/pool

Go Pooling Helpers

Primary LanguageGoMIT LicenseMIT

pool

GoDoc

Tiny memory reuse helpers for Go.

generic

Without use of subpackages, pool allows to reuse any struct distinguishable by size in generic way:

package main

import "github.com/gobwas/pool"

func main() {
	x, n := pool.Get(100) // Returns object with size 128 or nil.
	if x == nil {
		// Create x somehow with knowledge that n is 128.
	}
	defer pool.Put(x, n)
	
	// Work with x.
}

Pool allows you to pass specific options for constructing custom pool:

package main

import "github.com/gobwas/pool"

func main() {
	p := pool.Custom(
        pool.WithLogSizeMapping(),      // Will ceil size n passed to Get(n) to nearest power of two.
        pool.WithLogSizeRange(64, 512), // Will reuse objects in logarithmic range [64, 512].
        pool.WithSize(65536),           // Will reuse object with size 65536.
    )
	x, n := p.Get(1000)  // Returns nil and 1000 because mapped size 1000 => 1024 is not reusing by the pool.
    defer pool.Put(x, n) // Will not reuse x.
	
	// Work with x.
}

Note that there are few non-generic pooling implementations inside subpackages.

pbytes

Subpackage pbytes is intended for []byte reuse.

package main

import "github.com/gobwas/pool/pbytes"

func main() {
	bts := pbytes.GetCap(100) // Returns make([]byte, 0, 128).
	defer pbytes.Put(bts)

	// Work with bts.
}

You can also create your own range for pooling:

package main

import "github.com/gobwas/pool/pbytes"

func main() {
	// Reuse only slices whose capacity is 128, 256, 512 or 1024.
	pool := pbytes.New(128, 1024) 

	bts := pool.GetCap(100) // Returns make([]byte, 0, 128).
	defer pool.Put(bts)

	// Work with bts.
}

pbufio

Subpackage pbufio is intended for *bufio.{Reader, Writer} reuse.

package main

import "github.com/gobwas/pool/pbufio"

func main() {
	bw := pbufio.GetWriter(os.Stdout, 100) // Returns bufio.NewWriterSize(128).
	defer pbufio.PutWriter(bw)

	// Work with bw.
}

Like with pbytes, you can also create pool with custom reuse bounds.