|
|
|
package collection
|
|
|
|
|
|
|
|
import "sync"
|
|
|
|
|
|
|
|
const (
|
|
|
|
copyThreshold = 1000
|
|
|
|
maxDeletion = 10000
|
|
|
|
)
|
|
|
|
|
|
|
|
// SafeMap provides a map alternative to avoid memory leak.
|
|
|
|
// This implementation is not needed until issue below fixed.
|
|
|
|
// https://github.com/golang/go/issues/20135
|
|
|
|
type SafeMap struct {
|
|
|
|
lock sync.RWMutex
|
|
|
|
deletionOld int
|
|
|
|
deletionNew int
|
|
|
|
dirtyOld map[interface{}]interface{}
|
|
|
|
dirtyNew map[interface{}]interface{}
|
|
|
|
}
|
|
|
|
|
|
|
|
// NewSafeMap returns a SafeMap.
|
|
|
|
func NewSafeMap() *SafeMap {
|
|
|
|
return &SafeMap{
|
|
|
|
dirtyOld: make(map[interface{}]interface{}),
|
|
|
|
dirtyNew: make(map[interface{}]interface{}),
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// Del deletes the value with the given key from m.
|
|
|
|
func (m *SafeMap) Del(key interface{}) {
|
|
|
|
m.lock.Lock()
|
|
|
|
if _, ok := m.dirtyOld[key]; ok {
|
|
|
|
delete(m.dirtyOld, key)
|
|
|
|
m.deletionOld++
|
|
|
|
} else if _, ok := m.dirtyNew[key]; ok {
|
|
|
|
delete(m.dirtyNew, key)
|
|
|
|
m.deletionNew++
|
|
|
|
}
|
|
|
|
if m.deletionOld >= maxDeletion && len(m.dirtyOld) < copyThreshold {
|
|
|
|
for k, v := range m.dirtyOld {
|
|
|
|
m.dirtyNew[k] = v
|
|
|
|
}
|
|
|
|
m.dirtyOld = m.dirtyNew
|
|
|
|
m.deletionOld = m.deletionNew
|
|
|
|
m.dirtyNew = make(map[interface{}]interface{})
|
|
|
|
m.deletionNew = 0
|
|
|
|
}
|
|
|
|
if m.deletionNew >= maxDeletion && len(m.dirtyNew) < copyThreshold {
|
|
|
|
for k, v := range m.dirtyNew {
|
|
|
|
m.dirtyOld[k] = v
|
|
|
|
}
|
|
|
|
m.dirtyNew = make(map[interface{}]interface{})
|
|
|
|
m.deletionNew = 0
|
|
|
|
}
|
|
|
|
m.lock.Unlock()
|
|
|
|
}
|
|
|
|
|
|
|
|
// Get gets the value with the given key from m.
|
|
|
|
func (m *SafeMap) Get(key interface{}) (interface{}, bool) {
|
|
|
|
m.lock.RLock()
|
|
|
|
defer m.lock.RUnlock()
|
|
|
|
|
|
|
|
if val, ok := m.dirtyOld[key]; ok {
|
|
|
|
return val, true
|
|
|
|
}
|
|
|
|
|
|
|
|
val, ok := m.dirtyNew[key]
|
|
|
|
return val, ok
|
|
|
|
}
|
|
|
|
|
|
|
|
// Set sets the value into m with the given key.
|
|
|
|
func (m *SafeMap) Set(key, value interface{}) {
|
|
|
|
m.lock.Lock()
|
|
|
|
if m.deletionOld <= maxDeletion {
|
|
|
|
if _, ok := m.dirtyNew[key]; ok {
|
|
|
|
delete(m.dirtyNew, key)
|
|
|
|
m.deletionNew++
|
|
|
|
}
|
|
|
|
m.dirtyOld[key] = value
|
|
|
|
} else {
|
|
|
|
if _, ok := m.dirtyOld[key]; ok {
|
|
|
|
delete(m.dirtyOld, key)
|
|
|
|
m.deletionOld++
|
|
|
|
}
|
|
|
|
m.dirtyNew[key] = value
|
|
|
|
}
|
|
|
|
m.lock.Unlock()
|
|
|
|
}
|
|
|
|
|
|
|
|
// Size returns the size of m.
|
|
|
|
func (m *SafeMap) Size() int {
|
|
|
|
m.lock.RLock()
|
|
|
|
size := len(m.dirtyOld) + len(m.dirtyNew)
|
|
|
|
m.lock.RUnlock()
|
|
|
|
return size
|
|
|
|
}
|
|
|
|
|
|
|
|
// Range calls f sequentially for each key and value present in the map.
|
|
|
|
// If f returns false, range stops the iteration.
|
|
|
|
// Range m .
|
|
|
|
func (m *SafeMap) Range(f func(key, value interface{}) bool) {
|
|
|
|
m.lock.RLock()
|
|
|
|
defer m.lock.RUnlock()
|
|
|
|
var wg sync.WaitGroup
|
|
|
|
|
|
|
|
wg.Add(2)
|
|
|
|
go func() {
|
|
|
|
for k, v := range m.dirtyOld {
|
|
|
|
if !f(k, v) {
|
|
|
|
break
|
|
|
|
}
|
|
|
|
}
|
|
|
|
wg.Done()
|
|
|
|
}()
|
|
|
|
go func() {
|
|
|
|
for k, v := range m.dirtyNew {
|
|
|
|
if !f(k, v) {
|
|
|
|
break
|
|
|
|
}
|
|
|
|
}
|
|
|
|
wg.Done()
|
|
|
|
}()
|
|
|
|
wg.Wait()
|
|
|
|
}
|