mirror of
https://github.com/golang/go
synced 2024-11-13 20:00:23 -07:00
a4ede9f9a6
ReadDir provides a portable, efficient way to read a directory and discover the type of directory entries. This enables a more efficient file system walk, yet to be added. See #41467 for the proposal review for the API. Fixes #41467. Change-Id: I461a526793ae46df48821aa448b04f1705546739 Reviewed-on: https://go-review.googlesource.com/c/go/+/261540 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Rob Pike <r@golang.org>
56 lines
1.3 KiB
Go
56 lines
1.3 KiB
Go
// Copyright 2020 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package os
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import (
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"syscall"
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"unsafe"
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)
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func direntIno(buf []byte) (uint64, bool) {
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return readInt(buf, unsafe.Offsetof(syscall.Dirent{}.Fileno), unsafe.Sizeof(syscall.Dirent{}.Fileno))
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}
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func direntReclen(buf []byte) (uint64, bool) {
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namlen, ok := direntNamlen(buf)
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if !ok {
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return 0, false
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}
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return (16 + namlen + 1 + 7) &^ 7, true
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}
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func direntNamlen(buf []byte) (uint64, bool) {
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return readInt(buf, unsafe.Offsetof(syscall.Dirent{}.Namlen), unsafe.Sizeof(syscall.Dirent{}.Namlen))
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}
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func direntType(buf []byte) FileMode {
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off := unsafe.Offsetof(syscall.Dirent{}.Type)
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if off >= uintptr(len(buf)) {
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return ^FileMode(0) // unknown
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}
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typ := buf[off]
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switch typ {
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case syscall.DT_BLK:
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return ModeDevice
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case syscall.DT_CHR:
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return ModeDevice | ModeCharDevice
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case syscall.DT_DBF:
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// DT_DBF is "database record file".
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// fillFileStatFromSys treats as regular file.
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return 0
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case syscall.DT_DIR:
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return ModeDir
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case syscall.DT_FIFO:
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return ModeNamedPipe
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case syscall.DT_LNK:
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return ModeSymlink
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case syscall.DT_REG:
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return 0
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case syscall.DT_SOCK:
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return ModeSocket
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}
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return ^FileMode(0) // unknown
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}
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