RPC and ZeroMQ APIs to support p2pool

Adds the following:

- "get_miner_data" to RPC API
- "json-miner-data" to ZeroMQ subscriber contexts

Both provide the necessary data to create a custom block template. They are used by p2pool.

Data provided:

- major fork version
- current height
- previous block id
- RandomX seed hash
- network difficulty
- median block weight
- coins mined by the network so far
- mineable mempool transactions

1 files changed, 35 insertions, 4 deletions

diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index a7e96e23a..84605d6f5 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -913,6 +913,32 @@ namespace cryptonote
     }, false, category);
   }
   //------------------------------------------------------------------
+  void tx_memory_pool::get_block_template_backlog(std::vector<tx_block_template_backlog_entry>& backlog, bool include_sensitive) const
+  {
+    CRITICAL_REGION_LOCAL(m_transactions_lock);
+    CRITICAL_REGION_LOCAL1(m_blockchain);
+    const relay_category category = include_sensitive ? relay_category::all : relay_category::broadcasted;
+    backlog.reserve(m_blockchain.get_txpool_tx_count(include_sensitive));
+    txpool_tx_meta_t tmp_meta;
+    m_blockchain.for_all_txpool_txes([this, &backlog, &tmp_meta](const crypto::hash &txid, const txpool_tx_meta_t &meta, const cryptonote::blobdata_ref *bd){
+      transaction tx;
+      if (!(meta.pruned ? parse_and_validate_tx_base_from_blob(*bd, tx) : parse_and_validate_tx_from_blob(*bd, tx)))
+      {
+        MERROR("Failed to parse tx from txpool");
+        // continue
+        return true;
+      }
+      tx.set_hash(txid);
+
+      tmp_meta = meta;
+
+      if (is_transaction_ready_to_go(tmp_meta, txid, *bd, tx))
+        backlog.push_back({txid, meta.weight, meta.fee});
+
+      return true;
+    }, true, category);
+  }
+  //------------------------------------------------------------------
   void tx_memory_pool::get_transaction_stats(struct txpool_stats& stats, bool include_sensitive) const
   {
     CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -1222,11 +1248,11 @@ namespace cryptonote
     return ret;
   }
   //---------------------------------------------------------------------------------
-  bool tx_memory_pool::is_transaction_ready_to_go(txpool_tx_meta_t& txd, const crypto::hash &txid, const cryptonote::blobdata &txblob, transaction &tx) const
+  bool tx_memory_pool::is_transaction_ready_to_go(txpool_tx_meta_t& txd, const crypto::hash &txid, const cryptonote::blobdata_ref& txblob, transaction &tx) const
   {
-    struct transction_parser
+    struct transaction_parser
     {
-      transction_parser(const cryptonote::blobdata &txblob, const crypto::hash &txid, transaction &tx): txblob(txblob), txid(txid), tx(tx), parsed(false) {}
+      transaction_parser(const cryptonote::blobdata_ref &txblob, const crypto::hash &txid, transaction &tx): txblob(txblob), txid(txid), tx(tx), parsed(false) {}
       cryptonote::transaction &operator()()
       {
         if (!parsed)
@@ -1238,7 +1264,7 @@ namespace cryptonote
         }
         return tx;
       }
-      const cryptonote::blobdata &txblob;
+      const cryptonote::blobdata_ref &txblob;
       const crypto::hash &txid;
       transaction &tx;
       bool parsed;
@@ -1289,6 +1315,11 @@ namespace cryptonote
     return true;
   }
   //---------------------------------------------------------------------------------
+  bool tx_memory_pool::is_transaction_ready_to_go(txpool_tx_meta_t& txd, const crypto::hash &txid, const cryptonote::blobdata& txblob, transaction &tx) const
+  {
+    return is_transaction_ready_to_go(txd, txid, cryptonote::blobdata_ref{txblob.data(), txblob.size()}, tx);
+  }
+  //---------------------------------------------------------------------------------
   bool tx_memory_pool::have_key_images(const std::unordered_set<crypto::key_image>& k_images, const transaction_prefix& tx)
   {
     for(size_t i = 0; i!= tx.vin.size(); i++)