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Diffstat (limited to 'src/leap/mail/imap/messageparts.py')
| -rw-r--r-- | src/leap/mail/imap/messageparts.py | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/src/leap/mail/imap/messageparts.py b/src/leap/mail/imap/messageparts.py new file mode 100644 index 0000000..a47ea1d --- /dev/null +++ b/src/leap/mail/imap/messageparts.py @@ -0,0 +1,262 @@ +# -*- coding: utf-8 -*- +# messageparts.py +# Copyright (C) 2014 LEAP +# +# This program 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. +# +# This program 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 this program. If not, see <http://www.gnu.org/licenses/>. +""" +MessagePart implementation. Used from LeapMessage. +""" +import logging +import re +import StringIO + +from enum import Enum +from zope.interface import implements +from twisted.mail import imap4 + +from leap.common.decorators import memoized_method +from leap.common.mail import get_email_charset +from leap.mail.imap.fields import fields +from leap.mail.utils import first + +MessagePartType = Enum("hdoc", "fdoc", "cdoc") + + +logger = logging.getLogger(__name__) + + +CHARSET_PATTERN = r"""charset=([\w-]+)""" +CHARSET_RE = re.compile(CHARSET_PATTERN, re.IGNORECASE) + + +class MessagePart(object): + """ + IMessagePart implementor. + It takes a subpart message and is able to find + the inner parts. + + Excusatio non petita: see the interface documentation. + """ + + implements(imap4.IMessagePart) + + def __init__(self, soledad, part_map): + """ + Initializes the MessagePart. + + :param part_map: a dictionary containing the parts map for this + message + :type part_map: dict + """ + # TODO + # It would be good to pass the uid/mailbox also + # for references while debugging. + + # We have a problem on bulk moves, and is + # that when the fetch on the new mailbox is done + # the parts maybe are not complete. + # So we should be able to fail with empty + # docs until we solve that. The ideal would be + # to gather the results of the deferred operations + # to signal the operation is complete. + #leap_assert(part_map, "part map dict cannot be null") + self._soledad = soledad + self._pmap = part_map + + def getSize(self): + """ + Return the total size, in octets, of this message part. + + :return: size of the message, in octets + :rtype: int + """ + if not self._pmap: + return 0 + size = self._pmap.get('size', None) + if not size: + logger.error("Message part cannot find size in the partmap") + return size + + def getBodyFile(self): + """ + Retrieve a file object containing only the body of this message. + + :return: file-like object opened for reading + :rtype: StringIO + """ + fd = StringIO.StringIO() + if self._pmap: + multi = self._pmap.get('multi') + if not multi: + phash = self._pmap.get("phash", None) + else: + pmap = self._pmap.get('part_map') + first_part = pmap.get('1', None) + if first_part: + phash = first_part['phash'] + + if not phash: + logger.warning("Could not find phash for this subpart!") + payload = str("") + else: + payload = self._get_payload_from_document(phash) + + else: + logger.warning("Message with no part_map!") + payload = str("") + + if payload: + content_type = self._get_ctype_from_document(phash) + charset = first(CHARSET_RE.findall(content_type)) + logger.debug("Got charset from header: %s" % (charset,)) + if not charset: + charset = self._get_charset(payload) + try: + payload = payload.encode(charset) + except UnicodeError as exc: + logger.error("Unicode error {0}".format(exc)) + payload = payload.encode(charset, 'replace') + + fd.write(payload) + fd.seek(0) + return fd + + # TODO cache the phash retrieval + def _get_payload_from_document(self, phash): + """ + Gets the message payload from the content document. + + :param phash: the payload hash to retrieve by. + :type phash: basestring + """ + cdocs = self._soledad.get_from_index( + fields.TYPE_P_HASH_IDX, + fields.TYPE_CONTENT_VAL, str(phash)) + + cdoc = first(cdocs) + if not cdoc: + logger.warning( + "Could not find the content doc " + "for phash %s" % (phash,)) + payload = cdoc.content.get(fields.RAW_KEY, "") + return payload + + # TODO cache the pahash retrieval + def _get_ctype_from_document(self, phash): + """ + Gets the content-type from the content document. + + :param phash: the payload hash to retrieve by. + :type phash: basestring + """ + cdocs = self._soledad.get_from_index( + fields.TYPE_P_HASH_IDX, + fields.TYPE_CONTENT_VAL, str(phash)) + + cdoc = first(cdocs) + if not cdoc: + logger.warning( + "Could not find the content doc " + "for phash %s" % (phash,)) + ctype = cdoc.content.get('ctype', "") + return ctype + + @memoized_method + def _get_charset(self, stuff): + # TODO put in a common class with LeapMessage + """ + Gets (guesses?) the charset of a payload. + + :param stuff: the stuff to guess about. + :type stuff: basestring + :returns: charset + """ + # XXX existential doubt 2. shouldn't we make the scope + # of the decorator somewhat more persistent? + # ah! yes! and put memory bounds. + return get_email_charset(unicode(stuff)) + + def getHeaders(self, negate, *names): + """ + Retrieve a group of message headers. + + :param names: The names of the headers to retrieve or omit. + :type names: tuple of str + + :param negate: If True, indicates that the headers listed in names + should be omitted from the return value, rather + than included. + :type negate: bool + + :return: A mapping of header field names to header field values + :rtype: dict + """ + if not self._pmap: + logger.warning("No pmap in Subpart!") + return {} + headers = dict(self._pmap.get("headers", [])) + + # twisted imap server expects *some* headers to be lowercase + # We could use a CaseInsensitiveDict here... + headers = dict( + (str(key), str(value)) if key.lower() != "content-type" + else (str(key.lower()), str(value)) + for (key, value) in headers.items()) + + names = map(lambda s: s.upper(), names) + if negate: + cond = lambda key: key.upper() not in names + else: + cond = lambda key: key.upper() in names + + # unpack and filter original dict by negate-condition + filter_by_cond = [ + map(str, (key, val)) for + key, val in headers.items() + if cond(key)] + filtered = dict(filter_by_cond) + return filtered + + def isMultipart(self): + """ + Return True if this message is multipart. + """ + if not self._pmap: + logger.warning("Could not get part map!") + return False + multi = self._pmap.get("multi", False) + return multi + + def getSubPart(self, part): + """ + Retrieve a MIME submessage + + :type part: C{int} + :param part: The number of the part to retrieve, indexed from 0. + :raise IndexError: Raised if the specified part does not exist. + :raise TypeError: Raised if this message is not multipart. + :rtype: Any object implementing C{IMessagePart}. + :return: The specified sub-part. + """ + if not self.isMultipart(): + raise TypeError + sub_pmap = self._pmap.get("part_map", {}) + try: + part_map = sub_pmap[str(part + 1)] + except KeyError: + logger.debug("getSubpart for %s: KeyError" % (part,)) + raise IndexError + + # XXX check for validity + return MessagePart(self._soledad, part_map) |