Massive digester rework.

This moves actual digest creation and sending into a new queue runner.  That
way, digest creation does not block the main incoming processor.  Lots of code
clean up and reorganization too, and many fixes.

digest_last_sent_at: Make this a DateTime
digest_size_threshold: Make this a Float
digest_volume_frequency: Make this an Enum

DigestFrequency: new enum

Fix up IMailingList interface to reflect reality.

In Runner base class, allow for msg.get_sender() to return a False value.  If
this happens (as it can with the empty marker messages used to signal the
digester that there's work to do), just use the list's preferred language.

Give the retry.py and incoming.py queue runner modules some proper epilogues.

The EmptyingRunner (for testing) logs itself as the runner its wrapping.

The digest file name now ends in .mmdf since that's the format we're using.

Add 'create_list' to doctest globals.

Add a Mailbox class to add support for the context manager protocol.

1 files changed, 426 insertions, 0 deletions

diff --git a/src/mailman/app/digests.py b/src/mailman/app/digests.py
new file mode 100644
index 000000000..812ae1649
--- /dev/null
+++ b/src/mailman/app/digests.py
@@ -0,0 +1,426 @@
+# Copyright (C) 1998-2009 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman 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.
+#
+# GNU Mailman 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
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Add the message to the list's current digest and possibly send it."""
+
+# Messages are accumulated to a Unix mailbox compatible file containing all
+# the messages destined for the digest.  This file must be parsable by the
+# mailbox.UnixMailbox class (i.e. it must be ^From_ quoted).
+#
+# When the file reaches the size threshold, it is moved to the qfiles/digest
+# directory and the DigestRunner will craft the MIME, rfc1153, and
+# (eventually) URL-subject linked digests from the mbox.
+
+from __future__ import absolute_import, unicode_literals
+
+__metaclass__ = type
+__all__ = [
+    'ToDigest',
+    ]
+
+
+import os
+import re
+import copy
+import time
+import logging
+
+from StringIO import StringIO          # cStringIO can't handle unicode.
+from email.charset import Charset
+from email.generator import Generator
+from email.header import decode_header, make_header, Header
+from email.mime.base import MIMEBase
+from email.mime.message import MIMEMessage
+from email.mime.text import MIMEText
+from email.parser import Parser
+from email.utils import formatdate, getaddresses, make_msgid
+from zope.interface import implements
+
+from mailman import Message
+from mailman import Utils
+from mailman import i18n
+from mailman.Mailbox import Mailbox
+from mailman.Mailbox import Mailbox
+from mailman.config import config
+from mailman.core import errors
+from mailman.interfaces.handler import IHandler
+from mailman.interfaces.member import DeliveryMode, DeliveryStatus
+from mailman.pipeline.decorate import decorate
+from mailman.pipeline.scrubber import process as scrubber
+
+
+_ = i18n._
+
+UEMPTYSTRING = ''
+EMPTYSTRING = ''
+
+log = logging.getLogger('mailman.error')
+
+
+
+def process(mlist, msg, msgdata):
+    # Short circuit non-digestable lists.
+    if not mlist.digestable or msgdata.get('isdigest'):
+        return
+    mboxfile = os.path.join(mlist.data_path, 'digest.mbox')
+    mboxfp = open(mboxfile, 'a+')
+    mbox = Mailbox(mboxfp)
+    mbox.AppendMessage(msg)
+    # Calculate the current size of the accumulation file.  This will not tell
+    # us exactly how big the MIME, rfc1153, or any other generated digest
+    # message will be, but it's the most easily available metric to decide
+    # whether the size threshold has been reached.
+    mboxfp.flush()
+    size = os.path.getsize(mboxfile)
+    if size / 1024.0 >= mlist.digest_size_threshold:
+        # This is a bit of a kludge to get the mbox file moved to the digest
+        # queue directory.
+        try:
+            # Enclose in try/except here because a error in send_digest() can
+            # silently stop regular delivery.  Unsuccessful digest delivery
+            # should be tried again by cron and the site administrator will be
+            # notified of any error explicitly by the cron error message.
+            mboxfp.seek(0)
+            send_digests(mlist, mboxfp)
+            os.unlink(mboxfile)
+        except Exception, errmsg:
+            # Bare except is generally prohibited in Mailman, but we can't
+            # forecast what exceptions can occur here.
+            log.exception('send_digests() failed: %s', errmsg)
+    mboxfp.close()
+
+
+
+def send_digests(mlist, mboxfp):
+    # Set the digest volume and time
+    if mlist.digest_last_sent_at:
+        bump = False
+        # See if we should bump the digest volume number
+        timetup = time.localtime(mlist.digest_last_sent_at)
+        now = time.localtime(time.time())
+        freq = mlist.digest_volume_frequency
+        if freq == 0 and timetup[0] < now[0]:
+            # Yearly
+            bump = True
+        elif freq == 1 and timetup[1] <> now[1]:
+            # Monthly, but we take a cheap way to calculate this.  We assume
+            # that the clock isn't going to be reset backwards.
+            bump = True
+        elif freq == 2 and (timetup[1] % 4 <> now[1] % 4):
+            # Quarterly, same caveat
+            bump = True
+        elif freq == 3:
+            # Once again, take a cheap way of calculating this
+            weeknum_last = int(time.strftime('%W', timetup))
+            weeknum_now = int(time.strftime('%W', now))
+            if weeknum_now > weeknum_last or timetup[0] > now[0]:
+                bump = True
+        elif freq == 4 and timetup[7] <> now[7]:
+            # Daily
+            bump = True
+        if bump:
+            mlist.bump_digest_volume()
+    mlist.digest_last_sent_at = time.time()
+    # Wrapper around actually digest crafter to set up the language context
+    # properly.  All digests are translated to the list's preferred language.
+    with i18n.using_language(mlist.preferred_language):
+        send_i18n_digests(mlist, mboxfp)
+
+
+
+def send_i18n_digests(mlist, mboxfp):
+    mbox = Mailbox(mboxfp)
+    # Prepare common information (first lang/charset)
+    lang = mlist.preferred_language
+    lcset = Utils.GetCharSet(lang)
+    lcset_out = Charset(lcset).output_charset or lcset
+    # Common Information (contd)
+    realname = mlist.real_name
+    volume = mlist.volume
+    issue = mlist.next_digest_number
+    digestid = _('$realname Digest, Vol $volume, Issue $issue')
+    digestsubj = Header(digestid, lcset, header_name='Subject')
+    # Set things up for the MIME digest.  Only headers not added by
+    # CookHeaders need be added here.
+    # Date/Message-ID should be added here also.
+    mimemsg = Message.Message()
+    mimemsg['Content-Type'] = 'multipart/mixed'
+    mimemsg['MIME-Version'] = '1.0'
+    mimemsg['From'] = mlist.request_address
+    mimemsg['Subject'] = digestsubj
+    mimemsg['To'] = mlist.posting_address
+    mimemsg['Reply-To'] = mlist.posting_address
+    mimemsg['Date'] = formatdate(localtime=1)
+    mimemsg['Message-ID'] = make_msgid()
+    # Set things up for the rfc1153 digest
+    plainmsg = StringIO()
+    rfc1153msg = Message.Message()
+    rfc1153msg['From'] = mlist.request_address
+    rfc1153msg['Subject'] = digestsubj
+    rfc1153msg['To'] = mlist.posting_address
+    rfc1153msg['Reply-To'] = mlist.posting_address
+    rfc1153msg['Date'] = formatdate(localtime=1)
+    rfc1153msg['Message-ID'] = make_msgid()
+    separator70 = '-' * 70
+    separator30 = '-' * 30
+    # In the rfc1153 digest, the masthead contains the digest boilerplate plus
+    # any digest header.  In the MIME digests, the masthead and digest header
+    # are separate MIME subobjects.  In either case, it's the first thing in
+    # the digest, and we can calculate it now, so go ahead and add it now.
+    mastheadtxt = Utils.maketext(
+        'masthead.txt',
+        {'real_name' :        mlist.real_name,
+         'got_list_email':    mlist.posting_address,
+         'got_listinfo_url':  mlist.script_url('listinfo'),
+         'got_request_email': mlist.request_address,
+         'got_owner_email':   mlist.owner_address,
+         }, mlist=mlist)
+    # MIME
+    masthead = MIMEText(mastheadtxt.encode(lcset), _charset=lcset)
+    masthead['Content-Description'] = digestid
+    mimemsg.attach(masthead)
+    # RFC 1153
+    print >> plainmsg, mastheadtxt
+    print >> plainmsg
+    # Now add the optional digest header
+    if mlist.digest_header:
+        headertxt = decorate(mlist, mlist.digest_header, _('digest header'))
+        # MIME
+        header = MIMEText(headertxt.encode(lcset), _charset=lcset)
+        header['Content-Description'] = _('Digest Header')
+        mimemsg.attach(header)
+        # RFC 1153
+        print >> plainmsg, headertxt
+        print >> plainmsg
+    # Now we have to cruise through all the messages accumulated in the
+    # mailbox file.  We can't add these messages to the plainmsg and mimemsg
+    # yet, because we first have to calculate the table of contents
+    # (i.e. grok out all the Subjects).  Store the messages in a list until
+    # we're ready for them.
+    #
+    # Meanwhile prepare things for the table of contents
+    toc = StringIO()
+    print >> toc, _("Today's Topics:\n")
+    # Now cruise through all the messages in the mailbox of digest messages,
+    # building the MIME payload and core of the RFC 1153 digest.  We'll also
+    # accumulate Subject: headers and authors for the table-of-contents.
+    messages = []
+    msgcount = 0
+    msg = mbox.next()
+    while msg is not None:
+        if msg == '':
+            # It was an unparseable message
+            msg = mbox.next()
+            continue
+        msgcount += 1
+        messages.append(msg)
+        # Get the Subject header
+        msgsubj = msg.get('subject', _('(no subject)'))
+        subject = Utils.oneline(msgsubj, in_unicode=True)
+        # Don't include the redundant subject prefix in the toc
+        mo = re.match('(re:? *)?(%s)' % re.escape(mlist.subject_prefix),
+                      subject, re.IGNORECASE)
+        if mo:
+            subject = subject[:mo.start(2)] + subject[mo.end(2):]
+        username = ''
+        addresses = getaddresses([Utils.oneline(msg.get('from', ''),
+                                                in_unicode=True)])
+        # Take only the first author we find
+        if isinstance(addresses, list) and addresses:
+            username = addresses[0][0]
+            if not username:
+                username = addresses[0][1]
+        if username:
+            username = ' ({0})'.format(username)
+        # Put count and Wrap the toc subject line
+        wrapped = Utils.wrap('{0:2}. {1}'.format(msgcount, subject), 65)
+        slines = wrapped.split('\n')
+        # See if the user's name can fit on the last line
+        if len(slines[-1]) + len(username) > 70:
+            slines.append(username)
+        else:
+            slines[-1] += username
+        # Add this subject to the accumulating topics
+        first = True
+        for line in slines:
+            if first:
+                print >> toc, ' ', line
+                first = False
+            else:
+                print >> toc, '     ', line.lstrip()
+        # We do not want all the headers of the original message to leak
+        # through in the digest messages.  For this phase, we'll leave the
+        # same set of headers in both digests, i.e. those required in RFC 1153
+        # plus a couple of other useful ones.  We also need to reorder the
+        # headers according to RFC 1153.  Later, we'll strip out headers for
+        # for the specific MIME or plain digests.
+        keeper = {}
+        all_keepers = set(
+            header for header in
+            config.digests.mime_digest_keep_headers.split() +
+            config.digests.plain_digest_keep_headers.split())
+        for keep in all_keepers:
+            keeper[keep] = msg.get_all(keep, [])
+        # Now remove all unkempt headers :)
+        for header in msg.keys():
+            del msg[header]
+        # And add back the kept header in the RFC 1153 designated order
+        for keep in all_keepers:
+            for field in keeper[keep]:
+                msg[keep] = field
+        # And a bit of extra stuff
+        msg['Message'] = repr(msgcount)
+        # Get the next message in the digest mailbox
+        msg = mbox.next()
+    # Now we're finished with all the messages in the digest.  First do some
+    # sanity checking and then on to adding the toc.
+    if msgcount == 0:
+        # Why did we even get here?
+        return
+    toctext = toc.getvalue()
+    # MIME
+    try:
+        tocpart = MIMEText(toctext.encode(lcset), _charset=lcset)
+    except UnicodeError:
+        tocpart = MIMEText(toctext.encode('utf-8'), _charset='utf-8')
+    tocpart['Content-Description']= _("Today's Topics ($msgcount messages)")
+    mimemsg.attach(tocpart)
+    # RFC 1153
+    print >> plainmsg, toctext
+    print >> plainmsg
+    # For RFC 1153 digests, we now need the standard separator
+    print >> plainmsg, separator70
+    print >> plainmsg
+    # Now go through and add each message
+    mimedigest = MIMEBase('multipart', 'digest')
+    mimemsg.attach(mimedigest)
+    first = True
+    for msg in messages:
+        # MIME.  Make a copy of the message object since the rfc1153
+        # processing scrubs out attachments.
+        mimedigest.attach(MIMEMessage(copy.deepcopy(msg)))
+        # rfc1153
+        if first:
+            first = False
+        else:
+            print >> plainmsg, separator30
+            print >> plainmsg
+        # Use Mailman.pipeline.scrubber.process() to get plain text
+        try:
+            msg = scrubber(mlist, msg)
+        except errors.DiscardMessage:
+            print >> plainmsg, _('[Message discarded by content filter]')
+            continue
+        # Honor the default setting
+        for h in config.digests.plain_digest_keep_headers.split():
+            if msg[h]:
+                uh = Utils.wrap('{0}: {1}'.format(
+                    h, Utils.oneline(msg[h], in_unicode=True)))
+                uh = '\n\t'.join(uh.split('\n'))
+                print >> plainmsg, uh
+        print >> plainmsg
+        # If decoded payload is empty, this may be multipart message.
+        # -- just stringfy it.
+        payload = msg.get_payload(decode=True) \
+                  or msg.as_string().split('\n\n',1)[1]
+        mcset = msg.get_content_charset('us-ascii')
+        try:
+            payload = unicode(payload, mcset, 'replace')
+        except (LookupError, TypeError):
+            # unknown or empty charset
+            payload = unicode(payload, 'us-ascii', 'replace')
+        print >> plainmsg, payload
+        if not payload.endswith('\n'):
+            print >> plainmsg
+    # Now add the footer
+    if mlist.digest_footer:
+        footertxt = decorate(mlist, mlist.digest_footer)
+        # MIME
+        footer = MIMEText(footertxt.encode(lcset), _charset=lcset)
+        footer['Content-Description'] = _('Digest Footer')
+        mimemsg.attach(footer)
+        # RFC 1153
+        # BAW: This is not strictly conformant RFC 1153.  The trailer is only
+        # supposed to contain two lines, i.e. the "End of ... Digest" line and
+        # the row of asterisks.  If this screws up MUAs, the solution is to
+        # add the footer as the last message in the RFC 1153 digest.  I just
+        # hate the way that VM does that and I think it's confusing to users,
+        # so don't do it unless there's a clamor.
+        print >> plainmsg, separator30
+        print >> plainmsg
+        print >> plainmsg, footertxt
+        print >> plainmsg
+    # Do the last bit of stuff for each digest type
+    signoff = _('End of ') + digestid
+    # MIME
+    # BAW: This stuff is outside the normal MIME goo, and it's what the old
+    # MIME digester did.  No one seemed to complain, probably because you
+    # won't see it in an MUA that can't display the raw message.  We've never
+    # got complaints before, but if we do, just wax this.  It's primarily
+    # included for (marginally useful) backwards compatibility.
+    mimemsg.postamble = signoff
+    # rfc1153
+    print >> plainmsg, signoff
+    print >> plainmsg, '*' * len(signoff)
+    # Do our final bit of housekeeping, and then send each message to the
+    # outgoing queue for delivery.
+    mlist.next_digest_number += 1
+    virginq = config.switchboards['virgin']
+    # Calculate the recipients lists
+    plainrecips = set()
+    mimerecips = set()
+    # When someone turns off digest delivery, they will get one last digest to
+    # ensure that there will be no gaps in the messages they receive.
+    # Currently, this dictionary contains the email addresses of those folks
+    # who should get one last digest.  We need to find the corresponding
+    # IMember records.
+    digest_members = set(mlist.digest_members.members)
+    for address in mlist.one_last_digest:
+        member = mlist.digest_members.get_member(address)
+        if member:
+            digest_members.add(member)
+    for member in digest_members:
+        if member.delivery_status <> DeliveryStatus.enabled:
+            continue
+        # Send the digest to the case-preserved address of the digest members.
+        email_address = member.address.original_address
+        if member.delivery_mode == DeliveryMode.plaintext_digests:
+            plainrecips.add(email_address)
+        elif member.delivery_mode == DeliveryMode.mime_digests:
+            mimerecips.add(email_address)
+        else:
+            raise AssertionError(
+                'Digest member "{0}" unexpected delivery mode: {1}'.format(
+                    email_address, member.delivery_mode))
+    # Zap this since we're now delivering the last digest to these folks.
+    mlist.one_last_digest.clear()
+    # MIME
+    virginq.enqueue(mimemsg,
+                    recips=mimerecips,
+                    listname=mlist.fqdn_listname,
+                    isdigest=True)
+    # RFC 1153
+    # If the entire digest message can't be encoded by list charset, fall
+    # back to 'utf-8'.
+    try:
+        rfc1153msg.set_payload(plainmsg.getvalue().encode(lcset), lcset)
+    except UnicodeError:
+        rfc1153msg.set_payload(plainmsg.getvalue().encode('utf-8'), 'utf-8')
+    virginq.enqueue(rfc1153msg,
+                    recips=plainrecips,
+                    listname=mlist.fqdn_listname,
+                    isdigest=True)