mirror of https://github.com/k3d-io/k3d
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
77 lines
2.2 KiB
77 lines
2.2 KiB
2 years ago
|
/*
|
||
|
|
Copyright 2022 The Kubernetes Authors.
|
||
|
|
|
||
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
you may not use this file except in compliance with the License.
|
||
|
|
You may obtain a copy of the License at
|
||
|
|
|
||
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
|
||
|
|
Unless required by applicable law or agreed to in writing, software
|
||
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
See the License for the specific language governing permissions and
|
||
|
|
limitations under the License.
|
||
|
|
*/
|
||
|
|
|
||
|
|
package runtime
|
||
|
|
|
||
|
|
import (
|
||
|
|
"sync"
|
||
|
|
)
|
||
|
|
|
||
|
|
// AllocatorPool simply stores Allocator objects to avoid additional memory allocations
|
||
|
|
// by caching created but unused items for later reuse, relieving pressure on the garbage collector.
|
||
|
|
//
|
||
|
|
// Usage:
|
||
|
|
//
|
||
|
|
// memoryAllocator := runtime.AllocatorPool.Get().(*runtime.Allocator)
|
||
|
|
// defer runtime.AllocatorPool.Put(memoryAllocator)
|
||
|
|
//
|
||
|
|
// A note for future:
|
||
|
|
//
|
||
|
|
// consider introducing multiple pools for storing buffers of different sizes
|
||
|
|
// perhaps this could allow us to be more efficient.
|
||
|
|
var AllocatorPool = sync.Pool{
|
||
|
|
New: func() interface{} {
|
||
|
|
return &Allocator{}
|
||
|
|
},
|
||
|
|
}
|
||
|
|
|
||
|
|
// Allocator knows how to allocate memory
|
||
|
|
// It exists to make the cost of object serialization cheaper.
|
||
|
|
// In some cases, it allows for allocating memory only once and then reusing it.
|
||
|
|
// This approach puts less load on GC and leads to less fragmented memory in general.
|
||
|
|
type Allocator struct {
|
||
|
|
buf []byte
|
||
|
|
}
|
||
|
|
|
||
|
|
var _ MemoryAllocator = &Allocator{}
|
||
|
|
|
||
|
|
// Allocate reserves memory for n bytes only if the underlying array doesn't have enough capacity
|
||
|
|
// otherwise it returns previously allocated block of memory.
|
||
|
|
//
|
||
|
|
// Note that the returned array is not zeroed, it is the caller's
|
||
|
|
// responsibility to clean the memory if needed.
|
||
|
|
func (a *Allocator) Allocate(n uint64) []byte {
|
||
|
|
if uint64(cap(a.buf)) >= n {
|
||
|
|
a.buf = a.buf[:n]
|
||
|
|
return a.buf
|
||
|
|
}
|
||
|
|
// grow the buffer
|
||
|
|
size := uint64(2*cap(a.buf)) + n
|
||
|
|
a.buf = make([]byte, size)
|
||
|
|
a.buf = a.buf[:n]
|
||
|
|
return a.buf
|
||
|
|
}
|
||
|
|
|
||
|
|
// SimpleAllocator a wrapper around make([]byte)
|
||
|
|
// conforms to the MemoryAllocator interface
|
||
|
|
type SimpleAllocator struct{}
|
||
|
|
|
||
|
|
var _ MemoryAllocator = &SimpleAllocator{}
|
||
|
|
|
||
|
|
func (sa *SimpleAllocator) Allocate(n uint64) []byte {
|
||
|
|
return make([]byte, n)
|
||
|
|
}
|