blockchain: speed up getting N blocks weights/long term weights

4 files changed, 94 insertions, 0 deletions

diff --git a/src/blockchain_db/blockchain_db.h b/src/blockchain_db/blockchain_db.h
index ed13de5b5..8eb1d7fa5 100644
--- a/src/blockchain_db/blockchain_db.h
+++ b/src/blockchain_db/blockchain_db.h
@@ -947,6 +947,17 @@ public:
   virtual size_t get_block_weight(const uint64_t& height) const = 0;
 
   /**
+   * @brief fetch the last N blocks' weights
+   *
+   * If there are fewer than N blocks, the returned array will be smaller than N
+   *
+   * @param count the number of blocks requested
+   *
+   * @return the weights
+   */
+  virtual std::vector<uint64_t> get_block_weights(uint64_t start_height, size_t count) const = 0;
+
+  /**
    * @brief fetch a block's cumulative difficulty
    *
    * The subclass should return the cumulative difficulty of the block with the
@@ -1000,6 +1011,17 @@ public:
   virtual uint64_t get_block_long_term_weight(const uint64_t& height) const = 0;
 
   /**
+   * @brief fetch the last N blocks' long term weights
+   *
+   * If there are fewer than N blocks, the returned array will be smaller than N
+   *
+   * @param count the number of blocks requested
+   *
+   * @return the weights
+   */
+  virtual std::vector<uint64_t> get_long_term_block_weights(uint64_t start_height, size_t count) const = 0;
+
+  /**
    * @brief fetch a block's hash
    *
    * The subclass should return hash of the block with the
diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
index e2db5e04e..2cc070ed8 100644
--- a/src/blockchain_db/lmdb/db_lmdb.cpp
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -2445,6 +2445,70 @@ size_t BlockchainLMDB::get_block_weight(const uint64_t& height) const
   return ret;
 }
 
+std::vector<uint64_t> BlockchainLMDB::get_block_info_64bit_fields(uint64_t start_height, size_t count, off_t offset) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  TXN_PREFIX_RDONLY();
+  RCURSOR(block_info);
+
+  const uint64_t h = height();
+  if (start_height >= h)
+    throw0(DB_ERROR(("Height " + std::to_string(start_height) + " not in blockchain").c_str()));
+
+  std::vector<uint64_t> ret;
+  ret.reserve(count);
+
+  MDB_val v;
+  uint64_t range_begin = 0, range_end = 0;
+  for (uint64_t height = start_height; height < h && count--; ++height)
+  {
+    if (height >= range_begin && height < range_end)
+    {
+      // nothing to do
+    }
+    else
+    {
+      int result = 0;
+      if (range_end > 0)
+      {
+        MDB_val k2;
+        result = mdb_cursor_get(m_cur_block_info, &k2, &v, MDB_NEXT_MULTIPLE);
+        range_begin = ((const mdb_block_info*)v.mv_data)->bi_height;
+        range_end = range_begin + v.mv_size / sizeof(mdb_block_info); // whole records please
+        if (height < range_begin || height >= range_end)
+          throw0(DB_ERROR(("Height " + std::to_string(height) + " not included in multiple record range: " + std::to_string(range_begin) + "-" + std::to_string(range_end)).c_str()));
+      }
+      else
+      {
+        v.mv_size = sizeof(uint64_t);
+        v.mv_data = (void*)&height;
+        result = mdb_cursor_get(m_cur_block_info, (MDB_val *)&zerokval, &v, MDB_GET_BOTH);
+        range_begin = height;
+        range_end = range_begin + 1;
+      }
+      if (result)
+        throw0(DB_ERROR(lmdb_error("Error attempting to retrieve block_info from the db: ", result).c_str()));
+    }
+    const mdb_block_info *bi = ((const mdb_block_info *)v.mv_data) + (height - range_begin);
+    ret.push_back(*(const uint64_t*)(((const char*)bi) + offset));
+  }
+
+  TXN_POSTFIX_RDONLY();
+  return ret;
+}
+
+std::vector<uint64_t> BlockchainLMDB::get_block_weights(uint64_t start_height, size_t count) const
+{
+  return get_block_info_64bit_fields(start_height, count, offsetof(mdb_block_info, bi_weight));
+}
+
+std::vector<uint64_t> BlockchainLMDB::get_long_term_block_weights(uint64_t start_height, size_t count) const
+{
+  return get_block_info_64bit_fields(start_height, count, offsetof(mdb_block_info, bi_long_term_block_weight));
+}
+
 difficulty_type BlockchainLMDB::get_block_cumulative_difficulty(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__ << "  height: " << height);
diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h
index 82016c17a..fcf87b646 100644
--- a/src/blockchain_db/lmdb/db_lmdb.h
+++ b/src/blockchain_db/lmdb/db_lmdb.h
@@ -219,6 +219,8 @@ public:
 
   virtual size_t get_block_weight(const uint64_t& height) const;
 
+  virtual std::vector<uint64_t> get_block_weights(uint64_t start_height, size_t count) const;
+
   virtual difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const;
 
   virtual difficulty_type get_block_difficulty(const uint64_t& height) const;
@@ -227,6 +229,8 @@ public:
 
   virtual uint64_t get_block_long_term_weight(const uint64_t& height) const;
 
+  virtual std::vector<uint64_t> get_long_term_block_weights(uint64_t start_height, size_t count) const;
+
   virtual crypto::hash get_block_hash_from_height(const uint64_t& height) const;
 
   virtual std::vector<block> get_blocks_range(const uint64_t& h1, const uint64_t& h2) const;
@@ -394,6 +398,8 @@ private:
 
   virtual uint64_t get_database_size() const;
 
+  std::vector<uint64_t> get_block_info_64bit_fields(uint64_t start_height, size_t count, off_t offset) const;
+
   // fix up anything that may be wrong due to past bugs
   virtual void fixup();
 
diff --git a/src/blockchain_db/testdb.h b/src/blockchain_db/testdb.h
index ac1849b5f..2ead91c3e 100644
--- a/src/blockchain_db/testdb.h
+++ b/src/blockchain_db/testdb.h
@@ -72,10 +72,12 @@ public:
   virtual std::vector<uint64_t> get_block_cumulative_rct_outputs(const std::vector<uint64_t> &heights) const { return {}; }
   virtual uint64_t get_top_block_timestamp() const { return 0; }
   virtual size_t get_block_weight(const uint64_t& height) const { return 128; }
+  virtual std::vector<uint64_t> get_block_weights(uint64_t start_height, size_t count) const { return {}; }
   virtual cryptonote::difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const { return 10; }
   virtual cryptonote::difficulty_type get_block_difficulty(const uint64_t& height) const { return 0; }
   virtual uint64_t get_block_already_generated_coins(const uint64_t& height) const { return 10000000000; }
   virtual uint64_t get_block_long_term_weight(const uint64_t& height) const { return 128; }
+  virtual std::vector<uint64_t> get_long_term_block_weights(uint64_t start_height, size_t count) const { return {}; }
   virtual crypto::hash get_block_hash_from_height(const uint64_t& height) const { return crypto::hash(); }
   virtual std::vector<cryptonote::block> get_blocks_range(const uint64_t& h1, const uint64_t& h2) const { return std::vector<cryptonote::block>(); }
   virtual std::vector<crypto::hash> get_hashes_range(const uint64_t& h1, const uint64_t& h2) const { return std::vector<crypto::hash>(); }