Files
ortools-clone/ortools/util/file_util.h
Laurent Perron 70e73d8754 clang-format
2018-06-08 16:40:43 +02:00

121 lines
4.2 KiB
C++

// Copyright 2010-2017 Google
// Licensed under the Apache License, Version 2.0 (the "License");
// 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.
#ifndef OR_TOOLS_UTIL_FILE_UTIL_H_
#define OR_TOOLS_UTIL_FILE_UTIL_H_
#include <limits>
#include <vector>
#include "google/protobuf/message.h"
#include "ortools/base/file.h"
#include "ortools/base/recordio.h"
#include "ortools/base/string_view.h"
namespace operations_research {
// Reads a proto from a file. Supports the following formats: binary, text,
// JSON, all of those optionally gzipped. Returns false on failure.
bool ReadFileToProto(absl::string_view filename,
google::protobuf::Message* proto);
template <typename Proto>
Proto ReadFileToProtoOrDie(absl::string_view filename) {
Proto proto;
CHECK(ReadFileToProto(filename, &proto));
return proto;
}
enum class ProtoWriteFormat { kProtoText, kProtoBinary, kJson };
// Writes a proto to a file. Supports the following formats: binary, text, JSON,
// all of those optionally gzipped. Returns false on failure.
// If 'proto_write_format' is kProtoBinary, ".bin" is appended to file_name. If
// 'proto_write_format' is kJson, ".json" is appended to file_name. If 'gzipped'
// is true, ".gz" is appended to file_name.
bool WriteProtoToFile(absl::string_view filename,
const google::protobuf::Message& proto,
ProtoWriteFormat proto_write_format, bool gzipped);
namespace internal {
// General method to read expected_num_records from a file. If
// expected_num_records is -1, then reads all records from the file. If not,
// dies if the file doesn't contain exactly expected_num_records.
template <typename Proto>
std::vector<Proto> ReadNumRecords(File* file, int expected_num_records) {
recordio::RecordReader reader(file);
std::vector<Proto> protos;
Proto proto;
int num_read = 0;
while (num_read != expected_num_records &&
reader.ReadProtocolMessage(&proto)) {
protos.push_back(proto);
++num_read;
}
if (expected_num_records >= 0) {
CHECK_EQ(num_read, expected_num_records)
<< "There were less than the expected " << expected_num_records
<< " in the file.";
}
return protos;
}
// Ditto, taking a filename as argument.
template <typename Proto>
std::vector<Proto> ReadNumRecords(absl::string_view filename,
int expected_num_records) {
return ReadNumRecords<Proto>(file::OpenOrDie(filename, "r", file::Defaults()),
expected_num_records);
}
} // namespace internal
// Reads all records in Proto format in 'file'. Silently does nothing if the
// file is empty. Dies if the file doesn't exist or contains something else than
// protos encoded in RecordIO format.
template <typename Proto>
std::vector<Proto> ReadAllRecordsOrDie(absl::string_view filename) {
return internal::ReadNumRecords<Proto>(filename, -1);
}
template <typename Proto>
std::vector<Proto> ReadAllRecordsOrDie(File* file) {
return internal::ReadNumRecords<Proto>(file, -1);
}
// Reads one record in Proto format in 'file'. Dies if the file doesn't exist,
// doesn't contain exactly one record, or contains something else than protos
// encoded in RecordIO format.
template <typename Proto>
Proto ReadOneRecordOrDie(absl::string_view filename) {
Proto p;
p.Swap(&internal::ReadNumRecords<Proto>(filename, 1)[0]);
return p;
}
// Writes all records in Proto format to 'file'. Dies if it is unable to open
// the file or write to it.
template <typename Proto>
void WriteRecordsOrDie(absl::string_view filename,
const std::vector<Proto>& protos) {
recordio::RecordWriter writer(
file::OpenOrDie(filename, "w", file::Defaults()));
for (const Proto& proto : protos) {
CHECK(writer.WriteProtocolMessage(proto));
}
}
} // namespace operations_research
#endif // OR_TOOLS_UTIL_FILE_UTIL_H_