platform_file_win.cc revision ddb351dbec246cf1fab5ec20d2d5520909041de1 
1// Copyright (c) 2006-2008 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#include "base/platform_file.h"
6
7#include "base/file_path.h"
8#include "base/logging.h"
9#include "base/threading/thread_restrictions.h"
10
11namespace base {
12
13PlatformFile CreatePlatformFile(const FilePath& name,
14                                int flags,
15                                bool* created,
16                                PlatformFileError* error_code) {
17  base::ThreadRestrictions::AssertIOAllowed();
18
19  DWORD disposition = 0;
20
21  if (flags & PLATFORM_FILE_OPEN)
22    disposition = OPEN_EXISTING;
23
24  if (flags & PLATFORM_FILE_CREATE) {
25    DCHECK(!disposition);
26    disposition = CREATE_NEW;
27  }
28
29  if (flags & PLATFORM_FILE_OPEN_ALWAYS) {
30    DCHECK(!disposition);
31    disposition = OPEN_ALWAYS;
32  }
33
34  if (flags & PLATFORM_FILE_CREATE_ALWAYS) {
35    DCHECK(!disposition);
36    disposition = CREATE_ALWAYS;
37  }
38
39  if (flags & PLATFORM_FILE_TRUNCATE) {
40    DCHECK(!disposition);
41    DCHECK(flags & PLATFORM_FILE_WRITE);
42    disposition = TRUNCATE_EXISTING;
43  }
44
45  if (!disposition) {
46    NOTREACHED();
47    return NULL;
48  }
49
50  DWORD access = (flags & PLATFORM_FILE_READ) ? GENERIC_READ : 0;
51  if (flags & PLATFORM_FILE_WRITE)
52    access |= GENERIC_WRITE;
53  if (flags & PLATFORM_FILE_WRITE_ATTRIBUTES)
54    access |= FILE_WRITE_ATTRIBUTES;
55
56  DWORD sharing = (flags & PLATFORM_FILE_EXCLUSIVE_READ) ? 0 : FILE_SHARE_READ;
57  if (!(flags & PLATFORM_FILE_EXCLUSIVE_WRITE))
58    sharing |= FILE_SHARE_WRITE;
59
60  DWORD create_flags = 0;
61  if (flags & PLATFORM_FILE_ASYNC)
62    create_flags |= FILE_FLAG_OVERLAPPED;
63  if (flags & PLATFORM_FILE_TEMPORARY)
64    create_flags |= FILE_ATTRIBUTE_TEMPORARY;
65  if (flags & PLATFORM_FILE_HIDDEN)
66    create_flags |= FILE_ATTRIBUTE_HIDDEN;
67  if (flags & PLATFORM_FILE_DELETE_ON_CLOSE)
68    create_flags |= FILE_FLAG_DELETE_ON_CLOSE;
69
70  HANDLE file = CreateFile(name.value().c_str(), access, sharing, NULL,
71                           disposition, create_flags, NULL);
72
73  if (created && (INVALID_HANDLE_VALUE != file)) {
74    if (flags & (PLATFORM_FILE_OPEN_ALWAYS))
75      *created = (ERROR_ALREADY_EXISTS != GetLastError());
76    else if (flags & (PLATFORM_FILE_CREATE_ALWAYS | PLATFORM_FILE_CREATE))
77      *created = true;
78  }
79
80  if (error_code) {
81    if (file != kInvalidPlatformFileValue)
82      *error_code = PLATFORM_FILE_OK;
83    else {
84      DWORD last_error = GetLastError();
85      switch (last_error) {
86        case ERROR_SHARING_VIOLATION:
87          *error_code = PLATFORM_FILE_ERROR_IN_USE;
88          break;
89        case ERROR_FILE_EXISTS:
90          *error_code = PLATFORM_FILE_ERROR_EXISTS;
91          break;
92        case ERROR_FILE_NOT_FOUND:
93          *error_code = PLATFORM_FILE_ERROR_NOT_FOUND;
94          break;
95        case ERROR_ACCESS_DENIED:
96          *error_code = PLATFORM_FILE_ERROR_ACCESS_DENIED;
97          break;
98        default:
99          *error_code = PLATFORM_FILE_ERROR_FAILED;
100      }
101    }
102  }
103
104  return file;
105}
106
107bool ClosePlatformFile(PlatformFile file) {
108  base::ThreadRestrictions::AssertIOAllowed();
109  return (CloseHandle(file) != 0);
110}
111
112int ReadPlatformFile(PlatformFile file, int64 offset, char* data, int size) {
113  base::ThreadRestrictions::AssertIOAllowed();
114  if (file == kInvalidPlatformFileValue)
115    return -1;
116
117  LARGE_INTEGER offset_li;
118  offset_li.QuadPart = offset;
119
120  OVERLAPPED overlapped = {0};
121  overlapped.Offset = offset_li.LowPart;
122  overlapped.OffsetHigh = offset_li.HighPart;
123
124  DWORD bytes_read;
125  if (::ReadFile(file, data, size, &bytes_read, &overlapped) != 0)
126    return bytes_read;
127  else if (ERROR_HANDLE_EOF == GetLastError())
128    return 0;
129
130  return -1;
131}
132
133int WritePlatformFile(PlatformFile file, int64 offset,
134                      const char* data, int size) {
135  base::ThreadRestrictions::AssertIOAllowed();
136  if (file == kInvalidPlatformFileValue)
137    return -1;
138
139  LARGE_INTEGER offset_li;
140  offset_li.QuadPart = offset;
141
142  OVERLAPPED overlapped = {0};
143  overlapped.Offset = offset_li.LowPart;
144  overlapped.OffsetHigh = offset_li.HighPart;
145
146  DWORD bytes_written;
147  if (::WriteFile(file, data, size, &bytes_written, &overlapped) != 0)
148    return bytes_written;
149
150  return -1;
151}
152
153bool TruncatePlatformFile(PlatformFile file, int64 length) {
154  base::ThreadRestrictions::AssertIOAllowed();
155  if (file == kInvalidPlatformFileValue)
156    return false;
157
158  // Get the current file pointer.
159  LARGE_INTEGER file_pointer;
160  LARGE_INTEGER zero;
161  zero.QuadPart = 0;
162  if (::SetFilePointerEx(file, zero, &file_pointer, FILE_CURRENT) == 0)
163    return false;
164
165  LARGE_INTEGER length_li;
166  length_li.QuadPart = length;
167  // If length > file size, SetFilePointerEx() should extend the file
168  // with zeroes on all Windows standard file systems (NTFS, FATxx).
169  if (!::SetFilePointerEx(file, length_li, NULL, FILE_BEGIN))
170    return false;
171
172  // Set the new file length and move the file pointer to its old position.
173  // This is consistent with ftruncate()'s behavior, even when the file
174  // pointer points to a location beyond the end of the file.
175  return ((::SetEndOfFile(file) != 0) &&
176          (::SetFilePointerEx(file, file_pointer, NULL, FILE_BEGIN) != 0));
177}
178
179bool FlushPlatformFile(PlatformFile file) {
180  base::ThreadRestrictions::AssertIOAllowed();
181  return ((file != kInvalidPlatformFileValue) && ::FlushFileBuffers(file));
182}
183
184bool TouchPlatformFile(PlatformFile file, const base::Time& last_access_time,
185                       const base::Time& last_modified_time) {
186  base::ThreadRestrictions::AssertIOAllowed();
187  if (file == kInvalidPlatformFileValue)
188    return false;
189
190  FILETIME last_access_filetime = last_access_time.ToFileTime();
191  FILETIME last_modified_filetime = last_modified_time.ToFileTime();
192  return (::SetFileTime(file, NULL, &last_access_filetime,
193                        &last_modified_filetime) != 0);
194}
195
196bool GetPlatformFileInfo(PlatformFile file, PlatformFileInfo* info) {
197  base::ThreadRestrictions::AssertIOAllowed();
198  if (!info)
199    return false;
200
201  BY_HANDLE_FILE_INFORMATION file_info;
202  if (GetFileInformationByHandle(file, &file_info) == 0)
203    return false;
204
205  LARGE_INTEGER size;
206  size.HighPart = file_info.nFileSizeHigh;
207  size.LowPart = file_info.nFileSizeLow;
208  info->size = size.QuadPart;
209  info->is_directory =
210      file_info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY != 0;
211  info->is_symbolic_link = false; // Windows doesn't have symbolic links.
212  info->last_modified = base::Time::FromFileTime(file_info.ftLastWriteTime);
213  info->last_accessed = base::Time::FromFileTime(file_info.ftLastAccessTime);
214  info->creation_time = base::Time::FromFileTime(file_info.ftCreationTime);
215  return true;
216}
217
218}  // namespace disk_cache
219