Repository: uber-go/zap
File: buffer/pool.go (Go)

Code before:
// Copyright (c) 2016 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package buffer

import "sync"

// A Pool is a type-safe wrapper around a sync.Pool.
type Pool sync.Pool

// NewPool constructs a new Pool.
func NewPool() *Pool {
	p := sync.Pool{
		New: func() interface{} {
			return &Buffer{bs: make([]byte, 0, _size)}
		},
	}
	return (*Pool)(&p)
}

// Get retrieves a Buffer from the pool, creating one if necessary.
func (p *Pool) Get() *Buffer {
	buf := (*sync.Pool)(p).Get().(*Buffer)
	buf.Reset()
	buf.pool = p
	return buf
}

func (p *Pool) put(buf *Buffer) {
	(*sync.Pool)(p).Put(buf)
}


Review comment (suggestion):
i think this code will be cleaner if we make this a struct with a `sync.Pool` as a field. Retyping is useful for slices and maps since it lets callers create them more easily, but there's no advantage here, and we don't want users to get access to the underlying `sync.Pool`.

Code after:
// Copyright (c) 2016 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package buffer

import "sync"

// A Pool is a type-safe wrapper around a sync.Pool.
type Pool struct {
	p *sync.Pool
}

// NewPool constructs a new Pool.
func NewPool() Pool {
	return Pool{p: &sync.Pool{
		New: func() interface{} {
			return &Buffer{bs: make([]byte, 0, _size)}
		},
	}}
}

// Get retrieves a Buffer from the pool, creating one if necessary.
func (p Pool) Get() *Buffer {
	buf := p.p.Get().(*Buffer)
	buf.Reset()
	buf.pool = p
	return buf
}

func (p Pool) put(buf *Buffer) {
	p.p.Put(buf)
}