wallet: option to merge destinations

With the change from the original transfer method to the new
algorithm, payments to the same destination were merged. It
seemed like a good idea, optimizing space. However, it is a
useful tool for people who want to split large outputs into
several smaller ones (ie, service providers making frequent
payments, and who do not like a large chunk of their balance
being locked for 10 blocks after each payment).

Default to off, which is a change from the previous behavior.

4 files changed, 42 insertions, 7 deletions

diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index 5518138b1..f5a469af4 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -651,6 +651,17 @@ bool simple_wallet::set_min_output_value(const std::vector<std::string> &args/*
   return true;
 }
 
+bool simple_wallet::set_merge_destinations(const std::vector<std::string> &args/* = std::vector<std::string>()*/)
+{
+  const auto pwd_container = get_and_verify_password();
+  if (pwd_container)
+  {
+    m_wallet->merge_destinations(is_it_true(args[1]));
+    m_wallet->rewrite(m_wallet_file, pwd_container->password());
+  }
+  return true;
+}
+
 bool simple_wallet::help(const std::vector<std::string> &args/* = std::vector<std::string>()*/)
 {
   success_msg_writer() << get_commands_str();
@@ -690,7 +701,7 @@ simple_wallet::simple_wallet()
   m_cmd_binder.set_handler("viewkey", boost::bind(&simple_wallet::viewkey, this, _1), tr("Display private view key"));
   m_cmd_binder.set_handler("spendkey", boost::bind(&simple_wallet::spendkey, this, _1), tr("Display private spend key"));
   m_cmd_binder.set_handler("seed", boost::bind(&simple_wallet::seed, this, _1), tr("Display Electrum-style mnemonic seed"));
-  m_cmd_binder.set_handler("set", boost::bind(&simple_wallet::set_variable, this, _1), tr("Available options: seed language - set wallet seed language; always-confirm-transfers <1|0> - whether to confirm unsplit txes; print-ring-members <1|0> - whether to print detailed information about ring members during confirmation; store-tx-info <1|0> - whether to store outgoing tx info (destination address, payment ID, tx secret key) for future reference; default-mixin <n> - set default mixin (default is 4); auto-refresh <1|0> - whether to automatically sync new blocks from the daemon; refresh-type <full|optimize-coinbase|no-coinbase|default> - set wallet refresh behaviour; priority [0|1|2|3|4] - default/unimportant/normal/elevated/priority fee; confirm-missing-payment-id <1|0>; ask-password <1|0>; unit <monero|millinero|micronero|nanonero|piconero> - set default monero (sub-)unit; min-output-count [n] - try to keep at least that many outputs of value at least min-output-value; min-output-value [n] - try to keep at least min-output-count outputs of at least that value"));
+  m_cmd_binder.set_handler("set", boost::bind(&simple_wallet::set_variable, this, _1), tr("Available options: seed language - set wallet seed language; always-confirm-transfers <1|0> - whether to confirm unsplit txes; print-ring-members <1|0> - whether to print detailed information about ring members during confirmation; store-tx-info <1|0> - whether to store outgoing tx info (destination address, payment ID, tx secret key) for future reference; default-mixin <n> - set default mixin (default is 4); auto-refresh <1|0> - whether to automatically sync new blocks from the daemon; refresh-type <full|optimize-coinbase|no-coinbase|default> - set wallet refresh behaviour; priority [0|1|2|3|4] - default/unimportant/normal/elevated/priority fee; confirm-missing-payment-id <1|0>; ask-password <1|0>; unit <monero|millinero|micronero|nanonero|piconero> - set default monero (sub-)unit; min-output-count [n] - try to keep at least that many outputs of value at least min-output-value; min-output-value [n] - try to keep at least min-output-count outputs of at least that value - merge-destinations <1|0> - whether to merge multiple payments to the same destination address"));
   m_cmd_binder.set_handler("rescan_spent", boost::bind(&simple_wallet::rescan_spent, this, _1), tr("Rescan blockchain for spent outputs"));
   m_cmd_binder.set_handler("get_tx_key", boost::bind(&simple_wallet::get_tx_key, this, _1), tr("Get transaction key (r) for a given <txid>"));
   m_cmd_binder.set_handler("check_tx_key", boost::bind(&simple_wallet::check_tx_key, this, _1), tr("Check amount going to <address> in <txid>"));
@@ -728,6 +739,7 @@ bool simple_wallet::set_variable(const std::vector<std::string> &args)
     success_msg_writer() << "unit = " << cryptonote::get_unit(m_wallet->get_default_decimal_point());
     success_msg_writer() << "min-outputs-count = " << m_wallet->get_min_output_count();
     success_msg_writer() << "min-outputs-value = " << cryptonote::print_money(m_wallet->get_min_output_value());
+    success_msg_writer() << "merge-destinations = " << m_wallet->merge_destinations();
     return true;
   }
   else
@@ -902,6 +914,19 @@ bool simple_wallet::set_variable(const std::vector<std::string> &args)
         return true;
       }
     }
+    else if (args[0] == "merge-destinations")
+    {
+      if (args.size() <= 1)
+      {
+        fail_msg_writer() << tr("set merge-destinations: needs an argument (0 or 1)");
+        return true;
+      }
+      else
+      {
+        set_merge_destinations(args);
+        return true;
+      }
+    }
   }
   fail_msg_writer() << tr("set: unrecognized argument(s)");
   return true;
diff --git a/src/simplewallet/simplewallet.h b/src/simplewallet/simplewallet.h
index bb668b123..14722e942 100644
--- a/src/simplewallet/simplewallet.h
+++ b/src/simplewallet/simplewallet.h
@@ -119,6 +119,7 @@ namespace cryptonote
     bool set_unit(const std::vector<std::string> &args = std::vector<std::string>());
     bool set_min_output_count(const std::vector<std::string> &args = std::vector<std::string>());
     bool set_min_output_value(const std::vector<std::string> &args = std::vector<std::string>());
+    bool set_merge_destinations(const std::vector<std::string> &args = std::vector<std::string>());
     bool help(const std::vector<std::string> &args = std::vector<std::string>());
     bool start_mining(const std::vector<std::string> &args);
     bool stop_mining(const std::vector<std::string> &args);
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 09df30e66..ed31f34a4 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -1927,6 +1927,9 @@ bool wallet2::store_keys(const std::string& keys_file_name, const std::string& p
   value2.SetInt(cryptonote::get_default_decimal_point());
   json.AddMember("default_decimal_point", value2, json.GetAllocator());
 
+  value2.SetInt(m_merge_destinations ? 1 :0);
+  json.AddMember("merge_destinations", value2, json.GetAllocator());
+
   // Serialize the JSON object
   rapidjson::StringBuffer buffer;
   rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
@@ -1997,6 +2000,7 @@ bool wallet2::load_keys(const std::string& keys_file_name, const std::string& pa
     m_ask_password = true;
     m_min_output_count = 0;
     m_min_output_value = 0;
+    m_merge_destinations = false;
   }
   else
   {
@@ -2065,6 +2069,8 @@ bool wallet2::load_keys(const std::string& keys_file_name, const std::string& pa
     m_min_output_count = field_min_output_count;
     GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, min_output_value, uint64_t, Uint64, false, 0);
     m_min_output_value = field_min_output_value;
+    GET_FIELD_FROM_JSON_RETURN_ON_ERROR(json, merge_destinations, int, Int, false, false);
+    m_merge_destinations = field_merge_destinations;
   }
 
   const cryptonote::account_keys& keys = m_account.get_keys();
@@ -4238,10 +4244,10 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
     pending_tx ptx;
     size_t bytes;
 
-    void add(const account_public_address &addr, uint64_t amount) {
+    void add(const account_public_address &addr, uint64_t amount, bool merge_destinations) {
       std::vector<cryptonote::tx_destination_entry>::iterator i;
       i = std::find_if(dsts.begin(), dsts.end(), [&](const cryptonote::tx_destination_entry &d) { return !memcmp (&d.addr, &addr, sizeof(addr)); });
-      if (i == dsts.end())
+      if (!merge_destinations || i == dsts.end())
         dsts.push_back(tx_destination_entry(amount,addr));
       else
         i->amount += amount;
@@ -4408,7 +4414,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         // we can fully pay that destination
         LOG_PRINT_L2("We can fully pay " << get_account_address_as_str(m_testnet, dsts[0].addr) <<
           " for " << print_money(dsts[0].amount));
-        tx.add(dsts[0].addr, dsts[0].amount);
+        tx.add(dsts[0].addr, dsts[0].amount, m_merge_destinations);
         available_amount -= dsts[0].amount;
         dsts[0].amount = 0;
         pop_index(dsts, 0);
@@ -4418,7 +4424,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_2(std::vector<cryp
         // we can partially fill that destination
         LOG_PRINT_L2("We can partially pay " << get_account_address_as_str(m_testnet, dsts[0].addr) <<
           " for " << print_money(available_amount) << "/" << print_money(dsts[0].amount));
-        tx.add(dsts[0].addr, available_amount);
+        tx.add(dsts[0].addr, available_amount, m_merge_destinations);
         dsts[0].amount -= available_amount;
         available_amount = 0;
       }
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index d0d2cda3c..6d7bca2a5 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -105,7 +105,7 @@ namespace tools
     };
 
   private:
-    wallet2(const wallet2&) : m_run(true), m_callback(0), m_testnet(false), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
+    wallet2(const wallet2&) : m_run(true), m_callback(0), m_testnet(false), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_merge_destinations(false), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
 
   public:
     static const char* tr(const char* str);
@@ -126,7 +126,7 @@ namespace tools
     //! Uses stdin and stdout. Returns a wallet2 and password for wallet with no file if no errors.
     static std::pair<std::unique_ptr<wallet2>, password_container> make_new(const boost::program_options::variables_map& vm);
 
-    wallet2(bool testnet = false, bool restricted = false) : m_run(true), m_callback(0), m_testnet(testnet), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_restricted(restricted), is_old_file_format(false), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
+    wallet2(bool testnet = false, bool restricted = false) : m_run(true), m_callback(0), m_testnet(testnet), m_always_confirm_transfers(true), m_print_ring_members(false), m_store_tx_info(true), m_default_mixin(0), m_default_priority(0), m_refresh_type(RefreshOptimizeCoinbase), m_auto_refresh(true), m_refresh_from_block_height(0), m_confirm_missing_payment_id(true), m_ask_password(true), m_min_output_count(0), m_min_output_value(0), m_merge_destinations(false), m_restricted(restricted), is_old_file_format(false), m_node_rpc_proxy(m_http_client, m_daemon_rpc_mutex) {}
 
     struct transfer_details
     {
@@ -531,6 +531,8 @@ namespace tools
     uint32_t get_min_output_count() const { return m_min_output_count; }
     void set_min_output_value(uint64_t value) { m_min_output_value = value; }
     uint64_t get_min_output_value() const { return m_min_output_value; }
+    void merge_destinations(bool merge) { m_merge_destinations = merge; }
+    bool merge_destinations() const { return m_merge_destinations; }
 
     bool get_tx_key(const crypto::hash &txid, crypto::secret_key &tx_key) const;
 
@@ -689,6 +691,7 @@ namespace tools
     bool m_ask_password;
     uint32_t m_min_output_count;
     uint64_t m_min_output_value;
+    bool m_merge_destinations;
     NodeRPCProxy m_node_rpc_proxy;
     std::unordered_set<crypto::hash> m_scanned_pool_txs[2];
   };