bpool

package module
Version: v0.0.0-...-03653db Latest Latest
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Published: May 30, 2019 License: Apache-2.0 Imports: 1 Imported by: 438

README

bpool GoDoc

Package bpool implements leaky pools of byte arrays and Buffers as bounded channels. It is based on the leaky buffer example from the Effective Go documentation: http://golang.org/doc/effective_go.html#leaky_buffer

bpool provides the following pool types:

  • bpool.BufferPool which provides a fixed-size pool of bytes.Buffers.
  • bpool.BytePool which provides a fixed-size pool of []byte slices with a pre-set width (length).
  • bpool.SizedBufferPool, which is an alternative to bpool.BufferPool that pre-sizes the capacity of buffers issued from the pool and discards buffers that have grown too large upon return.

A common use case for this package is to use buffers to execute HTML templates against (via ExecuteTemplate) or encode JSON into (via json.NewEncoder). This allows you to catch any rendering or marshalling errors prior to writing to a http.ResponseWriter, which helps to avoid writing incomplete or malformed data to the response.

Install

go get github.com/oxtoacart/bpool

Documentation

See godoc.org or use godoc github.com/oxtoacart/bpool

Example

Here's a quick example for using bpool.BufferPool. We create a pool of the desired size, call the Get() method to obtain a buffer for use, and call Put(buf) to return the buffer to the pool.


var bufpool *bpool.BufferPool

func main() {

    bufpool = bpool.NewBufferPool(48)

}

func someFunction() error {

     // Get a buffer from the pool
     buf := bufpool.Get()
     ...
     ...
     ...
     // Return the buffer to the pool
     bufpool.Put(buf)

     return nil
}

License

Apache 2.0 Licensed. See the LICENSE file for details.

Documentation

Overview

Package bpool implements leaky pools of byte arrays and Buffers as bounded channels. It is based on the leaky buffer example from the Effective Go documentation: http://golang.org/doc/effective_go.html#leaky_buffer

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

This section is empty.

Types

type BufferPool

type BufferPool struct {
	// contains filtered or unexported fields
}

BufferPool implements a pool of bytes.Buffers in the form of a bounded channel.

func NewBufferPool

func NewBufferPool(size int) (bp *BufferPool)

NewBufferPool creates a new BufferPool bounded to the given size.

func (*BufferPool) Get

func (bp *BufferPool) Get() (b *bytes.Buffer)

Get gets a Buffer from the BufferPool, or creates a new one if none are available in the pool.

func (*BufferPool) NumPooled

func (bp *BufferPool) NumPooled() int

NumPooled returns the number of items currently pooled.

func (*BufferPool) Put

func (bp *BufferPool) Put(b *bytes.Buffer)

Put returns the given Buffer to the BufferPool.

type BytePool

type BytePool struct {
	// contains filtered or unexported fields
}

BytePool implements a leaky pool of []byte in the form of a bounded channel.

func NewBytePool

func NewBytePool(maxSize int, width int) (bp *BytePool)

NewBytePool creates a new BytePool bounded to the given maxSize, with new byte arrays sized based on width.

func (*BytePool) Get

func (bp *BytePool) Get() (b []byte)

Get gets a []byte from the BytePool, or creates a new one if none are available in the pool.

func (*BytePool) GetSlice

func (bp *BytePool) GetSlice() ByteSlice

GetSlice implements the method from interface ByteSlicePool

func (*BytePool) NumPooled

func (bp *BytePool) NumPooled() int

NumPooled returns the number of items currently pooled.

func (*BytePool) Put

func (bp *BytePool) Put(b []byte)

Put returns the given Buffer to the BytePool.

func (*BytePool) PutSlice

func (bp *BytePool) PutSlice(b ByteSlice)

PutSlice implements the method from interface ByteSlicePool

func (*BytePool) Width

func (bp *BytePool) Width() (n int)

Width returns the width of the byte arrays in this pool.

type ByteSlice

type ByteSlice struct {
	// contains filtered or unexported fields
}

ByteSlice provides a wrapper around []byte with some added convenience

func WrapByteSlice

func WrapByteSlice(full []byte, headerLength int) ByteSlice

WrapByteSlice wraps a []byte as a ByteSlice

func (ByteSlice) Bytes

func (b ByteSlice) Bytes() []byte

Bytes returns the current slice

func (ByteSlice) BytesWithHeader

func (b ByteSlice) BytesWithHeader() []byte

BytesWithHeader returns the current slice preceded by the header

func (ByteSlice) Full

func (b ByteSlice) Full() []byte

Full returns the full original buffer underlying the ByteSlice

func (ByteSlice) ResliceTo

func (b ByteSlice) ResliceTo(end int) ByteSlice

ResliceTo reslices the end of the current slice.

type ByteSlicePool

type ByteSlicePool interface {
	// Get gets a byte slice from the pool
	GetSlice() ByteSlice
	// Put returns a byte slice to the pool
	PutSlice(ByteSlice)
	// NumPooled returns the number of currently pooled items
	NumPooled() int
}

ByteSlicePool is a bool of byte slices

func NewByteSlicePool

func NewByteSlicePool(maxSize int, width int) ByteSlicePool

NewByteSlicePool creates a new ByteSlicePool bounded to the given maxSize, with new byte arrays sized based on width

func NewHeaderPreservingByteSlicePool

func NewHeaderPreservingByteSlicePool(maxSize int, width int, headerLength int) ByteSlicePool

NewHeaderPreservingByteSlicePool creates a new ByteSlicePool bounded to the given maxSize, with new byte arrays sized based on width and headerLength preserved at the beginning of the slice.

type SizedBufferPool

type SizedBufferPool struct {
	// contains filtered or unexported fields
}

SizedBufferPool implements a pool of bytes.Buffers in the form of a bounded channel. Buffers are pre-allocated to the requested size.

func NewSizedBufferPool

func NewSizedBufferPool(size int, alloc int) (bp *SizedBufferPool)

SizedBufferPool creates a new BufferPool bounded to the given size. size defines the number of buffers to be retained in the pool and alloc sets the initial capacity of new buffers to minimize calls to make().

The value of alloc should seek to provide a buffer that is representative of most data written to the the buffer (i.e. 95th percentile) without being overly large (which will increase static memory consumption). You may wish to track the capacity of your last N buffers (i.e. using an []int) prior to returning them to the pool as input into calculating a suitable alloc value.

func (*SizedBufferPool) Get

func (bp *SizedBufferPool) Get() (b *bytes.Buffer)

Get gets a Buffer from the SizedBufferPool, or creates a new one if none are available in the pool. Buffers have a pre-allocated capacity.

func (*SizedBufferPool) Put

func (bp *SizedBufferPool) Put(b *bytes.Buffer)

Put returns the given Buffer to the SizedBufferPool.

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