# SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD # SPDX-License-Identifier: Apache-2.0 import os from datetime import datetime from typing import List, Optional, Tuple, Union from .entry import Entry from .exceptions import FatalError, WriteDirectoryException from .fat import FAT, Cluster from .fatfs_state import FATFSState from .long_filename_utils import (build_lfn_full_name, build_lfn_unique_entry_name_order, get_required_lfn_entries_count, split_name_to_lfn_entries, split_name_to_lfn_entry_blocks) from .utils import (DATETIME, MAX_EXT_SIZE, MAX_NAME_SIZE, FATDefaults, build_lfn_short_entry_name, lfn_checksum, required_clusters_count, split_content_into_sectors, split_to_name_and_extension) class File: """ The class File provides API to write into the files. It represents file in the FS. """ ATTR_ARCHIVE: int = 0x20 ENTITY_TYPE: int = ATTR_ARCHIVE def __init__(self, name: str, fat: FAT, fatfs_state: FATFSState, entry: Entry, extension: str = '') -> None: self.name: str = name self.extension: str = extension self.fatfs_state: FATFSState = fatfs_state self.fat: FAT = fat self.size: int = 0 self._first_cluster: Optional[Cluster] = None self._entry: Entry = entry @property def entry(self) -> Entry: return self._entry @property def first_cluster(self) -> Optional[Cluster]: return self._first_cluster @first_cluster.setter def first_cluster(self, value: Cluster) -> None: self._first_cluster = value def name_equals(self, name: str, extension: str) -> bool: return self.name == name and self.extension == extension def write(self, content: bytes) -> None: self.entry.update_content_size(len(content)) # we assume that the correct amount of clusters is allocated current_cluster = self._first_cluster for content_part in split_content_into_sectors(content, self.fatfs_state.boot_sector_state.sector_size): content_as_list = content_part if current_cluster is None: raise FatalError('No free space left!') address: int = current_cluster.cluster_data_address self.fatfs_state.binary_image[address: address + len(content_part)] = content_as_list current_cluster = current_cluster.next_cluster class Directory: """ The Directory class provides API to add files and directories into the directory and to find the file according to path and write it. """ ATTR_DIRECTORY: int = 0x10 ATTR_ARCHIVE: int = 0x20 ENTITY_TYPE: int = ATTR_DIRECTORY CURRENT_DIRECTORY = '.' PARENT_DIRECTORY = '..' def __init__(self, name, fat, fatfs_state, entry=None, cluster=None, size=None, extension='', parent=None): # type: (str, FAT, FATFSState, Optional[Entry], Cluster, Optional[int], str, Directory) -> None self.name: str = name self.fatfs_state: FATFSState = fatfs_state self.extension: str = extension self.fat: FAT = fat self.size: int = size or self.fatfs_state.boot_sector_state.sector_size # if directory is root its parent is itself self.parent: Directory = parent or self self._first_cluster: Cluster = cluster # entries will be initialized after the cluster allocation self.entries: List[Entry] = [] self.entities: List[Union[File, Directory]] = [] # type: ignore self._entry = entry # currently not in use (will use later for e.g. modification time, etc.) @property def is_root(self) -> bool: return self.parent is self @property def first_cluster(self) -> Cluster: return self._first_cluster @first_cluster.setter def first_cluster(self, value: Cluster) -> None: self._first_cluster = value def name_equals(self, name: str, extension: str) -> bool: return self.name == name and self.extension == extension @property def entries_count(self) -> int: entries_count_: int = self.size // FATDefaults.ENTRY_SIZE return entries_count_ def create_entries(self, cluster: Cluster) -> List[Entry]: return [Entry(entry_id=i, parent_dir_entries_address=cluster.cluster_data_address, fatfs_state=self.fatfs_state) for i in range(self.entries_count)] def init_directory(self) -> None: self.entries = self.create_entries(self._first_cluster) # the root directory doesn't contain link to itself nor the parent if self.is_root: return # if the directory is not root we initialize the reference to itself and to the parent directory for dir_id, name_ in ((self, self.CURRENT_DIRECTORY), (self.parent, self.PARENT_DIRECTORY)): new_dir_: Entry = self.find_free_entry() or self.chain_directory() new_dir_.allocate_entry(first_cluster_id=dir_id.first_cluster.id, entity_name=name_, entity_extension='', entity_type=dir_id.ENTITY_TYPE) def lookup_entity(self, object_name: str, extension: str): # type: ignore for entity in self.entities: if entity.name == object_name and entity.extension == extension: return entity return None @staticmethod def _is_end_of_path(path_as_list: List[str]) -> bool: """ :param path_as_list: path split into the list :returns: True if the file is the leaf of the directory tree, False otherwise The method is part of the base of recursion, determines if the path is target file or directory in the tree folder structure. """ return len(path_as_list) == 1 def recursive_search(self, path_as_list, current_dir): # type: ignore name, extension = split_to_name_and_extension(path_as_list[0]) next_obj = current_dir.lookup_entity(name, extension) if next_obj is None: raise FileNotFoundError('No such file or directory!') if self._is_end_of_path(path_as_list) and next_obj.name_equals(name, extension): return next_obj return self.recursive_search(path_as_list[1:], next_obj) def find_free_entry(self) -> Optional[Entry]: for entry in self.entries: if entry.is_empty: return entry return None def _extend_directory(self) -> None: current: Cluster = self.first_cluster while current.next_cluster is not None: current = current.next_cluster new_cluster: Cluster = self.fat.find_free_cluster() current.set_in_fat(new_cluster.id) assert current is not new_cluster current.next_cluster = new_cluster self.entries += self.create_entries(new_cluster) def chain_directory(self) -> Entry: """ :returns: First free entry The method adds new Cluster to the Directory and returns first free entry. """ self._extend_directory() free_entry: Entry = self.find_free_entry() if free_entry is None: raise FatalError('No more space left!') return free_entry @staticmethod def allocate_long_name_object(free_entry, name, extension, target_dir, free_cluster, entity_type, date, time): # type: (Entry, str, str, Directory, Cluster, int, DATETIME, DATETIME) -> Tuple[Cluster, Entry, Directory] lfn_full_name: str = build_lfn_full_name(name, extension) lfn_unique_entry_order: int = build_lfn_unique_entry_name_order(target_dir.entities, name) lfn_short_entry_name: str = build_lfn_short_entry_name(name, extension, lfn_unique_entry_order) checksum: int = lfn_checksum(lfn_short_entry_name) entries_count: int = get_required_lfn_entries_count(lfn_full_name) # entries in long file name entries chain starts with the last entry split_names_reversed = reversed(list(enumerate(split_name_to_lfn_entries(lfn_full_name, entries_count)))) for i, name_split_to_entry in split_names_reversed: order: int = i + 1 blocks_: List[bytes] = split_name_to_lfn_entry_blocks(name_split_to_entry) lfn_names: List[bytes] = list(map(lambda x: x.lower(), blocks_)) free_entry.allocate_entry(first_cluster_id=free_cluster.id, entity_name=name, entity_extension=extension, entity_type=entity_type, lfn_order=order, lfn_names=lfn_names, lfn_checksum_=checksum, lfn_is_last=order == entries_count) free_entry = target_dir.find_free_entry() or target_dir.chain_directory() free_entry.allocate_entry(first_cluster_id=free_cluster.id, entity_name=lfn_short_entry_name[:MAX_NAME_SIZE], entity_extension=lfn_short_entry_name[MAX_NAME_SIZE:], entity_type=entity_type, lfn_order=Entry.SHORT_ENTRY_LN, date=date, time=time) return free_cluster, free_entry, target_dir def allocate_object(self, name, entity_type, object_timestamp_, path_from_root=None, extension=''): # type: (str, int, datetime, Optional[List[str]], str) -> Tuple[Cluster, Entry, Directory] """ Method finds the target directory in the path and allocates cluster (both the record in FAT and cluster in the data region) and entry in the specified directory """ free_cluster: Cluster = self.fat.find_free_cluster() target_dir: Directory = self if not path_from_root else self.recursive_search(path_from_root, self) free_entry: Entry = target_dir.find_free_entry() or target_dir.chain_directory() name_fits_short_struct: bool = len(name) <= MAX_NAME_SIZE and len(extension) <= MAX_EXT_SIZE fatfs_date_ = (object_timestamp_.year, object_timestamp_.month, object_timestamp_.day) fatfs_time_ = (object_timestamp_.hour, object_timestamp_.minute, object_timestamp_.second) if not self.fatfs_state.long_names_enabled or name_fits_short_struct: free_entry.allocate_entry(first_cluster_id=free_cluster.id, entity_name=name, entity_extension=extension, date=fatfs_date_, time=fatfs_time_, fits_short=True, entity_type=entity_type) return free_cluster, free_entry, target_dir return self.allocate_long_name_object(free_entry=free_entry, name=name, extension=extension, target_dir=target_dir, free_cluster=free_cluster, entity_type=entity_type, date=fatfs_date_, time=fatfs_time_) def new_file(self, name: str, extension: str, path_from_root: Optional[List[str]], object_timestamp_: datetime) -> None: free_cluster, free_entry, target_dir = self.allocate_object(name=name, extension=extension, entity_type=Directory.ATTR_ARCHIVE, path_from_root=path_from_root, object_timestamp_=object_timestamp_) file: File = File(name=name, fat=self.fat, extension=extension, fatfs_state=self.fatfs_state, entry=free_entry) file.first_cluster = free_cluster target_dir.entities.append(file) def new_directory(self, name, parent, path_from_root, object_timestamp_): # type: (str, Directory, Optional[List[str]], datetime) -> None free_cluster, free_entry, target_dir = self.allocate_object(name=name, entity_type=Directory.ATTR_DIRECTORY, path_from_root=path_from_root, object_timestamp_=object_timestamp_) directory: Directory = Directory(name=name, fat=self.fat, parent=parent, fatfs_state=self.fatfs_state, entry=free_entry) directory.first_cluster = free_cluster directory.init_directory() target_dir.entities.append(directory) def write_to_file(self, path: List[str], content: bytes) -> None: """ Writes to file existing in the directory structure. :param path: path split into the list :param content: content as a string to be written into a file :returns: None :raises WriteDirectoryException: raised is the target object for writing is a directory """ entity_to_write: Entry = self.recursive_search(path, self) if isinstance(entity_to_write, File): clusters_cnt: int = required_clusters_count(cluster_size=self.fatfs_state.boot_sector_state.sector_size, content=content) self.fat.allocate_chain(entity_to_write.first_cluster, clusters_cnt) entity_to_write.write(content) else: raise WriteDirectoryException(f'`{os.path.join(*path)}` is a directory!')