dir_reader_linux.h revision 3345a6884c488ff3a535c2c9acdd33d74b37e311 
1// Copyright (c) 2010 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_DIR_READER_LINUX_H_
6#define BASE_DIR_READER_LINUX_H_
7#pragma once
8
9#include <errno.h>
10#include <fcntl.h>
11#include <stdint.h>
12#include <sys/syscall.h>
13#include <unistd.h>
14
15#include "base/logging.h"
16#include "base/eintr_wrapper.h"
17
18// See the comments in dir_reader_posix.h about this.
19
20namespace base {
21
22struct linux_dirent {
23  uint64_t        d_ino;
24  int64_t         d_off;
25  unsigned short  d_reclen;
26  unsigned char   d_type;
27  char            d_name[0];
28};
29
30class DirReaderLinux {
31 public:
32  explicit DirReaderLinux(const char* directory_path)
33      : fd_(open(directory_path, O_RDONLY | O_DIRECTORY)),
34        offset_(0),
35        size_(0) {
36  }
37
38  ~DirReaderLinux() {
39    if (fd_ >= 0) {
40      if (HANDLE_EINTR(close(fd_)))
41        RAW_LOG(ERROR, "Failed to close directory handle");
42    }
43  }
44
45  bool IsValid() const {
46    return fd_ >= 0;
47  }
48
49  // Move to the next entry returning false if the iteration is complete.
50  bool Next() {
51    if (size_) {
52      linux_dirent* dirent = reinterpret_cast<linux_dirent*>(&buf_[offset_]);
53      offset_ += dirent->d_reclen;
54    }
55
56    if (offset_ != size_)
57      return true;
58
59    const int r = syscall(__NR_getdents64, fd_, buf_, sizeof(buf_));
60    if (r == 0)
61      return false;
62    if (r == -1) {
63      DPLOG(FATAL) << "getdents64 returned an error: " << errno;
64      return false;
65    }
66    size_ = r;
67    offset_ = 0;
68    return true;
69  }
70
71  const char* name() const {
72    if (!size_)
73      return NULL;
74
75    const linux_dirent* dirent =
76        reinterpret_cast<const linux_dirent*>(&buf_[offset_]);
77    return dirent->d_name;
78  }
79
80  int fd() const {
81    return fd_;
82  }
83
84  static bool IsFallback() {
85    return false;
86  }
87
88 private:
89  const int fd_;
90  unsigned char buf_[512];
91  size_t offset_, size_;
92
93  DISALLOW_COPY_AND_ASSIGN(DirReaderLinux);
94};
95
96}  // namespace base
97
98#endif // BASE_DIR_READER_LINUX_H_
99