notmuch/bindings/python/notmuch/filename.py
2012-01-02 16:34:56 +01:00

121 lines
4.5 KiB
Python

"""
This file is part of notmuch.
Notmuch is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
Notmuch is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with notmuch. If not, see <http://www.gnu.org/licenses/>.
Copyright 2010 Sebastian Spaeth <Sebastian@SSpaeth.de>'
"""
from ctypes import c_char_p
from notmuch.globals import (nmlib, STATUS, NotmuchError,
NotmuchFilenamesP, NotmuchMessageP, _str, Python3StringMixIn)
class Filenames(Python3StringMixIn):
"""Represents a list of filenames as returned by notmuch
This object contains the Filenames iterator. The main function is
as_generator() which will return a generator so we can do a Filenamesth an
iterator over a list of notmuch filenames. Do note that the underlying
library only provides a one-time iterator (it cannot reset the iterator to
the start). Thus iterating over the function will "exhaust" the list of
tags, and a subsequent iteration attempt will raise a :exc:`NotmuchError`
STATUS.NOT_INITIALIZED. Also note, that any function that uses iteration
(nearly all) will also exhaust the tags. So both::
for name in filenames: print name
as well as::
number_of_names = len(names)
and even a simple::
#str() iterates over all tags to construct a space separated list
print(str(filenames))
will "exhaust" the Filenames. However, you can use
:meth:`Message.get_filenames` repeatedly to get fresh Filenames
objects to perform various actions on filenames.
"""
#notmuch_filenames_get
_get = nmlib.notmuch_filenames_get
_get.argtypes = [NotmuchFilenamesP]
_get.restype = c_char_p
def __init__(self, files_p, parent):
"""
:param files_p: A pointer to an underlying *notmuch_tags_t*
structure. These are not publically exposed, so a user
will almost never instantiate a :class:`Tags` object
herself. They are usually handed back as a result,
e.g. in :meth:`Database.get_all_tags`. *tags_p* must be
valid, we will raise an :exc:`NotmuchError`
(STATUS.NULL_POINTER) if it is `None`.
:type files_p: :class:`ctypes.c_void_p`
:param parent: The parent object (ie :class:`Message` these
filenames are derived from, and saves a
reference to it, so we can automatically delete the db object
once all derived objects are dead.
"""
if files_p is None:
raise NotmuchError(STATUS.NULL_POINTER)
self._files = files_p
#save reference to parent object so we keep it alive
self._parent = parent
_valid = nmlib.notmuch_filenames_valid
_valid.argtypes = [NotmuchFilenamesP]
_valid.restype = bool
_move_to_next = nmlib.notmuch_filenames_move_to_next
_move_to_next.argtypes = [NotmuchFilenamesP]
_move_to_next.restype = None
def as_generator(self):
"""Return generator of Filenames
This is the main function that will usually be used by the
user."""
if self._files is None:
raise NotmuchError(STATUS.NOT_INITIALIZED)
while self._valid(self._files):
yield Filenames._get(self._files).decode('utf-8', errors='ignore')
self._move_to_next(self._files)
self._files = None
def __unicode__(self):
"""Represent Filenames() as newline-separated list of full paths
.. note:: As this iterates over the filenames, we will not be
able to iterate over them again (as in retrieve them)! If
the tags have been exhausted already, this will raise a
:exc:`NotmuchError` STATUS.NOT_INITIALIZED on subsequent
attempts. However, you can use
:meth:`Message.get_filenames` repeatedly to perform
various actions on filenames.
"""
return "\n".join(self)
_destroy = nmlib.notmuch_filenames_destroy
_destroy.argtypes = [NotmuchMessageP]
_destroy.restype = None
def __del__(self):
"""Close and free the notmuch filenames"""
if self._files is not None:
self._destroy(self._files)