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ortools-clone/examples/cpp/solve.cc
Corentin Le Molgat c7120439d4 Bump license date
2022-06-17 14:23:23 +02:00

357 lines
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// Copyright 2010-2022 Google LLC
// 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.
// Command line interface to the MPSolver class.
// See linear_solver.h and kUsageStr below.
//
// Examples.
//
// 1. To run SCIP for 90 seconds, dumping available information use:
//
// solve --solver=scip \
// --time_limit=90s \
// --logtostderr \
// --linear_solver_enable_verbose_output \
// --input=/tmp/foo.mps \
// --dump_model=/tmp/foo.model \
// --dump_request=/tmp/foo.request \
// --dump_response=/tmp/foo.response \
// >/tmp/foo.out 2>/tmp/foo.err
//
// 2. To run CP_SAT for 10 minutes with 8 workers, you can use
// CP-SAT parameters:
//
// solve --solver=sat \
// --params="max_time_in_seconds:600, num_search_workers:8"
// --logtostderr \
// --input=/tmp/foo.mps \
// 2>/tmp/foo.err
//
// or use the solve binary flags:
//
// solve --solver=sat \
// --time_limit=10m \
// --num_threads=8 \
// --logtostderr \
// --input=/tmp/foo.mps \
// --dump_model=/tmp/foo.model \
// --dump_request=/tmp/foo.request \
// --dump_response=/tmp/foo.response \
// 2>/tmp/foo.err
#include <algorithm>
#include <cstdio>
#include <string>
#include <vector>
#include "absl/flags/flag.h"
#include "absl/flags/parse.h"
#include "absl/flags/usage.h"
#include "absl/strings/match.h"
#include "absl/strings/str_format.h"
#include "absl/time/time.h"
#include "ortools/base/commandlineflags.h"
#include "ortools/base/file.h"
#include "ortools/base/integral_types.h"
#include "ortools/base/logging.h"
#include "ortools/base/timer.h"
#include "ortools/linear_solver/linear_solver.h"
#include "ortools/linear_solver/linear_solver.pb.h"
#include "ortools/lp_data/mps_reader.h"
#include "ortools/lp_data/proto_utils.h"
#include "ortools/sat/cp_model.pb.h"
#include "ortools/sat/cp_model_solver.h"
#include "ortools/util/file_util.h"
#include "ortools/util/sigint.h"
ABSL_FLAG(std::string, input, "", "REQUIRED: Input file name.");
ABSL_FLAG(std::string, solver, "glop",
"The solver to use: bop, cbc, clp, glop, glpk_lp, glpk_mip, "
"gurobi_lp, gurobi_mip, pdlp, scip, knapsack, sat.");
ABSL_FLAG(int, num_threads, 1,
"Number of threads to use by the underlying solver.");
ABSL_FLAG(std::string, params_file, "",
"Solver specific parameters file. "
"If this flag is set, the --params flag is ignored.");
ABSL_FLAG(std::string, params, "", "Solver specific parameters");
ABSL_FLAG(absl::Duration, time_limit, absl::InfiniteDuration(),
"It specifies a limit on the solving time. The duration must be must "
"be positive. It default to an infinite duration meaning that no "
"time limit will be imposed.");
ABSL_FLAG(std::string, output_csv, "",
"If non-empty, write the returned solution in csv format with "
"each line formed by a variable name and its value.");
ABSL_FLAG(std::string, dump_format, "text",
"Format in which to dump protos (if flags --dump_model, "
"--dump_request, or --dump_response are used). Possible values: "
"'text', 'binary', 'json' which correspond to text proto format "
"binary proto format, and json. If 'binary' or 'json' are used, "
"we append '.bin' and '.json' to file names.");
ABSL_FLAG(bool, dump_gzip, false,
"Whether to gzip dumped protos. Appends .gz to their name.");
ABSL_FLAG(std::string, dump_model, "",
"If non-empty, dumps MPModelProto there.");
ABSL_FLAG(std::string, dump_request, "",
"If non-empty, dumps MPModelRequest there.");
ABSL_FLAG(std::string, dump_response, "",
"If non-empty, dumps MPSolutionResponse there.");
ABSL_FLAG(std::string, sol_file, "",
"If non-empty, output the best solution in Miplib .sol format.");
ABSL_DECLARE_FLAG(bool, verify_solution); // Defined in ./linear_solver.cc
ABSL_DECLARE_FLAG(
bool,
linear_solver_enable_verbose_output); // Defined in ./linear_solver.cc
static const char kUsageStr[] =
"Run MPSolver on the given input file. Many formats are supported: \n"
" - a .mps or .mps.gz file,\n"
" - an MPModelProto (binary or text, possibly gzipped),\n"
" - an MPModelRequest (binary or text, possibly gzipped).";
namespace operations_research {
namespace {
MPModelRequest ReadMipModel(const std::string& input) {
MPModelRequest request_proto;
MPModelProto model_proto;
if (absl::EndsWith(input, ".mps") || absl::EndsWith(input, ".mps.gz")) {
QCHECK_OK(glop::MPSReader().ParseFile(input, &model_proto))
<< "Error while parsing the mps file '" << input << "'.";
} else {
ReadFileToProto(input, &model_proto);
ReadFileToProto(input, &request_proto);
}
// If the input is a proto in binary format, both ReadFileToProto could
// return true. Instead use the actual number of variables found to test the
// correct format of the input.
const bool is_model_proto = model_proto.variable_size() > 0;
const bool is_request_proto = request_proto.model().variable_size() > 0;
if (!is_model_proto && !is_request_proto) {
LOG(FATAL) << "Failed to parse '" << input
<< "' as an MPModelProto or an MPModelRequest.";
} else {
CHECK(!(is_model_proto && is_request_proto));
}
if (is_request_proto) {
LOG(INFO) << "Read input proto as an MPModelRequest.";
} else {
LOG(INFO) << "Read input proto as an MPModelProto.";
model_proto.Swap(request_proto.mutable_model());
}
return request_proto;
}
// Returns false if an error was encountered.
// More details should be available in the logs.
bool Run(MPSolver::OptimizationProblemType type) {
MPModelRequest request_proto = ReadMipModel(absl::GetFlag(FLAGS_input));
printf("%-12s: '%s'\n", "File", absl::GetFlag(FLAGS_input).c_str());
// Detect format to dump protos.
operations_research::ProtoWriteFormat write_format;
if (absl::GetFlag(FLAGS_dump_format) == "text") {
write_format = ProtoWriteFormat::kProtoText;
} else if (absl::GetFlag(FLAGS_dump_format) == "binary") {
write_format = ProtoWriteFormat::kProtoBinary;
} else if (absl::GetFlag(FLAGS_dump_format) == "json") {
write_format = ProtoWriteFormat::kJson;
} else {
LOG(FATAL) << "Unsupported --dump_format: "
<< absl::GetFlag(FLAGS_dump_format);
}
// Create the solver, we use the name of the model as the solver name.
MPSolver solver(request_proto.model().name(), type);
const absl::Status set_num_threads_status =
solver.SetNumThreads(absl::GetFlag(FLAGS_num_threads));
if (set_num_threads_status.ok()) {
LOG(INFO) << "Set number of threads to " << absl::GetFlag(FLAGS_num_threads)
<< ".";
} else if (absl::GetFlag(FLAGS_num_threads) != 1) {
LOG(ERROR) << "Failed to set number of threads due to: "
<< set_num_threads_status.message() << ". Using 1 as default.";
}
solver.EnableOutput();
if (!absl::GetFlag(FLAGS_params_file).empty()) {
std::string file_contents;
CHECK_OK(file::GetContents(absl::GetFlag(FLAGS_params_file), &file_contents,
file::Defaults()))
<< "Could not read parameters file.";
CHECK(solver.SetSolverSpecificParametersAsString(file_contents));
} else if (!absl::GetFlag(FLAGS_params).empty()) {
CHECK(
solver.SetSolverSpecificParametersAsString(absl::GetFlag(FLAGS_params)))
<< "Wrong --params format.";
}
absl::PrintF(
"%-12s: %s\n", "Solver",
MPModelRequest::SolverType_Name(
static_cast<MPModelRequest::SolverType>(solver.ProblemType()))
.c_str());
// Load the proto into the solver.
std::string error_message;
// If requested, save the model to file.
if (!absl::GetFlag(FLAGS_dump_model).empty()) {
CHECK(WriteProtoToFile(absl::GetFlag(FLAGS_dump_model),
request_proto.model(), write_format,
absl::GetFlag(FLAGS_dump_gzip)));
}
const MPSolverResponseStatus status =
solver.LoadModelFromProtoWithUniqueNamesOrDie(request_proto.model(),
&error_message);
// Note, the underlying MPSolver treats time limit equal to 0 as no limit.
if (status != MPSOLVER_MODEL_IS_VALID) {
LOG(ERROR) << MPSolverResponseStatus_Name(status) << ": " << error_message;
return false;
}
// Time limits.
if (absl::GetFlag(FLAGS_time_limit) != absl::InfiniteDuration()) {
LOG(INFO) << "Setting a time limit of " << absl::GetFlag(FLAGS_time_limit);
// Overwrite the request time limit.
request_proto.set_solver_time_limit_seconds(
absl::ToDoubleSeconds(absl::GetFlag(FLAGS_time_limit)));
}
if (request_proto.has_solver_time_limit_seconds()) {
solver.SetTimeLimit(
absl::Seconds(request_proto.solver_time_limit_seconds()));
}
absl::PrintF("%-12s: %d x %d\n", "Dimension", solver.NumConstraints(),
solver.NumVariables());
// Register a signal handler to interrupt the solve when the user presses ^C.
// Note that we ignore all previously registered handler here. If SCIP is
// used, this handler will be overridden by the one of SCIP that does the same
// thing.
SigintHandler handler;
handler.Register([&solver] { solver.InterruptSolve(); });
// Solve.
MPSolverParameters param;
MPSolver::ResultStatus solve_status = MPSolver::NOT_SOLVED;
absl::Duration solving_time;
const absl::Time time_before = absl::Now();
solve_status = solver.Solve(param);
solving_time = absl::Now() - time_before;
// If requested, re-create a corresponding MPModelRequest and save it to file.
if (!absl::GetFlag(FLAGS_dump_request).empty()) {
request_proto.set_solver_type(
static_cast<MPModelRequest::SolverType>(solver.ProblemType()));
request_proto.set_solver_time_limit_seconds(solver.time_limit_in_secs());
request_proto.set_solver_specific_parameters(
solver.GetSolverSpecificParametersAsString());
CHECK(WriteProtoToFile(absl::GetFlag(FLAGS_dump_request), request_proto,
write_format, absl::GetFlag(FLAGS_dump_gzip)));
}
const bool has_solution =
solve_status == MPSolver::OPTIMAL || solve_status == MPSolver::FEASIBLE;
if (!absl::GetFlag(FLAGS_sol_file).empty() && has_solution) {
operations_research::MPSolutionResponse response;
solver.FillSolutionResponseProto(&response);
std::string sol_string;
absl::StrAppend(&sol_string, "=obj= ", response.objective_value(), "\n");
for (int i = 0; i < response.variable_value().size(); ++i) {
absl::StrAppend(&sol_string, request_proto.model().variable(i).name(),
" ", response.variable_value(i), "\n");
}
LOG(INFO) << "Writing .sol solution to '" << absl::GetFlag(FLAGS_sol_file)
<< "'.\n";
CHECK_OK(file::SetContents(absl::GetFlag(FLAGS_sol_file), sol_string,
file::Defaults()));
}
// If requested, get the MPSolutionResponse and save it to file.
if (!absl::GetFlag(FLAGS_dump_response).empty() && has_solution) {
operations_research::MPSolutionResponse response;
solver.FillSolutionResponseProto(&response);
CHECK(WriteProtoToFile(absl::GetFlag(FLAGS_dump_response), response,
write_format, absl::GetFlag(FLAGS_dump_gzip)));
}
if (!absl::GetFlag(FLAGS_output_csv).empty() && has_solution) {
operations_research::MPSolutionResponse result;
solver.FillSolutionResponseProto(&result);
std::string csv_file;
for (int i = 0; i < result.variable_value_size(); ++i) {
csv_file +=
absl::StrFormat("%s,%e\n", request_proto.model().variable(i).name(),
result.variable_value(i));
}
CHECK_OK(file::SetContents(absl::GetFlag(FLAGS_output_csv), csv_file,
file::Defaults()));
}
// If --verify_solution is true, we already verified it. If not, we add
// a verification step here.
if (has_solution && !absl::GetFlag(FLAGS_verify_solution)) {
LOG(INFO) << "Verifying the solution";
solver.VerifySolution(/*tolerance=*/param.GetDoubleParam(
MPSolverParameters::PRIMAL_TOLERANCE),
/*log_errors=*/true);
}
absl::PrintF("%-12s: %s\n", "Status",
MPSolverResponseStatus_Name(
static_cast<MPSolverResponseStatus>(solve_status))
.c_str());
absl::PrintF("%-12s: %15.15e\n", "Objective",
has_solution ? solver.Objective().Value() : 0.0);
absl::PrintF("%-12s: %15.15e\n", "BestBound",
has_solution ? solver.Objective().BestBound() : 0.0);
absl::PrintF("%-12s: %d\n", "Iterations", solver.iterations());
// NOTE(user): nodes() for non-MIP solvers crashes in debug mode by design.
if (solver.IsMIP()) {
absl::PrintF("%-12s: %d\n", "Nodes", solver.nodes());
}
absl::PrintF("%-12s: %-6.4g\n", "Time", absl::ToDoubleSeconds(solving_time));
return true;
}
} // namespace
} // namespace operations_research
int main(int argc, char** argv) {
absl::SetFlag(&FLAGS_logtostderr, true);
google::InitGoogleLogging(kUsageStr);
absl::ParseCommandLine(argc, argv);
QCHECK(!absl::GetFlag(FLAGS_input).empty()) << "--input is required";
QCHECK_GE(absl::GetFlag(FLAGS_time_limit), absl::ZeroDuration())
<< "--time_limit must be given a positive duration";
operations_research::MPSolver::OptimizationProblemType type;
CHECK(operations_research::MPSolver::ParseSolverType(
absl::GetFlag(FLAGS_solver), &type))
<< "Unsupported --solver: " << absl::GetFlag(FLAGS_solver);
if (!operations_research::Run(type)) {
// If the solver is SAT and we encountered an error, display it in a format
// interpretable by our scripts.
if (type == operations_research::MPSolver::SAT_INTEGER_PROGRAMMING) {
operations_research::sat::CpSolverResponse response;
response.set_status(
operations_research::sat::CpSolverStatus::MODEL_INVALID);
LOG(INFO) << operations_research::sat::CpSolverResponseStats(response);
}
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}