| 1 | // Copyright 2022 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | //go:build darwin && cgo |
| 6 | // +build darwin,cgo |
| 7 | |
| 8 | package fastwalk |
| 9 | |
| 10 | /* |
| 11 | #include <dirent.h> |
| 12 | |
| 13 | // fastwalk_readdir_r wraps readdir_r so that we don't have to pass a dirent** |
| 14 | // result pointer which triggers CGO's "Go pointer to Go pointer" check unless |
| 15 | // we allocat the result dirent* with malloc. |
| 16 | // |
| 17 | // fastwalk_readdir_r returns 0 on success, -1 upon reaching the end of the |
| 18 | // directory, or a positive error number to indicate failure. |
| 19 | static int fastwalk_readdir_r(DIR *fd, struct dirent *entry) { |
| 20 | struct dirent *result; |
| 21 | int ret = readdir_r(fd, entry, &result); |
| 22 | if (ret == 0 && result == NULL) { |
| 23 | ret = -1; // EOF |
| 24 | } |
| 25 | return ret; |
| 26 | } |
| 27 | */ |
| 28 | import "C" |
| 29 | |
| 30 | import ( |
| 31 | "os" |
| 32 | "syscall" |
| 33 | "unsafe" |
| 34 | ) |
| 35 | |
| 36 | func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) error) error { |
| 37 | fd, err := openDir(dirName) |
| 38 | if err != nil { |
| 39 | return &os.PathError{Op: "opendir", Path: dirName, Err: err} |
| 40 | } |
| 41 | defer C.closedir(fd) |
| 42 | |
| 43 | skipFiles := false |
| 44 | var dirent syscall.Dirent |
| 45 | for { |
| 46 | ret := int(C.fastwalk_readdir_r(fd, (*C.struct_dirent)(unsafe.Pointer(&dirent)))) |
| 47 | if ret != 0 { |
| 48 | if ret == -1 { |
| 49 | break // EOF |
| 50 | } |
| 51 | if ret == int(syscall.EINTR) { |
| 52 | continue |
| 53 | } |
| 54 | return &os.PathError{Op: "readdir", Path: dirName, Err: syscall.Errno(ret)} |
| 55 | } |
| 56 | if dirent.Ino == 0 { |
| 57 | continue |
| 58 | } |
| 59 | typ := dtToType(dirent.Type) |
| 60 | if skipFiles && typ.IsRegular() { |
| 61 | continue |
| 62 | } |
| 63 | name := (*[len(syscall.Dirent{}.Name)]byte)(unsafe.Pointer(&dirent.Name))[:] |
| 64 | name = name[:dirent.Namlen] |
| 65 | for i, c := range name { |
| 66 | if c == 0 { |
| 67 | name = name[:i] |
| 68 | break |
| 69 | } |
| 70 | } |
| 71 | // Check for useless names before allocating a string. |
| 72 | if string(name) == "." || string(name) == ".." { |
| 73 | continue |
| 74 | } |
| 75 | if err := fn(dirName, string(name), typ); err != nil { |
| 76 | if err != ErrSkipFiles { |
| 77 | return err |
| 78 | } |
| 79 | skipFiles = true |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | return nil |
| 84 | } |
| 85 | |
| 86 | func dtToType(typ uint8) os.FileMode { |
| 87 | switch typ { |
| 88 | case syscall.DT_BLK: |
| 89 | return os.ModeDevice |
| 90 | case syscall.DT_CHR: |
| 91 | return os.ModeDevice | os.ModeCharDevice |
| 92 | case syscall.DT_DIR: |
| 93 | return os.ModeDir |
| 94 | case syscall.DT_FIFO: |
| 95 | return os.ModeNamedPipe |
| 96 | case syscall.DT_LNK: |
| 97 | return os.ModeSymlink |
| 98 | case syscall.DT_REG: |
| 99 | return 0 |
| 100 | case syscall.DT_SOCK: |
| 101 | return os.ModeSocket |
| 102 | } |
| 103 | return ^os.FileMode(0) |
| 104 | } |
| 105 | |
| 106 | // openDir wraps opendir(3) and handles any EINTR errors. The returned *DIR |
| 107 | // needs to be closed with closedir(3). |
| 108 | func openDir(path string) (*C.DIR, error) { |
| 109 | name, err := syscall.BytePtrFromString(path) |
| 110 | if err != nil { |
| 111 | return nil, err |
| 112 | } |
| 113 | for { |
| 114 | fd, err := C.opendir((*C.char)(unsafe.Pointer(name))) |
| 115 | if err != syscall.EINTR { |
| 116 | return fd, err |
| 117 | } |
| 118 | } |
| 119 | } |
| 120 |
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