OR-Tools  8.2
file_util.h
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1// Copyright 2010-2018 Google LLC
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14#ifndef OR_TOOLS_UTIL_FILE_UTIL_H_
15#define OR_TOOLS_UTIL_FILE_UTIL_H_
16
17#include <limits>
18#include <vector>
19
20#include "absl/status/statusor.h"
21#include "absl/strings/string_view.h"
22#include "google/protobuf/message.h"
23#include "ortools/base/file.h"
25
26namespace operations_research {
27
28// Reads a file, optionally gzipped, to a string.
29absl::StatusOr<std::string> ReadFileToString(absl::string_view filename);
30
31// Reads a proto from a file. Supports the following formats: binary, text,
32// JSON, all of those optionally gzipped. Crashes on filesystem failures, e.g.
33// file unreadable. Returns false on format failures, e.g. the file could be
34// read, but the contents couldn't be parsed -- or maybe it was a valid JSON,
35// text proto, or binary proto, but not of the right proto message.
36// Returns true on success.
37bool ReadFileToProto(absl::string_view filename,
38 google::protobuf::Message* proto);
39
40template <typename Proto>
41Proto ReadFileToProtoOrDie(absl::string_view filename) {
42 Proto proto;
43 CHECK(ReadFileToProto(filename, &proto)) << "with file: '" << filename << "'";
44 return proto;
45}
46
48
49// Writes a proto to a file. Supports the following formats: binary, text, JSON,
50// all of those optionally gzipped. Returns false on failure.
51// If 'proto_write_format' is kProtoBinary, ".bin" is appended to file_name. If
52// 'proto_write_format' is kJson, ".json" is appended to file_name. If 'gzipped'
53// is true, ".gz" is appended to file_name.
54bool WriteProtoToFile(absl::string_view filename,
55 const google::protobuf::Message& proto,
56 ProtoWriteFormat proto_write_format, bool gzipped = false,
57 bool append_extension_to_file_name = true);
58
59namespace internal {
60// General method to read expected_num_records from a file. If
61// expected_num_records is -1, then reads all records from the file. If not,
62// dies if the file doesn't contain exactly expected_num_records.
63template <typename Proto>
64std::vector<Proto> ReadNumRecords(File* file, int expected_num_records) {
66 std::vector<Proto> protos;
67 Proto proto;
68 int num_read = 0;
69 while (num_read != expected_num_records &&
70 reader.ReadProtocolMessage(&proto)) {
71 protos.push_back(proto);
72 ++num_read;
73 }
74
75 CHECK(reader.Close())
76 << "File '" << file->filename()
77 << "'was not fully read, or something went wrong when closing "
78 "it. Is it the right format? (RecordIO of Protocol Buffers).";
79
80 if (expected_num_records >= 0) {
81 CHECK_EQ(num_read, expected_num_records)
82 << "There were less than the expected " << expected_num_records
83 << " in the file.";
84 }
85
86 return protos;
87}
88
89// Ditto, taking a filename as argument.
90template <typename Proto>
91std::vector<Proto> ReadNumRecords(absl::string_view filename,
92 int expected_num_records) {
93 return ReadNumRecords<Proto>(file::OpenOrDie(filename, "r", file::Defaults()),
94 expected_num_records);
95}
96} // namespace internal
97
98// Reads all records in Proto format in 'file'. Silently does nothing if the
99// file is empty. Dies if the file doesn't exist or contains something else than
100// protos encoded in RecordIO format.
101template <typename Proto>
102std::vector<Proto> ReadAllRecordsOrDie(absl::string_view filename) {
103 return internal::ReadNumRecords<Proto>(filename, -1);
104}
105template <typename Proto>
106std::vector<Proto> ReadAllRecordsOrDie(File* file) {
107 return internal::ReadNumRecords<Proto>(file, -1);
108}
109
110// Reads one record from file, which must be in RecordIO binary proto format.
111// Dies if the file can't be read, doesn't contain exactly one record, or
112// contains something else than the expected proto in RecordIO format.
113template <typename Proto>
114Proto ReadOneRecordOrDie(absl::string_view filename) {
115 Proto p;
116 p.Swap(&internal::ReadNumRecords<Proto>(filename, 1)[0]);
117 return p;
118}
119
120// Writes all records in Proto format to 'file'. Dies if it is unable to open
121// the file or write to it.
122template <typename Proto>
123void WriteRecordsOrDie(absl::string_view filename,
124 const std::vector<Proto>& protos) {
126 file::OpenOrDie(filename, "w", file::Defaults()));
127 for (const Proto& proto : protos) {
129 }
130 CHECK(writer.Close());
131}
132
133} // namespace operations_research
134
135#endif // OR_TOOLS_UTIL_FILE_UTIL_H_
#define CHECK(condition)
Definition: base/logging.h:495
#define CHECK_EQ(val1, val2)
Definition: base/logging.h:697
Definition: base/file.h:32
bool ReadProtocolMessage(P *const proto)
Definition: recordio.h:91
bool WriteProtocolMessage(const P &proto)
Definition: recordio.h:41
CpModelProto proto
Definition: file.cc:141
File * OpenOrDie(const absl::string_view &filename, const absl::string_view &mode, int flags)
Definition: file.cc:154
int Defaults()
Definition: base/file.h:119
std::vector< Proto > ReadNumRecords(File *file, int expected_num_records)
Definition: file_util.h:64
The vehicle routing library lets one model and solve generic vehicle routing problems ranging from th...
absl::StatusOr< std::string > ReadFileToString(absl::string_view filename)
Definition: file_util.cc:32
bool WriteProtoToFile(absl::string_view filename, const google::protobuf::Message &proto, ProtoWriteFormat proto_write_format, bool gzipped, bool append_extension_to_file_name)
Definition: file_util.cc:102
std::vector< Proto > ReadAllRecordsOrDie(absl::string_view filename)
Definition: file_util.h:102
void WriteRecordsOrDie(absl::string_view filename, const std::vector< Proto > &protos)
Definition: file_util.h:123
Proto ReadFileToProtoOrDie(absl::string_view filename)
Definition: file_util.h:41
bool ReadFileToProto(absl::string_view filename, google::protobuf::Message *proto)
Definition: file_util.cc:43
Proto ReadOneRecordOrDie(absl::string_view filename)
Definition: file_util.h:114