Add conversion functions for writePoolData

[koalabearguo]

Because writePoolData is not export,so it can not config WriteBufferPool field in Upgrader and Dialer

What type of PR is this? (check all applicable)

• Refactor
• Feature
• Bug Fix
• Optimization
• Documentation Update
• Go Version Update
• Dependency Update

Description

Related Tickets & Documents

• Related Issue #
• Closes #

Added/updated tests?

• Yes
• No, and this is why: please replace this line with details on why tests
  have not been included
• I need help with writing tests

Run verifications and test

• make verify is passing
• make test is passing

[mantidsboring]

Explain the situation where you need to know the type of the value in the pool. Based on the documentation, the type is intentionally hidden.

[koalabearguo]

the writePoolData struct is not exported,so when impl BufferPool interface Get/Put,it can not return writePoolData type.

the bellow code line 517 use the writePoolData in conn.go ,it will translate the interface fail。

 512         mw.c = c
 513         mw.frameType = messageType
 514         mw.pos = maxFrameHeaderSize
 515 
 516         if c.writeBuf == nil {
 517                 wpd, ok := c.writePool.Get().(writePoolData)
 518                 if ok {
 519                         c.writeBuf = wpd.buf
 520                 } else {
 521                         c.writeBuf = make([]byte, c.writeBufSize)
 522                 }
 523         }
 524         return nil

[koalabearguo]

Maybe you can give a demo for using BufferPool in Upgrader and Dialer,I can not run progam normal.

[mantidsboring]

The pool implication stores values with type any. The pool does not need to know the types of the values. Per the documentation in this package, the *sync.Pool type can be used as a pool. *sync.Pool is a good choice for most applicaitons. Example use:

// create a pool
pool := &sync.Pool{}


// use it in the upgrader
u := websocket.Upgrader{
      ...
       WriteBufferPool: pool
}

A trivial implementation with a pool size of of one is:

package mypool

import (
	"sync/atomic"
)

type Pool struct {
	v atomic.Value
}

func (p *Pool) Put(v any) {
	p.v.Store(v)
}

func (p *Pool) Get() any {
	return p.v.Swap(nil)
}

Notice that the pool does not need to know the type of the value.

[koalabearguo]

Thanks for getting back to me.

I use the bellow code to initial my program as you mentioned.

websocket.DefaultDialer.WriteBufferPool = &sync.Pool{}

but in conn.go bellow，the ok var is false forever，it forever log the "Error........."，the pool is not used！

 517         if c.writeBuf == nil {
 518                 wpd, ok := c.writePool.Get().(writePoolData)
 519                 if ok {
 520                         c.writeBuf = wpd.buf
 521                 } else {
 522                         c.writeBuf = make([]byte, c.writeBufSize)
 523                         log.Println("Error........")
 524                 }
 525         }
 526         return nil
 527 }

[koalabearguo]

ok，my program has only one byte pool，I dont want websocket to new byteslice，maybe i can manage bytepool outside the websocket package

so this is my requirement,i need conversion functions for writePoolData,just new byteslice outside the package

[mantidsboring]

Two things:

• I’m not a maintainer, but if I were, I’d want to see a use case that clearly cannot be solved without this PR.
• The maintainers haven’t merged a PR in almost a year, even though there are some high-quality submissions. I wouldn’t expect this to be merged anytime soon.

[koalabearguo]

ok,i see.
thanks.
i has a bytepool in my main package,i just want to reuse the bytepool,this is the key point.
i just opt the memory usage for some docker env which is memory limited.

now i can use it local.so it dose not matter

thanks again.