Merge pull request #4720

5f614ba9 simplewallet: print the number of show/all transfers (moneromooo-monero)
8d71b2b1 wallet2: only export necessary outputs and key images (moneromooo-monero)
769ae42a wallet2: faster output and key image import/export (moneromooo-monero)

9 files changed, 194 insertions, 73 deletions

diff --git a/src/device_trezor/device_trezor.cpp b/src/device_trezor/device_trezor.cpp
index 07c03fc66..f55cbb15d 100644
--- a/src/device_trezor/device_trezor.cpp
+++ b/src/device_trezor/device_trezor.cpp
@@ -212,9 +212,10 @@ namespace trezor {
                                 tools::wallet2::signed_tx_set & signed_tx,
                                 hw::tx_aux_data & aux_data)
     {
+      CHECK_AND_ASSERT_THROW_MES(unsigned_tx.transfers.first == 0, "Unsuported non zero offset");
       size_t num_tx = unsigned_tx.txes.size();
       signed_tx.key_images.clear();
-      signed_tx.key_images.resize(unsigned_tx.transfers.size());
+      signed_tx.key_images.resize(unsigned_tx.transfers.second.size());
 
       for(size_t tx_idx = 0; tx_idx < num_tx; ++tx_idx) {
         std::shared_ptr<protocol::tx::Signer> signer;
@@ -360,4 +361,4 @@ namespace trezor {
     }
 
 #endif //WITH_DEVICE_TREZOR
-}}
\ No newline at end of file
+}}
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index 58d4cdced..f54f3f129 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -4483,7 +4483,7 @@ bool simple_wallet::show_incoming_transfers(const std::vector<std::string>& args
   tools::wallet2::transfer_container transfers;
   m_wallet->get_transfers(transfers);
 
-  bool transfers_found = false;
+  size_t transfers_found = 0;
   for (const auto& td : transfers)
   {
     if (!filter || available != td.m_spent)
@@ -4496,7 +4496,6 @@ bool simple_wallet::show_incoming_transfers(const std::vector<std::string>& args
         if (verbose)
           verbose_string = (boost::format("%68s%68s") % tr("pubkey") % tr("key image")).str();
         message_writer() << boost::format("%21s%8s%12s%8s%16s%68s%16s%s") % tr("amount") % tr("spent") % tr("unlocked") % tr("ringct") % tr("global index") % tr("tx id") % tr("addr index") % verbose_string;
-        transfers_found = true;
       }
       std::string verbose_string;
       if (verbose)
@@ -4511,6 +4510,7 @@ bool simple_wallet::show_incoming_transfers(const std::vector<std::string>& args
         td.m_txid %
         td.m_subaddr_index.minor %
         verbose_string;
+      ++transfers_found;
     }
   }
 
@@ -4529,6 +4529,10 @@ bool simple_wallet::show_incoming_transfers(const std::vector<std::string>& args
       success_msg_writer() << tr("No incoming unavailable transfers");
     }
   }
+  else
+  {
+    success_msg_writer() << boost::format("Found %u/%u transfers") % transfers_found % transfers.size();
+  }
 
   return true;
 }
@@ -6105,8 +6109,8 @@ bool simple_wallet::accept_loaded_tx(const std::function<size_t()> get_num_txes,
 bool simple_wallet::accept_loaded_tx(const tools::wallet2::unsigned_tx_set &txs)
 {
   std::string extra_message;
-  if (!txs.transfers.empty())
-    extra_message = (boost::format("%u outputs to import. ") % (unsigned)txs.transfers.size()).str();
+  if (!txs.transfers.second.empty())
+    extra_message = (boost::format("%u outputs to import. ") % (unsigned)txs.transfers.second.size()).str();
   return accept_loaded_tx([&txs](){return txs.txes.size();}, [&txs](size_t n)->const tools::wallet2::tx_construction_data&{return txs.txes[n];}, extra_message);
 }
 //----------------------------------------------------------------------------------------------------
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index c27e4e820..a90a93321 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -69,6 +69,7 @@ using namespace epee;
 #include "common/base58.h"
 #include "common/dns_utils.h"
 #include "common/notify.h"
+#include "common/perf_timer.h"
 #include "ringct/rctSigs.h"
 #include "ringdb.h"
 #include "device/device_cold.hpp"
@@ -112,11 +113,11 @@ using namespace cryptonote;
 #define SUBADDRESS_LOOKAHEAD_MAJOR 50
 #define SUBADDRESS_LOOKAHEAD_MINOR 200
 
-#define KEY_IMAGE_EXPORT_FILE_MAGIC "Monero key image export\002"
+#define KEY_IMAGE_EXPORT_FILE_MAGIC "Monero key image export\003"
 
 #define MULTISIG_EXPORT_FILE_MAGIC "Monero multisig export\001"
 
-#define OUTPUT_EXPORT_FILE_MAGIC "Monero output export\003"
+#define OUTPUT_EXPORT_FILE_MAGIC "Monero output export\004"
 
 #define SEGREGATION_FORK_HEIGHT 99999999
 #define TESTNET_SEGREGATION_FORK_HEIGHT 99999999
@@ -1605,6 +1606,7 @@ void wallet2::process_new_transaction(const crypto::hash &txid, const cryptonote
 	    td.m_txid = txid;
             td.m_key_image = tx_scan_info[o].ki;
             td.m_key_image_known = !m_watch_only && !m_multisig;
+            td.m_key_image_requested = false;
             td.m_key_image_partial = m_multisig;
             td.m_amount = amount;
             td.m_pk_index = pk_index - 1;
@@ -5465,7 +5467,7 @@ std::string wallet2::dump_tx_to_str(const std::vector<pending_tx> &ptx_vector) c
     txs.txes.push_back(get_construction_data_with_decrypted_short_payment_id(tx, m_account.get_device()));
   }
   
-  txs.transfers = m_transfers;
+  txs.transfers = export_outputs();
   // save as binary
   std::ostringstream oss;
   boost::archive::portable_binary_oarchive ar(oss);
@@ -7951,6 +7953,7 @@ void wallet2::light_wallet_get_unspent_outs()
     
     td.m_key_image = unspent_key_image;
     td.m_key_image_known = !m_watch_only && !m_multisig;
+    td.m_key_image_requested = false;
     td.m_key_image_partial = m_multisig;
     td.m_amount = o.amount;
     td.m_pk_index = 0;
@@ -9124,7 +9127,7 @@ void wallet2::cold_sign_tx(const std::vector<pending_tx>& ptx_vector, signed_tx_
   {
     txs.txes.push_back(get_construction_data_with_decrypted_short_payment_id(tx, m_account.get_device()));
   }
-  txs.transfers = m_transfers;
+  txs.transfers = std::make_pair(0, m_transfers);
 
   auto dev_cold = dynamic_cast<::hw::device_cold*>(&hwdev);
   CHECK_AND_ASSERT_THROW_MES(dev_cold, "Device does not implement cold signing interface");
@@ -9155,7 +9158,7 @@ uint64_t wallet2::cold_key_image_sync(uint64_t &spent, uint64_t &unspent) {
 
   dev_cold->ki_sync(&wallet_shim, m_transfers, ski);
 
-  return import_key_images(ski, spent, unspent);
+  return import_key_images(ski, 0, spent, unspent);
 }
 //----------------------------------------------------------------------------------------------------
 void wallet2::get_hard_fork_info(uint8_t version, uint64_t &earliest_height) const
@@ -10517,31 +10520,45 @@ crypto::public_key wallet2::get_tx_pub_key_from_received_outs(const tools::walle
 
 bool wallet2::export_key_images(const std::string &filename) const
 {
-  std::vector<std::pair<crypto::key_image, crypto::signature>> ski = export_key_images();
+  PERF_TIMER(export_key_images);
+  std::pair<size_t, std::vector<std::pair<crypto::key_image, crypto::signature>>> ski = export_key_images();
   std::string magic(KEY_IMAGE_EXPORT_FILE_MAGIC, strlen(KEY_IMAGE_EXPORT_FILE_MAGIC));
   const cryptonote::account_public_address &keys = get_account().get_keys().m_account_address;
+  const uint32_t offset = ski.first;
 
   std::string data;
+  data.reserve(4 + ski.second.size() * (sizeof(crypto::key_image) + sizeof(crypto::signature)) + 2 * sizeof(crypto::public_key));
+  data.resize(4);
+  data[0] = offset & 0xff;
+  data[1] = (offset >> 8) & 0xff;
+  data[2] = (offset >> 16) & 0xff;
+  data[3] = (offset >> 24) & 0xff;
   data += std::string((const char *)&keys.m_spend_public_key, sizeof(crypto::public_key));
   data += std::string((const char *)&keys.m_view_public_key, sizeof(crypto::public_key));
-  for (const auto &i: ski)
+  for (const auto &i: ski.second)
   {
     data += std::string((const char *)&i.first, sizeof(crypto::key_image));
     data += std::string((const char *)&i.second, sizeof(crypto::signature));
   }
 
   // encrypt data, keep magic plaintext
+  PERF_TIMER(export_key_images_encrypt);
   std::string ciphertext = encrypt_with_view_secret_key(data);
   return epee::file_io_utils::save_string_to_file(filename, magic + ciphertext);    
 }
 
 //----------------------------------------------------------------------------------------------------
-std::vector<std::pair<crypto::key_image, crypto::signature>> wallet2::export_key_images() const
+std::pair<size_t, std::vector<std::pair<crypto::key_image, crypto::signature>>> wallet2::export_key_images() const
 {
+  PERF_TIMER(export_key_images_raw);
   std::vector<std::pair<crypto::key_image, crypto::signature>> ski;
 
-  ski.reserve(m_transfers.size());
-  for (size_t n = 0; n < m_transfers.size(); ++n)
+  size_t offset = 0;
+  while (offset < m_transfers.size() && !m_transfers[offset].m_key_image_requested)
+    ++offset;
+
+  ski.reserve(m_transfers.size() - offset);
+  for (size_t n = offset; n < m_transfers.size(); ++n)
   {
     const transfer_details &td = m_transfers[n];
 
@@ -10585,11 +10602,12 @@ std::vector<std::pair<crypto::key_image, crypto::signature>> wallet2::export_key
 
     ski.push_back(std::make_pair(td.m_key_image, signature));
   }
-  return ski;
+  return std::make_pair(offset, ski);
 }
 
 uint64_t wallet2::import_key_images(const std::string &filename, uint64_t &spent, uint64_t &unspent)
 {
+  PERF_TIMER(import_key_images_fsu);
   std::string data;
   bool r = epee::file_io_utils::load_file_to_string(filename, data);
 
@@ -10603,6 +10621,7 @@ uint64_t wallet2::import_key_images(const std::string &filename, uint64_t &spent
 
   try
   {
+    PERF_TIMER(import_key_images_decrypt);
     data = decrypt_with_view_secret_key(std::string(data, magiclen));
   }
   catch (const std::exception &e)
@@ -10610,15 +10629,17 @@ uint64_t wallet2::import_key_images(const std::string &filename, uint64_t &spent
     THROW_WALLET_EXCEPTION(error::wallet_internal_error, std::string("Failed to decrypt ") + filename + ": " + e.what());
   }
 
-  const size_t headerlen = 2 * sizeof(crypto::public_key);
+  const size_t headerlen = 4 + 2 * sizeof(crypto::public_key);
   THROW_WALLET_EXCEPTION_IF(data.size() < headerlen, error::wallet_internal_error, std::string("Bad data size from file ") + filename);
-  const crypto::public_key &public_spend_key = *(const crypto::public_key*)&data[0];
-  const crypto::public_key &public_view_key = *(const crypto::public_key*)&data[sizeof(crypto::public_key)];
+  const uint32_t offset = (uint8_t)data[0] | (((uint8_t)data[1]) << 8) | (((uint8_t)data[2]) << 16) | (((uint8_t)data[3]) << 24);
+  const crypto::public_key &public_spend_key = *(const crypto::public_key*)&data[4];
+  const crypto::public_key &public_view_key = *(const crypto::public_key*)&data[4 + sizeof(crypto::public_key)];
   const cryptonote::account_public_address &keys = get_account().get_keys().m_account_address;
   if (public_spend_key != keys.m_spend_public_key || public_view_key != keys.m_view_public_key)
   {
     THROW_WALLET_EXCEPTION(error::wallet_internal_error, std::string( "Key images from ") + filename + " are for a different account");
   }
+  THROW_WALLET_EXCEPTION_IF(offset > m_transfers.size(), error::wallet_internal_error, "Offset larger than known outputs");
 
   const size_t record_size = sizeof(crypto::key_image) + sizeof(crypto::signature);
   THROW_WALLET_EXCEPTION_IF((data.size() - headerlen) % record_size,
@@ -10635,28 +10656,33 @@ uint64_t wallet2::import_key_images(const std::string &filename, uint64_t &spent
     ski.push_back(std::make_pair(key_image, signature));
   }
   
-  return import_key_images(ski, spent, unspent);    
+  return import_key_images(ski, offset, spent, unspent);
 }
 
 //----------------------------------------------------------------------------------------------------
-uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_image, crypto::signature>> &signed_key_images, uint64_t &spent, uint64_t &unspent, bool check_spent)
+uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_image, crypto::signature>> &signed_key_images, size_t offset, uint64_t &spent, uint64_t &unspent, bool check_spent)
 {
+  PERF_TIMER(import_key_images_lots);
   COMMAND_RPC_IS_KEY_IMAGE_SPENT::request req = AUTO_VAL_INIT(req);
   COMMAND_RPC_IS_KEY_IMAGE_SPENT::response daemon_resp = AUTO_VAL_INIT(daemon_resp);
 
-  THROW_WALLET_EXCEPTION_IF(signed_key_images.size() > m_transfers.size(), error::wallet_internal_error,
+  THROW_WALLET_EXCEPTION_IF(offset > m_transfers.size(), error::wallet_internal_error, "Offset larger than known outputs");
+  THROW_WALLET_EXCEPTION_IF(signed_key_images.size() > m_transfers.size() - offset, error::wallet_internal_error,
       "The blockchain is out of date compared to the signed key images");
 
-  if (signed_key_images.empty())
+  if (signed_key_images.empty() && offset == 0)
   {
     spent = 0;
     unspent = 0;
     return 0;
   }
 
+  req.key_images.reserve(signed_key_images.size());
+
+  PERF_TIMER_START(import_key_images_A);
   for (size_t n = 0; n < signed_key_images.size(); ++n)
   {
-    const transfer_details &td = m_transfers[n];
+    const transfer_details &td = m_transfers[n + offset];
     const crypto::key_image &key_image = signed_key_images[n].first;
     const crypto::signature &signature = signed_key_images[n].second;
 
@@ -10667,30 +10693,37 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
     const cryptonote::txout_to_key &o = boost::get<cryptonote::txout_to_key>(out.target);
     const crypto::public_key pkey = o.key;
 
-    std::vector<const crypto::public_key*> pkeys;
-    pkeys.push_back(&pkey);
-    THROW_WALLET_EXCEPTION_IF(!(rct::scalarmultKey(rct::ki2rct(key_image), rct::curveOrder()) == rct::identity()),
-        error::wallet_internal_error, "Key image out of validity domain: input " + boost::lexical_cast<std::string>(n) + "/"
-        + boost::lexical_cast<std::string>(signed_key_images.size()) + ", key image " + epee::string_tools::pod_to_hex(key_image));
-
-    THROW_WALLET_EXCEPTION_IF(!crypto::check_ring_signature((const crypto::hash&)key_image, key_image, pkeys, &signature),
-        error::signature_check_failed, boost::lexical_cast<std::string>(n) + "/"
-        + boost::lexical_cast<std::string>(signed_key_images.size()) + ", key image " + epee::string_tools::pod_to_hex(key_image)
-        + ", signature " + epee::string_tools::pod_to_hex(signature) + ", pubkey " + epee::string_tools::pod_to_hex(*pkeys[0]));
+    if (!td.m_key_image_known || !(key_image == td.m_key_image))
+    {
+      std::vector<const crypto::public_key*> pkeys;
+      pkeys.push_back(&pkey);
+      THROW_WALLET_EXCEPTION_IF(!(rct::scalarmultKey(rct::ki2rct(key_image), rct::curveOrder()) == rct::identity()),
+          error::wallet_internal_error, "Key image out of validity domain: input " + boost::lexical_cast<std::string>(n + offset) + "/"
+          + boost::lexical_cast<std::string>(signed_key_images.size()) + ", key image " + epee::string_tools::pod_to_hex(key_image));
 
+      THROW_WALLET_EXCEPTION_IF(!crypto::check_ring_signature((const crypto::hash&)key_image, key_image, pkeys, &signature),
+          error::signature_check_failed, boost::lexical_cast<std::string>(n + offset) + "/"
+          + boost::lexical_cast<std::string>(signed_key_images.size()) + ", key image " + epee::string_tools::pod_to_hex(key_image)
+          + ", signature " + epee::string_tools::pod_to_hex(signature) + ", pubkey " + epee::string_tools::pod_to_hex(*pkeys[0]));
+    }
     req.key_images.push_back(epee::string_tools::pod_to_hex(key_image));
   }
+  PERF_TIMER_STOP(import_key_images_A);
 
+  PERF_TIMER_START(import_key_images_B);
   for (size_t n = 0; n < signed_key_images.size(); ++n)
   {
-    m_transfers[n].m_key_image = signed_key_images[n].first;
-    m_key_images[m_transfers[n].m_key_image] = n;
-    m_transfers[n].m_key_image_known = true;
-    m_transfers[n].m_key_image_partial = false;
+    m_transfers[n + offset].m_key_image = signed_key_images[n].first;
+    m_key_images[m_transfers[n + offset].m_key_image] = n + offset;
+    m_transfers[n + offset].m_key_image_known = true;
+    m_transfers[n + offset].m_key_image_requested = false;
+    m_transfers[n + offset].m_key_image_partial = false;
   }
+  PERF_TIMER_STOP(import_key_images_B);
 
   if(check_spent)
   {
+    PERF_TIMER(import_key_images_RPC);
     m_daemon_rpc_mutex.lock();
     bool r = epee::net_utils::invoke_http_json("/is_key_image_spent", req, daemon_resp, m_http_client, rpc_timeout);
     m_daemon_rpc_mutex.unlock();
@@ -10702,7 +10735,7 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
       std::to_string(daemon_resp.spent_status.size()) + ", expected " +  std::to_string(signed_key_images.size()));
     for (size_t n = 0; n < daemon_resp.spent_status.size(); ++n)
     {
-      transfer_details &td = m_transfers[n];
+      transfer_details &td = m_transfers[n + offset];
       td.m_spent = daemon_resp.spent_status[n] != COMMAND_RPC_IS_KEY_IMAGE_SPENT::UNSPENT;
     }
   }
@@ -10713,6 +10746,7 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
                                                   // was created by sweep_all, so we can't know the spent height and other detailed info.
   std::unordered_map<crypto::key_image, crypto::hash> spent_key_images;
 
+  PERF_TIMER_START(import_key_images_C);
   for (const transfer_details &td: m_transfers)
   {
     for (const cryptonote::txin_v& in : td.m_tx.vin)
@@ -10721,10 +10755,12 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
         spent_key_images.insert(std::make_pair(boost::get<cryptonote::txin_to_key>(in).k_image, td.m_txid));
     }
   }
+  PERF_TIMER_STOP(import_key_images_C);
 
+  PERF_TIMER_START(import_key_images_D);
   for(size_t i = 0; i < signed_key_images.size(); ++i)
   {
-    transfer_details &td = m_transfers[i];
+    const transfer_details &td = m_transfers[i + offset];
     uint64_t amount = td.amount();
     if (td.m_spent)
       spent += amount;
@@ -10742,6 +10778,8 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
         spent_txids.insert(skii->second);
     }
   }
+  PERF_TIMER_STOP(import_key_images_D);
+
   MDEBUG("Total: " << print_money(spent) << " spent, " << print_money(unspent) << " unspent");
 
   if (check_spent)
@@ -10751,8 +10789,12 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
     COMMAND_RPC_GET_TRANSACTIONS::response gettxs_res;
     gettxs_req.decode_as_json = false;
     gettxs_req.prune = false;
+    gettxs_req.txs_hashes.reserve(spent_txids.size());
     for (const crypto::hash& spent_txid : spent_txids)
       gettxs_req.txs_hashes.push_back(epee::string_tools::pod_to_hex(spent_txid));
+
+
+    PERF_TIMER_START(import_key_images_E);
     m_daemon_rpc_mutex.lock();
     bool r = epee::net_utils::invoke_http_json("/gettransactions", gettxs_req, gettxs_res, m_http_client, rpc_timeout);
     m_daemon_rpc_mutex.unlock();
@@ -10760,8 +10802,10 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
     THROW_WALLET_EXCEPTION_IF(gettxs_res.status == CORE_RPC_STATUS_BUSY, error::daemon_busy, "gettransactions");
     THROW_WALLET_EXCEPTION_IF(gettxs_res.txs.size() != spent_txids.size(), error::wallet_internal_error,
       "daemon returned wrong response for gettransactions, wrong count = " + std::to_string(gettxs_res.txs.size()) + ", expected " + std::to_string(spent_txids.size()));
+    PERF_TIMER_STOP(import_key_images_E);
 
     // process each outgoing tx
+    PERF_TIMER_START(import_key_images_F);
     auto spent_txid = spent_txids.begin();
     hw::device &hwdev =  m_account.get_device();
     for (const COMMAND_RPC_GET_TRANSACTIONS::entry& e : gettxs_res.txs)
@@ -10857,7 +10901,9 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
 
       ++spent_txid;
     }
+    PERF_TIMER_STOP(import_key_images_F);
 
+    PERF_TIMER_START(import_key_images_G);
     for (size_t n : swept_transfers)
     {
       const transfer_details& td = m_transfers[n];
@@ -10868,6 +10914,7 @@ uint64_t wallet2::import_key_images(const std::vector<std::pair<crypto::key_imag
       const crypto::hash &spent_txid = crypto::null_hash; // spent txid is unknown
       m_confirmed_txs.insert(std::make_pair(spent_txid, pd));
     }
+    PERF_TIMER_STOP(import_key_images_G);
   }
 
   return m_transfers[signed_key_images.size() - 1].m_block_height;
@@ -10888,6 +10935,7 @@ bool wallet2::import_key_images(std::vector<crypto::key_image> key_images)
     td.m_key_image = key_images[i];
     m_key_images[m_transfers[i].m_key_image] = i;
     td.m_key_image_known = true;
+    td.m_key_image_requested = false;
     td.m_key_image_partial = false;
     m_pub_keys[m_transfers[i].get_public_key()] = i;
   }
@@ -10953,50 +11001,86 @@ void wallet2::import_blockchain(const std::tuple<size_t, crypto::hash, std::vect
   m_last_block_reward = cryptonote::get_outs_money_amount(genesis.miner_tx);
 }
 //----------------------------------------------------------------------------------------------------
-std::vector<tools::wallet2::transfer_details> wallet2::export_outputs() const
+std::pair<size_t, std::vector<tools::wallet2::transfer_details>> wallet2::export_outputs() const
 {
+  PERF_TIMER(export_outputs);
   std::vector<tools::wallet2::transfer_details> outs;
 
-  outs.reserve(m_transfers.size());
-  for (size_t n = 0; n < m_transfers.size(); ++n)
+  size_t offset = 0;
+  while (offset < m_transfers.size() && m_transfers[offset].m_key_image_known)
+    ++offset;
+
+  outs.reserve(m_transfers.size() - offset);
+  for (size_t n = offset; n < m_transfers.size(); ++n)
   {
     const transfer_details &td = m_transfers[n];
 
     outs.push_back(td);
   }
 
-  return outs;
+  return std::make_pair(offset, outs);
 }
 //----------------------------------------------------------------------------------------------------
 std::string wallet2::export_outputs_to_str() const
 {
-  std::vector<tools::wallet2::transfer_details> outs = export_outputs();
+  PERF_TIMER(export_outputs_to_str);
 
   std::stringstream oss;
   boost::archive::portable_binary_oarchive ar(oss);
-  ar << outs;
+  ar << export_outputs();
 
   std::string magic(OUTPUT_EXPORT_FILE_MAGIC, strlen(OUTPUT_EXPORT_FILE_MAGIC));
   const cryptonote::account_public_address &keys = get_account().get_keys().m_account_address;
   std::string header;
   header += std::string((const char *)&keys.m_spend_public_key, sizeof(crypto::public_key));
   header += std::string((const char *)&keys.m_view_public_key, sizeof(crypto::public_key));
+  PERF_TIMER(export_outputs_encryption);
   std::string ciphertext = encrypt_with_view_secret_key(header + oss.str());
   return magic + ciphertext;
 }
 //----------------------------------------------------------------------------------------------------
-size_t wallet2::import_outputs(const std::vector<tools::wallet2::transfer_details> &outputs)
+size_t wallet2::import_outputs(const std::pair<size_t, std::vector<tools::wallet2::transfer_details>> &outputs)
 {
-  m_transfers.clear();
-  m_transfers.reserve(outputs.size());
-  for (size_t i = 0; i < outputs.size(); ++i)
+  PERF_TIMER(import_outputs);
+
+  THROW_WALLET_EXCEPTION_IF(outputs.first > m_transfers.size(), error::wallet_internal_error,
+      "Imported outputs omit more outputs that we know of");
+
+  const size_t offset = outputs.first;
+  const size_t original_size = m_transfers.size();
+  m_transfers.resize(offset + outputs.second.size());
+  for (size_t i = 0; i < offset; ++i)
+    m_transfers[i].m_key_image_requested = false;
+  for (size_t i = 0; i < outputs.second.size(); ++i)
   {
-    transfer_details td = outputs[i];
+    transfer_details td = outputs.second[i];
+
+    // skip those we've already imported, or which have different data
+    if (i + offset < original_size)
+    {
+      // compare the data used to create the key image below
+      const transfer_details &org_td = m_transfers[i + offset];
+      if (!org_td.m_key_image_known)
+        goto process;
+#define CMPF(f) if (!(td.f == org_td.f)) goto process
+      CMPF(m_txid);
+      CMPF(m_key_image);
+      CMPF(m_internal_output_index);
+#undef CMPF
+      if (!(get_transaction_prefix_hash(td.m_tx) == get_transaction_prefix_hash(org_td.m_tx)))
+        goto process;
+
+      // copy anyway, since the comparison does not include ancillary fields which may have changed
+      m_transfers[i + offset] = std::move(td);
+      continue;
+    }
+
+process:
 
     // the hot wallet wouldn't have known about key images (except if we already exported them)
     cryptonote::keypair in_ephemeral;
 
-    THROW_WALLET_EXCEPTION_IF(td.m_tx.vout.empty(), error::wallet_internal_error, "tx with no outputs at index " + boost::lexical_cast<std::string>(i));
+    THROW_WALLET_EXCEPTION_IF(td.m_tx.vout.empty(), error::wallet_internal_error, "tx with no outputs at index " + boost::lexical_cast<std::string>(i + offset));
     crypto::public_key tx_pub_key = get_tx_pub_key_from_received_outs(td);
     const std::vector<crypto::public_key> additional_tx_pub_keys = get_additional_tx_pub_keys_from_extra(td.m_tx);
 
@@ -11007,13 +11091,14 @@ size_t wallet2::import_outputs(const std::vector<tools::wallet2::transfer_detail
     THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "Failed to generate key image");
     expand_subaddresses(td.m_subaddr_index);
     td.m_key_image_known = true;
+    td.m_key_image_requested = true;
     td.m_key_image_partial = false;
     THROW_WALLET_EXCEPTION_IF(in_ephemeral.pub != out_key,
-        error::wallet_internal_error, "key_image generated ephemeral public key not matched with output_key at index " + boost::lexical_cast<std::string>(i));
+        error::wallet_internal_error, "key_image generated ephemeral public key not matched with output_key at index " + boost::lexical_cast<std::string>(i + offset));
 
-    m_key_images[td.m_key_image] = m_transfers.size();
-    m_pub_keys[td.get_public_key()] = m_transfers.size();
-    m_transfers.push_back(std::move(td));
+    m_key_images[td.m_key_image] = i + offset;
+    m_pub_keys[td.get_public_key()] = i + offset;
+    m_transfers[i + offset] = std::move(td);
   }
 
   return m_transfers.size();
@@ -11021,6 +11106,7 @@ size_t wallet2::import_outputs(const std::vector<tools::wallet2::transfer_detail
 //----------------------------------------------------------------------------------------------------
 size_t wallet2::import_outputs_from_str(const std::string &outputs_st)
 {
+  PERF_TIMER(import_outputs_from_str);
   std::string data = outputs_st;
   const size_t magiclen = strlen(OUTPUT_EXPORT_FILE_MAGIC);
   if (data.size() < magiclen || memcmp(data.data(), OUTPUT_EXPORT_FILE_MAGIC, magiclen))
@@ -11030,6 +11116,7 @@ size_t wallet2::import_outputs_from_str(const std::string &outputs_st)
 
   try
   {
+    PERF_TIMER(import_outputs_decrypt);
     data = decrypt_with_view_secret_key(std::string(data, magiclen));
   }
   catch (const std::exception &e)
@@ -11056,7 +11143,7 @@ size_t wallet2::import_outputs_from_str(const std::string &outputs_st)
     std::string body(data, headerlen);
     std::stringstream iss;
     iss << body;
-    std::vector<tools::wallet2::transfer_details> outputs;
+    std::pair<size_t, std::vector<tools::wallet2::transfer_details>> outputs;
     try
     {
       boost::archive::portable_binary_iarchive ar(iss);
@@ -11248,6 +11335,7 @@ void wallet2::update_multisig_rescan_info(const std::vector<std::vector<rct::key
   m_key_images.erase(td.m_key_image);
   td.m_key_image = get_multisig_composite_key_image(n);
   td.m_key_image_known = true;
+  td.m_key_image_requested = false;
   td.m_key_image_partial = false;
   td.m_multisig_k = multisig_k[n];
   m_key_images[td.m_key_image] = n;
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 7d78a3fee..964724d17 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -247,6 +247,7 @@ namespace tools
       uint64_t m_amount;
       bool m_rct;
       bool m_key_image_known;
+      bool m_key_image_requested;
       size_t m_pk_index;
       cryptonote::subaddress_index m_subaddr_index;
       bool m_key_image_partial;
@@ -270,6 +271,7 @@ namespace tools
         FIELD(m_amount)
         FIELD(m_rct)
         FIELD(m_key_image_known)
+        FIELD(m_key_image_requested)
         FIELD(m_pk_index)
         FIELD(m_subaddr_index)
         FIELD(m_key_image_partial)
@@ -417,7 +419,7 @@ namespace tools
     struct unsigned_tx_set
     {
       std::vector<tx_construction_data> txes;
-      wallet2::transfer_container transfers;
+      std::pair<size_t, wallet2::transfer_container> transfers;
     };
 
     struct signed_tx_set
@@ -1071,9 +1073,9 @@ namespace tools
     bool verify_with_public_key(const std::string &data, const crypto::public_key &public_key, const std::string &signature) const;
 
     // Import/Export wallet data
-    std::vector<tools::wallet2::transfer_details> export_outputs() const;
+    std::pair<size_t, std::vector<tools::wallet2::transfer_details>> export_outputs() const;
     std::string export_outputs_to_str() const;
-    size_t import_outputs(const std::vector<tools::wallet2::transfer_details> &outputs);
+    size_t import_outputs(const std::pair<size_t, std::vector<tools::wallet2::transfer_details>> &outputs);
     size_t import_outputs_from_str(const std::string &outputs_st);
     payment_container export_payments() const;
     void import_payments(const payment_container &payments);
@@ -1081,8 +1083,8 @@ namespace tools
     std::tuple<size_t, crypto::hash, std::vector<crypto::hash>> export_blockchain() const;
     void import_blockchain(const std::tuple<size_t, crypto::hash, std::vector<crypto::hash>> &bc);
     bool export_key_images(const std::string &filename) const;
-    std::vector<std::pair<crypto::key_image, crypto::signature>> export_key_images() const;
-    uint64_t import_key_images(const std::vector<std::pair<crypto::key_image, crypto::signature>> &signed_key_images, uint64_t &spent, uint64_t &unspent, bool check_spent = true);
+    std::pair<size_t, std::vector<std::pair<crypto::key_image, crypto::signature>>> export_key_images() const;
+    uint64_t import_key_images(const std::vector<std::pair<crypto::key_image, crypto::signature>> &signed_key_images, size_t offset, uint64_t &spent, uint64_t &unspent, bool check_spent = true);
     uint64_t import_key_images(const std::string &filename, uint64_t &spent, uint64_t &unspent);
     bool import_key_images(std::vector<crypto::key_image> key_images);
     crypto::public_key get_tx_pub_key_from_received_outs(const tools::wallet2::transfer_details &td) const;
@@ -1396,7 +1398,7 @@ namespace tools
   };
 }
 BOOST_CLASS_VERSION(tools::wallet2, 26)
-BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 9)
+BOOST_CLASS_VERSION(tools::wallet2::transfer_details, 10)
 BOOST_CLASS_VERSION(tools::wallet2::multisig_info, 1)
 BOOST_CLASS_VERSION(tools::wallet2::multisig_info::LR, 0)
 BOOST_CLASS_VERSION(tools::wallet2::multisig_tx_set, 1)
@@ -1454,6 +1456,10 @@ namespace boost
           x.m_multisig_k.clear();
           x.m_multisig_info.clear();
         }
+        if (ver < 10)
+        {
+          x.m_key_image_requested = false;
+        }
     }
 
     template <class Archive>
@@ -1535,6 +1541,12 @@ namespace boost
       a & x.m_multisig_info;
       a & x.m_multisig_k;
       a & x.m_key_image_partial;
+      if (ver < 10)
+      {
+        initialize_transfer_details(a, x, ver);
+        return;
+      }
+      a & x.m_key_image_requested;
     }
 
     template <class Archive>
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 5e6100dfd..eabdd9a6a 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -2460,12 +2460,13 @@ namespace tools
     if (!m_wallet) return not_open(er);
     try
     {
-      std::vector<std::pair<crypto::key_image, crypto::signature>> ski = m_wallet->export_key_images();
-      res.signed_key_images.resize(ski.size());
-      for (size_t n = 0; n < ski.size(); ++n)
+      std::pair<size_t, std::vector<std::pair<crypto::key_image, crypto::signature>>> ski = m_wallet->export_key_images();
+      res.offset = ski.first;
+      res.signed_key_images.resize(ski.second.size());
+      for (size_t n = 0; n < ski.second.size(); ++n)
       {
-         res.signed_key_images[n].key_image = epee::string_tools::pod_to_hex(ski[n].first);
-         res.signed_key_images[n].signature = epee::string_tools::pod_to_hex(ski[n].second);
+         res.signed_key_images[n].key_image = epee::string_tools::pod_to_hex(ski.second[n].first);
+         res.signed_key_images[n].signature = epee::string_tools::pod_to_hex(ski.second[n].second);
       }
     }
 
@@ -2518,7 +2519,7 @@ namespace tools
         ski[n].second = *reinterpret_cast<const crypto::signature*>(bd.data());
       }
       uint64_t spent = 0, unspent = 0;
-      uint64_t height = m_wallet->import_key_images(ski, spent, unspent);
+      uint64_t height = m_wallet->import_key_images(ski, req.offset, spent, unspent);
       res.spent = spent;
       res.unspent = unspent;
       res.height = height;
diff --git a/src/wallet/wallet_rpc_server_commands_defs.h b/src/wallet/wallet_rpc_server_commands_defs.h
index 924f3a0f1..026b75a9e 100644
--- a/src/wallet/wallet_rpc_server_commands_defs.h
+++ b/src/wallet/wallet_rpc_server_commands_defs.h
@@ -47,7 +47,7 @@
 // advance which version they will stop working with
 // Don't go over 32767 for any of these
 #define WALLET_RPC_VERSION_MAJOR 1
-#define WALLET_RPC_VERSION_MINOR 5
+#define WALLET_RPC_VERSION_MINOR 6
 #define MAKE_WALLET_RPC_VERSION(major,minor) (((major)<<16)|(minor))
 #define WALLET_RPC_VERSION MAKE_WALLET_RPC_VERSION(WALLET_RPC_VERSION_MAJOR, WALLET_RPC_VERSION_MINOR)
 namespace tools
@@ -1579,9 +1579,11 @@ namespace wallet_rpc
 
     struct response
     {
+      uint32_t offset;
       std::vector<signed_key_image> signed_key_images;
 
       BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE(offset);
         KV_SERIALIZE(signed_key_images);
       END_KV_SERIALIZE_MAP()
     };
@@ -1602,9 +1604,11 @@ namespace wallet_rpc
 
     struct request
     {
+      uint32_t offset;
       std::vector<signed_key_image> signed_key_images;
 
       BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE_OPT(offset, (uint32_t)0);
         KV_SERIALIZE(signed_key_images);
       END_KV_SERIALIZE_MAP()
     };
diff --git a/tests/data/fuzz/cold-outputs/OUTPUTS2 b/tests/data/fuzz/cold-outputs/OUTPUTS2
index 907bcdb91..33cf39024 100644
--- a/tests/data/fuzz/cold-outputs/OUTPUTS2
+++ b/tests/data/fuzz/cold-outputs/OUTPUTS2
diff --git a/tests/fuzz/cold-outputs.cpp b/tests/fuzz/cold-outputs.cpp
index 488a3b931..29b3ed267 100644
--- a/tests/fuzz/cold-outputs.cpp
+++ b/tests/fuzz/cold-outputs.cpp
@@ -77,7 +77,7 @@ int ColdOutputsFuzzer::run(const std::string &filename)
   s = std::string("\x01\x16serialization::archive") + s;
   try
   {
-    std::vector<tools::wallet2::transfer_details> outputs;
+    std::pair<size_t, std::vector<tools::wallet2::transfer_details>> outputs;
     std::stringstream iss;
     iss << s;
     boost::archive::portable_binary_iarchive ar(iss);
diff --git a/tests/unit_tests/serialization.cpp b/tests/unit_tests/serialization.cpp
index 2f7b5aac7..b4517af2f 100644
--- a/tests/unit_tests/serialization.cpp
+++ b/tests/unit_tests/serialization.cpp
@@ -908,6 +908,17 @@ TEST(Serialization, portability_outputs)
   ASSERT_TRUE(td2.m_pk_index == 0);
 }
 
+struct unsigned_tx_set
+{
+  std::vector<tools::wallet2::tx_construction_data> txes;
+  tools::wallet2::transfer_container transfers;
+};
+template <class Archive>
+inline void serialize(Archive &a, unsigned_tx_set &x, const boost::serialization::version_type ver)
+{
+  a & x.txes;
+  a & x.transfers;
+}
 #define UNSIGNED_TX_PREFIX "Monero unsigned tx set\003"
 TEST(Serialization, portability_unsigned_tx)
 {
@@ -918,7 +929,7 @@ TEST(Serialization, portability_unsigned_tx)
   ASSERT_TRUE(r);
   const size_t magiclen = strlen(UNSIGNED_TX_PREFIX);
   ASSERT_FALSE(strncmp(s.c_str(), UNSIGNED_TX_PREFIX, magiclen));
-  tools::wallet2::unsigned_tx_set exported_txs;
+  unsigned_tx_set exported_txs;
   s = s.substr(magiclen);
   r = false;
   try