Source code for swh.vault.to_disk

# Copyright (C) 2016-2020 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 collections
import functools
import os
from typing import Any, Dict, Iterator, List

from swh.model import hashutil
from swh.model.from_disk import DentryPerms, mode_to_perms
from swh.storage.algos.dir_iterators import dir_iterator
from swh.storage.interface import StorageInterface

SKIPPED_MESSAGE = (
    b"This content has not been retrieved in the "
    b"Software Heritage archive due to its size."
)

HIDDEN_MESSAGE = b"This content is hidden."


[docs]def get_filtered_files_content( storage: StorageInterface, files_data: List[Dict] ) -> Iterator[Dict[str, Any]]: """Retrieve the files specified by files_data and apply filters for skipped and missing contents. Args: storage: the storage from which to retrieve the objects files_data: list of file entries as returned by directory_ls() Yields: The entries given in files_data with a new 'content' key that points to the file content in bytes. The contents can be replaced by a specific message to indicate that they could not be retrieved (either due to privacy policy or because their sizes were too big for us to archive it). """ for file_data in files_data: status = file_data["status"] if status == "absent": content = SKIPPED_MESSAGE elif status == "hidden": content = HIDDEN_MESSAGE elif status == "visible": sha1 = file_data["sha1"] data = storage.content_get_data(sha1) if data is None: content = SKIPPED_MESSAGE else: content = data else: assert False, ( f"unexpected status {status!r} " f"for content {hashutil.hash_to_hex(file_data['target'])}" ) yield {"content": content, **file_data}
[docs]def apply_chunked(func, input_list, chunk_size): """Apply func on input_list divided in chunks of size chunk_size""" for i in range(0, len(input_list), chunk_size): yield from func(input_list[i : i + chunk_size])
[docs]class DirectoryBuilder: """Reconstructs the on-disk representation of a directory in the storage. """ def __init__(self, storage, root, dir_id): """Initialize the directory builder. Args: storage: the storage object root: the path where the directory should be reconstructed dir_id: the identifier of the directory in the storage """ self.storage = storage self.root = root self.dir_id = dir_id
[docs] def build(self): """Perform the reconstruction of the directory in the given root.""" # Retrieve data from the database. # Split into files, revisions and directory data. entries = collections.defaultdict(list) for entry in dir_iterator(self.storage, self.dir_id): entries[entry["type"]].append(entry) # Recreate the directory's subtree and then the files into it. self._create_tree(entries["dir"]) self._create_files(entries["file"]) self._create_revisions(entries["rev"])
def _create_tree(self, directories): """Create a directory tree from the given paths The tree is created from `root` and each given directory in `directories` will be created. """ # Directories are sorted by depth so they are created in the # right order bsep = os.path.sep.encode() directories = sorted(directories, key=lambda x: len(x["path"].split(bsep))) for dir in directories: os.makedirs(os.path.join(self.root, dir["path"])) def _create_files(self, files_data): """Create the files in the tree and fetch their contents.""" f = functools.partial(get_filtered_files_content, self.storage) files_data = apply_chunked(f, files_data, 1000) for file_data in files_data: path = os.path.join(self.root, file_data["path"]) self._create_file(path, file_data["content"], file_data["perms"]) def _create_revisions(self, revs_data): """Create the revisions in the tree as broken symlinks to the target identifier.""" for file_data in revs_data: path = os.path.join(self.root, file_data["path"]) target = hashutil.hash_to_hex(file_data["target"]) self._create_file(path, target, mode=DentryPerms.symlink) def _create_file(self, path, content, mode=DentryPerms.content): """Create the given file and fill it with content.""" perms = mode_to_perms(mode) if perms == DentryPerms.symlink: os.symlink(content, path) else: with open(path, "wb") as f: f.write(content) os.chmod(path, perms.value)