root / pykota / trunk / bin / pykota @ 909

#! /usr/bin/env python

# PyKota accounting filter
#
# PyKota - Print Quotas for CUPS
#
# (c) 2003 Jerome Alet <alet@librelogiciel.com>
# 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.
#
# $Id$
#
# $Log$
# Revision 1.21  2003/04/12 17:20:14  jalet
# Better formula for HP workaround
#
# Revision 1.20  2003/04/12 16:58:28  jalet
# The workaround for HP printers was not correct, and there's probably no
# correct way to workaround the problem because we can't save the internal
# page counter in real time. The last job's size is unconditionnally set to
# 5 pages in this case.
#
# Revision 1.19  2003/04/11 08:56:49  jalet
# Comment
#
# Revision 1.18  2003/04/11 08:50:39  jalet
# Workaround for the HP "feature" of saving the page counter to NVRAM
# only every time 10 new pages are printed...
# Workaround for printers with volatile page counters.
#
# Revision 1.17  2003/04/10 21:47:20  jalet
# Job history added. Upgrade script neutralized for now !
#
# Revision 1.16  2003/04/08 20:38:08  jalet
# The last job Id is saved now for each printer, this will probably
# allow other accounting methods in the future.
#
# Revision 1.15  2003/03/29 13:45:27  jalet
# GPL paragraphs were incorrectly (from memory) copied into the sources.
# Two README files were added.
# Upgrade script for PostgreSQL pre 1.01 schema was added.
#
# Revision 1.14  2003/03/07 22:16:57  jalet
# Algorithmically incorrect : last user quota wasn't updated if current
# user wasn't allowed to print.
#
# Revision 1.13  2003/02/27 23:59:28  jalet
# Stupid bug wrt exception handlingand value conversion
#
# Revision 1.12  2003/02/27 23:48:41  jalet
# Correctly maps PyKota's log levels to syslog log levels
#
# Revision 1.11  2003/02/27 22:55:20  jalet
# WARN log priority doesn't exist.
#
# Revision 1.10  2003/02/27 22:43:21  jalet
# Missing import
#
# Revision 1.9  2003/02/27 22:40:26  jalet
# Correctly handles cases where the printer is off.
#
# Revision 1.8  2003/02/09 12:56:53  jalet
# Internationalization begins...
#
# Revision 1.7  2003/02/07 10:23:48  jalet
# Avoid a possible future name clash
#
# Revision 1.6  2003/02/06 22:54:33  jalet
# warnpykota should be ok
#
# Revision 1.5  2003/02/05 22:45:25  jalet
# Forgotten import
#
# Revision 1.4  2003/02/05 22:42:51  jalet
# Typo
#
# Revision 1.3  2003/02/05 22:38:39  jalet
# Typo
#
# Revision 1.2  2003/02/05 22:16:20  jalet
# DEVICE_URI is undefined outside of CUPS, i.e. for normal command line tools
#
# Revision 1.1  2003/02/05 21:28:17  jalet
# Initial import into CVS
#
#
#

import sys
import os

from pykota.tool import PyKotaTool, PyKotaToolError
from pykota.requester import openRequester, PyKotaRequesterError

class PyKotaFilter(PyKotaTool) :    
    """Class for the PyKota filter."""
    def __init__(self, username) :
        PyKotaTool.__init__(self, isfilter=1)
        self.username = username
        self.requester = openRequester(self.config, self.printername)
        self.printerhostname = self.getPrinterHostname()
    
    def getPrinterHostname(self) :
        """Returns the printer hostname."""
        device_uri = os.environ.get("DEVICE_URI", "")
        # TODO : check this for more complex urls than ipp://myprinter.dot.com:631/printers/lp
        try :
            (backend, destination) = device_uri.split(":", 1) 
        except ValueError :    
            raise PyKotaToolError, "Invalid DEVICE_URI : %s\n" % device_uri
        while destination.startswith("/") :
            destination = destination[1:]
        return destination.split("/")[0].split(":")[0]
        
    def filterInput(self, inputfile) :
        """Transparent filter."""
        mustclose = 0    
        if inputfile is not None :    
            infile = open(inputfile, "rb")
            mustclose = 1
        else :    
            infile = sys.stdin
        data = infile.read(256*1024)    
        while data :
            sys.stdout.write(data)
            data = infile.read(256*1024)
        if mustclose :    
            infile.close()
            
def main() :    
    """Do it, and do it right !"""
    #
    # This is a CUPS filter, so we should act and die like a CUPS filter when needed
    narg = len(sys.argv)
    if narg not in (6, 7) :    
        sys.stderr.write("ERROR: %s job-id user title copies options [file]\n" % sys.argv[0])
        return 1
    elif narg == 7 :    
        # input file
        inputfile = sys.argv[6]
    else :    
        # stdin
        inputfile = None
        
    #    
    # According to CUPS documentation, the job id is the second command line argument
    jobid = sys.argv[1].strip()
    
    #    
    # According to CUPS documentation, the username is the third command line argument
    username = sys.argv[2].strip()    
    
    # Initializes the current tool
    kotafilter = PyKotaFilter(username)    
    
    # Get the page counter directly from the printer itself
    try :
        counterbeforejob = kotafilter.requester.getPrinterPageCounter(kotafilter.printerhostname) # TODO use printername instead, make them match from CUPS' config files
    except PyKotaRequesterError, msg :
        # can't get actual page counter, assume printer is off, but warns in log
        kotafilter.logger.log_message("%s" % msg, "warn")
        counterbeforejob = None
        printerIsOff = 1
    else :    
        printerIsOff = 0
        
    # Get the last page counter and last username from the Quota Storage backend
    printerid = kotafilter.storage.getPrinterId(kotafilter.printername)
    if printerid is None :
        # The printer is unknown from the Quota Storage perspective
        # we let the job pass through, but log a warning message
        kotafilter.logger.log_message(_("Printer %s not registered in the PyKota system") % kotafilter.printername, "warn")
    else :    
        userid = kotafilter.storage.getUserId(username)
        if userid is None :
            # The user is unknown from the Quota Storage perspective
            # we let the job pass through, but log a warning message
            kotafilter.logger.log_message(_("User %s not registered in the PyKota system") % username, "warn")
        else :
            # get last job information for this printer
            pgc = kotafilter.storage.getPrinterPageCounter(printerid)    
            if pgc is None :
                # The printer hasn't been used yet, from PyKota's point of view
                lasthistoryid = None
                lastjobid = jobid
                lastuserid = userid
                lastusername = username
                lastpagecounter = counterbeforejob
            else :    
                # get last values from Quota Storage
                (lasthistoryid, lastjobid, lastuserid, lastusername, lastpagecounter) = (pgc["id"], pgc["jobid"], pgc["userid"], pgc["username"], pgc["pagecounter"])
                
            # if printer is off then we assume the correct counter value is the last one
            if printerIsOff :
                counterbeforejob = lastpagecounter
                
            # if the internal lifetime page counter for this printer is 0    
            # then this may be a printer with a volatile counter (never
            # saved to NVRAM) which has just been switched off and then on
            # so we use the last page counter from the Quota Storage instead
            # explanation at : http://web.mit.edu/source/third/lprng/doc/LPRng-HOWTO-15.html
            if counterbeforejob == 0 :
                counterbeforejob = lastpagecounter
                
            # Computes the last job size as the difference between internal page
            # counter in the printer and last page counter taken from the Quota
            # Storage database for this particular printer
            jobsize = (counterbeforejob - lastpagecounter)    
            if jobsize < 0 :
                # Probably an HP printer which was switched off and back on, 
                # its primary counter is only saved in a 10 increment, so
                # it may be lower than the last page counter saved in the
                # Quota Storage. 
                # We unconditionnally set the last job's size to 
                # abs(int((10 - abs(lastcounter(snmp) - lastcounter(storage)) / 2))
                # For more accurate accounting, don't switch off your HP printers !
                # explanation at : http://web.mit.edu/source/third/lprng/doc/LPRng-HOWTO-15.html
                kotafilter.logger.log_message(_("Error in page count value %i for user %s on printer %s") % (jobsize, lastusername, kotafilter.printername), "error")
                jobsize = abs(int((10 - abs(jobsize)) / 2))     # Workaround for HP printers' feature !
                
            # update the quota for the previous user on this printer 
            kotafilter.storage.updateUserPQuota(lastuserid, printerid, jobsize)
            
            # update the last job size in the history
            kotafilter.storage.updateJobSizeInHistory(lasthistoryid, jobsize)
            
            # warns the last user if he is over quota
            kotafilter.warnUserPQuota(lastusername)
                
            # Is the current user allowed to print at all ?
            action = kotafilter.warnUserPQuota(username)
            
            # adds the current job to history    
            kotafilter.storage.addJobToHistory(jobid, kotafilter.storage.getUserId(username), printerid, counterbeforejob, action)
            
            # if not allowed to print then die, else proceed.
            if action == "DENY" :
                # No, just die cleanly
                return 1
        
    # pass the job untouched to the underlying layer
    kotafilter.filterInput(inputfile)      
    
    return 0

if __name__ == "__main__" :    
    sys.exit(main() or 0)