github.com/pawelgaczynski/gain@v0.4.0-alpha.0.20230821120126-41f1e60a18da/key_pool.go (about) 1 // Copyright (c) 2023 Paweł Gaczyński 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package gain 16 17 import ( 18 "sync/atomic" 19 20 "github.com/pawelgaczynski/gain/pkg/stack" 21 ) 22 23 const firstFreeKey = 2 24 25 type keyPool struct { 26 stack stack.LockFreeStack[uint64] 27 nextKey uint64 28 } 29 30 func (p *keyPool) get() uint64 { 31 key := p.stack.Pop() 32 if key == 0 { 33 value := atomic.AddUint64(&p.nextKey, 1) - 1 34 35 return value 36 } 37 38 return key 39 } 40 41 func (p *keyPool) put(key uint64) { 42 p.stack.Push(key) 43 } 44 45 func newKeyPool() *keyPool { 46 return &keyPool{ 47 stack: stack.NewLockFreeStack[uint64](), 48 // 0 is invalid key, 1 is reserved for main socket 49 nextKey: firstFreeKey, 50 } 51 }