Snippet

Reusing allocated memory buffers with sync.Pool

Using sync.Pool allows recycling temporary objects, which significantly reduces the workload on the Garbage Collector (GC) during high-throughput operations. The Pool stores temporarily unused buffers and returns them when requested.

snippet.go

package main
 
import (
	"bytes"
	"fmt"
	"sync"
)
 
var bufPool = sync.Pool{
	New: func() any {
		return new(bytes.Buffer)
	},
}
 
func process(val string) {
	buf := bufPool.Get().(*bytes.Buffer)
	defer func() {
		buf.Reset()
		bufPool.Put(buf)
	}()
 
	buf.WriteString("Processed: ")
	buf.WriteString(val)
	fmt.Println(buf.String())
}
 
func main() {
	process("hello")
	process("world")
}

Breakdown

var bufPool = sync.Pool{

Declares a global sync.Pool and defines a builder function for when the pool is empty.

buf := bufPool.Get().(*bytes.Buffer)

Retrieves an available buffer from the pool and type-asserts it back to a bytes.Buffer pointer.

bufPool.Put(buf)

Resets the buffer contents and returns the buffer back to the pool for reuse.

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Reusing allocated memory buffers with sync.Pool

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