tdlight/td/telegram/files/FileLoaderUtils.cpp

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//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2019
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/telegram/files/FileLoaderUtils.h"
#include "td/telegram/files/FileLocation.h"
#include "td/telegram/Global.h"
#include "td/telegram/TdDb.h"
#include "td/utils/common.h"
#include "td/utils/filesystem.h"
#include "td/utils/format.h"
#include "td/utils/logging.h"
#include "td/utils/misc.h"
#include "td/utils/PathView.h"
#include "td/utils/port/FileFd.h"
#include "td/utils/port/path.h"
#include "td/utils/Random.h"
#include "td/utils/StringBuilder.h"
#include <tuple>
namespace td {
namespace {
Result<std::pair<FileFd, string>> try_create_new_file(Result<CSlice> result_name) {
TRY_RESULT(name, std::move(result_name));
TRY_RESULT(fd, FileFd::open(name, FileFd::Read | FileFd::Write | FileFd::CreateNew, 0640));
return std::make_pair(std::move(fd), name.str());
}
Result<std::pair<FileFd, string>> try_open_file(Result<CSlice> result_name) {
TRY_RESULT(name, std::move(result_name));
TRY_RESULT(fd, FileFd::open(name, FileFd::Read, 0640));
return std::make_pair(std::move(fd), name.str());
}
struct RandSuff {
int len;
};
StringBuilder &operator<<(StringBuilder &sb, const RandSuff &) {
for (int i = 0; i < 6; i++) {
sb << format::hex_digit(Random::fast(0, 15));
}
return sb;
}
struct Ext {
Slice ext;
};
StringBuilder &operator<<(StringBuilder &sb, const Ext &ext) {
if (ext.ext.empty()) {
return sb;
}
return sb << "." << ext.ext;
}
} // namespace
Result<std::pair<FileFd, string>> open_temp_file(FileType file_type) {
auto pmc = G()->td_db()->get_binlog_pmc();
// TODO: CAS?
int32 file_id = to_integer<int32>(pmc->get("tmp_file_id"));
pmc->set("tmp_file_id", to_string(file_id + 1));
auto temp_dir = get_files_temp_dir(file_type);
auto res = try_create_new_file(PSLICE_SAFE() << temp_dir << file_id);
if (res.is_error()) {
res = try_create_new_file(PSLICE_SAFE() << temp_dir << file_id << "_" << RandSuff{6});
}
return res;
}
template <class F>
bool for_suggested_file_name(CSlice name, bool use_pmc, bool use_random, F &&callback) {
auto try_callback = [&](Result<CSlice> r_path) {
if (r_path.is_error()) {
return true;
}
LOG(DEBUG) << "Trying " << r_path.ok();
return callback(r_path.move_as_ok());
};
auto cleaned_name = clean_filename(name);
PathView path_view(cleaned_name);
auto stem = path_view.file_stem();
auto ext = path_view.extension();
bool active = true;
if (!stem.empty() && !G()->parameters().ignore_file_names) {
active = try_callback(PSLICE_SAFE() << stem << Ext{ext});
for (int i = 0; active && i < 10; i++) {
active = try_callback(PSLICE_SAFE() << stem << "_(" << i << ")" << Ext{ext});
}
for (int i = 2; active && i < 12 && use_random; i++) {
active = try_callback(PSLICE_SAFE() << stem << "_(" << RandSuff{i} << ")" << Ext{ext});
}
} else if (use_pmc) {
auto pmc = G()->td_db()->get_binlog_pmc();
int32 file_id = to_integer<int32>(pmc->get("perm_file_id"));
pmc->set("perm_file_id", to_string(file_id + 1));
active = try_callback(PSLICE_SAFE() << "file_" << file_id << Ext{ext});
if (active) {
active = try_callback(PSLICE_SAFE() << "file_" << file_id << "_" << RandSuff{6} << Ext{ext});
}
}
return active;
}
Result<string> create_from_temp(CSlice temp_path, CSlice dir, CSlice name) {
LOG(INFO) << "Create file in directory " << dir << " with suggested name " << name << " from temporary file "
<< temp_path;
Result<std::pair<FileFd, string>> res = Status::Error(500, "Can't find suitable file name");
for_suggested_file_name(name, true, true, [&](CSlice suggested_name) {
res = try_create_new_file(PSLICE_SAFE() << dir << suggested_name);
return res.is_error();
});
TRY_RESULT(tmp, std::move(res));
tmp.first.close();
auto perm_path = std::move(tmp.second);
TRY_STATUS(rename(temp_path, perm_path));
return perm_path;
}
Result<string> search_file(CSlice dir, CSlice name, int64 expected_size) {
Result<std::string> res = Status::Error(500, "Can't find suitable file name");
for_suggested_file_name(name, false, false, [&](CSlice suggested_name) {
auto r_pair = try_open_file(PSLICE_SAFE() << dir << suggested_name);
if (r_pair.is_error()) {
return false;
}
FileFd fd;
std::string path;
std::tie(fd, path) = r_pair.move_as_ok();
if (fd.stat().size_ != expected_size) {
return true;
}
fd.close();
res = std::move(path);
return false;
});
return res;
}
Result<FullLocalFileLocation> save_file_bytes(FileType type, BufferSlice bytes, CSlice file_name) {
TRY_RESULT(fd_path, open_temp_file(type));
FileFd fd = std::move(fd_path.first);
string path = std::move(fd_path.second);
TRY_RESULT(size, fd.write(bytes.as_slice()));
fd.close();
if (size != bytes.size()) {
return Status::Error("Failed to write bytes to the file");
}
auto dir = get_files_dir(type);
TRY_RESULT(perm_path, create_from_temp(path, dir, file_name));
return FullLocalFileLocation(type, std::move(perm_path), 0);
}
static Slice get_file_base_dir(const FileDirType &file_dir_type) {
switch (file_dir_type) {
case FileDirType::Secure:
return G()->get_dir();
case FileDirType::Common:
return G()->get_files_dir();
default:
UNREACHABLE();
return Slice();
}
}
Slice get_files_base_dir(FileType file_type) {
return get_file_base_dir(get_file_dir_type(file_type));
}
string get_files_temp_dir(FileType file_type) {
return PSTRING() << get_files_base_dir(file_type) << "temp" << TD_DIR_SLASH;
}
string get_files_dir(FileType file_type) {
return PSTRING() << get_files_base_dir(file_type) << get_file_type_name(file_type) << TD_DIR_SLASH;
}
} // namespace td