) + int(n)
@ -219,9 +212,11 @@ func (c *cache) IncrementFloat(k string, n float64) error {
c.Unlock() c.Unlock()
return fmt.Errorf("Item %s not found", k) return fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) { switch v.Object.(type) {
case float32: case float32:
v.Object = v.Object.(float32) + float32(n) v.Object = v.Object.(float32) + float32(n)
@ -245,9 +240,11 @@ func (c *cache) IncrementInt(k string, n int) (int, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int) rv, ok := v.Object.(int)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -269,9 +266,11 @@ func (c *cache) IncrementInt8(k string, n int8) (int8, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int8) rv, ok := v.Object.(int8)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -293,9 +292,11 @@ func (c *cache) IncrementInt16(k string, n int16) (int16, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int16) rv, ok := v.Object.(int16)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -317,9 +318,11 @@ func (c *cache) IncrementInt32(k string, n int32) (int32, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int32) rv, ok := v.Object.(int32)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -341,9 +344,11 @@ func (c *cache) IncrementInt64(k string, n int64) (int64, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int64) rv, ok := v.Object.(int64)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -365,9 +370,11 @@ func (c *cache) IncrementUint(k string, n uint) (uint, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint) rv, ok := v.Object.(uint)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -389,9 +396,11 @@ func (c *cache) IncrementUintptr(k string, n uintptr) (uintptr, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uintptr) rv, ok := v.Object.(uintptr)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -413,9 +422,11 @@ func (c *cache) IncrementUint8(k string, n uint8) (uint8, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint8) rv, ok := v.Object.(uint8)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -438,7 +449,9 @@ func (c *cache) IncrementUint16(k string, n uint16) (uint16, error) {
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint16) rv, ok := v.Object.(uint16)
if !ok { if !ok {
@ -461,9 +474,11 @@ func (c *cache) IncrementUint32(k string, n uint32) (uint32, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint32) rv, ok := v.Object.(uint32)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -485,9 +500,11 @@ func (c *cache) IncrementUint64(k string, n uint64) (uint64, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint64) rv, ok := v.Object.(uint64)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -509,9 +526,11 @@ func (c *cache) IncrementFloat32(k string, n float32) (float32, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(float32) rv, ok := v.Object.(float32)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -533,9 +552,11 @@ func (c *cache) IncrementFloat64(k string, n float64) (float64, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(float64) rv, ok := v.Object.(float64)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -561,9 +582,11 @@ func (c *cache) Decrement(k string, n int64) error {
c.Unlock() c.Unlock()
return fmt.Errorf("Item not found") return fmt.Errorf("Item not found")
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) { switch v.Object.(type) {
case int: case int:
v.Object = v.Object.(int) - int(n) v.Object = v.Object.(int) - int(n)
@ -612,8 +635,10 @@ func (c *cache) DecrementFloat(k string, n float64) error {
return fmt.Errorf("Item %s not found", k) return fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) { switch v.Object.(type) {
case float32: case float32:
v.Object = v.Object.(float32) - float32(n) v.Object = v.Object.(float32) - float32(n)
@ -637,9 +662,11 @@ func (c *cache) DecrementInt(k string, n int) (int, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int) rv, ok := v.Object.(int)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -661,9 +688,11 @@ func (c *cache) DecrementInt8(k string, n int8) (int8, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int8) rv, ok := v.Object.(int8)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -685,9 +714,11 @@ func (c *cache) DecrementInt16(k string, n int16) (int16, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int16) rv, ok := v.Object.(int16)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -709,9 +740,11 @@ func (c *cache) DecrementInt32(k string, n int32) (int32, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int32) rv, ok := v.Object.(int32)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -733,9 +766,11 @@ func (c *cache) DecrementInt64(k string, n int64) (int64, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(int64) rv, ok := v.Object.(int64)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -757,9 +792,11 @@ func (c *cache) DecrementUint(k string, n uint) (uint, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint) rv, ok := v.Object.(uint)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -781,9 +818,11 @@ func (c *cache) DecrementUintptr(k string, n uintptr) (uintptr, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uintptr) rv, ok := v.Object.(uintptr)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -805,9 +844,11 @@ func (c *cache) DecrementUint8(k string, n uint8) (uint8, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint8) rv, ok := v.Object.(uint8)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -829,9 +870,11 @@ func (c *cache) DecrementUint16(k string, n uint16) (uint16, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint16) rv, ok := v.Object.(uint16)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -853,9 +896,11 @@ func (c *cache) DecrementUint32(k string, n uint32) (uint32, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint32) rv, ok := v.Object.(uint32)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -878,8 +923,10 @@ func (c *cache) DecrementUint64(k string, n uint64) (uint64, error) {
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint64) rv, ok := v.Object.(uint64)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -901,9 +948,11 @@ func (c *cache) DecrementFloat32(k string, n float32) (float32, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(float32) rv, ok := v.Object.(float32)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -925,9 +974,11 @@ func (c *cache) DecrementFloat64(k string, n float64) (float64, error) {
c.Unlock() c.Unlock()
return 0, fmt.Errorf("Item %s not found", k) return 0, fmt.Errorf("Item %s not found", k)
} }
if c.maxItems > 0 { v.Accessed() } if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(float64) rv, ok := v.Object.(float64)
if !ok { if !ok {
c.Unlock() c.Unlock()
@ -1059,8 +1110,8 @@ func (c *cache) ItemCount() int {
return n return n
} }
// Returns the number of items in the cache without locking. This may include // 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 // items that have expired, but have not yet been cleaned up. Equivalent to
// len(c.Items()). // len(c.Items()).
func (c *cache) itemCount() int { func (c *cache) itemCount() int {
n := len(c.items) n := len(c.items)
@ -1076,8 +1127,9 @@ func (c *cache) Flush() {
// Find oldest N items, and delete them. // Find oldest N items, and delete them.
func (c *cache) DeleteLRU(numItems int) { func (c *cache) DeleteLRU(numItems int) {
c.Lock() c.Lock()
defer c.Unlock()
var lastTime int64 = 0 var lastTime int64 = 0
lastItems := make([]string, numItems) // ringbuffer for the last numItems lastItems := make([]string, numItems) // ringbuffer for the last numItems
@ -1087,18 +1139,18 @@ func (c *cache) DeleteLRU(numItems int) {
for k, v := range c.items { for k, v := range c.items {
if v.Expired() == false { if v.Expired() == false {
// unexpired item // unexpired item
atime := v.LastAccessed().UnixNano() atime := v.LastAccessed().UnixNano()
if full == false || atime < lastTime { if full == false || atime < lastTime {
// We found a least-recently-used item, // We found a least-recently-used item,
// or our purge buffer isn't full yet // or our purge buffer isn't full yet
lastTime = atime lastTime = atime
// Append it to the buffer, // Append it to the buffer,
// or start overwriting it // or start overwriting it
if liCount < numItems { if liCount < numItems {
lastItems[liCount] = k lastItems[liCount] = k
liCount ++ liCount++
} else { } else {
lastItems[0] = k lastItems[0] = k
liCount = 1 liCount = 1
@ -1107,7 +1159,7 @@ func (c *cache) DeleteLRU(numItems int) {
} }
} }
} }
if lastTime > 0 { if lastTime > 0 {
// Clean up the items // Clean up the items
for i := 0; i < len(lastItems) && lastItems[i] != ""; i++ { for i := 0; i < len(lastItems) && lastItems[i] != ""; i++ {
@ -1115,8 +1167,6 @@ func (c *cache) DeleteLRU(numItems int) {
c.delete(lastName) c.delete(lastName)
} }
} }
c.Unlock()
} }
type janitor struct { type janitor struct {
@ -1131,7 +1181,7 @@ func (j *janitor) Run(c *cache) {
select { select {
case <-tick: case <-tick:
c.DeleteExpired() c.DeleteExpired()
if c.maxItems > 0 { if c.maxItems > 0 {
// Purge any LRU overages // Purge any LRU overages
overCount := c.itemCount() - c.maxItems overCount := c.itemCount() - c.maxItems
@ -1195,13 +1245,13 @@ func New(defaultExpiration, cleanupInterval time.Duration) *Cache {
} }
// Return a new cache with a given default expiration duration, cleanup // Return a new cache with a given default expiration duration, cleanup
// interval, and maximum-ish number of items. If the expiration duration // interval, and maximum-ish number of items. If the expiration duration
// is less than one (or NoExpiration), the items in the cache never expire // 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 // (by default), and must be deleted manually. If the cleanup interval is
// less than one, expired items are not deleted from the cache before // less than one, expired items are not deleted from the cache before
// calling c.DeleteExpired() and/or c.DeleteLRU(). If maxItems is not greater // calling c.DeleteExpired() and/or c.DeleteLRU(). If maxItems is not greater
// than zero, then there will be no soft cap on the number of items in the cache. // than zero, then there will be no soft cap on the number of items in the cache.
func NewWithLRU(defaultExpiration, cleanupInterval time.Duration, maxItems int) *Cache { func NewWithLRU(defaultExpiration, cleanupInterval time.Duration, maxItems int) *Cache {
items := make(map[string]*Item) items := make(map[string]*Item)
return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, maxItems) return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, maxItems)
} }
@ -1227,6 +1277,10 @@ func NewWithLRU(defaultExpiration, cleanupInterval time.Duration, maxItems int)
// gob.Register() the individual types stored in the cache before encoding a // gob.Register() the individual types stored in the cache before encoding a
// map retrieved with c.Items(), and to register those same types before // map retrieved with c.Items(), and to register those same types before
// decoding a blob containing an items map. // decoding a blob containing an items map.
func NewFrom(defaultExpiration, cleanupInterval time.Duration, items map[string]*Item, maxItems int) *Cache { func NewFrom(defaultExpiration, cleanupInterval time.Duration, items map[string]*Item) *Cache {
return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, 0)
}
func NewFromWithLRU(defaultExpiration, cleanupInterval time.Duration, items map[string]*Item, maxItems int) *Cache {
return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, maxItems) return newCacheWithJanitor(defaultExpiration, cleanupInterval, items, maxItems)
} }