Source code for swh.objstorage.objstorage

# Copyright (C) 2015-2022  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

import abc
import bz2
from itertools import dropwhile, islice
import lzma
from typing import Callable, Dict, Iterator, List, Optional
import zlib

from swh.model import hashutil

from .constants import DEFAULT_LIMIT, ID_HASH_ALGO
from .exc import ObjNotFoundError
from .interface import CompositeObjId, ObjId, ObjStorageInterface


[docs]def objid_to_default_hex(obj_id: ObjId) -> str: """Converts SHA1 hashes and multi-hashes to the hexadecimal representation of the SHA1.""" if isinstance(obj_id, bytes): return hashutil.hash_to_hex(obj_id) elif isinstance(obj_id, str): return obj_id else: return hashutil.hash_to_hex(obj_id[ID_HASH_ALGO])
[docs]def compute_hash(content, algo=ID_HASH_ALGO): """Compute the content's hash. Args: content (bytes): The raw content to hash hash_name (str): Hash's name (default to ID_HASH_ALGO) Returns: The ID_HASH_ALGO for the content """ return ( hashutil.MultiHash.from_data( content, hash_names=[algo], ) .digest() .get(algo) )
[docs]class NullCompressor:
[docs] def compress(self, data): return data
[docs] def flush(self): return b""
[docs]class NullDecompressor:
[docs] def decompress(self, data: bytes) -> bytes: return data
@property def unused_data(self) -> bytes: return b""
class _CompressorProtocol: def compress(self, data: bytes) -> bytes: ... def flush(self) -> bytes: ... class _DecompressorProtocol: def decompress(self, data: bytes) -> bytes: ... unused_data: bytes decompressors: Dict[str, Callable[[], _DecompressorProtocol]] = { "bz2": bz2.BZ2Decompressor, # type: ignore "lzma": lzma.LZMADecompressor, # type: ignore "gzip": lambda: zlib.decompressobj(wbits=31), # type: ignore "zlib": zlib.decompressobj, # type: ignore "none": NullDecompressor, # type: ignore } compressors: Dict[str, Callable[[], _CompressorProtocol]] = { "bz2": bz2.BZ2Compressor, # type: ignore "lzma": lzma.LZMACompressor, # type: ignore "gzip": lambda: zlib.compressobj(wbits=31), # type: ignore "zlib": zlib.compressobj, # type: ignore "none": NullCompressor, # type: ignore }
[docs]class ObjStorage(metaclass=abc.ABCMeta): def __init__(self, *, allow_delete=False, **kwargs): # A more complete permission system could be used in place of that if # it becomes needed self.allow_delete = allow_delete
[docs] def add_batch(self: ObjStorageInterface, contents, check_presence=True) -> Dict: summary = {"object:add": 0, "object:add:bytes": 0} for obj_id, content in contents.items(): if check_presence and obj_id in self: continue self.add(content, obj_id, check_presence=False) summary["object:add"] += 1 summary["object:add:bytes"] += len(content) return summary
[docs] def restore(self: ObjStorageInterface, content: bytes, obj_id: ObjId) -> None: # check_presence to false will erase the potential previous content. self.add(content, obj_id, check_presence=False)
[docs] def get_batch( self: ObjStorageInterface, obj_ids: List[ObjId] ) -> Iterator[Optional[bytes]]: for obj_id in obj_ids: try: yield self.get(obj_id) except ObjNotFoundError: yield None
[docs] @abc.abstractmethod def delete(self, obj_id: ObjId): if not self.allow_delete: raise PermissionError("Delete is not allowed.")
[docs] def list_content( self: ObjStorageInterface, last_obj_id: Optional[ObjId] = None, limit: int = DEFAULT_LIMIT, ) -> Iterator[CompositeObjId]: it = iter(self) if last_obj_id: last_obj_id_hex = objid_to_default_hex(last_obj_id) it = dropwhile(lambda x: objid_to_default_hex(x) <= last_obj_id_hex, it) return islice(it, limit)