faster read_headers

lbry/wallet/server/leveldb.py

@@ -415,14 +415,14 @@ class LevelDB:
         # Truncate header_mc: header count is 1 more than the height.
         self.header_mc.truncate(height + 1)
 
-    async def raw_header(self, height):
+    def raw_header(self, height):
         """Return the binary header at the given height."""
-        header, n = await self.read_headers(height, 1)
+        header, n = self.read_headers(height, 1)
         if n != 1:
             raise IndexError(f'height {height:,d} out of range')
         return header
 
-    async def read_headers(self, start_height, count, b16=False, b64=False):
+    def read_headers(self, start_height, count) -> typing.Tuple[bytes, int]:
         """Requires start_height >= 0, count >= 0.  Reads as many headers as
         are available starting at start_height up to count.  This
         would be zero if start_height is beyond self.db_height, for
@@ -436,25 +436,11 @@ class LevelDB:
             raise self.DBError(f'{count:,d} headers starting at '
                                f'{start_height:,d} not on disk')
 
-        def read_headers():
-            # Read some from disk
         disk_count = max(0, min(count, self.db_height + 1 - start_height))
         if disk_count:
-                headers = b''.join(self.headers[start_height:start_height+disk_count])
-                if b16:
-                    return headers.hex().encode(), disk_count
-                elif b64:
-                    compressobj = zlib.compressobj(wbits=-15, level=1, memLevel=9)
-                    return base64.b64encode(compressobj.compress(headers) + compressobj.flush()), disk_count
-                return headers, disk_count
+            return b''.join(self.headers[start_height:start_height + disk_count]), disk_count
         return b'', 0
 
-        if not b16 and not b64:
-            disk_count = max(0, min(count, self.db_height + 1 - start_height))
-            return b''.join(header for header in self.headers[start_height:start_height + disk_count]), disk_count
-
-        return await asyncio.get_event_loop().run_in_executor(self.executor, read_headers)
-
     def fs_tx_hash(self, tx_num):
         """Return a par (tx_hash, tx_height) for the given tx number.
 

lbry/wallet/server/peers.py

@@ -319,7 +319,7 @@ class PeerManager:
 
         # Check prior header too in case of hard fork.
         check_height = min(our_height, their_height)
-        raw_header = await self.db.raw_header(check_height)
+        raw_header = self.db.raw_header(check_height)
         if ptuple >= (1, 4):
             ours = raw_header.hex()
             message = 'blockchain.block.header'

lbry/wallet/server/session.py

@@ -607,7 +607,7 @@ class SessionManager:
     async def raw_header(self, height):
         """Return the binary header at the given height."""
         try:
-            return await self.db.raw_header(height)
+            return self.db.raw_header(height)
         except IndexError:
             raise RPCError(BAD_REQUEST, f'height {height:,d} '
                                         'out of range') from None
@@ -1329,31 +1329,12 @@ class LBRYElectrumX(SessionBase):
                            f'require header height {height:,d} <= '
                            f'cp_height {cp_height:,d} <= '
                            f'chain height {max_height:,d}')
-        branch, root = await self.db.header_branch_and_root(cp_height + 1,
-                                                            height)
+        branch, root = await self.db.header_branch_and_root(cp_height + 1, height)
         return {
             'branch': [hash_to_hex_str(elt) for elt in branch],
             'root': hash_to_hex_str(root),
         }
 
-    async def block_header(self, height, cp_height=0):
-        """Return a raw block header as a hexadecimal string, or as a
-        dictionary with a merkle proof."""
-        height = non_negative_integer(height)
-        cp_height = non_negative_integer(cp_height)
-        raw_header_hex = (await self.session_mgr.raw_header(height)).hex()
-        if cp_height == 0:
-            return raw_header_hex
-        result = {'header': raw_header_hex}
-        result.update(await self._merkle_proof(cp_height, height))
-        return result
-
-    async def block_header_13(self, height):
-        """Return a raw block header as a hexadecimal string.
-
-        height: the header's height"""
-        return await self.block_header(height)
-
     async def block_headers(self, start_height, count, cp_height=0, b64=False):
         """Return count concatenated block headers as hex for the main chain;
         starting at start_height.
@@ -1367,9 +1348,15 @@ class LBRYElectrumX(SessionBase):
 
         max_size = self.MAX_CHUNK_SIZE
         count = min(count, max_size)
-        headers, count = await self.db.read_headers(start_height, count, b16=not b64, b64=b64)
+        headers, count = self.db.read_headers(start_height, count)
+
+        if b64:
+            compressobj = zlib.compressobj(wbits=-15, level=1, memLevel=9)
+            headers = base64.b64encode(compressobj.compress(headers) + compressobj.flush()).decode()
+        else:
+            headers = headers.hex()
         result = {
-            'base64' if b64 else 'hex': headers.decode(),
+            'base64' if b64 else 'hex': headers,
             'count': count,
             'max': max_size
         }
@@ -1385,7 +1372,7 @@ class LBRYElectrumX(SessionBase):
         index = non_negative_integer(index)
         size = self.coin.CHUNK_SIZE
         start_height = index * size
-        headers, _ = await self.db.read_headers(start_height, size)
+        headers, _ = self.db.read_headers(start_height, size)
         return headers.hex()
 
     async def block_get_header(self, height):
@@ -1537,6 +1524,7 @@ class LBRYElectrumX(SessionBase):
             assert_tx_hash(tx_hash)
         batch_result = await self.db.fs_transactions(tx_hashes)
         needed_merkles = {}
+
         for tx_hash in tx_hashes:
             if tx_hash in batch_result and batch_result[tx_hash][0]:
                 continue