add grpc service file for CP-SAT

ortools/sat/cp_model_service.proto

@@ -0,0 +1,48 @@
+// Copyright 2010-2018 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.
+
+syntax = "proto3";
+
+package operations_research.sat;
+
+import "google/protobuf/duration.proto";
+import "ortools/sat/cp_model.proto";
+
+option csharp_namespace = "Google.OrTools.Sat";
+option java_package = "com.google.ortools.sat";
+option java_multiple_files = true;
+
+// Experimental rpc code.
+
+message SolveRequest {
+  CpModelProto model = 1;
+  int32 num_search_workers = 2;
+  google.protobuf.Duration time_limit = 3;
+  string search_parameters_as_string = 4;
+  bool log_search_progress = 5;
+}
+
+message SolveAnswer {
+  CpSolverResponse response = 1;
+  string search_log = 2;
+}
+
+// This service enables sending a CpModelProto to a server and getting back
+// the optimal solution or all intermediate solutions of the problem.
+service CpSatRemoveSolve {
+  // Single solve, sends a model, expects the optimal solution.
+  rpc Solve(SolveRequest) returns (SolveAnswer) {}
+  // Streaming solve, sends a model, expects all intermediate solutions as well
+  // as the final one.
+  rpc StreamingSolve(SolveRequest) returns (stream SolveAnswer) {}
+}