forked from seaweedfs/seaweedfs
/
concurrent_read_map.go
60 lines (51 loc) · 1.16 KB
/
concurrent_read_map.go
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package util
import (
"sync"
)
// A mostly for read map, which can thread-safely
// initialize the map entries.
type ConcurrentReadMap struct {
sync.RWMutex
items map[string]interface{}
}
func NewConcurrentReadMap() *ConcurrentReadMap {
return &ConcurrentReadMap{items: make(map[string]interface{})}
}
func (m *ConcurrentReadMap) initMapEntry(key string, newEntry func() interface{}) (value interface{}) {
m.Lock()
defer m.Unlock()
if value, ok := m.items[key]; ok {
return value
}
value = newEntry()
m.items[key] = value
return value
}
func (m *ConcurrentReadMap) Get(key string, newEntry func() interface{}) interface{} {
m.RLock()
if value, ok := m.items[key]; ok {
m.RUnlock()
return value
}
m.RUnlock()
return m.initMapEntry(key, newEntry)
}
func (m *ConcurrentReadMap) Find(key string) (interface{}, bool) {
m.RLock()
value, ok := m.items[key]
m.RUnlock()
return value, ok
}
func (m *ConcurrentReadMap) Items() (itemsCopy []interface{}) {
m.RLock()
for _, i := range m.items {
itemsCopy = append(itemsCopy, i)
}
m.RUnlock()
return itemsCopy
}
func (m *ConcurrentReadMap) Delete(key string) {
m.Lock()
delete(m.items, key)
m.Unlock()
}