Mailman 3 May 2002 - Twisted

[Twisted-Python] Twisted 0.18.0rc1, Bugs 0.2.0, and Twisted Emacs 0.1.0
by Christopher Armstrong May 30, 2002

May 30, 2002

I just made a release and posted it to the web site, check out http://twistedmatrix.com/ for more information. >From the News section:: ---- It's been a while since our last release, so we made up for it by making major improvements to Twisted, and overhauling PB for Emacs and doing an official release of it. Also, Twisted Bugs has been updated to work with the latest changes. We're going to start doing release candidates (that's what the "rc" stands for) before major releases from now on, so you don't have to fear the point-oh releases any more ;) Oh, and be on the lookout for 0.99.0 very soon! Once that's released we'll be concentrating hard on documentation and testing (ie, stability) for the coming 1.0 release! ---- Once 0.18.0 proper is released, I'll do a bigger release announcement. But I'd like to ask everyone working with Twisted to _please_ download and try 0.18.0rc1! There were a lot of changes, and we'd like to make sure everything's working OK! On the other hand, the core devel team is pretty confident about this release -- we've made a lot of improvements and we didn't rush (*ahem*) the release, so it should be OK. :-) -- Chris Armstrong << radix(a)twistedmatrix.com >> http://twistedmatrix.com/users/carmstro.twistd/

1 0

[Twisted-Python] Removing Perspectives
by exarkun＠meson.dyndns.org May 29, 2002

May 29, 2002

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Yes, I want to remove a perspective. It seems this hasn't come up before (at least there is little provisioning for it in the API). So, what's the best way to do this? It seems that cred.service.Service should have something like removePerspectiveNamed or removePerspectiveRequest (depending on whether the action can be taken immediately or not) to take care of this, taking the name of the perspective to squish. I don't see any reason that the action shouldn't be able to be taken immediately, so I would consider removePerspectiveNamed(perspectiveName) preferable, with no return value and raising a KeyError or something on the case where there is no perspective of the given name. This sound reasonable, or is there more to do / a better way to do it? Jp (A PART OF TEH TWISTARD DVELEPER COMUNITE) - -- It is practically impossible to teach good programming style to students that have had prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration. -- Dijkstra - -- 10:10pm up 7 days, 22:50, 0 users, load average: 0.02, 0.13, 0.46 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (GNU/Linux) iD8DBQE89DlJedcO2BJA+4YRAi0DAJ9mi7C3+7aLmXEL4JQH12cZ57wlqwCfatE/ KI0Cb1SghE7DpFKNdsTkJWc= =MOJi -----END PGP SIGNATURE-----

1 0

[Twisted-Python] Twisted.bugs ate my balls!
by Andrew Bennetts May 27, 2002

May 27, 2002

libpq.OperationalError: ERROR: value too long for type character varying(16) ... ("INSERT INTO bugs_items\n (submittor_name, submittor_email, assigned, date_submitted, date_modified,\n version, os, security, type, status, summary, description) VALUES\n (%s, %s, NULL, now(), now(), %s, %s, %s, %s, 'open', %s, %s)\n ", 'Andrew Bennetts', 'andrew-twistedbugs(a)puzzling.org', '0.18.0-prerelease', 'Win32', 'f', 'normal', 'connectionFailed might not get called', 'On Win32, connecting to a closed port doesn\'t fail immediately, but instead only calls connectionFailed after timing out. However, timeouts are optional, so it is possible it will never be called.\r\n\r\nFor the default (select) reactor, the problem is winsock\'s select reports failed connections as "exceptional", rather than as readable/writeable, and Twisted ignores exceptional socket events.\r\n\r\nPerhaps if platform is win32, do something like:\r\n\r\ndef win32select(reads, writes, ignored, timeout=None):\r\n """Kludge around winsock\'s select() function"""\r\n r, w, e = select.select(reads, writes, reads, timeout)\r\n return r+e, w, []\r\nselect = win32select') *sigh* It turns out Itamar has submitted the same bug: http://www.twistedmatrix.com/users/itamarst.twistd/bugs/view_bug?bug_id=19 Anyway, bug I'm trying to submit reads: Summary: connectionFailed might not get called Description: On Win32, connecting to a closed port doesn't fail immediately, but instead only calls connectionFailed after timing out. However, timeouts are optional, so it is possible it will never be called. For the default (select) reactor, the problem is winsock's select reports failed connections as "exceptional", rather than as readable/writeable, and Twisted ignores exceptional socket events. Perhaps if platform is win32, do something like: def win32select(reads, writes, ignored, timeout=None): """Kludge around winsock's select() function""" r, w, e = select.select(reads, writes, reads, timeout) return r+e, w, [] select = win32select

2 1

Re: [Twisted-Python] adding a new connection type
by Eric C. Newton May 27, 2002

May 27, 2002

Itamar Shtull-Trauring <twisted(a)itamarst.org> writes: > Well, first of all, what does it run over? X.25. Be afraid. > And in what languages is it written? It runs in Python of course. > And, what is it good for? X.25 is an international standard for wide area communications widely adopted by companies in the 1970's and early 80's using packet-oriented, synchronous serial communications devices. I'm using Linux, and playing with 2-year-old patches for version 2.4 of the kernel which enables me to play with the API over a loopback device. Sometimes it even works. The linux X.25 API is broadly based upon BSD sockets. Unfortunately, the python sockets module only really supports INET and UNIX domain addresses. I've written my own C module to provide an alternative interface because doing X.25 is just so much fun. I've managed to get past all the Twisted (.tap) stuff and I've got the process accepting these faux X.25 connections and data is flying back and forth. I subclassed from the tcp.Port class, and re-wrote the startListening() method. I haven't tried the client side of things yet. Among other things, I needed to add a shutdown() method, which socket provides and Twisted seems to need. -Eric

2 1

[Twisted-Python] runtest
by David Rufino May 26, 2002

May 26, 2002

Hello! Here are my runtest logs from FreeBSD 4.6-PRERELEASE running python 2.1, with cvs from today ====================================================================== ERROR: testBasicIdentity (twisted.test.test_persisted.MarmaladeTestCase) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/local/lib/python2.1/site-packages/twisted/test/test_persisted.py", line 219, in testBasicIdentity uj = marmalade.unjellyFromXML(marmalade.jellyToXML([l, l])) File "/usr/local/lib/python2.1/site-packages/twisted/persisted/marmalade.py", line 380, in unjellyFromXML document = parseString(stringOrFile) File "/usr/local/lib/python2.1/xml/dom/minidom.py", line 915, in parseString return _doparse(pulldom.parseString, args, kwargs) File "/usr/local/lib/python2.1/xml/dom/minidom.py", line 901, in _doparse events = apply(func, args, kwargs) File "/usr/local/lib/python2.1/xml/dom/pulldom.py", line 301, in parseString parser = xml.sax.make_parser() File "/usr/local/lib/python2.1/xml/sax/__init__.py", line 88, in make_parser raise SAXReaderNotAvailable("No parsers found", None) SAXReaderNotAvailable: No parsers found ====================================================================== ERROR: testMarmaladeable (twisted.test.test_persisted.MarmaladeTestCase) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/local/lib/python2.1/site-packages/twisted/test/test_persisted.py", line 188, in testMarmaladeable u = marmalade.unjellyFromXML(s) File "/usr/local/lib/python2.1/site-packages/twisted/persisted/marmalade.py", line 380, in unjellyFromXML document = parseString(stringOrFile) File "/usr/local/lib/python2.1/xml/dom/minidom.py", line 915, in parseString return _doparse(pulldom.parseString, args, kwargs) File "/usr/local/lib/python2.1/xml/dom/minidom.py", line 901, in _doparse events = apply(func, args, kwargs) File "/usr/local/lib/python2.1/xml/dom/pulldom.py", line 301, in parseString parser = xml.sax.make_parser() File "/usr/local/lib/python2.1/xml/sax/__init__.py", line 76, in make_parser return _create_parser(parser_name) File "/usr/local/lib/python2.1/xml/sax/__init__.py", line 101, in _create_parser return drv_module.create_parser() AttributeError: 'xml.sax.expatreader' module has no attribute 'create_parser' ====================================================================== ERROR: testMethodSelfIdentity (twisted.test.test_persisted.MarmaladeTestCase) ---------------------------------------------------------------------- Traceback (most recent call last): File "/usr/local/lib/python2.1/site-packages/twisted/test/test_persisted.py", line 201, in testMethodSelfIdentity im_ = marmalade.unjellyFromXML(marmalade.jellyToXML(b)).a.bmethod File "/usr/local/lib/python2.1/site-packages/twisted/persisted/marmalade.py", line 380, in unjellyFromXML document = parseString(stringOrFile) File "/usr/local/lib/python2.1/xml/dom/minidom.py", line 915, in parseString return _doparse(pulldom.parseString, args, kwargs) File "/usr/local/lib/python2.1/xml/dom/minidom.py", line 901, in _doparse events = apply(func, args, kwargs) File "/usr/local/lib/python2.1/xml/dom/pulldom.py", line 301, in parseString parser = xml.sax.make_parser() File "/usr/local/lib/python2.1/xml/sax/__init__.py", line 76, in make_parser return _create_parser(parser_name) File "/usr/local/lib/python2.1/xml/sax/__init__.py", line 101, in _create_parser return drv_module.create_parser() AttributeError: 'xml.sax.expatreader' module has no attribute 'create_parser' ---------------------------------------------------------------------- Ran 272 tests in 20.532s FAILED (errors=3) The following test modules had errors when loading: * test_nntp: Traceback (most recent call last): File "/usr/local/lib/python2.1/site-packages/twisted/test/test_all.py", line 76, in loadTestsFromMyPackage locals(), globals(), [name]) File "/usr/local/lib/python2.1/site-packages/twisted/test/test_nntp.py", line 19, in ? from twisted.news import news, database ImportError: No module named news The following test modules had errors when loading: * test_nntp: Traceback (most recent call last): File "/usr/local/lib/python2.1/site-packages/twisted/test/test_all.py", line 76, in loadTestsFromMyPackage locals(), globals(), [name]) File "/usr/local/lib/python2.1/site-packages/twisted/test/test_nntp.py", line 19, in ? from twisted.news import news, database ImportError: No module named news The following test modules had errors when loading: * test_nntp: Traceback (most recent call last): File "/usr/local/lib/python2.1/site-packages/twisted/test/test_all.py", line 76, in loadTestsFromMyPackage locals(), globals(), [name]) File "/usr/local/lib/python2.1/site-packages/twisted/test/test_nntp.py", line 19, in ? from twisted.news import news, database ImportError: No module named news Cheers

3 2

[Twisted-Python] adding a new connection type
by Eric C. Newton May 26, 2002

May 26, 2002

I want to add a new kind of connection to Twisted. I have wrapped up the API for this connection with an interface very similar to the socket object interface. It supports fileno(), bind(), connect(), listen(), accept(), send(), recv(), and of course, setblocking(). One interface difference is that the address type is just a string. Another subtle difference is that connect() calls should always bind to a local address before connecting. I'm new to Twisted, but I have extensive experience in ACE. I could use a clue on where I should start. -Eric

2 1

[Twisted-Python] Twisted Enterprise (newbie question)
by Steve Waterbury May 24, 2002

May 24, 2002

Twisted Gurus, I'm just starting to experiment with Twisted, and am trying out the example in the "Introduction to Twisted Enterprise", slightly modified: I have a PostgreSQL database called "test", which has a table called "schema", which has columns called "schema_name" and "identification" (among others), and the value of schema_name in one row is "pgpdm_schema"). My script is: ------------------------------------------------------------------------ from twisted.enterprise import adbapi import sys class TestDatabase(adbapi.Augmentation): def getSchemaByName(self,schemaname): sql = """SELECT identification from schema WHERE schema_name = %s""" return self.runOperation(sql,schemaname) def gotSchemaByName(resultlist): ident = resultlist[0][0] print resultlist print "Schema has identifier %s." % ident # dbpool = adbapi.ConnectionPool("psycopg","test","waterbug","") dbpool = adbapi.ConnectionPool("pyPgSQL.PgSQL","test","waterbug","") db = TestDatabase(dbpool) db.getSchemaByName("pgpdm_schema").addCallbacks(gotSchemaByName, db.operationError).arm() ------------------------------------------------------------------------ I've tested the sql using both psycopg and pyPgSQL in interactive sessions, so I know this query should produce an output of [['PGPDM-1.0']] I've tried it with both pyPgSQL and psycopg ... in both cases, the output is: -------------------------------------------------------------------------- [waterbug@beeblebrox twisted]$ python db_test.py Enabling Multithreading. Connecting to database: pyPgSQL.PgSQL ('test', 'waterbug', '') {} -------------------------------------------------------------------------- Shouldn't the print statements be producing output on stdout? (I'm new to callbacks, so I'm sure I've missed something ...) TIA! -- Steve. Stephen C. Waterbury http://misspiggy.gsfc.nasa.gov/people/waterbug.html "An idiot with a computer is a faster, better idiot." - Rick Julius

3 5

[Twisted-Python] Reality and global Thing tables
by exarkun＠meson.dyndns.org May 24, 2002

May 24, 2002

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 This is mostly addressed to Glyph, but any feedback is appreciated :) From what brief conversations we've had on the topic, my understanding of the situation is this: I like to have large global tables, each for a certain "type" of Thing, that references every instance in the game; an alternative approach favored by others is for references to only those objects that will be useful to be kept around locally (locally with respect to the objects that will find them useful). The main argument I've heard against global tables is they use resources unnecessarily. A game with a billion Widgets will have an unreasonably large table, which must apparently be kept entirely in memory (whereas, with a bit of cleverness, the Widgets themselves can be tossed onto disk when not needed). Are there other arguments against using global tables? I don't find this to be convincing for a few reasons. Firstly (and least importantly), hardware is cheap and expanding a server to meet the needs of a game isn't all that unreasonable. Besides, I'll never have to worry about it because my game will never become that large or popular ;) Second, distributing references locally gives us a large performance hit for certain operations. Consider the common case of game-wide communication. This can either be an inherent ability (think "tell" from most MUDs) or something granted by a device (the commlinks of SWR). Either way brings essentially the same programmatic challenges. Determine who the message is addressed to and deliver it. Using global tables, we can look up a player name (in linear time) and deliver the message or look up a "device address" (cellphone number, frequency ID, whatever floats your boat) and deliver the message to anyone in close proximity to the Thing. Contrast this with a system lacking global tables. To determine who the message is addressed to, one essentially has to walk through the graph of the entire game. Start with your highest level organizational unit ("areas" on most MUDs) and work down to rooms, then room contents (including players and containers, and containers in containers, etc). A very expensive operation that could end up costing many levels of recursion along with numerous unneeded levels of indirection in the form of rooms and containers. Of course, after the first lookup you can cache the result (and hope it doesn't change in the mean time) obviating the need for further lookups, but this comes with the problem of eventually costing as much memory as the global solution (if not more) unless you do cache management and culling and all sorts of other complexities. Fun? No. So, am I just missing some clever way to operate without global tables, or some other disadvantage to keeping them around? I am as an empty pot, fill me up. Jp (exarkun) "I quite agree with you," said the Duchess; "and the moral of that is -- Be what you would seem to be' -- or, if you'd like it put more simply -- Never imagine yourself not to be otherwise than what it might appear to others that what you were or might have been was not otherwise than what you had been would have appeared to them to be otherwise.'" -- Lewis Carrol, "Alice in Wonderland" - -- 5:58pm up 2 days, 18:37, 0 users, load average: 0.06, 0.07, 0.02 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (GNU/Linux) iD8DBQE87W4/edcO2BJA+4YRAk6UAJ4g7/zFzd6l0rWE05rGI1QZMRhe2QCgzSIO zElP/O5c7F4d9LJ++3gvpJc= =HegD -----END PGP SIGNATURE-----

2 1

[Twisted-Python] Small bug in code example in doc/howto/time.html
by Jeremy Fincher May 23, 2002

May 23, 2002

This: def OnceAMinute: """Should be run once a minute.""" print "a minute has passed" Should be this: def OnceAMinute(): """Should be run once a minute.""" print "a minute has passed" Also, a question: Later on in that code example, there's a "d.loop(OnceAMinute, 6)" line. How does d.loop know how to call OnceAMinute? Does it just assume that it takes no arguments (and thus, all functions that would be added there need to take no arguments)? Thanks! Jeremy

2 1

[Twisted-Python] How should this mailing list be used?
by Jeremy Fincher May 22, 2002

May 22, 2002

I'll be reading a lot of Twisted code in the next while, and will undoubtedly notice little things that might be optimized or tiny bugs that could be fixed. Is it alright if I send mails to this list with those things? Is that how I should handle things when I find those things? (As I mentioned before in the IRC channel, I honestly just don't have the time to make patches and test them and submit them, but I can generally find the time to make a note about them somewhere, and it's been mentioned on the IRC channel (by radix) that here might be the most appropriate place to do so.) Thanks! Jeremy

3 4