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Changeset 3175

Timestamp:

05/28/07 18:47:32 (17 years ago)

Author:

jerome

Message:

Rewrote PJL accounter using threads and non-blocking I/O.
Move shared constants to a dedicated module.

Location:

pykota/trunk/pykota

Files:

: 2 modified
: 1 copied

accounters/pjl.py (modified) (8 diffs)
accounters/snmp.py (modified) (6 diffs)
constants.py (copied) (copied from pykota/trunk/pykota/__init__.py) (2 diffs)

Legend:

: Unmodified
: Added
: Removed

pykota/trunk/pykota/accounters/pjl.py

r3163	r3175
26	26	import os
27	27	import socket
	28	import errno
28	29	import time
29		import signal
30
31		# NB : in fact these variables don't do much, since the time
32		# is in fact wasted in the sock.recv() blocking call, with the timeout
33		ITERATIONDELAY = 1 # 1 Second
34		STABILIZATIONDELAY = 3 # We must read three times the same value to consider it to be stable
35		NOPRINTINGMAXDELAY = 60 # The printer must begin to print within 60 seconds byb default.
36
37		# Here's the real thing :
38		TIMEOUT = 5
	30	import threading
	31	import Queue
	32
	33	from pykota import constants
	34
	35	FORMFEEDCHAR = 0x0c # Form Feed character, ends PJL answers.
39	36
40	37	# Old method : pjlMessage = "\033%-12345X@PJL USTATUSOFF\r\n@PJL INFO STATUS\r\n@PJL INFO PAGECOUNT\r\n\033%-12345X"
…	…
67	64	self.port = 9100
68	65	self.printerInternalPageCounter = self.printerStatus = None
69		self.timedout = 0
70
71		def alarmHandler(self, signum, frame) :
72		"""Query has timedout, handle this."""
73		self.timedout = 1
74		raise IOError, "Waiting for PJL answer timed out. Please try again later."
75
76		def retrievePJLValues(self) :
77		"""Retrieves a printer's internal page counter and status via PJL."""
	66	self.closed = False
	67	self.sock = None
	68	self.queue = None
	69	self.readthread = None
	70	self.quitEvent = threading.Event()
	71
	72	def __del__(self) :
	73	"""Ensures the network connection is closed at object deletion time."""
	74	self.close()
	75
	76	def open(self) :
	77	"""Opens the network connection."""
78	78	sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
79	79	try :
…	…
81	81	except socket.error, msg :
82	82	self.parent.filter.printInfo(_("Problem during connection to %s:%s : %s") % (self.printerHostname, self.port, str(msg)), "warn")
	83	return False
83	84	else :
84		self.parent.filter.logdebug("Connected to printer %s" % self.printerHostname)
	85	sock.setblocking(False)
	86	self.sock = sock
	87	self.closed = False
	88	self.quitEvent.clear()
	89	self.queue = Queue.Queue(0)
	90	self.readthread = threading.Thread(target=self.readloop)
	91	self.readthread.start()
	92	self.parent.filter.logdebug("Connected to printer %s:%s" % (self.printerHostname, self.port))
	93	return True
	94
	95	def close(self) :
	96	"""Closes the network connection."""
	97	if not self.closed :
	98	self.quitEvent.set()
	99	if self.readthread is not None :
	100	self.readthread.join()
	101	self.readthread = None
	102	if self.sock is not None :
	103	self.sock.close()
	104	self.sock = None
	105	self.parent.filter.logdebug("Connection to %s:%s is now closed." % (self.printerHostname, self.port))
	106	self.queue = None
	107	self.closed = True
	108
	109	def readloop(self) :
	110	"""Reading loop thread."""
	111	self.parent.filter.logdebug("Reading thread started.")
	112	buffer = []
	113	while not self.quitEvent.isSet() :
85	114	try :
86		sock.send(pjlMessage)
87		except socket.error, msg :
88		self.parent.filter.printInfo(_("Problem while sending PJL query to %s:%s : %s") % (self.printerHostname, self.port, str(msg)), "warn")
	115	answer = self.sock.recv(4096)
	116	except socket.error, (err, msg) :
	117	time.sleep(0.1) # We will try again later in all cases
	118	if err != errno.EAGAIN :
	119	self.parent.filter.printInfo(_("Problem while receiving PJL answer from %s:%s : %s") % (self.printerHostname, self.port, str(msg)), "warn")
89	120	else :
90		self.parent.filter.logdebug("Query sent to %s : %s" % (self.printerHostname, repr(pjlMessage)))
91		actualpagecount = self.printerStatus = None
92		self.timedout = 0
93		while (self.timedout == 0) or (actualpagecount is None) or (self.printerStatus is None) :
94		signal.signal(signal.SIGALRM, self.alarmHandler)
95		signal.alarm(TIMEOUT)
96		try :
97		answer = sock.recv(1024)
98		except IOError, msg :
99		self.parent.filter.logdebug("I/O Error [%s] : alarm handler probably called" % msg)
100		break # our alarm handler was launched, probably
101		except socket.error, msg :
102		self.parent.filter.printInfo(_("Problem while receiving PJL answer from %s:%s : %s") % (self.printerHostname, self.port, str(msg)), "warn")
103		else :
104		readnext = 0
105		self.parent.filter.logdebug("PJL answer : %s" % repr(answer))
106		for line in [l.strip() for l in answer.split()] :
107		if line.startswith("CODE=") :
108		self.printerStatus = line.split("=")[1]
109		self.parent.filter.logdebug("Found status : %s" % self.printerStatus)
110		elif line.startswith("PAGECOUNT=") :
111		try :
112		actualpagecount = int(line.split('=')[1].strip())
113		except ValueError :
114		self.parent.filter.logdebug("Received incorrect datas : [%s]" % line.strip())
115		else :
116		self.parent.filter.logdebug("Found pages counter : %s" % actualpagecount)
117		elif line.startswith("PAGECOUNT") :
118		readnext = 1 # page counter is on next line
119		elif readnext :
120		try :
121		actualpagecount = int(line.strip())
122		except ValueError :
123		self.parent.filter.logdebug("Received incorrect datas : [%s]" % line.strip())
124		else :
125		self.parent.filter.logdebug("Found pages counter : %s" % actualpagecount)
126		readnext = 0
127		signal.alarm(0)
128		self.printerInternalPageCounter = max(actualpagecount, self.printerInternalPageCounter)
129		sock.close()
130		self.parent.filter.logdebug("Connection to %s is now closed." % self.printerHostname)
	121	buffer.append(answer)
	122	if answer.endswith(constants.FORMFEEDCHAR) :
	123	self.queue.put("".join(buffer))
	124	buffer = []
	125	if buffer :
	126	self.queue.put("".join(buffer))
	127	self.parent.filter.logdebug("Reading thread ended.")
	128
	129	def retrievePJLValues(self) :
	130	"""Retrieves a printer's internal page counter and status via PJL."""
	131	try :
	132	self.sock.send(pjlMessage)
	133	except socket.error, msg :
	134	self.parent.filter.printInfo(_("Problem while sending PJL query to %s:%s : %s") % (self.printerHostname, self.port, str(msg)), "warn")
	135	else :
	136	self.parent.filter.logdebug("Query sent to %s : %s" % (self.printerHostname, repr(pjlMessage)))
	137	actualpagecount = self.printerStatus = None
	138	while (actualpagecount is None) or (self.printerStatus is None) :
	139	try :
	140	answer = self.queue.get(True, 5)
	141	except Queue.Empty :
	142	self.parent.filter.logdebug("Timeout when reading printer's answer from %s:%s" % (self.printerHostname, self.port))
	143	else :
	144	readnext = False
	145	self.parent.filter.logdebug("PJL answer : %s" % repr(answer))
	146	for line in [l.strip() for l in answer.split()] :
	147	if line.startswith("CODE=") :
	148	self.printerStatus = line.split("=")[1]
	149	self.parent.filter.logdebug("Found status : %s" % self.printerStatus)
	150	elif line.startswith("PAGECOUNT=") :
	151	try :
	152	actualpagecount = int(line.split('=')[1].strip())
	153	except ValueError :
	154	self.parent.filter.logdebug("Received incorrect datas : [%s]" % line.strip())
	155	else :
	156	self.parent.filter.logdebug("Found pages counter : %s" % actualpagecount)
	157	elif line.startswith("PAGECOUNT") :
	158	readnext = True # page counter is on next line
	159	elif readnext :
	160	try :
	161	actualpagecount = int(line.strip())
	162	except ValueError :
	163	self.parent.filter.logdebug("Received incorrect datas : [%s]" % line.strip())
	164	else :
	165	self.parent.filter.logdebug("Found pages counter : %s" % actualpagecount)
	166	readnext = False
	167	self.printerInternalPageCounter = max(actualpagecount, self.printerInternalPageCounter)
131	168
132	169	def waitPrinting(self) :
…	…
135	172	noprintingmaxdelay = int(self.parent.filter.config.getNoPrintingMaxDelay(self.parent.filter.PrinterName))
136	173	except (TypeError, AttributeError) : # NB : AttributeError in testing mode because I'm lazy !
137		noprintingmaxdelay = NOPRINTINGMAXDELAY
	174	noprintingmaxdelay = constants.NOPRINTINGMAXDELAY
138	175	self.parent.filter.logdebug("No max delay defined for printer %s, using %i seconds." % (self.parent.filter.PrinterName, noprintingmaxdelay))
139	176	if not noprintingmaxdelay :
…	…
144	181	timebefore = time.time()
145	182	firstvalue = None
146		while 1:
	183	while True :
147	184	self.retrievePJLValues()
148	185	if self.printerStatus in ('10023', '10003') :
…	…
175	212	break
176	213	self.parent.filter.logdebug(_("Waiting for printer %s to be printing...") % self.parent.filter.PrinterName)
177		time.sleep(ITERATIONDELAY)
	214	time.sleep(constants.ITERATIONDELAY)
178	215
179	216	def waitIdle(self) :
180	217	"""Waits for printer status being 'idle'."""
181	218	idle_num = 0
182		while 1 :
	219	while True :
183	220	self.retrievePJLValues()
184	221	if self.printerStatus in ('10000', '10001', '35078', '40000') :
…	…
189	226	return
190	227	idle_num += 1
191		if idle_num >= STABILIZATIONDELAY :
	228	if idle_num >= constants.STABILIZATIONDELAY :
192	229	# printer status is stable, we can exit
193	230	break
…	…
195	232	idle_num = 0
196	233	self.parent.filter.logdebug(_("Waiting for printer %s's idle status to stabilize...") % self.parent.filter.PrinterName)
197		time.sleep(ITERATIONDELAY)
	234	time.sleep(constants.ITERATIONDELAY)
198	235
199	236	def retrieveInternalPageCounter(self) :
200	237	"""Returns the page counter from the printer via internal PJL handling."""
201		try :
202		if (os.environ.get("PYKOTASTATUS") != "CANCELLED") and \
203		(os.environ.get("PYKOTAACTION") == "ALLOW") and \
204		(os.environ.get("PYKOTAPHASE") == "AFTER") and \
205		self.parent.filter.JobSizeBytes :
206		self.waitPrinting()
207		self.waitIdle()
208		except :
209		self.parent.filter.printInfo(_("PJL querying stage interrupted. Using latest value seen for internal page counter (%s) on printer %s.") % (self.printerInternalPageCounter, self.parent.filter.PrinterName), "warn")
210		raise
211		return self.printerInternalPageCounter
	238	while not self.open() :
	239	self.parent.filter.logdebug("Will retry in 1 second.")
	240	time.sleep(1)
	241	try :
	242	try :
	243	if (os.environ.get("PYKOTASTATUS") != "CANCELLED") and \
	244	(os.environ.get("PYKOTAACTION") == "ALLOW") and \
	245	(os.environ.get("PYKOTAPHASE") == "AFTER") and \
	246	self.parent.filter.JobSizeBytes :
	247	self.waitPrinting()
	248	self.waitIdle()
	249	except :
	250	self.parent.filter.printInfo(_("PJL querying stage interrupted. Using latest value seen for internal page counter (%s) on printer %s.") % (self.printerInternalPageCounter, self.parent.filter.PrinterName), "warn")
	251	raise
	252	else :
	253	return self.printerInternalPageCounter
	254	finally :
	255	self.close()
212	256
213	257	def main(hostname) :

pykota/trunk/pykota/accounters/snmp.py

r3163	r3175
29	29	"""
30	30
31		~~ITERATIONDELAY = 4 # time to sleep between two loops~~
32		~~STABILIZATIONDELAY = 5 # number of consecutive times the idle status must be seen before we consider it to be stable~~
33		~~NOPRINTINGMAXDELAY = 60 # The printer must begin to print within 60 seconds by default.~~
34	31
35	32	import sys
…	…
52	49	else :
53	50	hasV4 = True
	51
	52	from pykota import constants
54	53
55	54	#
…	…
158	157	noprintingmaxdelay = int(self.parent.filter.config.getNoPrintingMaxDelay(self.parent.filter.PrinterName))
159	158	except (TypeError, AttributeError) : # NB : AttributeError in testing mode because I'm lazy !
160		noprintingmaxdelay = NOPRINTINGMAXDELAY
	159	noprintingmaxdelay = constants.NOPRINTINGMAXDELAY
161	160	self.parent.filter.logdebug("No max delay defined for printer %s, using %i seconds." % (self.parent.filter.PrinterName, noprintingmaxdelay))
162	161	if not noprintingmaxdelay :
…	…
204	203	break
205	204	self.parent.filter.logdebug(_("Waiting for printer %s to be printing...") % self.parent.filter.PrinterName)
206		time.sleep(ITERATIONDELAY)
	205	time.sleep(constants.ITERATIONDELAY)
207	206
208	207	def waitIdle(self) :
…	…
226	225	return
227	226	idle_num += 1
228		if idle_num >= STABILIZATIONDELAY :
	227	if idle_num >= constants.STABILIZATIONDELAY :
229	228	# printer status is stable, we can exit
230	229	break
…	…
232	231	idle_num = 0
233	232	self.parent.filter.logdebug(_("Waiting for printer %s's idle status to stabilize...") % self.parent.filter.PrinterName)
234		time.sleep(ITERATIONDELAY)
	233	time.sleep(constants.ITERATIONDELAY)
235	234
236	235	def retrieveInternalPageCounter(self) :

pykota/trunk/pykota/constants.py

r3133	r3175
2	2	# -- coding: ISO-8859-15 --
3	3	#
4		# PyKota : Print Quotas for CUPS ~~and LPRng~~
	4	# PyKota : Print Quotas for CUPS
5	5	#
6	6	# (c) 2003, 2004, 2005, 2006, 2007 Jerome Alet <alet@librelogiciel.com>
…	…
21	21	# $Id$
22	22	#
	23
	24	"""This module contains the definitions of constants used by PyKota."""
	25
	26	ITERATIONDELAY = 4 # time to sleep between two loops
	27	STABILIZATIONDELAY = 5 # number of consecutive times the idle status must be seen before we consider it to be stable
	28	NOPRINTINGMAXDELAY = 60 # The printer must begin to print within 60 seconds by default.