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IDGenerator.go
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/
IDGenerator.go
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package server
import (
"sync"
)
type ID int32
type IDGenerator struct {
lastID ID
ids []ID
locker *sync.Mutex
threadSafe bool
}
func NewIDGenerator(buffer int, threadSafe bool) *IDGenerator {
gen := &IDGenerator{0, make([]ID, 0, buffer), &sync.Mutex{}, threadSafe}
if threadSafe {
gen.locker.Lock()
defer gen.locker.Unlock()
}
gen.genIDs()
return gen
}
func (gen *IDGenerator) genIDs() {
gen.lastID += ID(cap(gen.ids) / 2)
id := gen.lastID - 1
for i := 0; i < cap(gen.ids)/2; i++ {
gen.ids = append(gen.ids, id)
id--
}
}
func (gen *IDGenerator) NextID() ID {
id := ID(0)
if gen.threadSafe {
gen.locker.Lock()
defer gen.locker.Unlock()
}
id, gen.ids = gen.ids[len(gen.ids)-1], gen.ids[:len(gen.ids)-1]
if len(gen.ids) == 0 {
gen.genIDs()
}
return id
}
func (gen *IDGenerator) PutID(id ID) {
if gen.threadSafe {
gen.locker.Lock()
defer gen.locker.Unlock()
}
gen.ids = append(gen.ids, id)
}