# Copyright (C) 2001-2004 by the Free Software Foundation, Inc. # # 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 2 # 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, write to the Free Software # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. """Reading and writing message objects and message metadata. """ # enqueue() and dequeue() are not symmetric. enqueue() takes a Message # object. dequeue() returns a email.Message object tree. # # Message metadata is represented internally as a Python dictionary. Keys and # values must be strings. When written to a queue directory, the metadata is # written into an externally represented format, as defined here. Because # components of the Mailman system may be written in something other than # Python, the external interchange format should be chosen based on what those # other components can read and write. # # Most efficient, and recommended if everything is Python, is Python marshal # format. Also supported by default is Berkeley db format (using the default # bsddb module compiled into your Python executable -- usually Berkeley db # 2), and rfc822 style plain text. You can write your own if you have other # needs. import os import sha import time import email import errno import cPickle import marshal from Mailman import mm_cfg from Mailman import Utils from Mailman import Message from Mailman.Logging.Syslog import syslog # 20 bytes of all bits set, maximum sha.digest() value shamax = 0xffffffffffffffffffffffffffffffffffffffffL try: True, False except NameError: True = 1 False = 0 # This flag causes messages to be written as pickles (when True) or text files # (when False). Pickles are more efficient because the message doesn't need # to be re-parsed every time it's unqueued, but pickles are not human readable. SAVE_MSGS_AS_PICKLES = True class Switchboard: def __init__(self, whichq, slice=None, numslices=1): self.__whichq = whichq # Create the directory if it doesn't yet exist. # FIXME omask = os.umask(0) # rwxrws--- try: try: os.mkdir(self.__whichq, 0770) except OSError, e: if e.errno <> errno.EEXIST: raise finally: os.umask(omask) # Fast track for no slices self.__lower = None self.__upper = None # BAW: test performance and end-cases of this algorithm if numslices <> 1: self.__lower = ((shamax+1) * slice) / numslices self.__upper = (((shamax+1) * (slice+1)) / numslices) - 1 def whichq(self): return self.__whichq def enqueue(self, _msg, _metadata={}, **_kws): # Calculate the SHA hexdigest of the message to get a unique base # filename. We're also going to use the digest as a hash into the set # of parallel qrunner processes. data = _metadata.copy() data.update(_kws) listname = data.get('listname', '--nolist--') # Get some data for the input to the sha hash now = time.time() if SAVE_MSGS_AS_PICKLES and not data.get('_plaintext'): protocol = 1 msgsave = cPickle.dumps(_msg, protocol) else: protocol = 0 msgsave = cPickle.dumps(str(_msg), protocol) hashfood = msgsave + listname + `now` # Encode the current time into the file name for FIFO sorting in # files(). The file name consists of two parts separated by a `+': # the received time for this message (i.e. when it first showed up on # this system) and the sha hex digest. #rcvtime = data.setdefault('received_time', now) rcvtime = data.setdefault('received_time', now) filebase = `rcvtime` + '+' + sha.new(hashfood).hexdigest() filename = os.path.join(self.__whichq, filebase + '.pck') tmpfile = filename + '.tmp' # Always add the metadata schema version number data['version'] = mm_cfg.QFILE_SCHEMA_VERSION # Filter out volatile entries for k in data.keys(): if k.startswith('_'): del data[k] # We have to tell the dequeue() method whether to parse the message # object or not. data['_parsemsg'] = (protocol == 0) # Write to the pickle file the message object and metadata. omask = os.umask(007) # -rw-rw---- try: fp = open(tmpfile, 'w') try: fp.write(msgsave) cPickle.dump(data, fp, protocol) fp.flush() os.fsync(fp.fileno()) finally: fp.close() finally: os.umask(omask) os.rename(tmpfile, filename) return filebase def dequeue(self, filebase): # Calculate the filename from the given filebase. filename = os.path.join(self.__whichq, filebase + '.pck') # Read the message object and metadata. fp = open(filename) os.unlink(filename) try: msg = cPickle.load(fp) data = cPickle.load(fp) finally: fp.close() if data.get('_parsemsg'): msg = email.message_from_string(msg, Message.Message) return msg, data def files(self): times = {} lower = self.__lower upper = self.__upper for f in os.listdir(self.__whichq): # By ignoring anything that doesn't end in .pck, we ignore # tempfiles and avoid a race condition. if not f.endswith('.pck'): continue filebase = os.path.splitext(f)[0] when, digest = filebase.split('+') # Throw out any files which don't match our bitrange. BAW: test # performance and end-cases of this algorithm. if lower is None or (lower <= long(digest, 16) < upper): times[float(when)] = filebase # FIFO sort keys = times.keys() keys.sort() return [times[k] for k in keys]