mirror of
https://github.com/e1732a364fed/v2ray_simple.git
synced 2025-12-24 13:27:56 +08:00
113 lines
2.3 KiB
Go
113 lines
2.3 KiB
Go
package utils
|
||
|
||
import (
|
||
"io"
|
||
"sync"
|
||
"syscall"
|
||
)
|
||
|
||
var (
|
||
// readv pool, 缓存 mr和buffers，进一步减轻内存分配负担
|
||
readvPool sync.Pool
|
||
)
|
||
|
||
const (
|
||
Readv_buffer_allocLen = 8
|
||
ReadvSingleBufLen = 4096
|
||
)
|
||
|
||
func init() {
|
||
|
||
readvPool = sync.Pool{
|
||
New: newReadvMem,
|
||
}
|
||
|
||
//预先放进去两个
|
||
|
||
readvPool.Put(newReadvMem())
|
||
readvPool.Put(newReadvMem())
|
||
}
|
||
|
||
// 缓存 ReadvMem 以及对应分配的系统相关的 SystemReadver.
|
||
// 使用 ReadvMem的最大好处就是 buffers 和 mr 都是不需要 释放的.
|
||
//
|
||
// 因为不需释放mr, 所以也就节省了多次 mr.Init 的开销.
|
||
//
|
||
// 该 ReadvMem 以及 readvPool 专门服务于 TryCopy 函数.
|
||
type ReadvMem struct {
|
||
Buffers [][]byte
|
||
Mr SystemReadver
|
||
}
|
||
|
||
func allocReadvBuffers(mr SystemReadver, len int) [][]byte {
|
||
bs := make([][]byte, len)
|
||
|
||
for i := range bs {
|
||
// 这里单独make，而不是从 其它pool中获取, 这样可以做到专用
|
||
bs[i] = make([]byte, ReadvSingleBufLen)
|
||
}
|
||
mr.Init(bs, ReadvSingleBufLen)
|
||
return bs
|
||
}
|
||
|
||
func newReadvMem() any {
|
||
mr := GetReadVReader()
|
||
return &ReadvMem{
|
||
Mr: mr,
|
||
Buffers: allocReadvBuffers(mr, Readv_buffer_allocLen),
|
||
}
|
||
}
|
||
|
||
func Get_readvMem() *ReadvMem {
|
||
return readvPool.Get().(*ReadvMem)
|
||
|
||
}
|
||
|
||
// 将创建好的rm放回 readvPool
|
||
func Put_readvMem(rm *ReadvMem) {
|
||
rm.Buffers = RecoverBuffers(rm.Buffers, Readv_buffer_allocLen, ReadvSingleBufLen)
|
||
readvPool.Put(rm)
|
||
}
|
||
|
||
/*
|
||
ReadvFrom 用于读端 为rawRead的情况，如 从socks5或direct读取 数据, 等裸协议的情况。
|
||
|
||
rm可为nil，但不建议，因为提供非nil的readvMem 可以节省内存分配开销。
|
||
|
||
返回错误时，会返回 原buffer 或 在函数内部新分配的buffer.
|
||
|
||
本函数不负责 释放分配的内存. 因为有时需要重复利用缓存。
|
||
|
||
TryCopy函数使用到了本函数 来进行readv相关操作。
|
||
*/
|
||
func ReadvFrom(rawReadConn syscall.RawConn, rm *ReadvMem) ([][]byte, error) {
|
||
|
||
if rm == nil {
|
||
rm = Get_readvMem()
|
||
}
|
||
|
||
allocedBuffers := rm.Buffers
|
||
|
||
var nBytes uint32
|
||
err := rawReadConn.Read(func(fd uintptr) bool {
|
||
n, e := rm.Mr.Read(fd)
|
||
if e != nil {
|
||
return false
|
||
}
|
||
|
||
nBytes = n
|
||
return true
|
||
})
|
||
if err != nil {
|
||
|
||
return allocedBuffers, err
|
||
}
|
||
if nBytes == 0 {
|
||
return allocedBuffers, io.EOF
|
||
}
|
||
|
||
nBuf := ShrinkBuffers(allocedBuffers, int(nBytes), ReadvSingleBufLen)
|
||
|
||
return allocedBuffers[:nBuf], nil
|
||
}
|