blob: 09c3d2eb61cc5b9b5af43304c50ddcb64db08ce5 [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin dragonfly freebsd js,wasm linux nacl netbsd openbsd solaris
package os
import (
"io"
"runtime"
"syscall"
)
const (
blockSize = 4096
)
func (f *File) readdir(n int) (fi []FileInfo, err error) {
dirname := f.name
if dirname == "" {
dirname = "."
}
names, err := f.Readdirnames(n)
fi = make([]FileInfo, 0, len(names))
for _, filename := range names {
fip, lerr := lstat(dirname + "/" + filename)
if IsNotExist(lerr) {
// File disappeared between readdir + stat.
// Just treat it as if it didn't exist.
continue
}
if lerr != nil {
return fi, lerr
}
fi = append(fi, fip)
}
if len(fi) == 0 && err == nil && n > 0 {
// Per File.Readdir, the slice must be non-empty or err
// must be non-nil if n > 0.
err = io.EOF
}
return fi, err
}
func (f *File) readdirnames(n int) (names []string, err error) {
// If this file has no dirinfo, create one.
if f.dirinfo == nil {
f.dirinfo = new(dirInfo)
// The buffer must be at least a block long.
f.dirinfo.buf = make([]byte, blockSize)
}
d := f.dirinfo
size := n
if size <= 0 {
size = 100
n = -1
}
names = make([]string, 0, size) // Empty with room to grow.
for n != 0 {
// Refill the buffer if necessary
if d.bufp >= d.nbuf {
d.bufp = 0
var errno error
d.nbuf, errno = f.pfd.ReadDirent(d.buf)
runtime.KeepAlive(f)
if errno != nil {
return names, wrapSyscallError("readdirent", errno)
}
if d.nbuf <= 0 {
break // EOF
}
}
// Drain the buffer
var nb, nc int
nb, nc, names = syscall.ParseDirent(d.buf[d.bufp:d.nbuf], n, names)
d.bufp += nb
n -= nc
}
if n >= 0 && len(names) == 0 {
return names, io.EOF
}
return names, nil
}