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Various fixes for upstream acceptance, and formatting

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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
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304
cache.go
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@ -13,7 +13,6 @@ import (
type Item struct {
Object interface{}
Expiration *time.Time
Ctime *time.Time
Atime *time.Time
}
@ -30,16 +29,12 @@ func (item *Item) LastAccessed() *time.Time {
return item.Atime
}
// Set the Atime
func (item *Item) Accessed() {
now := time.Now()
item.Atime = &now
}
// Return the Ctime
func (item *Item) Created() *time.Time {
return item.Ctime
}
const (
// For use with functions that take an expiration time.
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) {
var e *time.Time
t := time.Now()
at := &t
ct := &t
if d == DefaultExpiration {
d = c.defaultExpiration
}
if d > 0 {
t = time.Now().Add(d)
t := time.Now().Add(d)
e = &t
}
if c.maxItems > 0 {
// We don't want to hit the expiration if we're updating.
_, found := c.get(k)
if found {
// Update means change the Ctime
ct = c.items[k].Created()
}
// Using maxItems (LRU)
now := time.Now()
at := &now
c.items[k] = &Item{
Object: x,
Expiration: e,
Ctime: ct,
Atime: at,
}
} else {
@ -151,9 +140,11 @@ func (c *cache) get(k string) (interface{}, bool) {
if !found || item.Expired() {
return nil, false
}
if c.maxItems > 0 { item.Accessed() }
if c.maxItems > 0 {
item.Accessed()
}
return item.Object, true
}
@ -169,9 +160,11 @@ func (c *cache) Increment(k string, n int64) error {
c.Unlock()
return fmt.Errorf("Item %s not found", k)
}
if c.maxItems > 0 { v.Accessed() }
if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) {
case int:
v.Object = v.Object.(int) + int(n)
@ -219,9 +212,11 @@ func (c *cache) IncrementFloat(k string, n float64) error {
c.Unlock()
return fmt.Errorf("Item %s not found", k)
}
if c.maxItems > 0 { v.Accessed() }
if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) {
case float32:
v.Object = v.Object.(float32) + float32(n)
@ -245,9 +240,11 @@ func (c *cache) IncrementInt(k string, n int) (int, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -269,9 +266,11 @@ func (c *cache) IncrementInt8(k string, n int8) (int8, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -293,9 +292,11 @@ func (c *cache) IncrementInt16(k string, n int16) (int16, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -317,9 +318,11 @@ func (c *cache) IncrementInt32(k string, n int32) (int32, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -341,9 +344,11 @@ func (c *cache) IncrementInt64(k string, n int64) (int64, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -365,9 +370,11 @@ func (c *cache) IncrementUint(k string, n uint) (uint, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -389,9 +396,11 @@ func (c *cache) IncrementUintptr(k string, n uintptr) (uintptr, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -413,9 +422,11 @@ func (c *cache) IncrementUint8(k string, n uint8) (uint8, error) {
c.Unlock()
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)
if !ok {
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)
}
if c.maxItems > 0 { v.Accessed() }
if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint16)
if !ok {
@ -461,9 +474,11 @@ func (c *cache) IncrementUint32(k string, n uint32) (uint32, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -485,9 +500,11 @@ func (c *cache) IncrementUint64(k string, n uint64) (uint64, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -509,9 +526,11 @@ func (c *cache) IncrementFloat32(k string, n float32) (float32, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -533,9 +552,11 @@ func (c *cache) IncrementFloat64(k string, n float64) (float64, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -561,9 +582,11 @@ func (c *cache) Decrement(k string, n int64) error {
c.Unlock()
return fmt.Errorf("Item not found")
}
if c.maxItems > 0 { v.Accessed() }
if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) {
case int:
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)
}
if c.maxItems > 0 { v.Accessed() }
if c.maxItems > 0 {
v.Accessed()
}
switch v.Object.(type) {
case float32:
v.Object = v.Object.(float32) - float32(n)
@ -637,9 +662,11 @@ func (c *cache) DecrementInt(k string, n int) (int, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -661,9 +688,11 @@ func (c *cache) DecrementInt8(k string, n int8) (int8, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -685,9 +714,11 @@ func (c *cache) DecrementInt16(k string, n int16) (int16, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -709,9 +740,11 @@ func (c *cache) DecrementInt32(k string, n int32) (int32, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -733,9 +766,11 @@ func (c *cache) DecrementInt64(k string, n int64) (int64, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -757,9 +792,11 @@ func (c *cache) DecrementUint(k string, n uint) (uint, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -781,9 +818,11 @@ func (c *cache) DecrementUintptr(k string, n uintptr) (uintptr, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -805,9 +844,11 @@ func (c *cache) DecrementUint8(k string, n uint8) (uint8, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -829,9 +870,11 @@ func (c *cache) DecrementUint16(k string, n uint16) (uint16, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -853,9 +896,11 @@ func (c *cache) DecrementUint32(k string, n uint32) (uint32, error) {
c.Unlock()
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)
if !ok {
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)
}
if c.maxItems > 0 { v.Accessed() }
if c.maxItems > 0 {
v.Accessed()
}
rv, ok := v.Object.(uint64)
if !ok {
c.Unlock()
@ -901,9 +948,11 @@ func (c *cache) DecrementFloat32(k string, n float32) (float32, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -925,9 +974,11 @@ func (c *cache) DecrementFloat64(k string, n float64) (float64, error) {
c.Unlock()
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)
if !ok {
c.Unlock()
@ -1059,8 +1110,8 @@ func (c *cache) ItemCount() int {
return n
}
// Returns the number of items in the cache without locking. This may include
// items that have expired, but have not yet been cleaned up. Equivalent to
// Returns the number of items in the cache without locking. This may include
// items that have expired, but have not yet been cleaned up. Equivalent to
// len(c.Items()).
func (c *cache) itemCount() int {
n := len(c.items)
@ -1076,8 +1127,9 @@ func (c *cache) Flush() {
// Find oldest N items, and delete them.
func (c *cache) DeleteLRU(numItems int) {
c.Lock()
defer c.Unlock()
var lastTime int64 = 0
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 {
if v.Expired() == false {
// unexpired item
atime := v.LastAccessed().UnixNano()
if full == false || atime < lastTime {
// We found a least-recently-used item,
// or our purge buffer isn't full yet
lastTime = atime
// Append it to the buffer,
// or start overwriting it
if liCount < numItems {
lastItems[liCount] = k
liCount ++
liCount++
} else {
lastItems[0] = k
liCount = 1
@ -1107,7 +1159,7 @@ func (c *cache) DeleteLRU(numItems int) {
}
}
}
if lastTime > 0 {
// Clean up the items
for i := 0; i < len(lastItems) && lastItems[i] != ""; i++ {
@ -1115,8 +1167,6 @@ func (c *cache) DeleteLRU(numItems int) {
c.delete(lastName)
}
}
c.Unlock()
}
type janitor struct {
@ -1131,7 +1181,7 @@ func (j *janitor) Run(c *cache) {
select {
case <-tick:
c.DeleteExpired()
if c.maxItems > 0 {
// Purge any LRU overages
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
// interval, and maximum-ish number of items. If the expiration duration
// is less than one (or NoExpiration), the items in the cache never expire
// (by default), and must be deleted manually. If the cleanup interval is
// less than one, expired items are not deleted from the cache before
// calling c.DeleteExpired() and/or c.DeleteLRU(). If maxItems is not greater
// interval, and maximum-ish number of items. If the expiration duration
// is less than one (or NoExpiration), the items in the cache never expire
// (by default), and must be deleted manually. If the cleanup interval is
// less than one, expired items are not deleted from the cache before
// calling c.DeleteExpired() 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.
func NewWithLRU(defaultExpiration, cleanupInterval time.Duration, maxItems int) *Cache {
func NewWithLRU(defaultExpiration, cleanupInterval time.Duration, maxItems int) *Cache {
items := make(map[string]*Item)
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
// 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, 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)
}