Prover optimizations (part 2) (#35)

* Changes for mcl support

* Extra info printing

* Added server mode + misc optimizations

* Changes for optimizations

* Reserve the necessary number of sha256 hashers for deposits/withdrawals

* Multi-threading fix for gcc

* Fixed problem with swapping between different sized buffers

* Fixed cli docs for pk_alt2mcl

Author: Brechtpd

Circuits/DepositCircuit.h

@@ -183,6 +183,8 @@ class DepositCircuit : public Circuit
         count.generate_r1cs_constraints(true);
 
         // Deposits
+        deposits.reserve(numDeposits);
+        hashers.reserve(numDeposits);
         for (size_t j = 0; j < numDeposits; j++)
         {
             VariableT depositAccountsRoot = (j == 0) ? merkleRootBefore.packed : deposits.back().getNewAccountsRoot();

Circuits/InternalTransferCircuit.h

@@ -349,6 +349,7 @@ class InternalTransferCircuit : public Circuit
         publicKeyX_notZero.generate_r1cs_constraints();
 
         // Internal transfers
+        transfers.reserve(numTransfers);
         for (size_t j = 0; j < numTransfers; j++)
         {
             VariableT transAccountsRoot = (j == 0) ? merkleRootBefore.packed : transfers.back().getNewAccountsRoot();

Circuits/OffchainWithdrawalCircuit.h

@@ -328,6 +328,7 @@ class OffchainWithdrawalCircuit : public Circuit
         publicKeyX_notZero.generate_r1cs_constraints();
 
         // Withdrawals
+        withdrawals.reserve(numWithdrawals);
         for (size_t j = 0; j < numWithdrawals; j++)
         {
             VariableT withdrawalAccountsRoot = (j == 0) ? merkleRootBefore.packed : withdrawals.back().getNewAccountsRoot();

Circuits/OnchainWithdrawalCircuit.h

@@ -242,6 +242,8 @@ class OnchainWithdrawalCircuit : public Circuit
         bShutdownMode.generate_r1cs_constraints();
 
         // Withdrawals
+        withdrawals.reserve(numWithdrawals);
+        hashers.reserve(numWithdrawals);
         for (size_t j = 0; j < numWithdrawals; j++)
         {
             VariableT withdrawalAccountsRoot = (j == 0) ? merkleRootBefore.packed : withdrawals.back().getNewAccountsRoot();

Circuits/OrderCancellationCircuit.h

@@ -331,6 +331,7 @@ class OrderCancellationCircuit : public Circuit
         publicKeyX_notZero.generate_r1cs_constraints();
 
         // Cancels
+        cancels.reserve(numCancels);
         for (size_t j = 0; j < numCancels; j++)
         {
             VariableT cancelAccountsRoot = (j == 0) ? merkleRootBefore.packed : cancels.back().getNewAccountsRoot();

Circuits/RingSettlementCircuit.h

@@ -544,6 +544,7 @@ class RingSettlementCircuit : public Circuit
         nonce_after.generate_r1cs_constraints();
 
         // Ring settlements
+        ringSettlements.reserve(numRings);
         for (size_t j = 0; j < numRings; j++)
         {
             const VariableT ringAccountsRoot = (j == 0) ? merkleRootBefore.packed : ringSettlements.back().getNewAccountsRoot();

Gadgets/MathGadgets.h

@@ -1381,6 +1381,7 @@ class LabelHasher : public GadgetT
         GadgetT(pb, prefix)
     {
         unsigned int numStages = (labels.size() + numInputs - 1) / numInputs;
+        stageHashers.reserve(numStages);
         for (unsigned int i = 0; i < numStages; i++)
         {
             std::vector<VariableT> inputs;
@@ -1392,7 +1393,6 @@ class LabelHasher : public GadgetT
             }
             stageHashers.emplace_back(pb, var_array(inputs), FMT(this->annotation_prefix, ".stage1"));
         }
-
         hash.reset(new libsnark::dual_variable_gadget<FieldT>(
             pb, stageHashers.back().result(), 256, ".labelHashToBits")
         );
@@ -1405,7 +1405,7 @@ class LabelHasher : public GadgetT
 
     void generate_r1cs_witness()
     {
-        for (auto hasher : stageHashers)
+        for (auto& hasher : stageHashers)
         {
             hasher.generate_r1cs_witness();
         }
@@ -1415,7 +1415,7 @@ class LabelHasher : public GadgetT
 
     void generate_r1cs_constraints()
     {
-        for (auto hasher : stageHashers)
+        for (auto& hasher : stageHashers)
         {
             hasher.generate_r1cs_constraints();
         }

Gadgets/MerkleTree.h

@@ -83,11 +83,6 @@ template<typename HashT>
 class merkle_path_compute_4 : public GadgetT
 {
 public:
-    const size_t m_depth;
-    const VariableArrayT m_address_bits;
-    const VariableT m_leaf;
-    const VariableArrayT m_path;
-
     std::vector<merkle_path_selector_4> m_selectors;
     std::vector<HashT> m_hashers;
 
@@ -99,16 +94,14 @@ class merkle_path_compute_4 : public GadgetT
         const VariableArrayT& in_path,
         const std::string &in_annotation_prefix
     ) :
-        GadgetT(in_pb, in_annotation_prefix),
-        m_depth(in_depth),
-        m_address_bits(in_address_bits),
-        m_leaf(in_leaf),
-        m_path(in_path)
+        GadgetT(in_pb, in_annotation_prefix)
     {
         assert( in_depth > 0 );
         assert( in_address_bits.size() == in_depth * 2 );
 
-        for( size_t i = 0; i < m_depth; i++ )
+        m_selectors.reserve(in_depth);
+        m_hashers.reserve(in_depth);
+        for( size_t i = 0; i < in_depth; i++ )
         {
             m_selectors.push_back(
                 merkle_path_selector_4(
@@ -117,11 +110,11 @@ class merkle_path_compute_4 : public GadgetT
                     in_address_bits[i*2 + 0], in_address_bits[i*2 + 1],
                     FMT(this->annotation_prefix, ".selector[%zu]", i)));
 
-            auto t = HashT(
-                    in_pb,
-                    var_array(m_selectors[i].getChildren()),
-                    FMT(this->annotation_prefix, ".hasher[%zu]", i));
-            m_hashers.push_back(t);
+            m_hashers.emplace_back(
+                in_pb,
+                var_array(m_selectors[i].getChildren()),
+                FMT(this->annotation_prefix, ".hasher[%zu]", i)
+            );
         }
     }
 

Utils/Data.h

@@ -3,7 +3,7 @@
 
 #include "Constants.h"
 
-#include "../ThirdParty/json.hpp"
+//#include "../ThirdParty/json.hpp"
 #include "ethsnarks.hpp"
 #include "jubjub/point.hpp"
 #include "jubjub/eddsa.hpp"