Files
scylladb/tests/linecount.cc
2015-03-15 14:48:52 +02:00

77 lines
2.4 KiB
C++

/*
* This file is open source software, licensed to you under the terms
* of the Apache License, Version 2.0 (the "License"). See the NOTICE file
* distributed with this work for additional information regarding copyright
* ownership. You may not use this file except in compliance with the License.
*
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/*
* Copyright (C) 2015 Cloudius Systems, Ltd.
*/
// Demonstration of file_input_stream. Don't expect stellar performance
// since no read-ahead or caching is done yet.
#include "core/fstream.hh"
#include "core/app-template.hh"
#include "core/shared_ptr.hh"
#include "core/reactor.hh"
#include <algorithm>
struct reader {
reader(file f) : is(make_file_input_stream(
make_lw_shared<file>(std::move(f)), 0, 4096)) {}
input_stream<char> is;
size_t count = 0;
// for input_stream::consume():
template <typename Done>
void operator()(temporary_buffer<char> data, Done&& done) {
if (data.empty()) {
done(std::move(data));
} else {
count += std::count(data.begin(), data.end(), '\n');
// FIXME: last line without \n?
}
}
};
int main(int ac, char** av) {
app_template app;
namespace bpo = boost::program_options;
app.add_positional_options({
{ "file", bpo::value<std::string>(), "File to process", 1 },
});
app.run(ac, av, [&app] {
auto fname = app.configuration()["file"].as<std::string>();
engine().open_file_dma(fname, open_flags::ro).then([] (file f) {
auto r = make_shared<reader>(std::move(f));
r->is.consume(*r).then([r] {
print("%d lines\n", r->count);
});
}).then_wrapped([] (future<> f) {
try {
f.get();
engine().exit(0);
} catch (std::exception& ex) {
std::cout << ex.what() << "\n";
engine().exit(1);
} catch (...) {
std::cout << "unknown exception\n";
engine().exit(0);
}
});
});
}