expose rocksdb multi_get api for column families

-use multi_get for fetching tx hashes when they're not all held in memory

scribe/blockchain/service.py

@@ -1255,8 +1255,8 @@ class BlockchainProcessorService(BlockchainService):
         else:
             tx_nums = self.hashX_history_cache[hashX]
         history = ''
-        for tx_num in tx_nums:
-            history += f'{hash_to_hex_str(self.db.get_tx_hash(tx_num))}:{bisect_right(self.db.tx_counts, tx_num):d}:'
+        for tx_num, tx_hash in zip(tx_nums, self.db.get_tx_hashes(tx_nums)):
+            history += f'{hash_to_hex_str(tx_hash)}:{bisect_right(self.db.tx_counts, tx_num):d}:'
         self.hashX_full_cache[hashX] = history
         return history
 
@@ -1269,8 +1269,8 @@ class BlockchainProcessorService(BlockchainService):
         else:
             tx_nums = self.hashX_history_cache[hashX]
         history = ''
-        for tx_num in tx_nums:
-            history += f'{hash_to_hex_str(self.db.get_tx_hash(tx_num))}:{bisect_right(self.db.tx_counts, tx_num):d}:'
+        for tx_num, tx_hash in zip(tx_nums, self.db.get_tx_hashes(tx_nums)):
+            history += f'{hash_to_hex_str(tx_hash)}:{bisect_right(self.db.tx_counts, tx_num):d}:'
         for tx_hash, height in new_history:
             history += f'{hash_to_hex_str(tx_hash)}:{height:d}:'
         if history:

scribe/db/db.py

@@ -863,6 +863,11 @@ class HubDB:
             return self.total_transactions[tx_num]
         return self.prefix_db.tx_hash.get(tx_num, deserialize_value=False)
 
+    def get_tx_hashes(self, tx_nums: List[int]) -> List[Optional[bytes]]:
+        if self._cache_all_tx_hashes:
+            return [None if tx_num > self.db_tx_count else self.total_transactions[tx_num] for tx_num in tx_nums]
+        return self.prefix_db.tx_hash.multi_get([(tx_num,) for tx_num in tx_nums], deserialize_value=False)
+
     def get_raw_mempool_tx(self, tx_hash: bytes) -> Optional[bytes]:
         return self.prefix_db.mempool_tx.get(tx_hash, deserialize_value=False)
 
@@ -1042,10 +1047,11 @@ class HubDB:
         tx_nums = await run_in_executor(self._executor, self.read_history, hashX, limit)
         history = []
         append_history = history.append
-        for tx_num in tx_nums:
-            tx_hash = self.get_tx_hash(tx_num) \
-                if self._cache_all_tx_hashes else await run_in_executor(self._executor, self.get_tx_hash, tx_num)
-            append_history((tx_hash, bisect_right(self.tx_counts, tx_num)))
+        while tx_nums:
+            batch, tx_nums = tx_nums[:100], tx_nums[100:]
+            batch_result = self.get_tx_hashes(batch) if self._cache_all_tx_hashes else await run_in_executor(self._executor, self.get_tx_hashes, batch)
+            for tx_num, tx_hash in zip(batch, batch_result):
+                append_history((tx_hash, bisect_right(self.tx_counts, tx_num)))
             await asyncio.sleep(0)
         return history
 

scribe/db/interface.py

@@ -88,6 +88,22 @@ class PrefixRow(metaclass=PrefixRowType):
         if v:
             return v if not deserialize_value else self.unpack_value(v)
 
+    def multi_get(self, key_args: typing.List[typing.Tuple], fill_cache=True, deserialize_value=True):
+        packed_keys = {tuple(args): self.pack_key(*args) for args in key_args}
+        result = {
+            k[-1]: v for k, v in (
+                self._db.multi_get([(self._column_family, packed_keys[tuple(args)]) for args in key_args],
+                                   fill_cache=fill_cache) or {}
+            ).items()
+        }
+
+        def handle_value(v):
+            return None if v is None else v if not deserialize_value else self.unpack_value(v)
+
+        return [
+            handle_value(result[packed_keys[tuple(k_args)]]) for k_args in key_args
+        ]
+
     def get_pending(self, *key_args, fill_cache=True, deserialize_value=True):
         packed_key = self.pack_key(*key_args)
         last_op = self._op_stack.get_last_op_for_key(packed_key)