well-goknown/vendor/github.com/gobwas/pool/README.md

107 lines
2.1 KiB
Markdown

# pool
[![GoDoc][godoc-image]][godoc-url]
> Tiny memory reuse helpers for Go.
## generic
Without use of subpackages, `pool` allows to reuse any struct distinguishable
by size in generic way:
```go
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:
```go
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.
```go
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:
```go
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.
```go
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.
[godoc-image]: https://godoc.org/github.com/gobwas/pool?status.svg
[godoc-url]: https://godoc.org/github.com/gobwas/pool