CFBReader

Overview

CFBReader provides low-level, read-only access to a Compound File Binary (CFB) container. It exposes the sector layout, directory tree, and raw stream bytes without loading the entire file into memory. CFBReader implements the context-manager protocol; always use it inside a with block to ensure file handles are released correctly.

Obtain an instance via the from_file class method and navigate the directory tree using iter_storages, iter_streams, or iter_tree.

from aspose.email_foss.cfb import CFBReader

with CFBReader.from_file("archive.cfb") as reader:
    print(f"sector_size={reader.sector_size}")
    for entry in reader.iter_storages():
        print(f"storage: {entry.name}")
    for entry in reader.iter_streams():
        data = reader.get_stream_data(entry.stream_id)
        print(f"stream: {entry.name}, {len(data)} bytes")

Class Methods

Method	Returns	Description
`from_file(path)`	`CFBReader`	Opens the CFB file at `path` and returns a ready-to-use `CFBReader`.

Properties

Name	Type	Description
`data_size`	`int`	Total size of the data region in bytes.
`major_version`	`int`	CFB major version number (3 or 4).
`sector_size`	`int`	Size of a single FAT sector in bytes.
`mini_sector_size`	`int`	Size of a mini-stream sector in bytes.
`fat_sector_count`	`int`	Number of FAT sectors in the container.
`directory_entry_count`	`int`	Total number of directory entries.
`materialized_stream_count`	`int`	Number of streams loaded into memory.
`file_size`	`int`	Total file size in bytes.

Methods

Method	Returns	Description
`close()`	`None`	Closes the underlying file handle; called automatically when used as a context manager.
`get_entry(stream_id)`	`DirectoryEntry`	Returns the `DirectoryEntry` for the given `stream_id`.
`get_stream_data(stream_id)`	`bytes`	Returns the raw bytes of the stream identified by `stream_id`.
`iter_storages()`	`Iterator[DirectoryEntry]`	Iterates over all STORAGE_OBJECT entries in the directory tree.
`iter_streams()`	`Iterator[DirectoryEntry]`	Iterates over all STREAM_OBJECT entries in the directory tree.
`iter_children(storage_stream_id)`	`Iterator[DirectoryEntry]`	Iterates over the immediate children of the given storage entry.
`iter_tree(start_stream_id)`	`Iterator[Tuple[int, DirectoryEntry]]`	Depth-first traversal yielding `(depth, entry)` tuples from `start_stream_id`.
`find_child_by_name(storage_stream_id, name)`	`Optional[DirectoryEntry]`	Returns the first child of the given storage whose name matches `name`, or `None`.
`resolve_path(names, start_stream_id)`	`Optional[DirectoryEntry]`	Resolves a sequence of names as a path from `start_stream_id`; returns `None` if not found.

CFBReader

Overview

Class Methods

Properties

Methods

See Also