oggit/packages/libarchive-c/opengnsys-libarchive-c-5.1/libarchive/write.py

280 lines
10 KiB
Python

from contextlib import contextmanager
from ctypes import byref, cast, c_char, c_size_t, c_void_p, POINTER
from posixpath import join
import warnings
from . import ffi
from .entry import ArchiveEntry, FileType
from .ffi import (
OPEN_CALLBACK, WRITE_CALLBACK, CLOSE_CALLBACK, NO_OPEN_CB, NO_CLOSE_CB,
ARCHIVE_EOF,
page_size, entry_sourcepath, entry_clear, read_disk_new, read_disk_open_w,
read_next_header2, read_disk_descend, read_free, write_header, write_data,
write_finish_entry,
read_disk_set_behavior
)
@contextmanager
def new_archive_read_disk(path, flags=0, lookup=False):
archive_p = read_disk_new()
read_disk_set_behavior(archive_p, flags)
if lookup:
ffi.read_disk_set_standard_lookup(archive_p)
read_disk_open_w(archive_p, path)
try:
yield archive_p
finally:
read_free(archive_p)
class ArchiveWrite:
def __init__(self, archive_p, header_codec='utf-8'):
self._pointer = archive_p
self.header_codec = header_codec
def add_entries(self, entries):
"""Add the given entries to the archive.
"""
write_p = self._pointer
for entry in entries:
write_header(write_p, entry._entry_p)
for block in entry.get_blocks():
write_data(write_p, block, len(block))
write_finish_entry(write_p)
def add_files(
self, *paths, flags=0, lookup=False, pathname=None, recursive=True,
**attributes
):
"""Read files through the OS and add them to the archive.
Args:
paths (str): the paths of the files to add to the archive
flags (int):
passed to the C function `archive_read_disk_set_behavior`;
use the `libarchive.flags.READDISK_*` constants
lookup (bool):
when True, the C function `archive_read_disk_set_standard_lookup`
is called to enable the lookup of user and group names
pathname (str | None):
the path of the file in the archive, defaults to the source path
recursive (bool):
when False, if a path in `paths` is a directory,
only the directory itself is added.
attributes (dict): passed to `ArchiveEntry.modify()`
Raises:
ArchiveError: if a file doesn't exist or can't be accessed, or if
adding it to the archive fails
"""
write_p = self._pointer
block_size = ffi.write_get_bytes_per_block(write_p)
if block_size <= 0:
block_size = 10240 # pragma: no cover
entry = ArchiveEntry(header_codec=self.header_codec)
entry_p = entry._entry_p
destination_path = attributes.pop('pathname', None)
for path in paths:
with new_archive_read_disk(path, flags, lookup) as read_p:
while 1:
r = read_next_header2(read_p, entry_p)
if r == ARCHIVE_EOF:
break
entry_path = entry.pathname
if destination_path:
if entry_path == path:
entry_path = destination_path
else:
assert entry_path.startswith(path)
entry_path = join(
destination_path,
entry_path[len(path):].lstrip('/')
)
entry.pathname = entry_path.lstrip('/')
if attributes:
entry.modify(**attributes)
read_disk_descend(read_p)
write_header(write_p, entry_p)
if entry.isreg:
with open(entry_sourcepath(entry_p), 'rb') as f:
while 1:
data = f.read(block_size)
if not data:
break
write_data(write_p, data, len(data))
write_finish_entry(write_p)
entry_clear(entry_p)
if not recursive:
break
def add_file(self, path, **kw):
"Single-path alias of `add_files()`"
return self.add_files(path, **kw)
def add_file_from_memory(
self, entry_path, entry_size, entry_data,
filetype=FileType.REGULAR_FILE, permission=0o664,
**other_attributes
):
""""Add file from memory to archive.
Args:
entry_path (str | bytes): the file's path
entry_size (int): the file's size, in bytes
entry_data (bytes | Iterable[bytes]): the file's content
filetype (int): see `libarchive.entry.ArchiveEntry.modify()`
permission (int): see `libarchive.entry.ArchiveEntry.modify()`
other_attributes: see `libarchive.entry.ArchiveEntry.modify()`
"""
archive_pointer = self._pointer
if isinstance(entry_data, bytes):
entry_data = (entry_data,)
elif isinstance(entry_data, str):
raise TypeError(
"entry_data: expected bytes, got %r" % type(entry_data)
)
entry = ArchiveEntry(
pathname=entry_path, size=entry_size, filetype=filetype,
perm=permission, header_codec=self.header_codec,
**other_attributes
)
write_header(archive_pointer, entry._entry_p)
for chunk in entry_data:
if not chunk:
break
write_data(archive_pointer, chunk, len(chunk))
write_finish_entry(archive_pointer)
@contextmanager
def new_archive_write(format_name, filter_name=None, options='', passphrase=None):
archive_p = ffi.write_new()
try:
ffi.get_write_format_function(format_name)(archive_p)
if filter_name:
ffi.get_write_filter_function(filter_name)(archive_p)
if passphrase and 'encryption' not in options:
if format_name == 'zip':
warnings.warn(
"The default encryption scheme of zip archives is weak. "
"Use `options='encryption=$type'` to specify the encryption "
"type you want to use. The supported values are 'zipcrypt' "
"(the weak default), 'aes128' and 'aes256'."
)
options += ',encryption' if options else 'encryption'
if options:
if not isinstance(options, bytes):
options = options.encode('utf-8')
ffi.write_set_options(archive_p, options)
if passphrase:
if not isinstance(passphrase, bytes):
passphrase = passphrase.encode('utf-8')
try:
ffi.write_set_passphrase(archive_p, passphrase)
except AttributeError:
raise NotImplementedError(
f"the libarchive being used (version {ffi.version_number()}, "
f"path {ffi.libarchive_path}) doesn't support encryption"
)
yield archive_p
ffi.write_close(archive_p)
ffi.write_free(archive_p)
except Exception:
ffi.write_fail(archive_p)
ffi.write_free(archive_p)
raise
@property
def bytes_written(self):
return ffi.filter_bytes(self._pointer, -1)
@contextmanager
def custom_writer(
write_func, format_name, filter_name=None,
open_func=None, close_func=None, block_size=page_size,
archive_write_class=ArchiveWrite, options='', passphrase=None,
header_codec='utf-8',
):
"""Create an archive and send it in chunks to the `write_func` function.
For formats and filters, see `WRITE_FORMATS` and `WRITE_FILTERS` in the
`libarchive.ffi` module.
"""
def write_cb_internal(archive_p, context, buffer_, length):
data = cast(buffer_, POINTER(c_char * length))[0]
return write_func(data)
open_cb = OPEN_CALLBACK(open_func) if open_func else NO_OPEN_CB
write_cb = WRITE_CALLBACK(write_cb_internal)
close_cb = CLOSE_CALLBACK(close_func) if close_func else NO_CLOSE_CB
with new_archive_write(format_name, filter_name, options,
passphrase) as archive_p:
ffi.write_set_bytes_in_last_block(archive_p, 1)
ffi.write_set_bytes_per_block(archive_p, block_size)
ffi.write_open(archive_p, None, open_cb, write_cb, close_cb)
yield archive_write_class(archive_p, header_codec)
@contextmanager
def fd_writer(
fd, format_name, filter_name=None,
archive_write_class=ArchiveWrite, options='', passphrase=None,
header_codec='utf-8',
):
"""Create an archive and write it into a file descriptor.
For formats and filters, see `WRITE_FORMATS` and `WRITE_FILTERS` in the
`libarchive.ffi` module.
"""
with new_archive_write(format_name, filter_name, options,
passphrase) as archive_p:
ffi.write_open_fd(archive_p, fd)
yield archive_write_class(archive_p, header_codec)
@contextmanager
def file_writer(
filepath, format_name, filter_name=None,
archive_write_class=ArchiveWrite, options='', passphrase=None,
header_codec='utf-8',
):
"""Create an archive and write it into a file.
For formats and filters, see `WRITE_FORMATS` and `WRITE_FILTERS` in the
`libarchive.ffi` module.
"""
with new_archive_write(format_name, filter_name, options,
passphrase) as archive_p:
ffi.write_open_filename_w(archive_p, filepath)
yield archive_write_class(archive_p, header_codec)
@contextmanager
def memory_writer(
buf, format_name, filter_name=None,
archive_write_class=ArchiveWrite, options='', passphrase=None,
header_codec='utf-8',
):
"""Create an archive and write it into a buffer.
For formats and filters, see `WRITE_FORMATS` and `WRITE_FILTERS` in the
`libarchive.ffi` module.
"""
with new_archive_write(format_name, filter_name, options,
passphrase) as archive_p:
used = byref(c_size_t())
buf_p = cast(buf, c_void_p)
ffi.write_open_memory(archive_p, buf_p, len(buf), used)
yield archive_write_class(archive_p, header_codec)