| // Copyright 2014 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. |
| |
| #include "net/disk_cache/simple/simple_util.h" |
| |
| #include <windows.h> |
| |
| #include "base/files/file_util.h" |
| #include "base/format_macros.h" |
| #include "base/rand_util.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/stringprintf.h" |
| #include "net/disk_cache/cache_util.h" |
| |
| namespace disk_cache { |
| namespace simple_util { |
| |
| bool SimpleCacheDeleteFile(const base::FilePath& path) { |
| // Even if a file was opened with FLAG_SHARE_DELETE, it is not possible to |
| // create a new file with the same name until the original file is actually |
| // deleted. To allow new files to be created with the new name right away, |
| // the file is renamed before it is deleted. |
| |
| // Why a random name? Because if the name was derived from our original name, |
| // then churn on a particular cache entry could cause flakey behaviour. |
| |
| // TODO(morlovich): Ensure these "todelete_" files are cleaned up on periodic |
| // directory sweeps. |
| const base::FilePath rename_target = |
| path.DirName().AppendASCII(base::StringPrintf("todelete_%016" PRIx64, |
| base::RandUint64())); |
| |
| bool rename_succeeded = !!MoveFile(base::as_wcstr(path.value()), |
| base::as_wcstr(rename_target.value())); |
| if (rename_succeeded) |
| return DeleteCacheFile(rename_target); |
| |
| // The rename did not succeed. The fallback behaviour is to delete the file in |
| // place, which might cause some flake. |
| return DeleteCacheFile(path); |
| } |
| |
| } // namespace simple_util |
| } // namespace disk_cache |