wallet2, RPC: Optimize RPC calls for periodic refresh from 3 down to 1 call

9 files changed, 759 insertions, 205 deletions

diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index d8c782f78..0773dec7a 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -1739,6 +1739,11 @@ namespace cryptonote
     return true;
   }
   //-----------------------------------------------------------------------------------------------
+  bool core::get_pool_info(time_t start_time, bool include_sensitive_txes, std::vector<tx_memory_pool::tx_details>& added_txs, std::vector<crypto::hash>& removed_txs, bool& incremental) const
+  {
+    return m_mempool.get_pool_info(start_time, include_sensitive_txes, added_txs, removed_txs, incremental);
+  }
+  //-----------------------------------------------------------------------------------------------
   bool core::get_pool_transaction_stats(struct txpool_stats& stats, bool include_sensitive_data) const
   {
     m_mempool.get_transaction_stats(stats, include_sensitive_data);
diff --git a/src/cryptonote_core/cryptonote_core.h b/src/cryptonote_core/cryptonote_core.h
index 6dc513570..b0d99e1ce 100644
--- a/src/cryptonote_core/cryptonote_core.h
+++ b/src/cryptonote_core/cryptonote_core.h
@@ -510,6 +510,14 @@ namespace cryptonote
      bool get_pool_transaction_hashes(std::vector<crypto::hash>& txs, bool include_sensitive_txes = false) const;
 
      /**
+      * @copydoc tx_memory_pool::get_pool_info
+      * @param include_sensitive_txes include private transactions
+      *
+      * @note see tx_memory_pool::get_pool_info
+      */
+     bool get_pool_info(time_t start_time, bool include_sensitive_txes, std::vector<tx_memory_pool::tx_details>& added_txs, std::vector<crypto::hash>& removed_txs, bool& incremental) const;
+
+    /**
       * @copydoc tx_memory_pool::get_transactions
       * @param include_sensitive_txes include private transactions
       *
diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index 2a514ceae..243912768 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -133,6 +133,12 @@ namespace cryptonote
     // class code expects unsigned values throughout
     if (m_next_check < time_t(0))
       throw std::runtime_error{"Unexpected time_t (system clock) value"};
+
+    m_added_txs_start_time = (time_t)0;
+    m_removed_txs_start_time = (time_t)0;
+    // We don't set these to "now" already here as we don't know how long it takes from construction
+    // of the pool until it "goes to work". It's safer to set when the first actual txs enter the
+    // corresponding lists.
   }
   //---------------------------------------------------------------------------------
   bool tx_memory_pool::add_tx(transaction &tx, /*const crypto::hash& tx_prefix_hash,*/ const crypto::hash &id, const cryptonote::blobdata &blob, size_t tx_weight, tx_verification_context& tvc, relay_method tx_relay, bool relayed, uint8_t version)
@@ -281,7 +287,7 @@ namespace cryptonote
             return false;
 
           m_blockchain.add_txpool_tx(id, blob, meta);
-          m_txs_by_fee_and_receive_time.emplace(std::pair<double, std::time_t>(fee / (double)(tx_weight ? tx_weight : 1), receive_time), id);
+          add_tx_to_transient_lists(id, fee / (double)(tx_weight ? tx_weight : 1), receive_time);
           lock.commit();
         }
         catch (const std::exception &e)
@@ -352,7 +358,7 @@ namespace cryptonote
 
           m_blockchain.remove_txpool_tx(id);
           m_blockchain.add_txpool_tx(id, blob, meta);
-          m_txs_by_fee_and_receive_time.emplace(std::pair<double, std::time_t>(fee / (double)(tx_weight ? tx_weight : 1), receive_time), id);
+          add_tx_to_transient_lists(id, meta.fee / (double)(tx_weight ? tx_weight : 1), receive_time);
         }
         lock.commit();
       }
@@ -373,7 +379,7 @@ namespace cryptonote
 
     ++m_cookie;
 
-    MINFO("Transaction added to pool: txid " << id << " weight: " << tx_weight << " fee/byte: " << (fee / (double)(tx_weight ? tx_weight : 1)));
+    MINFO("Transaction added to pool: txid " << id << " weight: " << tx_weight << " fee/byte: " << (fee / (double)(tx_weight ? tx_weight : 1)) << ", count: " << m_added_txs_by_id.size());
 
     prune(m_txpool_max_weight);
 
@@ -464,7 +470,8 @@ namespace cryptonote
         reduce_txpool_weight(meta.weight);
         remove_transaction_keyimages(tx, txid);
         MINFO("Pruned tx " << txid << " from txpool: weight: " << meta.weight << ", fee/byte: " << it->first.first);
-        m_txs_by_fee_and_receive_time.erase(it--);
+        remove_tx_from_transient_lists(it, txid, !meta.matches(relay_category::broadcasted));
+        it--;
         changed = true;
       }
       catch (const std::exception &e)
@@ -546,8 +553,7 @@ namespace cryptonote
     CRITICAL_REGION_LOCAL(m_transactions_lock);
     CRITICAL_REGION_LOCAL1(m_blockchain);
 
-    auto sorted_it = find_tx_in_sorted_container(id);
-
+    bool sensitive = false;
     try
     {
       LockedTXN lock(m_blockchain.get_db());
@@ -578,6 +584,7 @@ namespace cryptonote
       do_not_relay = meta.do_not_relay;
       double_spend_seen = meta.double_spend_seen;
       pruned = meta.pruned;
+      sensitive = !meta.matches(relay_category::broadcasted);
 
       // remove first, in case this throws, so key images aren't removed
       m_blockchain.remove_txpool_tx(id);
@@ -591,8 +598,7 @@ namespace cryptonote
       return false;
     }
 
-    if (sorted_it != m_txs_by_fee_and_receive_time.end())
-      m_txs_by_fee_and_receive_time.erase(sorted_it);
+    remove_tx_from_transient_lists(find_tx_in_sorted_container(id), id, sensitive);
     ++m_cookie;
     return true;
   }
@@ -640,6 +646,7 @@ namespace cryptonote
       td.relayed = meta.relayed;
       td.do_not_relay = meta.do_not_relay;
       td.double_spend_seen = meta.double_spend_seen;
+      td.sensitive = !meta.matches(relay_category::broadcasted);
     }
     catch (const std::exception &e)
     {
@@ -710,15 +717,7 @@ namespace cryptonote
          (tx_age > CRYPTONOTE_MEMPOOL_TX_FROM_ALT_BLOCK_LIVETIME && meta.kept_by_block) )
       {
         LOG_PRINT_L1("Tx " << txid << " removed from tx pool due to outdated, age: " << tx_age );
-        auto sorted_it = find_tx_in_sorted_container(txid);
-        if (sorted_it == m_txs_by_fee_and_receive_time.end())
-        {
-          LOG_PRINT_L1("Removing tx " << txid << " from tx pool, but it was not found in the sorted txs container!");
-        }
-        else
-        {
-          m_txs_by_fee_and_receive_time.erase(sorted_it);
-        }
+        remove_tx_from_transient_lists(find_tx_in_sorted_container(txid), txid, !meta.matches(relay_category::broadcasted));
         m_timed_out_transactions.insert(txid);
         remove.push_back(std::make_pair(txid, meta.weight));
       }
@@ -872,9 +871,12 @@ namespace cryptonote
             meta.last_relayed_time = std::chrono::system_clock::to_time_t(now);
 
           m_blockchain.update_txpool_tx(hash, meta);
-
           // wait until db update succeeds to ensure tx is visible in the pool
           was_just_broadcasted = !already_broadcasted && meta.matches(relay_category::broadcasted);
+
+          if (was_just_broadcasted)
+            // Make sure the tx gets re-added with an updated time
+            add_tx_to_transient_lists(hash, meta.fee / (double)meta.weight, std::chrono::system_clock::to_time_t(now));
         }
       }
       catch (const std::exception &e)
@@ -927,6 +929,88 @@ namespace cryptonote
     }, false, category);
   }
   //------------------------------------------------------------------
+  bool tx_memory_pool::get_pool_info(time_t start_time, bool include_sensitive, std::vector<tx_details>& added_txs, std::vector<crypto::hash>& removed_txs, bool& incremental) const
+  {
+    CRITICAL_REGION_LOCAL(m_transactions_lock);
+    CRITICAL_REGION_LOCAL1(m_blockchain);
+
+    incremental = true;
+    if (start_time == (time_t)0)
+    {
+      // Giving no start time means give back whole pool
+      incremental = false;
+    }
+    else if ((m_added_txs_start_time != (time_t)0) && (m_removed_txs_start_time != (time_t)0))
+    {
+      if ((start_time <= m_added_txs_start_time) || (start_time <= m_removed_txs_start_time))
+      {
+        // If either of the two lists do not go back far enough it's not possible to
+        // deliver incremental pool info
+        incremental = false;
+      }
+      // The check uses "<=": We cannot be sure to have ALL txs exactly at start_time, only AFTER that time
+    }
+    else
+    {
+      // Some incremental info still missing completely
+      incremental = false;
+    }
+
+    added_txs.clear();
+    removed_txs.clear();
+
+    if (!incremental)
+    {
+      // Give back the whole pool in 'added_txs'; because calling 'get_transaction_info' right inside the
+      // anonymous method somehow results in an LMDB error with transactions we have to build a list of
+      // ids first and get the full info afterwards
+      std::vector<crypto::hash> txids;
+      const relay_category category = include_sensitive ? relay_category::all : relay_category::broadcasted;
+      m_blockchain.for_all_txpool_txes([&txids](const crypto::hash &txid, const txpool_tx_meta_t &meta, const cryptonote::blobdata_ref *bd){
+        txids.push_back(txid);
+        return true;
+      }, false, category);
+      tx_details details;
+      for (const auto &it: txids)
+      {
+        bool success = get_transaction_info(it, details);
+        if (success)
+        {
+          added_txs.push_back(std::move(details));
+        }
+      }
+      return true;
+    }
+
+    // Give back incrementally, based on time of entry into the map
+    tx_details details;
+    for (const auto &pit : m_added_txs_by_id)
+    {
+      if (pit.second >= start_time)
+      {
+        bool success = get_transaction_info(pit.first, details);
+        if (success)
+        {
+          if (include_sensitive || !details.sensitive)
+          {
+            added_txs.push_back(std::move(details));
+          }
+        }
+      }
+    }
+
+    std::multimap<time_t, removed_tx_info>::const_iterator rit = m_removed_txs_by_time.lower_bound(start_time);
+    while (rit != m_removed_txs_by_time.end())
+    {
+      if (include_sensitive || !rit->second.sensitive)
+      {
+        removed_txs.push_back(rit->second.txid);
+      }
+      ++rit;
+    }
+    return true;
+  }
+  //------------------------------------------------------------------
   void tx_memory_pool::get_transaction_backlog(std::vector<tx_backlog_entry>& backlog, bool include_sensitive) const
   {
     CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -1631,6 +1715,12 @@ namespace cryptonote
     CRITICAL_REGION_LOCAL(m_transactions_lock);
     CRITICAL_REGION_LOCAL1(m_blockchain);
 
+    // Simply throw away incremental info, too difficult to update
+    m_added_txs_by_id.clear();
+    m_added_txs_start_time = (time_t)0;
+    m_removed_txs_by_time.clear();
+    m_removed_txs_start_time = (time_t)0;
+
     MINFO("Validating txpool contents for v" << (unsigned)version);
 
     LockedTXN lock(m_blockchain.get_db());
@@ -1688,6 +1778,106 @@ namespace cryptonote
     return n_removed;
   }
   //---------------------------------------------------------------------------------
+  void tx_memory_pool::add_tx_to_transient_lists(const crypto::hash& txid, double fee, time_t receive_time)
+  {
+
+    time_t now = time(NULL);
+    const std::unordered_map<crypto::hash, time_t>::iterator it = m_added_txs_by_id.find(txid);
+    if (it == m_added_txs_by_id.end())
+    {
+       m_added_txs_by_id.insert(std::make_pair(txid, now));
+    }
+    else
+    {
+      // This tx was already added to the map earlier, probably because then it was in the "stem"
+      // phase of Dandelion++ and now is in the "fluff" phase i.e. got broadcasted: We have to set
+      // a new time for clients that are not allowed to see sensitive txs to make sure they will
+      // see it now if they query incrementally
+      it->second = now;
+
+      auto sorted_it = find_tx_in_sorted_container(txid);
+      if (sorted_it == m_txs_by_fee_and_receive_time.end())
+      {
+        MERROR("Re-adding tx " << txid << " to tx pool, but it was not found in the sorted txs container");
+      }
+      else
+      {
+        m_txs_by_fee_and_receive_time.erase(sorted_it);
+      }
+    }
+    m_txs_by_fee_and_receive_time.emplace(std::pair<double, time_t>(fee, receive_time), txid);
+
+    // Don't check for "resurrected" txs in case of reorgs i.e. don't check in 'm_removed_txs_by_time'
+    // whether we have that txid there and if yes remove it; this results in possible duplicates
+    // where we return certain txids as deleted AND in the pool at the same time which requires
+    // clients to process deleted ones BEFORE processing pool txs
+    if (m_added_txs_start_time == (time_t)0)
+    {
+      m_added_txs_start_time = now;
+    }
+  }
+  //---------------------------------------------------------------------------------
+  void tx_memory_pool::remove_tx_from_transient_lists(const cryptonote::sorted_tx_container::iterator& sorted_it, const crypto::hash& txid, bool sensitive)
+  {
+    if (sorted_it == m_txs_by_fee_and_receive_time.end())
+    {
+      LOG_PRINT_L1("Removing tx " << txid << " from tx pool, but it was not found in the sorted txs container!");
+    }
+    else
+    {
+      m_txs_by_fee_and_receive_time.erase(sorted_it);
+    }
+
+    const std::unordered_map<crypto::hash, time_t>::iterator it = m_added_txs_by_id.find(txid);
+    if (it != m_added_txs_by_id.end())
+    {
+       m_added_txs_by_id.erase(it);
+    }
+    else
+    {
+      MDEBUG("Removing tx " << txid << " from tx pool, but it was not found in the map of added txs");
+    }
+    track_removed_tx(txid, sensitive);
+  }
+  //---------------------------------------------------------------------------------
+  void tx_memory_pool::track_removed_tx(const crypto::hash& txid, bool sensitive)
+  {
+    time_t now = time(NULL);
+    m_removed_txs_by_time.insert(std::make_pair(now, removed_tx_info{txid, sensitive}));
+    MDEBUG("Transaction removed from pool: txid " << txid << ", total entries in removed list now " << m_removed_txs_by_time.size());
+    if (m_removed_txs_start_time == (time_t)0)
+    {
+      m_removed_txs_start_time = now;
+    }
+
+    // Simple system to make sure the list of removed ids does not swell to an unmanageable size: Set
+    // an absolute size limit plus delete entries that are x minutes old (which is ok because clients
+    // will sync with sensible time intervalls and should not ask for incremental info e.g. 1 hour back)
+    const int MAX_REMOVED = 20000;
+    if (m_removed_txs_by_time.size() > MAX_REMOVED)
+    {
+      auto erase_it = m_removed_txs_by_time.begin();
+      std::advance(erase_it, MAX_REMOVED / 4 + 1);
+      m_removed_txs_by_time.erase(m_removed_txs_by_time.begin(), erase_it);
+      m_removed_txs_start_time = m_removed_txs_by_time.begin()->first;
+      MDEBUG("Erased old transactions from big removed list, leaving " << m_removed_txs_by_time.size());
+    }
+    else
+    {
+      time_t earliest = now - (30 * 60);  // 30 minutes
+      std::map<time_t, removed_tx_info>::iterator from, to;
+      from = m_removed_txs_by_time.begin();
+      to = m_removed_txs_by_time.lower_bound(earliest);
+      int distance = std::distance(from, to);
+      if (distance > 0)
+      {
+        m_removed_txs_by_time.erase(from, to);
+        m_removed_txs_start_time = earliest;
+        MDEBUG("Erased " << distance << " old transactions from removed list, leaving " << m_removed_txs_by_time.size());
+      }
+    }
+  }
+  //---------------------------------------------------------------------------------
   bool tx_memory_pool::init(size_t max_txpool_weight, bool mine_stem_txes)
   {
     CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -1695,6 +1885,10 @@ namespace cryptonote
 
     m_txpool_max_weight = max_txpool_weight ? max_txpool_weight : DEFAULT_TXPOOL_MAX_WEIGHT;
     m_txs_by_fee_and_receive_time.clear();
+    m_added_txs_by_id.clear();
+    m_added_txs_start_time = (time_t)0;
+    m_removed_txs_by_time.clear();
+    m_removed_txs_start_time = (time_t)0;
     m_spent_key_images.clear();
     m_txpool_weight = 0;
     std::vector<crypto::hash> remove;
@@ -1719,7 +1913,7 @@ namespace cryptonote
           MFATAL("Failed to insert key images from txpool tx");
           return false;
         }
-        m_txs_by_fee_and_receive_time.emplace(std::pair<double, time_t>(meta.fee / (double)meta.weight, meta.receive_time), txid);
+        add_tx_to_transient_lists(txid, meta.fee / (double)meta.weight, meta.receive_time);
         m_txpool_weight += meta.weight;
         return true;
       }, true, relay_category::all);
diff --git a/src/cryptonote_core/tx_pool.h b/src/cryptonote_core/tx_pool.h
index 45623fd14..3e099cf2d 100644
--- a/src/cryptonote_core/tx_pool.h
+++ b/src/cryptonote_core/tx_pool.h
@@ -461,6 +461,7 @@ namespace cryptonote
       bool do_not_relay; //!< to avoid relay this transaction to the network
 
       bool double_spend_seen; //!< true iff another tx was seen double spending this one
+      bool sensitive;
     };
 
     /**
@@ -473,6 +474,13 @@ namespace cryptonote
      */
     bool get_complement(const std::vector<crypto::hash> &hashes, std::vector<cryptonote::blobdata> &txes) const;
 
+    /**
+     * @brief get info necessary for update of pool-related info in a wallet, preferably incremental
+     *
+     * @return true on success, false on error
+     */
+    bool get_pool_info(time_t start_time, bool include_sensitive, std::vector<tx_details>& added_txs, std::vector<crypto::hash>& removed_txs, bool& incremental) const;
+
   private:
 
     /**
@@ -577,6 +585,10 @@ namespace cryptonote
      */
     void prune(size_t bytes = 0);
 
+    void add_tx_to_transient_lists(const crypto::hash& txid, double fee, time_t receive_time);
+    void remove_tx_from_transient_lists(const cryptonote::sorted_tx_container::iterator& sorted_it, const crypto::hash& txid, bool sensitive);
+    void track_removed_tx(const crypto::hash& txid, bool sensitive);
+
     //TODO: confirm the below comments and investigate whether or not this
     //      is the desired behavior
     //! map key images to transactions which spent them
@@ -609,6 +621,26 @@ private:
 
     std::atomic<uint64_t> m_cookie; //!< incremented at each change
 
+    // Info when transactions entered the pool, accessible by txid
+    std::unordered_map<crypto::hash, time_t> m_added_txs_by_id;
+
+    // Info at what time the pool started to track the adding of transactions
+    time_t m_added_txs_start_time;
+
+    struct removed_tx_info
+    {
+      crypto::hash txid;
+      bool sensitive;
+    };
+
+    // Info about transactions that were removed from the pool, ordered by the time
+    // of deletion
+    std::multimap<time_t, removed_tx_info> m_removed_txs_by_time;
+
+    // Info how far back in time the list of removed tx ids currently reaches
+    // (it gets shorted periodically to prevent overflow)
+    time_t m_removed_txs_start_time;
+
     /**
      * @brief get an iterator to a transaction in the sorted container
      *
diff --git a/src/rpc/core_rpc_server.cpp b/src/rpc/core_rpc_server.cpp
index 16bcf2c04..0d48b6e7a 100644
--- a/src/rpc/core_rpc_server.cpp
+++ b/src/rpc/core_rpc_server.cpp
@@ -598,88 +598,162 @@ namespace cryptonote
 
     CHECK_PAYMENT(req, res, 1);
 
-    // quick check for noop
-    if (!req.block_ids.empty())
-    {
-      uint64_t last_block_height;
-      crypto::hash last_block_hash;
-      m_core.get_blockchain_top(last_block_height, last_block_hash);
-      if (last_block_hash == req.block_ids.front())
-      {
-        res.start_height = 0;
-        res.current_height = m_core.get_current_blockchain_height();
-        res.status = CORE_RPC_STATUS_OK;
+    res.daemon_time = (uint64_t)time(NULL);
+    // Always set daemon time, and set it early rather than late, as delivering some incremental pool
+    // info twice because of slightly overlapping time intervals is no problem, whereas producing gaps
+    // and never delivering something is
+
+    bool get_blocks = false;
+    bool get_pool = false;
+    switch (req.requested_info)
+    {
+      case COMMAND_RPC_GET_BLOCKS_FAST::BLOCKS_ONLY:
+        // Compatibility value 0: Clients that do not set 'requested_info' want blocks, and only blocks
+        get_blocks = true;
+        break;
+      case COMMAND_RPC_GET_BLOCKS_FAST::BLOCKS_AND_POOL:
+        get_blocks = true;
+        get_pool = true;
+        break;
+      case COMMAND_RPC_GET_BLOCKS_FAST::POOL_ONLY:
+        get_pool = true;
+        break;
+      default:
+        res.status = "Failed, wrong requested info";
         return true;
-      }
     }
 
-    size_t max_blocks = COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT;
-    if (m_rpc_payment)
+    res.pool_info_extent = COMMAND_RPC_GET_BLOCKS_FAST::NONE;
+
+    if (get_pool)
     {
-      max_blocks = res.credits / COST_PER_BLOCK;
-      if (max_blocks > COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT)
-        max_blocks = COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT;
-      if (max_blocks == 0)
+      const bool restricted = m_restricted && ctx;
+      const bool request_has_rpc_origin = ctx != NULL;
+      const bool allow_sensitive = !request_has_rpc_origin || !restricted;
+
+      bool incremental;
+      std::vector<tx_memory_pool::tx_details> added_pool_txs;
+      bool success = m_core.get_pool_info((time_t)req.pool_info_since, allow_sensitive, added_pool_txs, res.removed_pool_txids, incremental);
+      if (success)
+      {
+        res.added_pool_txs.clear();
+        if (m_rpc_payment)
+        {
+          CHECK_PAYMENT_SAME_TS(req, res, added_pool_txs.size() * COST_PER_TX + res.removed_pool_txids.size() * COST_PER_POOL_HASH);
+        }
+        for (auto tx_detail: added_pool_txs)
+        {
+          COMMAND_RPC_GET_BLOCKS_FAST::pool_tx_info info;
+          info.tx_hash = cryptonote::get_transaction_hash(tx_detail.tx);
+          std::stringstream oss;
+          binary_archive<true> ar(oss);
+          bool r = ::serialization::serialize(ar, tx_detail.tx);
+          if (!r)
+          {
+            res.status = "Failed to serialize transaction";
+            return true;
+          }
+          info.tx_blob = oss.str();
+          info.double_spend_seen = tx_detail.double_spend_seen;
+          res.added_pool_txs.push_back(std::move(info));
+        }
+      }
+      if (success)
       {
-        res.status = CORE_RPC_STATUS_PAYMENT_REQUIRED;
+        res.pool_info_extent = incremental ? COMMAND_RPC_GET_BLOCKS_FAST::INCREMENTAL : COMMAND_RPC_GET_BLOCKS_FAST::FULL;
+      }
+      else
+      {
+        res.status = "Failed to get pool info";
         return true;
       }
     }
 
-    std::vector<std::pair<std::pair<cryptonote::blobdata, crypto::hash>, std::vector<std::pair<crypto::hash, cryptonote::blobdata> > > > bs;
-    if(!m_core.find_blockchain_supplement(req.start_height, req.block_ids, bs, res.current_height, res.start_height, req.prune, !req.no_miner_tx, max_blocks, COMMAND_RPC_GET_BLOCKS_FAST_MAX_TX_COUNT))
-    {
-      res.status = "Failed";
-      add_host_fail(ctx);
-      return true;
-    }
-
-    CHECK_PAYMENT_SAME_TS(req, res, bs.size() * COST_PER_BLOCK);
-
-    size_t size = 0, ntxes = 0;
-    res.blocks.reserve(bs.size());
-    res.output_indices.reserve(bs.size());
-    for(auto& bd: bs)
+    if (get_blocks)
     {
-      res.blocks.resize(res.blocks.size()+1);
-      res.blocks.back().pruned = req.prune;
-      res.blocks.back().block = bd.first.first;
-      size += bd.first.first.size();
-      res.output_indices.push_back(COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices());
-      ntxes += bd.second.size();
-      res.output_indices.back().indices.reserve(1 + bd.second.size());
-      if (req.no_miner_tx)
-        res.output_indices.back().indices.push_back(COMMAND_RPC_GET_BLOCKS_FAST::tx_output_indices());
-      res.blocks.back().txs.reserve(bd.second.size());
-      for (std::vector<std::pair<crypto::hash, cryptonote::blobdata>>::iterator i = bd.second.begin(); i != bd.second.end(); ++i)
+      // quick check for noop
+      if (!req.block_ids.empty())
       {
-        res.blocks.back().txs.push_back({std::move(i->second), crypto::null_hash});
-        i->second.clear();
-        i->second.shrink_to_fit();
-        size += res.blocks.back().txs.back().blob.size();
+        uint64_t last_block_height;
+        crypto::hash last_block_hash;
+        m_core.get_blockchain_top(last_block_height, last_block_hash);
+        if (last_block_hash == req.block_ids.front())
+        {
+          res.start_height = 0;
+          res.current_height = last_block_height + 1;
+          res.status = CORE_RPC_STATUS_OK;
+          return true;
+        }
       }
 
-      const size_t n_txes_to_lookup = bd.second.size() + (req.no_miner_tx ? 0 : 1);
-      if (n_txes_to_lookup > 0)
+      size_t max_blocks = COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT;
+      if (m_rpc_payment)
       {
-        std::vector<std::vector<uint64_t>> indices;
-        bool r = m_core.get_tx_outputs_gindexs(req.no_miner_tx ? bd.second.front().first : bd.first.second, n_txes_to_lookup, indices);
-        if (!r)
+        max_blocks = res.credits / COST_PER_BLOCK;
+        if (max_blocks > COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT)
+          max_blocks = COMMAND_RPC_GET_BLOCKS_FAST_MAX_BLOCK_COUNT;
+        if (max_blocks == 0)
         {
-          res.status = "Failed";
+          res.status = CORE_RPC_STATUS_PAYMENT_REQUIRED;
           return true;
         }
-        if (indices.size() != n_txes_to_lookup || res.output_indices.back().indices.size() != (req.no_miner_tx ? 1 : 0))
+      }
+
+      std::vector<std::pair<std::pair<cryptonote::blobdata, crypto::hash>, std::vector<std::pair<crypto::hash, cryptonote::blobdata> > > > bs;
+      if(!m_core.find_blockchain_supplement(req.start_height, req.block_ids, bs, res.current_height, res.start_height, req.prune, !req.no_miner_tx, max_blocks, COMMAND_RPC_GET_BLOCKS_FAST_MAX_TX_COUNT))
+      {
+        res.status = "Failed";
+        add_host_fail(ctx);
+        return true;
+      }
+
+      CHECK_PAYMENT_SAME_TS(req, res, bs.size() * COST_PER_BLOCK);
+
+      size_t size = 0, ntxes = 0;
+      res.blocks.reserve(bs.size());
+      res.output_indices.reserve(bs.size());
+      for(auto& bd: bs)
+      {
+        res.blocks.resize(res.blocks.size()+1);
+        res.blocks.back().pruned = req.prune;
+        res.blocks.back().block = bd.first.first;
+        size += bd.first.first.size();
+        res.output_indices.push_back(COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices());
+        ntxes += bd.second.size();
+        res.output_indices.back().indices.reserve(1 + bd.second.size());
+        if (req.no_miner_tx)
+          res.output_indices.back().indices.push_back(COMMAND_RPC_GET_BLOCKS_FAST::tx_output_indices());
+        res.blocks.back().txs.reserve(bd.second.size());
+        for (std::vector<std::pair<crypto::hash, cryptonote::blobdata>>::iterator i = bd.second.begin(); i != bd.second.end(); ++i)
+        {
+          res.blocks.back().txs.push_back({std::move(i->second), crypto::null_hash});
+          i->second.clear();
+          i->second.shrink_to_fit();
+          size += res.blocks.back().txs.back().blob.size();
+        }
+
+        const size_t n_txes_to_lookup = bd.second.size() + (req.no_miner_tx ? 0 : 1);
+        if (n_txes_to_lookup > 0)
         {
-          res.status = "Failed";
-          return true;
+          std::vector<std::vector<uint64_t>> indices;
+          bool r = m_core.get_tx_outputs_gindexs(req.no_miner_tx ? bd.second.front().first : bd.first.second, n_txes_to_lookup, indices);
+          if (!r)
+          {
+            res.status = "Failed";
+            return true;
+          }
+          if (indices.size() != n_txes_to_lookup || res.output_indices.back().indices.size() != (req.no_miner_tx ? 1 : 0))
+          {
+            res.status = "Failed";
+            return true;
+          }
+          for (size_t i = 0; i < indices.size(); ++i)
+            res.output_indices.back().indices.push_back({std::move(indices[i])});
         }
-        for (size_t i = 0; i < indices.size(); ++i)
-          res.output_indices.back().indices.push_back({std::move(indices[i])});
       }
+      MDEBUG("on_get_blocks: " << bs.size() << " blocks, " << ntxes << " txes, size " << size);
     }
 
-    MDEBUG("on_get_blocks: " << bs.size() << " blocks, " << ntxes << " txes, size " << size);
     res.status = CORE_RPC_STATUS_OK;
     return true;
   }
diff --git a/src/rpc/core_rpc_server_commands_defs.h b/src/rpc/core_rpc_server_commands_defs.h
index e1222f6eb..a4876a395 100644
--- a/src/rpc/core_rpc_server_commands_defs.h
+++ b/src/rpc/core_rpc_server_commands_defs.h
@@ -162,18 +162,29 @@ namespace cryptonote
   struct COMMAND_RPC_GET_BLOCKS_FAST
   {
 
+    enum REQUESTED_INFO
+    {
+      BLOCKS_ONLY = 0,
+      BLOCKS_AND_POOL = 1,
+      POOL_ONLY = 2
+    };
+
     struct request_t: public rpc_access_request_base
     {
+      uint8_t     requested_info;
       std::list<crypto::hash> block_ids; //*first 10 blocks id goes sequential, next goes in pow(2,n) offset, like 2, 4, 8, 16, 32, 64 and so on, and the last one is always genesis block */
       uint64_t    start_height;
       bool        prune;
       bool        no_miner_tx;
+      uint64_t    pool_info_since;
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_PARENT(rpc_access_request_base)
+        KV_SERIALIZE_OPT(requested_info, (uint8_t)0)
         KV_SERIALIZE_CONTAINER_POD_AS_BLOB(block_ids)
         KV_SERIALIZE(start_height)
         KV_SERIALIZE(prune)
         KV_SERIALIZE_OPT(no_miner_tx, false)
+        KV_SERIALIZE_OPT(pool_info_since, (uint64_t)0)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<request_t> request;
@@ -196,12 +207,36 @@ namespace cryptonote
       END_KV_SERIALIZE_MAP()
     };
 
+    struct pool_tx_info
+    {
+      crypto::hash tx_hash;
+      blobdata tx_blob;
+      bool double_spend_seen;
+
+      BEGIN_KV_SERIALIZE_MAP()
+        KV_SERIALIZE_VAL_POD_AS_BLOB(tx_hash)
+        KV_SERIALIZE(tx_blob)
+        KV_SERIALIZE(double_spend_seen)
+      END_KV_SERIALIZE_MAP()
+    };
+
+    enum POOL_INFO_EXTENT
+    {
+      NONE = 0,
+      INCREMENTAL = 1,
+      FULL = 2
+    };
+
     struct response_t: public rpc_access_response_base
     {
       std::vector<block_complete_entry> blocks;
       uint64_t    start_height;
       uint64_t    current_height;
       std::vector<block_output_indices> output_indices;
+      uint64_t    daemon_time;
+      uint8_t     pool_info_extent;
+      std::vector<pool_tx_info> added_pool_txs;
+      std::vector<crypto::hash> removed_pool_txids;
 
       BEGIN_KV_SERIALIZE_MAP()
         KV_SERIALIZE_PARENT(rpc_access_response_base)
@@ -209,6 +244,10 @@ namespace cryptonote
         KV_SERIALIZE(start_height)
         KV_SERIALIZE(current_height)
         KV_SERIALIZE(output_indices)
+        KV_SERIALIZE(daemon_time)
+        KV_SERIALIZE(pool_info_extent)
+        KV_SERIALIZE(added_pool_txs)
+        KV_SERIALIZE_CONTAINER_POD_AS_BLOB(removed_pool_txids)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<response_t> response;
diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index f59af575e..984392b08 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -5894,7 +5894,10 @@ bool simple_wallet::refresh_main(uint64_t start_height, enum ResetType reset, bo
   {
     m_in_manual_refresh.store(true, std::memory_order_relaxed);
     epee::misc_utils::auto_scope_leave_caller scope_exit_handler = epee::misc_utils::create_scope_leave_handler([&](){m_in_manual_refresh.store(false, std::memory_order_relaxed);});
-    m_wallet->refresh(m_wallet->is_trusted_daemon(), start_height, fetched_blocks, received_money);
+    // For manual refresh don't allow incremental checking of the pool: Because we did not process the txs
+    // for us in the pool during automatic refresh we could miss some of them if we checked the pool
+    // incrementally here
+    m_wallet->refresh(m_wallet->is_trusted_daemon(), start_height, fetched_blocks, received_money, true, false);
 
     if (reset == ResetSoftKeepKI)
     {
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 1880d7ea0..2cbbda3f9 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -1224,6 +1224,7 @@ wallet2::wallet2(network_type nettype, uint64_t kdf_rounds, bool unattended, std
   m_load_deprecated_formats(false),
   m_credits_target(0),
   m_enable_multisig(false),
+  m_pool_info_query_time(0),
   m_has_ever_refreshed_from_node(false),
   m_allow_mismatched_daemon_version(false)
 {
@@ -2663,7 +2664,7 @@ void wallet2::parse_block_round(const cryptonote::blobdata &blob, cryptonote::bl
   error = !cryptonote::parse_and_validate_block_from_blob(blob, bl, bl_id);
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::pull_blocks(uint64_t start_height, uint64_t &blocks_start_height, const std::list<crypto::hash> &short_chain_history, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices> &o_indices, uint64_t &current_height)
+void wallet2::pull_blocks(bool first, bool try_incremental, uint64_t start_height, uint64_t &blocks_start_height, const std::list<crypto::hash> &short_chain_history, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices> &o_indices, uint64_t &current_height)
 {
   cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::request req = AUTO_VAL_INIT(req);
   cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::response res = AUTO_VAL_INIT(res);
@@ -2675,6 +2676,10 @@ void wallet2::pull_blocks(uint64_t start_height, uint64_t &blocks_start_height,
   req.start_height = start_height;
   req.no_miner_tx = m_refresh_type == RefreshNoCoinbase;
 
+  req.requested_info = first ? COMMAND_RPC_GET_BLOCKS_FAST::BLOCKS_AND_POOL : COMMAND_RPC_GET_BLOCKS_FAST::BLOCKS_ONLY;
+  if (try_incremental)
+    req.pool_info_since = m_pool_info_query_time;
+
   {
     const boost::lock_guard<boost::recursive_mutex> lock{m_daemon_rpc_mutex};
     uint64_t pre_call_credits = m_rpc_payment_state.credits;
@@ -2684,16 +2689,36 @@ void wallet2::pull_blocks(uint64_t start_height, uint64_t &blocks_start_height,
     THROW_WALLET_EXCEPTION_IF(res.blocks.size() != res.output_indices.size(), error::wallet_internal_error,
         "mismatched blocks (" + boost::lexical_cast<std::string>(res.blocks.size()) + ") and output_indices (" +
         boost::lexical_cast<std::string>(res.output_indices.size()) + ") sizes from daemon");
-    check_rpc_cost("/getblocks.bin", res.credits, pre_call_credits, 1 + res.blocks.size() * COST_PER_BLOCK);
+    uint64_t pool_info_cost = res.added_pool_txs.size() * COST_PER_TX + res.removed_pool_txids.size() * COST_PER_POOL_HASH;
+    check_rpc_cost("/getblocks.bin", res.credits, pre_call_credits, 1 + res.blocks.size() * COST_PER_BLOCK + pool_info_cost);
   }
 
   blocks_start_height = res.start_height;
   blocks = std::move(res.blocks);
   o_indices = std::move(res.output_indices);
   current_height = res.current_height;
+  if (res.pool_info_extent != COMMAND_RPC_GET_BLOCKS_FAST::NONE)
+    m_pool_info_query_time = res.daemon_time;
 
   MDEBUG("Pulled blocks: blocks_start_height " << blocks_start_height << ", count " << blocks.size()
-      << ", height " << blocks_start_height + blocks.size() << ", node height " << res.current_height);
+      << ", height " << blocks_start_height + blocks.size() << ", node height " << res.current_height
+      << ", pool info " << static_cast<unsigned int>(res.pool_info_extent));
+
+  if (first)
+  {
+    if (res.pool_info_extent != COMMAND_RPC_GET_BLOCKS_FAST::NONE)
+    {
+      update_pool_state_from_pool_data(res, m_process_pool_txs, true);
+    }
+    else
+    {
+      // If we did not get any pool info, neither incremental nor the whole pool, we probably talk
+      // to a daemon that does not yet support giving back pool info with the 'getblocks' call,
+      // and we have to update in the "old way"
+      update_pool_state_by_pool_query(m_process_pool_txs, true);
+    }
+  }
+
 }
 //----------------------------------------------------------------------------------------------------
 void wallet2::pull_hashes(uint64_t start_height, uint64_t &blocks_start_height, const std::list<crypto::hash> &short_chain_history, std::vector<crypto::hash> &hashes)
@@ -2943,7 +2968,7 @@ void check_block_hard_fork_version(cryptonote::network_type nettype, uint8_t hf_
   daemon_is_outdated = height < start_height || height >= end_height;
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::pull_and_parse_next_blocks(uint64_t start_height, uint64_t &blocks_start_height, std::list<crypto::hash> &short_chain_history, const std::vector<cryptonote::block_complete_entry> &prev_blocks, const std::vector<parsed_block> &prev_parsed_blocks, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<parsed_block> &parsed_blocks, bool &last, bool &error, std::exception_ptr &exception)
+void wallet2::pull_and_parse_next_blocks(bool first, bool try_incremental, uint64_t start_height, uint64_t &blocks_start_height, std::list<crypto::hash> &short_chain_history, const std::vector<cryptonote::block_complete_entry> &prev_blocks, const std::vector<parsed_block> &prev_parsed_blocks, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<parsed_block> &parsed_blocks, bool &last, bool &error, std::exception_ptr &exception)
 {
   error = false;
   last = false;
@@ -2965,7 +2990,7 @@ void wallet2::pull_and_parse_next_blocks(uint64_t start_height, uint64_t &blocks
     // pull the new blocks
     std::vector<cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices> o_indices;
     uint64_t current_height;
-    pull_blocks(start_height, blocks_start_height, short_chain_history, blocks, o_indices, current_height);
+    pull_blocks(first, try_incremental, start_height, blocks_start_height, short_chain_history, blocks, o_indices, current_height);
     THROW_WALLET_EXCEPTION_IF(blocks.size() != o_indices.size(), error::wallet_internal_error, "Mismatched sizes of blocks and o_indices");
 
     tools::threadpool& tpool = tools::threadpool::getInstanceForCompute();
@@ -3029,9 +3054,10 @@ void wallet2::pull_and_parse_next_blocks(uint64_t start_height, uint64_t &blocks
   }
 }
 
-void wallet2::remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashes)
+void wallet2::remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashes, bool remove_if_found)
 {
-  // remove pool txes to us that aren't in the pool anymore
+  // remove pool txes to us that aren't in the pool anymore (remove_if_found = false),
+  // or remove pool txes to us that were reported as removed (remove_if_found = true)
   std::unordered_multimap<crypto::hash, wallet2::pool_payment_details>::iterator uit = m_unconfirmed_payments.begin();
   while (uit != m_unconfirmed_payments.end())
   {
@@ -3046,9 +3072,9 @@ void wallet2::remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashe
       }
     }
     auto pit = uit++;
-    if (!found)
+    if ((!remove_if_found && !found) || (remove_if_found && found))
     {
-      MDEBUG("Removing " << txid << " from unconfirmed payments, not found in pool");
+      MDEBUG("Removing " << txid << " from unconfirmed payments");
       m_unconfirmed_payments.erase(pit);
       if (0 != m_callback)
         m_callback->on_pool_tx_removed(txid);
@@ -3057,9 +3083,183 @@ void wallet2::remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashe
 }
 
 //----------------------------------------------------------------------------------------------------
-void wallet2::update_pool_state(std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed)
+// Code that is common to 'update_pool_state_by_pool_query' and 'update_pool_state_from_pool_data':
+// Check wether a tx in the pool is worthy of processing because we did not see it
+// yet or because it is "interesting" out of special circumstances
+bool wallet2::accept_pool_tx_for_processing(const crypto::hash &txid)
+{
+  bool txid_found_in_up = false;
+  for (const auto &up: m_unconfirmed_payments)
+  {
+    if (up.second.m_pd.m_tx_hash == txid)
+    {
+      txid_found_in_up = true;
+      break;
+    }
+  }
+  if (m_scanned_pool_txs[0].find(txid) != m_scanned_pool_txs[0].end() || m_scanned_pool_txs[1].find(txid) != m_scanned_pool_txs[1].end())
+  {
+    // if it's for us, we want to keep track of whether we saw a double spend, so don't bail out
+    if (!txid_found_in_up)
+    {
+      LOG_PRINT_L2("Already seen " << txid << ", and not for us, skipped");
+      return false;
+    }
+  }
+  if (!txid_found_in_up)
+  {
+    LOG_PRINT_L1("Found new pool tx: " << txid);
+    bool found = false;
+    for (const auto &i: m_unconfirmed_txs)
+    {
+      if (i.first == txid)
+      {
+        found = true;
+        // if this is a payment to yourself at a different subaddress account, don't skip it
+        // so that you can see the incoming pool tx with 'show_transfers' on that receiving subaddress account
+        const unconfirmed_transfer_details& utd = i.second;
+        for (const auto& dst : utd.m_dests)
+        {
+          auto subaddr_index = m_subaddresses.find(dst.addr.m_spend_public_key);
+          if (subaddr_index != m_subaddresses.end() && subaddr_index->second.major != utd.m_subaddr_account)
+          {
+            found = false;
+            break;
+          }
+        }
+        break;
+      }
+    }
+    if (!found)
+    {
+      // not one of those we sent ourselves
+      return true;
+    }
+    else
+    {
+      LOG_PRINT_L1("We sent that one");
+      return false;
+    }
+  }
+  else {
+    return false;
+  }
+}
+//----------------------------------------------------------------------------------------------------
+// Code that is common to 'update_pool_state_by_pool_query' and 'update_pool_state_from_pool_data':
+// Process an unconfirmed transfer after we know whether it's in the pool or not
+void wallet2::process_unconfirmed_transfer(bool incremental, const crypto::hash &txid, wallet2::unconfirmed_transfer_details &tx_details, bool seen_in_pool, std::chrono::system_clock::time_point now, bool refreshed)
+{
+  // TODO: set tx_propagation_timeout to CRYPTONOTE_DANDELIONPP_EMBARGO_AVERAGE * 3 / 2 after v15 hardfork
+  constexpr const std::chrono::seconds tx_propagation_timeout{500};
+  if (seen_in_pool)
+  {
+    if (tx_details.m_state != wallet2::unconfirmed_transfer_details::pending_in_pool)
+    {
+      tx_details.m_state = wallet2::unconfirmed_transfer_details::pending_in_pool;
+      MINFO("Pending txid " << txid << " seen in pool, marking as pending in pool");
+    }
+  }
+  else
+  {
+    if (!incremental)
+    {
+      if (tx_details.m_state == wallet2::unconfirmed_transfer_details::pending_in_pool)
+      {
+        // For the probably unlikely case that a tx once seen in the pool vanishes
+        // again set back to 'pending'
+        tx_details.m_state = wallet2::unconfirmed_transfer_details::pending;
+        MINFO("Already seen txid " << txid << " vanished from pool, marking as pending");
+      }
+    }
+    // If a tx is pending for a "long time" without appearing in the pool, and if
+    // we have refreshed and thus had a chance to really see it if it was there,
+    // judge it as failed; the waiting for timeout and refresh happened avoids
+    // false alarms with txs going to 'failed' too early
+    if (tx_details.m_state == wallet2::unconfirmed_transfer_details::pending && refreshed &&
+      now > std::chrono::system_clock::from_time_t(tx_details.m_sent_time) + tx_propagation_timeout)
+    {
+      LOG_PRINT_L1("Pending txid " << txid << " not in pool after " << tx_propagation_timeout.count() <<
+        " seconds, marking as failed");
+      tx_details.m_state = wallet2::unconfirmed_transfer_details::failed;
+
+      // the inputs aren't spent anymore, since the tx failed
+      for (size_t vini = 0; vini < tx_details.m_tx.vin.size(); ++vini)
+      {
+        if (tx_details.m_tx.vin[vini].type() == typeid(txin_to_key))
+        {
+          txin_to_key &tx_in_to_key = boost::get<txin_to_key>(tx_details.m_tx.vin[vini]);
+          for (size_t i = 0; i < m_transfers.size(); ++i)
+          {
+            const transfer_details &td = m_transfers[i];
+            if (td.m_key_image == tx_in_to_key.k_image)
+            {
+                LOG_PRINT_L1("Resetting spent status for output " << vini << ": " << td.m_key_image);
+                set_unspent(i);
+                break;
+            }
+          }
+        }
+      }
+    }
+  }
+}
+//----------------------------------------------------------------------------------------------------
+// This public method is typically called to make sure that the wallet's pool state is up-to-date by
+// clients like simplewallet and the RPC daemon. Before incremental update this was the same method
+// that 'refresh' also used, but now it's more complicated because for the time being we support
+// the "old" and the "new" way of updating the pool and because only the 'getblocks' call supports
+// incremental update but we don't want any blocks here.
+//
+// simplewallet does NOT update the pool info during automatic refresh to avoid disturbing interactive
+// messages and prompts. When it finally calls this method here "to catch up" so to say we can't use
+// incremental update anymore, because with that we might miss some txs altogether.
+void wallet2::update_pool_state(std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed, bool try_incremental)
+{
+  bool updated = false;
+  if (m_pool_info_query_time != 0 && try_incremental)
+  {
+    // We are connected to a daemon that supports giving back pool data with the 'getblocks' call,
+    // thus use that, to get the chance to work incrementally and to keep working incrementally;
+    // 'POOL_ONLY' was created to support this case
+    cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::request req = AUTO_VAL_INIT(req);
+    cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::response res = AUTO_VAL_INIT(res);
+
+    req.requested_info = COMMAND_RPC_GET_BLOCKS_FAST::POOL_ONLY;
+    req.pool_info_since = m_pool_info_query_time;
+
+    {
+      const boost::lock_guard<boost::recursive_mutex> lock{m_daemon_rpc_mutex};
+      uint64_t pre_call_credits = m_rpc_payment_state.credits;
+      req.client = get_client_signature();
+      bool r = net_utils::invoke_http_bin("/getblocks.bin", req, res, *m_http_client, rpc_timeout);
+      THROW_ON_RPC_RESPONSE_ERROR(r, {}, res, "getblocks.bin", error::get_blocks_error, get_rpc_status(res.status));
+      uint64_t pool_info_cost = res.added_pool_txs.size() * COST_PER_TX + res.removed_pool_txids.size() * COST_PER_POOL_HASH;
+      check_rpc_cost("/getblocks.bin", res.credits, pre_call_credits, pool_info_cost);
+    }
+
+    m_pool_info_query_time = res.daemon_time;
+    if (res.pool_info_extent != COMMAND_RPC_GET_BLOCKS_FAST::NONE)
+    {
+      update_pool_state_from_pool_data(res, process_txs, refreshed);
+      updated = true;
+    }
+    // We SHOULD get pool data here, but if for some crazy reason we don't fall back to the "old" method
+  }
+  if (!updated)
+  {
+    update_pool_state_by_pool_query(process_txs, refreshed);
+  }
+}
+//----------------------------------------------------------------------------------------------------
+// This is the "old" way of updating the pool with separate queries to get the pool content, used before
+// the 'getblocks' command was able to give back pool data in addition to blocks. Before this code was
+// the public 'update_pool_state' method. The logic is unchanged. This is a candidate for elimination
+// when it's sure that no more "old" daemons can be possibly around.
+void wallet2::update_pool_state_by_pool_query(std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed)
 {
-  MTRACE("update_pool_state start");
+  MTRACE("update_pool_state_by_pool_query start");
+  process_txs.clear();
 
   auto keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this]() {
     m_encrypt_keys_after_refresh.reset();
@@ -3077,16 +3277,15 @@ void wallet2::update_pool_state(std::vector<std::tuple<cryptonote::transaction,
     THROW_ON_RPC_RESPONSE_ERROR(r, {}, res, "get_transaction_pool_hashes.bin", error::get_tx_pool_error);
     check_rpc_cost("/get_transaction_pool_hashes.bin", res.credits, pre_call_credits, 1 + res.tx_hashes.size() * COST_PER_POOL_HASH);
   }
-  MTRACE("update_pool_state got pool");
+  MTRACE("update_pool_state_by_pool_query got pool");
 
   // remove any pending tx that's not in the pool
-  // TODO: set tx_propagation_timeout to CRYPTONOTE_DANDELIONPP_EMBARGO_AVERAGE * 3 / 2 after v15 hardfork
-  constexpr const std::chrono::seconds tx_propagation_timeout{500};
   const auto now = std::chrono::system_clock::now();
   std::unordered_map<crypto::hash, wallet2::unconfirmed_transfer_details>::iterator it = m_unconfirmed_txs.begin();
   while (it != m_unconfirmed_txs.end())
   {
     const crypto::hash &txid = it->first;
+    MDEBUG("Checking m_unconfirmed_txs entry " << txid);
     bool found = false;
     for (const auto &it2: res.tx_hashes)
     {
@@ -3097,114 +3296,26 @@ void wallet2::update_pool_state(std::vector<std::tuple<cryptonote::transaction,
       }
     }
     auto pit = it++;
-    if (!found)
-    {
-      // we want to avoid a false positive when we ask for the pool just after
-      // a tx is removed from the pool due to being found in a new block, but
-      // just before the block is visible by refresh. So we keep a boolean, so
-      // that the first time we don't see the tx, we set that boolean, and only
-      // delete it the second time it is checked (but only when refreshed, so
-      // we're sure we've seen the blockchain state first)
-      if (pit->second.m_state == wallet2::unconfirmed_transfer_details::pending)
-      {
-        LOG_PRINT_L1("Pending txid " << txid << " not in pool, marking as not in pool");
-        pit->second.m_state = wallet2::unconfirmed_transfer_details::pending_not_in_pool;
-      }
-      else if (pit->second.m_state == wallet2::unconfirmed_transfer_details::pending_not_in_pool && refreshed &&
-        now > std::chrono::system_clock::from_time_t(pit->second.m_sent_time) + tx_propagation_timeout)
-      {
-        LOG_PRINT_L1("Pending txid " << txid << " not in pool after " << tx_propagation_timeout.count() <<
-          " seconds, marking as failed");
-        pit->second.m_state = wallet2::unconfirmed_transfer_details::failed;
-
-        // the inputs aren't spent anymore, since the tx failed
-        for (size_t vini = 0; vini < pit->second.m_tx.vin.size(); ++vini)
-        {
-          if (pit->second.m_tx.vin[vini].type() == typeid(txin_to_key))
-          {
-            txin_to_key &tx_in_to_key = boost::get<txin_to_key>(pit->second.m_tx.vin[vini]);
-            for (size_t i = 0; i < m_transfers.size(); ++i)
-            {
-              const transfer_details &td = m_transfers[i];
-              if (td.m_key_image == tx_in_to_key.k_image)
-              {
-                 LOG_PRINT_L1("Resetting spent status for output " << vini << ": " << td.m_key_image);
-                 set_unspent(i);
-                 break;
-              }
-            }
-          }
-        }
-      }
-    }
+    process_unconfirmed_transfer(false, txid, pit->second, found, now, refreshed);
+    MDEBUG("New state of that entry: " << pit->second.m_state);
   }
-  MTRACE("update_pool_state done first loop");
+  MTRACE("update_pool_state_by_pool_query done first loop");
 
   // remove pool txes to us that aren't in the pool anymore
   // but only if we just refreshed, so that the tx can go in
   // the in transfers list instead (or nowhere if it just
   // disappeared without being mined)
   if (refreshed)
-    remove_obsolete_pool_txs(res.tx_hashes);
+    remove_obsolete_pool_txs(res.tx_hashes, false);
 
-  MTRACE("update_pool_state done second loop");
+  MTRACE("update_pool_state_by_pool_query done second loop");
 
   // gather txids of new pool txes to us
   std::vector<std::pair<crypto::hash, bool>> txids;
   for (const auto &txid: res.tx_hashes)
   {
-    bool txid_found_in_up = false;
-    for (const auto &up: m_unconfirmed_payments)
-    {
-      if (up.second.m_pd.m_tx_hash == txid)
-      {
-        txid_found_in_up = true;
-        break;
-      }
-    }
-    if (m_scanned_pool_txs[0].find(txid) != m_scanned_pool_txs[0].end() || m_scanned_pool_txs[1].find(txid) != m_scanned_pool_txs[1].end())
-    {
-      // if it's for us, we want to keep track of whether we saw a double spend, so don't bail out
-      if (!txid_found_in_up)
-      {
-        LOG_PRINT_L2("Already seen " << txid << ", and not for us, skipped");
-        continue;
-      }
-    }
-    if (!txid_found_in_up)
-    {
-      LOG_PRINT_L1("Found new pool tx: " << txid);
-      bool found = false;
-      for (const auto &i: m_unconfirmed_txs)
-      {
-        if (i.first == txid)
-        {
-          found = true;
-          // if this is a payment to yourself at a different subaddress account, don't skip it
-          // so that you can see the incoming pool tx with 'show_transfers' on that receiving subaddress account
-          const unconfirmed_transfer_details& utd = i.second;
-          for (const auto& dst : utd.m_dests)
-          {
-            auto subaddr_index = m_subaddresses.find(dst.addr.m_spend_public_key);
-            if (subaddr_index != m_subaddresses.end() && subaddr_index->second.major != utd.m_subaddr_account)
-            {
-              found = false;
-              break;
-            }
-          }
-          break;
-        }
-      }
-      if (!found)
-      {
-        // not one of those we sent ourselves
-        txids.push_back({txid, false});
-      }
-      else
-      {
-        LOG_PRINT_L1("We sent that one");
-      }
-    }
+    if (accept_pool_tx_for_processing(txid))
+      txids.push_back({txid, false});
   }
 
   // get_transaction_pool_hashes.bin may return more transactions than we're allowed to request in restricted mode
@@ -3279,11 +3390,91 @@ void wallet2::update_pool_state(std::vector<std::tuple<cryptonote::transaction,
       LOG_PRINT_L0("Error calling gettransactions daemon RPC: r " << r << ", status " << get_rpc_status(res.status));
     }
   }
-  MTRACE("update_pool_state end");
+  MTRACE("update_pool_state_by_pool_query end");
+}
+//----------------------------------------------------------------------------------------------------
+// Update pool state from pool data we got together with block data, either incremental data with
+// txs that are new in the pool since the last time we queried and the ids of txs that were
+// removed from the pool since then, or the whole content of the pool if incremental was not
+// possible, e.g. because the server was just started or restarted.
+void wallet2::update_pool_state_from_pool_data(const cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::response &res, std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed)
+{
+  MTRACE("update_pool_state_from_pool_data start");
+  auto keys_reencryptor = epee::misc_utils::create_scope_leave_handler([&, this]() {
+    m_encrypt_keys_after_refresh.reset();
+  });
+
+  bool incremental = res.pool_info_extent == COMMAND_RPC_GET_BLOCKS_FAST::INCREMENTAL;
+
+  if (refreshed)
+  {
+    if (incremental)
+    {
+      // Delete from the list of unconfirmed payments what the daemon reported as tx that was removed from
+      // pool; do so only after refresh to not delete too early and too eagerly; maybe we will find the tx
+      // later in a block, or not, or find it again in the pool txs because it was first removed but then
+      // somehow quickly "resurrected" - that all does not matter here, we retrace the removal
+      remove_obsolete_pool_txs(res.removed_pool_txids, true);
+    }
+    else
+    {
+      // Delete from the list of unconfirmed payments what we don't find anymore in the pool; a bit
+      // unfortunate that we have to build a new vector with ids first, but better than copying and
+      // modifying the code of 'remove_obsolete_pool_txs' here
+      std::vector<crypto::hash> txids;
+      txids.reserve(res.added_pool_txs.size());
+      for (const auto &it: res.added_pool_txs)
+      {
+        txids.push_back(it.tx_hash);
+      }
+      remove_obsolete_pool_txs(txids, false);
+    }
+  }
+
+  // Possibly remove any pending tx that's not in the pool
+  const auto now = std::chrono::system_clock::now();
+  std::unordered_map<crypto::hash, wallet2::unconfirmed_transfer_details>::iterator it = m_unconfirmed_txs.begin();
+  while (it != m_unconfirmed_txs.end())
+  {
+    const crypto::hash &txid = it->first;
+    MDEBUG("Checking m_unconfirmed_txs entry " << txid);
+    bool found = false;
+    for (const auto &it2: res.added_pool_txs)
+    {
+      if (it2.tx_hash == txid)
+      {
+        found = true;
+        break;
+      }
+    }
+    auto pit = it++;
+    process_unconfirmed_transfer(incremental, txid, pit->second, found, now, refreshed);
+    MDEBUG("Resulting state of that entry: " << pit->second.m_state);
+  }
+
+  // Collect all pool txs that are "interesting" i.e. mostly those that we don't know about yet;
+  // if we work incrementally and thus see only new pool txs since last time we asked it should
+  // be rare that we know already about one of those, but check nevertheless
+  process_txs.clear();
+  for (const auto &pool_tx: res.added_pool_txs)
+  {
+    cryptonote::transaction tx;
+    THROW_WALLET_EXCEPTION_IF(!cryptonote::parse_and_validate_tx_from_blob(pool_tx.tx_blob, tx),
+        error::wallet_internal_error, "Failed to validate transaction from daemon");
+    const crypto::hash &txid = pool_tx.tx_hash;
+    bool take = accept_pool_tx_for_processing(txid);
+    if (take)
+    {
+      process_txs.push_back(std::make_tuple(tx, txid, pool_tx.double_spend_seen));
+    }
+  }
+
+  MTRACE("update_pool_state_from_pool_data end");
 }
 //----------------------------------------------------------------------------------------------------
 void wallet2::process_pool_state(const std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &txs)
 {
+  MTRACE("process_pool_state start");
   const time_t now = time(NULL);
   for (const auto &e: txs)
   {
@@ -3298,6 +3489,7 @@ void wallet2::process_pool_state(const std::vector<std::tuple<cryptonote::transa
       m_scanned_pool_txs[0].clear();
     }
   }
+  MTRACE("process_pool_state end");
 }
 //----------------------------------------------------------------------------------------------------
 void wallet2::fast_refresh(uint64_t stop_height, uint64_t &blocks_start_height, std::list<crypto::hash> &short_chain_history, bool force)
@@ -3418,7 +3610,7 @@ std::shared_ptr<std::map<std::pair<uint64_t, uint64_t>, size_t>> wallet2::create
   return cache;
 }
 //----------------------------------------------------------------------------------------------------
-void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blocks_fetched, bool& received_money, bool check_pool, uint64_t max_blocks)
+void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blocks_fetched, bool& received_money, bool check_pool, bool try_incremental, uint64_t max_blocks)
 {
   if (m_offline)
   {
@@ -3506,12 +3698,15 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
 
   auto scope_exit_handler_hwdev = epee::misc_utils::create_scope_leave_handler([&](){hwdev.computing_key_images(false);});
 
+  m_process_pool_txs.clear();
+  // Getting and processing the pool state has moved down into method 'pull_blocks' to
+  // allow for "conventional" as well as "incremental" update. However the following
+  // principle of getting all info first (pool AND blocks) and only process txs afterwards
+  // still holds and is still respected:
   // get updated pool state first, but do not process those txes just yet,
   // since that might cause a password prompt, which would introduce a data
   // leak allowing a passive adversary with traffic analysis capability to
   // infer when we get an incoming output
-  std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> process_pool_txs;
-  update_pool_state(process_pool_txs, true);
 
   bool first = true, last = false;
   while(m_run.load(std::memory_order_relaxed) && blocks_fetched < max_blocks)
@@ -3532,11 +3727,10 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
       if (!first && blocks.empty())
       {
         m_node_rpc_proxy.set_height(m_blockchain.size());
-        refreshed = true;
         break;
       }
       if (!last)
-        tpool.submit(&waiter, [&]{pull_and_parse_next_blocks(start_height, next_blocks_start_height, short_chain_history, blocks, parsed_blocks, next_blocks, next_parsed_blocks, last, error, exception);});
+        tpool.submit(&waiter, [&]{pull_and_parse_next_blocks(first, try_incremental, start_height, next_blocks_start_height, short_chain_history, blocks, parsed_blocks, next_blocks, next_parsed_blocks, last, error, exception);});
 
       if (!first)
       {
@@ -3590,7 +3784,6 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
       if(!first && blocks_start_height == next_blocks_start_height)
       {
         m_node_rpc_proxy.set_height(m_blockchain.size());
-        refreshed = true;
         break;
       }
 
@@ -3656,8 +3849,8 @@ void wallet2::refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blo
   try
   {
     // If stop() is called we don't need to check pending transactions
-    if (check_pool && m_run.load(std::memory_order_relaxed) && !process_pool_txs.empty())
-      process_pool_state(process_pool_txs);
+    if (check_pool && m_run.load(std::memory_order_relaxed) && !m_process_pool_txs.empty())
+      process_pool_state(m_process_pool_txs);
   }
   catch (...)
   {
@@ -9849,7 +10042,7 @@ void wallet2::light_wallet_get_address_txs()
     }    
   }
   // TODO: purge old unconfirmed_txs
-  remove_obsolete_pool_txs(pool_txs);
+  remove_obsolete_pool_txs(pool_txs, false);
 
   // Calculate wallet balance
   m_light_wallet_balance = ires.total_received-wallet_total_sent;
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 3ee40a5f0..5f7a39094 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -475,7 +475,7 @@ private:
       time_t m_sent_time;
       std::vector<cryptonote::tx_destination_entry> m_dests;
       crypto::hash m_payment_id;
-      enum { pending, pending_not_in_pool, failed } m_state;
+      enum { pending, pending_in_pool, failed } m_state;
       uint64_t m_timestamp;
       uint32_t m_subaddr_account;   // subaddress account of your wallet to be used in this transfer
       std::set<uint32_t> m_subaddr_indices;  // set of address indices used as inputs in this transfer
@@ -1023,7 +1023,7 @@ private:
     bool is_deprecated() const;
     void refresh(bool trusted_daemon);
     void refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blocks_fetched);
-    void refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blocks_fetched, bool& received_money, bool check_pool = true, uint64_t max_blocks = std::numeric_limits<uint64_t>::max());
+    void refresh(bool trusted_daemon, uint64_t start_height, uint64_t & blocks_fetched, bool& received_money, bool check_pool = true, bool try_incremental = true, uint64_t max_blocks = std::numeric_limits<uint64_t>::max());
     bool refresh(bool trusted_daemon, uint64_t & blocks_fetched, bool& received_money, bool& ok);
 
     void set_refresh_type(RefreshType refresh_type) { m_refresh_type = refresh_type; }
@@ -1506,9 +1506,9 @@ private:
     bool import_key_images(signed_tx_set & signed_tx, size_t offset=0, bool only_selected_transfers=false);
     crypto::public_key get_tx_pub_key_from_received_outs(const tools::wallet2::transfer_details &td) const;
 
-    void update_pool_state(std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed = false);
+    void update_pool_state(std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed = false, bool try_incremental = false);
     void process_pool_state(const std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &txs);
-    void remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashes);
+    void remove_obsolete_pool_txs(const std::vector<crypto::hash> &tx_hashes, bool remove_if_found);
 
     std::string encrypt(const char *plaintext, size_t len, const crypto::secret_key &skey, bool authenticated = true) const;
     std::string encrypt(const epee::span<char> &span, const crypto::secret_key &skey, bool authenticated = true) const;
@@ -1706,11 +1706,15 @@ private:
     void get_short_chain_history(std::list<crypto::hash>& ids, uint64_t granularity = 1) const;
     bool clear();
     void clear_soft(bool keep_key_images=false);
-    void pull_blocks(uint64_t start_height, uint64_t& blocks_start_height, const std::list<crypto::hash> &short_chain_history, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices> &o_indices, uint64_t &current_height);
+    void pull_blocks(bool first, bool try_incremental, uint64_t start_height, uint64_t& blocks_start_height, const std::list<crypto::hash> &short_chain_history, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::block_output_indices> &o_indices, uint64_t &current_height);
     void pull_hashes(uint64_t start_height, uint64_t& blocks_start_height, const std::list<crypto::hash> &short_chain_history, std::vector<crypto::hash> &hashes);
     void fast_refresh(uint64_t stop_height, uint64_t &blocks_start_height, std::list<crypto::hash> &short_chain_history, bool force = false);
-    void pull_and_parse_next_blocks(uint64_t start_height, uint64_t &blocks_start_height, std::list<crypto::hash> &short_chain_history, const std::vector<cryptonote::block_complete_entry> &prev_blocks, const std::vector<parsed_block> &prev_parsed_blocks, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<parsed_block> &parsed_blocks, bool &last, bool &error, std::exception_ptr &exception);
+    void pull_and_parse_next_blocks(bool first, bool try_incremental, uint64_t start_height, uint64_t &blocks_start_height, std::list<crypto::hash> &short_chain_history, const std::vector<cryptonote::block_complete_entry> &prev_blocks, const std::vector<parsed_block> &prev_parsed_blocks, std::vector<cryptonote::block_complete_entry> &blocks, std::vector<parsed_block> &parsed_blocks, bool &last, bool &error, std::exception_ptr &exception);
     void process_parsed_blocks(uint64_t start_height, const std::vector<cryptonote::block_complete_entry> &blocks, const std::vector<parsed_block> &parsed_blocks, uint64_t& blocks_added, std::map<std::pair<uint64_t, uint64_t>, size_t> *output_tracker_cache = NULL);
+    bool accept_pool_tx_for_processing(const crypto::hash &txid);
+    void process_unconfirmed_transfer(bool incremental, const crypto::hash &txid, wallet2::unconfirmed_transfer_details &tx_details, bool seen_in_pool, std::chrono::system_clock::time_point now, bool refreshed);
+    void update_pool_state_by_pool_query(std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed = false);
+    void update_pool_state_from_pool_data(const cryptonote::COMMAND_RPC_GET_BLOCKS_FAST::response &res, std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> &process_txs, bool refreshed);
     uint64_t select_transfers(uint64_t needed_money, std::vector<size_t> unused_transfers_indices, std::vector<size_t>& selected_transfers) const;
     bool prepare_file_names(const std::string& file_path);
     void process_unconfirmed(const crypto::hash &txid, const cryptonote::transaction& tx, uint64_t height);
@@ -1845,6 +1849,8 @@ private:
     // If m_refresh_from_block_height is explicitly set to zero we need this to differentiate it from the case that
     // m_refresh_from_block_height was defaulted to zero.*/
     bool m_explicit_refresh_from_block_height;
+    uint64_t m_pool_info_query_time;
+    std::vector<std::tuple<cryptonote::transaction, crypto::hash, bool>> m_process_pool_txs;
     bool m_confirm_non_default_ring_size;
     AskPasswordType m_ask_password;
     uint64_t m_max_reorg_depth;