restic/vendor/bazil.org/fuse/buffer.go

36 lines
732 B
Go

package fuse
import "unsafe"
// buffer provides a mechanism for constructing a message from
// multiple segments.
type buffer []byte
// alloc allocates size bytes and returns a pointer to the new
// segment.
func (w *buffer) alloc(size uintptr) unsafe.Pointer {
s := int(size)
if len(*w)+s > cap(*w) {
old := *w
*w = make([]byte, len(*w), 2*cap(*w)+s)
copy(*w, old)
}
l := len(*w)
*w = (*w)[:l+s]
return unsafe.Pointer(&(*w)[l])
}
// reset clears out the contents of the buffer.
func (w *buffer) reset() {
for i := range (*w)[:cap(*w)] {
(*w)[i] = 0
}
*w = (*w)[:0]
}
func newBuffer(extra uintptr) buffer {
const hdrSize = unsafe.Sizeof(outHeader{})
buf := make(buffer, hdrSize, hdrSize+extra)
return buf
}