1 // Copyright (c) 2011 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.
5 #include "base/test/test_file_util.h"
10 #include "base/logging.h"
11 #include "base/file_util.h"
12 #include "base/files/memory_mapped_file.h"
16 bool EvictFileFromSystemCache(const base::FilePath& file) {
17 // There aren't any really direct ways to purge a file from the UBC. From
18 // talking with Amit Singh, the safest is to mmap the file with MAP_FILE (the
19 // default) + MAP_SHARED, then do an msync to invalidate the memory. The next
20 // open should then have to load the file from disk.
23 if (!file_util::GetFileSize(file, &length)) {
24 DLOG(ERROR) << "failed to get size of " << file.value();
28 // When a file is empty, we do not need to evict it from cache.
29 // In fact, an attempt to map it to memory will result in error.
31 DLOG(WARNING) << "file size is zero, will not attempt to map to memory";
35 base::MemoryMappedFile mapped_file;
36 if (!mapped_file.Initialize(file)) {
37 DLOG(WARNING) << "failed to memory map " << file.value();
41 if (msync(const_cast<uint8*>(mapped_file.data()), mapped_file.length(),
42 MS_INVALIDATE) != 0) {
43 DLOG(WARNING) << "failed to invalidate memory map of " << file.value()
44 << ", errno: " << errno;
51 } // namespace file_util