From f75149b1e2cd532c653bc519b1d08873cbf6c989 Mon Sep 17 00:00:00 2001
From: Sam Stuewe <stuewe@mit.edu>
Date: Fri, 21 Oct 2022 10:52:12 -0500
Subject: [PATCH] Lift create_seeded_transaction outside hot loop

Also includes modifying twophase mode's transaction-creation
to reuse pedersen-commitments/range-proofs

Signed-off-by: Sam Stuewe <stuewe@mit.edu>
---
 tools/shard-seeder/shard-seeder.cpp | 37 +++++++++++++++--------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/tools/shard-seeder/shard-seeder.cpp b/tools/shard-seeder/shard-seeder.cpp
index fc3b85659..9d2d6c34b 100644
--- a/tools/shard-seeder/shard-seeder.cpp
+++ b/tools/shard-seeder/shard-seeder.cpp
@@ -128,6 +128,24 @@ auto main(int argc, char** argv) -> int {
                             " to database ",
                             shard_db_dir.str());
 
+                auto value = cbdc::commit(secp_context.get(),
+                                          cfg.m_seed_value,
+                                          {})
+                                 .value();
+                auto range
+                    = cbdc::transaction::prove(secp_context.get(),
+                                               bulletproof_gens.get(),
+                                               rng,
+                                               {{}, cfg.m_seed_value},
+                                               &value);
+                auto value_comm
+                    = cbdc::serialize_commitment(secp_context.get(),
+                                                 value);
+
+                auto tx = wal.create_seeded_transaction(0,
+                                                        value_comm,
+                                                        range)
+                              .value();
                 if(!cfg.m_twophase_mode) {
                     leveldb::Options opt;
                     opt.create_if_missing = true;
@@ -150,24 +168,8 @@ auto main(int argc, char** argv) -> int {
                     }
                     auto batch_size = 0;
                     leveldb::WriteBatch batch;
-                    auto value = cbdc::commit(secp_context.get(),
-                                              cfg.m_seed_value,
-                                              {})
-                                     .value();
-                    auto range
-                        = cbdc::transaction::prove(secp_context.get(),
-                                                   bulletproof_gens.get(),
-                                                   rng,
-                                                   {{}, cfg.m_seed_value},
-                                                   &value);
-                    auto value_comm
-                        = cbdc::serialize_commitment(secp_context.get(),
-                                                     value);
                     for(size_t tx_idx = 0; tx_idx != num_utxos; tx_idx++) {
-                        auto tx = wal.create_seeded_transaction(tx_idx,
-                                                                value_comm,
-                                                                range)
-                                      .value();
+                        tx.m_inputs[0].m_prevout.m_index = tx_idx;
                         cbdc::transaction::compact_tx ctx(tx);
                         const cbdc::hash_t& output_hash
                             = cbdc::transaction::calculate_uhs_id(
@@ -215,7 +217,6 @@ auto main(int argc, char** argv) -> int {
                     // write dummy size
                     auto ser = cbdc::ostream_serializer(out);
                     ser << count;
-                    auto tx = wal.create_seeded_transaction(0).value();
                     for(size_t tx_idx = 0; tx_idx != num_utxos; tx_idx++) {
                         tx.m_inputs[0].m_prevout.m_index = tx_idx;
                         cbdc::transaction::compact_tx ctx(tx);