summaryrefslogtreecommitdiffstats
path: root/ipc/chromium/src/base/dir_reader_linux.h
blob: e0466fc4c92c89af767c9a47447c0a830e38901a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_DIR_READER_LINUX_H_
#define BASE_DIR_READER_LINUX_H_
#pragma once

#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/syscall.h>
#include <unistd.h>

#include "base/logging.h"
#include "base/eintr_wrapper.h"

// See the comments in dir_reader_posix.h about this.

namespace base {

struct linux_dirent {
  uint64_t        d_ino;
  int64_t         d_off;
  unsigned short  d_reclen;
  unsigned char   d_type;
  char            d_name[0];
};

class DirReaderLinux {
 public:
  explicit DirReaderLinux(const char* directory_path)
      : fd_(open(directory_path, O_RDONLY | O_DIRECTORY)),
        offset_(0),
        size_(0) {
    memset(buf_, 0, sizeof(buf_));
  }

  ~DirReaderLinux() {
    if (fd_ >= 0) {
      if (HANDLE_EINTR(close(fd_)))
        DLOG(ERROR) << "Failed to close directory handle";
    }
  }

  bool IsValid() const {
    return fd_ >= 0;
  }

  // Move to the next entry returning false if the iteration is complete.
  bool Next() {
    if (size_) {
      linux_dirent* dirent = reinterpret_cast<linux_dirent*>(&buf_[offset_]);
      offset_ += dirent->d_reclen;
    }

    if (offset_ != size_)
      return true;

    const int r = syscall(__NR_getdents64, fd_, buf_, sizeof(buf_));
    if (r == 0)
      return false;
    if (r == -1) {
      DLOG(ERROR) << "getdents64 returned an error: " << errno;
      return false;
    }
    size_ = r;
    offset_ = 0;
    return true;
  }

  const char* name() const {
    if (!size_)
      return NULL;

    const linux_dirent* dirent =
        reinterpret_cast<const linux_dirent*>(&buf_[offset_]);
    return dirent->d_name;
  }

  int fd() const {
    return fd_;
  }

  static bool IsFallback() {
    return false;
  }

 private:
  const int fd_;
  union {
    linux_dirent dirent_;
    unsigned char buf_[512];
  };
  size_t offset_, size_;

  DISALLOW_COPY_AND_ASSIGN(DirReaderLinux);
};

}  // namespace base

#endif // BASE_DIR_READER_LINUX_H_