ObfuscatedFileSystemFileUtil class

This is functional and reasonably well-tested, but we'll still have to adapt the system a bit in order to use it.
BUG=none
TEST=included unit tests

Review URL: http://codereview.chromium.org/6955013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85332 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 12 insertions, 9 deletions

diff --git a/base/platform_file.h b/base/platform_file.h
index 461b060..dbac61a 100644
--- a/base/platform_file.h
+++ b/base/platform_file.h
@@ -96,9 +96,10 @@ struct BASE_API PlatformFileInfo {
   base::Time creation_time;
 };
 
-// Creates or opens the given file. If PLATFORM_FILE_OPEN_ALWAYS is used, and
-// |created| is provided, |created| will be set to true if the file was created
-// or to false in case the file was just opened. |error_code| can be NULL.
+// Creates or opens the given file. If |created| is provided, it will be set to
+// true if a new file was created [or an old one truncated to zero length to
+// simulate a new file, which can happen with PLATFORM_FILE_CREATE_ALWAYS], and
+// false otherwise.  |error_code| can be NULL.
 BASE_API PlatformFile CreatePlatformFile(const FilePath& name,
                                          int flags,
                                          bool* created,
diff --git a/base/platform_file_posix.cc b/base/platform_file_posix.cc
index 6e2cff6..2ffac06 100644
--- a/base/platform_file_posix.cc
+++ b/base/platform_file_posix.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -36,6 +36,9 @@ PlatformFile CreatePlatformFile(const FilePath& name, int flags,
   if (flags & PLATFORM_FILE_CREATE)
     open_flags = O_CREAT | O_EXCL;
 
+  if (created)
+    *created = false;
+
   if (flags & PLATFORM_FILE_CREATE_ALWAYS) {
     DCHECK(!open_flags);
     open_flags = O_CREAT | O_TRUNC;
@@ -70,10 +73,7 @@ PlatformFile CreatePlatformFile(const FilePath& name, int flags,
       HANDLE_EINTR(open(name.value().c_str(), open_flags, S_IRUSR | S_IWUSR));
 
   if (flags & PLATFORM_FILE_OPEN_ALWAYS) {
-    if (descriptor > 0) {
-      if (created)
-        *created = false;
-    } else {
+    if (descriptor <= 0) {
       open_flags |= O_CREAT;
       if (flags & PLATFORM_FILE_EXCLUSIVE_READ ||
           flags & PLATFORM_FILE_EXCLUSIVE_WRITE) {
diff --git a/base/platform_file_win.cc b/base/platform_file_win.cc
index 0cb3e53..7a6a586 100644
--- a/base/platform_file_win.cc
+++ b/base/platform_file_win.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -17,6 +17,8 @@ PlatformFile CreatePlatformFile(const FilePath& name,
   base::ThreadRestrictions::AssertIOAllowed();
 
   DWORD disposition = 0;
+  if (created)
+    *created = false;
 
   if (flags & PLATFORM_FILE_OPEN)
     disposition = OPEN_EXISTING;