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|
package vhost
import (
"bytes"
"io"
"net"
"sync/atomic"
"unsafe"
)
const (
initVhostBufSize = 1024 // allocate 1 KB up front to try to avoid resizing
)
func unsafePtr(ptr *interface{}) *unsafe.Pointer {
return (*unsafe.Pointer)(unsafe.Pointer(ptr))
}
type sharedConn struct {
net.Conn // the raw connection
vhostBuf *bytes.Buffer // all of the initial data that has to be read in order to vhost a connection is saved here
}
func newShared(conn net.Conn) (*sharedConn, io.Reader) {
c := &sharedConn{
Conn: conn,
vhostBuf: bytes.NewBuffer(make([]byte, 0, initVhostBufSize)),
}
return c, io.TeeReader(conn, c.vhostBuf)
}
func (c *sharedConn) Read(p []byte) (n int, err error) {
// atomic: if c.vhostBuf != nil
if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&c.vhostBuf))) != nil {
n, err = c.vhostBuf.Read(p)
// end of the request buffer
if err == io.EOF {
// let the request buffer get garbage collected
// and make sure we don't read from it again
// atomic: c.vhostBuf = nil
atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&c.vhostBuf)), unsafe.Pointer(nil))
// continue reading from the connection
var n2 int
n2, err = c.Conn.Read(p[n:])
// update total read
n += n2
}
return
}
return c.Conn.Read(p)
}
|
