naiveproxy/base/test/generate_fontconfig_caches.cc
2018-12-09 21:59:24 -05:00

64 lines
2.6 KiB
C++

// Copyright 2018 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 <sys/stat.h>
#include <time.h>
#include <utime.h>
#include <string>
#include "base/base_paths.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/path_service.h"
#include "base/strings/strcat.h"
#include "base/test/fontconfig_util_linux.h"
// GIANT WARNING: The point of this file is to front-load construction of the
// font cache [which takes 600ms] from test run time to compile time. This saves
// 600ms on each test shard which uses the font cache into compile time. The
// problem is that fontconfig cache construction is not intended to be
// deterministic. This executable tries to set some external state to ensure
// determinism. We have no way of guaranteeing that this produces correct
// results, or even has the intended effect.
int main() {
// fontconfig generates a random uuid and uses it to match font folders with
// the font cache. Rather than letting fontconfig generate a random uuid,
// which introduces build non-determinism, we place a fixed uuid in the font
// folder, which fontconfig will use to generate the cache.
base::FilePath dir_module;
base::PathService::Get(base::DIR_MODULE, &dir_module);
base::FilePath uuid_file_path =
dir_module.Append("test_fonts").Append(".uuid");
const char uuid[] = "df1acc8c-39d5-4a8b-8507-b1a7396ac3ac";
WriteFile(uuid_file_path, uuid, strlen(uuid));
// fontconfig writes the mtime of the test_fonts directory into the cache. It
// presumably checks this later to ensure that the cache is still up to date.
// We set the mtime to an arbitrary, fixed time in the past.
base::FilePath test_fonts_file_path = dir_module.Append("test_fonts");
struct stat old_times;
struct utimbuf new_times;
stat(test_fonts_file_path.value().c_str(), &old_times);
new_times.actime = old_times.st_atime;
// Use an arbitrary, fixed time.
new_times.modtime = 123456789;
utime(test_fonts_file_path.value().c_str(), &new_times);
base::FilePath fontconfig_caches = dir_module.Append("fontconfig_caches");
// Delete directory before generating fontconfig caches. This will notify
// future fontconfig_caches changes.
CHECK(base::DeleteFile(fontconfig_caches, /*recursive=*/true));
base::SetUpFontconfig();
base::TearDownFontconfig();
// Check existence of intended fontconfig cache file.
CHECK(base::PathExists(
fontconfig_caches.Append(base::StrCat({uuid, "-le64.cache-7"}))));
return 0;
}