blob: f2adcd04b898603b7e8d80cb8fc197f5565f8ed2 [file] [log] [blame]
// 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/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(gavinp): 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(path.value().c_str(),
rename_target.value().c_str());
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