Implement readline(s) for all stream-seek classes

disk_objectstore/container.py

@@ -15,7 +15,7 @@
 from contextlib import contextmanager
 from enum import Enum
 from pathlib import Path
-from typing import TYPE_CHECKING, overload
+from typing import TYPE_CHECKING, BinaryIO, ContextManager, overload
 
 from sqlalchemy.engine import Connection, Engine
 from sqlalchemy.orm.session import Session
@@ -576,7 +576,7 @@ def _get_objects_stream_meta_generator(  # pylint: disable=too-many-branches,too
         # to order in python instead
         session = self._get_operation_session()
 
-        obj_reader: StreamReadBytesType
+        obj_reader: StreamSeekBytesType
 
         if len(hashkeys_set) <= self._MAX_CHUNK_ITERATE_LENGTH:
             # Operate in chunks, due to the SQLite limits
@@ -1541,7 +1541,7 @@ def add_streamed_object_to_pack(  # pylint: disable=too-many-arguments
         )
 
         # Close the callback so the bar doesn't remain open
-        streams[0].close_callback()  # type: ignore[union-attr]
+        streams[0].close_callback()  # type: ignore[attr-defined]
 
         return retval[0]
 
@@ -1688,10 +1688,11 @@ def add_streamed_objects_to_pack(  # pylint: disable=too-many-locals, too-many-b
                     # Get next stream, possibly preparing it to be open, or wrapping it
                     # if it is already open so it does not get open again
                     next_stream = working_stream_list.pop()
+                    stream_context_manager: ContextManager[StreamSeekBytesType | BinaryIO]
                     if open_streams:
-                        stream_context_manager = next_stream
+                        stream_context_manager = next_stream  # type: ignore[assignment]
                     else:
-                        stream_context_manager = nullcontext(next_stream)  # type: ignore[assignment]
+                        stream_context_manager = nullcontext(next_stream)  # type: ignore[arg-type]
 
                     if callback:
                         since_last_update += 1
@@ -1708,12 +1709,14 @@ def add_streamed_objects_to_pack(  # pylint: disable=too-many-locals, too-many-b
                     obj_dict['compressed'] = compress
                     obj_dict['offset'] = pack_handle.tell()
                     with stream_context_manager as stream:
+                        # BinaryIO from LazyOpener and StreamSeekBytesType both have all required methods
+                        stream_typed: StreamSeekBytesType = stream  # type: ignore[assignment]
                         if no_holes and no_holes_read_twice:
                             # Compute the hash key before writing (I just read once)
                             (
                                 obj_dict['hashkey'],
                                 obj_dict['size'],
-                            ) = compute_hash_and_size(stream, hash_type=self.hash_type)
+                            ) = compute_hash_and_size(stream_typed, hash_type=self.hash_type)
                             if obj_dict['hashkey'] in known_packed_hashkeys:
                                 # I recomputed the hashkey and this was already there: I don't try to write on disk,
                                 # but I just continue.
@@ -1724,14 +1727,14 @@ def add_streamed_objects_to_pack(  # pylint: disable=too-many-locals, too-many-b
                             # I didn't continue. Then, I need to store on disk, as it is a new unknown object.
                             # I therefore need to seek back to zero, because the next line will read it again
                             # in _write_data_to_packfile.
-                            stream.seek(0)
+                            stream_typed.seek(0)
 
                         (
                             obj_dict['size'],
                             obj_dict['hashkey'],
                         ) = self._write_data_to_packfile(
                             pack_handle=pack_handle,
-                            read_handle=stream,
+                            read_handle=stream_typed,
                             compress=compress,
                             hash_type=self.hash_type,
                         )