From 720be5b909e2750f570f7d2a5778d8b226f372ce Mon Sep 17 00:00:00 2001
From: Daniel Kogtev <oclaw@nil.foundation>
Date: Tue, 29 Oct 2024 20:45:09 +0000
Subject: [PATCH] proof-generator: add circuit writer (#111)

---
 .../include/nil/proof-generator/prover.hpp    | 23 ++++-
 .../nil/proof-generator/circuit_writer.hpp    | 85 +++++++++++++++++++
 2 files changed, 107 insertions(+), 1 deletion(-)
 create mode 100644 proof-producer/libs/output_artifacts/include/nil/proof-generator/circuit_writer.hpp

diff --git a/proof-producer/bin/proof-producer/include/nil/proof-generator/prover.hpp b/proof-producer/bin/proof-producer/include/nil/proof-generator/prover.hpp
index 6930ed5cc7..7121b03971 100644
--- a/proof-producer/bin/proof-producer/include/nil/proof-generator/prover.hpp
+++ b/proof-producer/bin/proof-producer/include/nil/proof-generator/prover.hpp
@@ -59,6 +59,7 @@
 
 #include <nil/proof-generator/arithmetization_params.hpp>
 #include <nil/proof-generator/assignment_table_writer.hpp>
+#include <nil/proof-generator/circuit_writer.hpp>
 #include <nil/proof-generator/file_operations.hpp>
 
 namespace nil {
@@ -539,6 +540,26 @@ namespace nil {
                         *marshalled_value
                     )
                 );
+
+                return true;
+            }
+
+            bool save_circuit_to_file(boost::filesystem::path circuit_file) {
+                using writer = nil::proof_generator::circuit_writer<Endianness, BlueprintField>;
+
+                BOOST_LOG_TRIVIAL(info) << "Writing circuit to " << circuit_file;
+                if (!constraint_system_) {
+                    BOOST_LOG_TRIVIAL(error) << "No circuit is currently loaded";
+                    return false;
+                }
+
+                std::ofstream out(circuit_file.string(), std::ios::binary | std::ios::out);
+                if (!out.is_open()) {
+                    BOOST_LOG_TRIVIAL(error) << "Failed to open file " << circuit_file;
+                    return false;
+                }
+
+                writer::write_binary_circuit(out, *constraint_system_, constraint_system_->public_input_sizes());            
                 return true;
             }
 
@@ -589,7 +610,7 @@ namespace nil {
                 BOOST_LOG_TRIVIAL(info) << "Writing binary assignment table to " << output_filename;
                 
                 if (!assignment_table_.has_value() || !table_description_.has_value()) {
-                    BOOST_LOG_TRIVIAL(error) << "No assignment table is currently loaded into the Prover";
+                    BOOST_LOG_TRIVIAL(error) << "No assignment table is currently loaded";
                     return false;
                 }
 
diff --git a/proof-producer/libs/output_artifacts/include/nil/proof-generator/circuit_writer.hpp b/proof-producer/libs/output_artifacts/include/nil/proof-generator/circuit_writer.hpp
new file mode 100644
index 0000000000..118c793c6f
--- /dev/null
+++ b/proof-producer/libs/output_artifacts/include/nil/proof-generator/circuit_writer.hpp
@@ -0,0 +1,85 @@
+//---------------------------------------------------------------------------//
+// Copyright (c) 2024 Daniil Kogtev <oclaw@nil.foundation>
+//
+// 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 PROOF_GENERATOR_CIRCUIT_WRITER_HPP
+#define PROOF_GENERATOR_CIRCUIT_WRITER_HPP
+
+#include <ostream>
+#include <vector>
+
+#include <boost/assert.hpp>
+
+#include <nil/crypto3/marshalling/zk/types/plonk/constraint_system.hpp>
+#include <nil/crypto3/zk/snark/arithmetization/plonk/constraint_system.hpp>
+
+
+namespace nil {
+    namespace proof_generator {
+
+
+        template <typename Endianness, typename BlueprintField> 
+        class circuit_writer {
+                public:
+                    using TTypeBase = nil::marshalling::field_type<Endianness>;
+                    using Circuit = nil::crypto3::zk::snark::plonk_constraint_system<BlueprintField>;
+
+                    circuit_writer() = delete;
+
+                    /**
+                    * @brief Write circuit serialized into binary to output file.
+                    */
+                    static void write_binary_circuit(
+                            std::ostream& out,
+                            const Circuit& circuit,
+                            const std::vector<std::size_t>& public_input_column_sizes) {
+
+                        namespace marshalling_types = nil::crypto3::marshalling::types;
+                        using value_marshalling_type = marshalling_types::plonk_constraint_system<TTypeBase, Circuit>;
+
+                        // fill public input sizes
+                        marshalling_types::public_input_sizes_type<TTypeBase> public_input_sizes;
+                        using public_input_size_type = typename marshalling_types::public_input_sizes_type<TTypeBase>::element_type;
+
+                        const auto public_input_size = public_input_column_sizes.size();
+                        for (const auto i : public_input_column_sizes) {
+                            public_input_sizes.value().push_back(public_input_size_type(i));
+                        }
+
+                        auto filled_val =
+                            value_marshalling_type(std::make_tuple(
+                                marshalling_types::fill_plonk_gates<Endianness, typename Circuit::gates_container_type::value_type>(circuit.gates()),
+                                marshalling_types::fill_plonk_copy_constraints<Endianness, typename Circuit::field_type>(circuit.copy_constraints()),
+                                marshalling_types::fill_plonk_lookup_gates<Endianness, typename Circuit::lookup_gates_container_type::value_type>(circuit.lookup_gates()),
+                                marshalling_types::fill_plonk_lookup_tables<Endianness, typename Circuit::lookup_tables_type::value_type>(circuit.lookup_tables()),
+                                public_input_sizes
+                        ));
+
+
+                        std::vector<std::uint8_t> cv(filled_val.length(), 0x00);
+                        auto iter = cv.begin();
+                        BOOST_ASSERT(filled_val.write(iter, cv.size()) == nil::marshalling::status_type::success);
+                        out.write(reinterpret_cast<char*>(cv.data()), cv.size());
+                    }
+        };        
+
+    } // namespace proof_generator
+} // namespace nil
+
+
+#endif // PROOF_GENERATOR_CIRCUIT_WRITER_HPP
+
+
+