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Too Busy For Words - The PaulWay Weblog (20 unread)

Going to town on a train

Posted: December 3rd, 2008, 8:07am CET

I've always loved rail travel. So here I am on the 5:05 from Canberra, heading to Sydney. A plane and even a bus would be quicker, and there would be some possibility that I could have got a lift with someone going this way as well. So why put up with being constantly rocked around, with other people who swear and play the guitar?P For the fun of it, of course! I've never seen some of the countryside I'm travelling through, out the back of Bungendore and Tarago. I've driven under the railway bridges and followed the line from north of Goulburn to Bundanoon, but never been on the track watching the cars. And it really is quite beautiful in an Australian way - rocky creek canyonettes (canyoninas?) and river banks green with recent rains, the rolling hills that yellowy-browny-green that only Australia seems to call fertile, and sweeps of countryside seen from other vantage points. I'm just going past a a href=http://maps.google.com.au/?ie=UTF8ll=-34.722841,149.820213spn=0.002773,0.005268t=hz=18whole set of brick - brick! - pylons/a crossing a river that have no bridge or track on them. What is their story? What is that mysterious high-security spot just south of Bungendore that you see easily from the train but never see from the road? What is that a href=http://maps.google.com.au/?ie=UTF8ll=-35.084623,149.637501spn=0.011045,0.021071t=hz=16huge shipping container area/a - devoid of cargo - just near Tarago? So many new things to find out! So much countryside I now appreciate for its own character, its twists and turns and long straights, that car drivers never touch.P It's wonderful. And it doesn't cost that much either!P Footnote: added links to Google maps for the two places I could find - the mysterious high-security area isn't showing up where I expect it to be - it's like the track, road, fences with cleared area around them, dams and buildings all just ... don't exist ...
Going to town on a train

Posted: December 3rd, 2008, 1:21am CET

I've always loved rail travel. So here I am on the 5:05 from Canberra, heading to Sydney. A plane and even a bus would be quicker, and there would be some possibility that I could have got a lift with someone going this way as well. So why put up with being constantly rocked around, with other people who swear and play the guitar?P For the fun of it, of course! I've never seen some of the countryside I'm travelling through, out the back of Bungendore and Tarago. I've driven under the railway bridges and followed the line from north of Goulburn to Bundanoon, but never been on the track watching the cars. And it really is quite beautiful in an Australian way - rocky creek canyonettes (canyoninas?) and river banks green with recent rains, the rolling hills that yellowy-browny-green that only Australia seems to call fertile, and sweeps of countryside seen from other vantage points. I'm just going past a whole set of brick - brick! - pylons crossing a river that have no bridge or track on them. What is their story? What is that mysterious high-security spot just south of Bungendore that you see easily from the train but never see from the road? What is that huge shipping container area - devoid of cargo - just near Tarago? So many new things to find out! So much countryside I now appreciate for its own character, its twists and turns and long straights, that car drivers never touch.P It's wonderful. And it doesn't cost that much either!
Random randomness

Posted: November 25th, 2008, 6:00am CET

The SECRET_KEY setting in Django is used as a 'salt' in (one would hope) all hash calculations. When a new project is created, a piece of code generates a new random key for that site. I'd seen a couple of these and noted, in passing, that they seemed to have an unusually high amount of punctuation characters. But I didn't give it much thought.P Recently I had to generate a new one, and found a couple of recipes quite quickly. The routine (in Python) is:P pre from random import choice print ''.join([choice('abcdefghijklmnopqrstuvwxyz0123456789!@#$%^*(-_=+)') for i in range(50)]) /pre (Aside: Note how Python's idea of line breaks having grammatical meaning in the source code has meant making one liners is now back in style? Wasn't this supposed to be the readable language? Weren't one liners supposed to be a backward construction used in stupid languages? Is that the sound of a thousand Pythonistas hurriedly explaining that, yes, you can actually break that compound up into several lines, either on brackets or by \ characters or by partial construction? Oh, what a pity.)P Anyway. A friend of mine and I noted that it seemed a little odd that the upper case characters weren't included in the string. Maybe, we reasoned, there was some reason that they didn't include these characters (and the punctuation that isn't on the numeric keys). But, looking through a href=http://code.djangoproject.com/changeset/230the actual changeset/a that combined all the various salts and secrets into one thing, and looking at where the secret key was used in the code, it seems that it's always fed into the md5 hasher. This takes bytes, basically, so there was no reason to limit it to any particular character subset.P So my preferred snippet would be:P pre from random import choice s = [chr(i) for i in range(32,38) + range(40,127)] print ''.join([choice(s) for i in range(50)]) /pre So you can at least read your secret key, and it doesn't include the single quote character (ASCII 39) that would terminate the string early. The update to the original functionality is in a href=http://code.djangoproject.com/ticket/9687ticket 9687/a, so let's see what the Django admins make of it.
Talking for real

Posted: November 22nd, 2008, 1:49am CET

Right. With two weeks to go until OSDC, I feel like I'm actually nearly ready to give my talk. The slides are all written up, and my first practice talk-through took 25 minutes - should fit into the 30 minute slot nicely. I aim to do about a dozen more talk-throughs so I can get my notes up to speed, and so that I don't read from the slides, speak too fast or ramble too much. I've spoken at CLUG before but this is an order of magnitude larger audience and three orders of magnitude more important. I really want this to go well, and I'm determined to do it well.P Damian Conway is my inspiration here - I will not fail him!
Don't Repeat Yourself - Next Generation

Posted: November 7th, 2008, 8:57am CET

I've become a big fan of a href=http://djangoproject.orgDjango/a, a web framework that has a nice blend of python, good design and flexibility. The template system might not appeal to the people who like to write code inside templates, but to me it forces programmers to put the code where it belongs - in the views (i.e. the controllers, to non-Djangoistas) or models. I love the whole philosophy of Don't Repeat Yourself in Django - that configuration should exist in one place and it should be easy to refer to that rather than having to write the same thing somewhere else. The admin system is nice, you can make it do AJAX without much trouble, and it behaves with WCGI so you can run a site in django without it being too slow.P The one thing I've found myself struggling with in the various web pages I've designed is how to do the sort of general 'side bar menu' and 'pages list' - showing you a list of which applications (as Django calls them) are available and highlighting which you're currently in - without hard coding the templates. Not only do you have to override the base template in each application to get its page list to display list to display correctly, but when you add a new application you then have to go through all your other base templates and add the new application in. This smacks to me of repeating oneself, so I decided that there had to be a better way.P Django's settings has an ttINSTALLED_APPS/tt tuple listing all the installed applications. However, a friend pointed out that some things listed therein aren't actually to be displayed. Furthermore, the relationship between the application name and how you want it displayed is not obvious - likewise the URL you want to go to for the application. And I didn't want a separate list maintained somewhere that listed what applications needed to be displayed (Don't Repeat Yourself). I'm also not a hard-core Django hacker, so there may be some much better way of doing this that I haven't yet discovered. So my solution is a little complicated but basically goes like this:P First, you do actually need some settings for your 'shown' applications that's different from the 'silent' ones. For me this looks like: blockquotepre SILENT_APPS = ( 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', ) SHOWN_APPS = ( ('portal', { 'display_name' : 'Info', 'url_name' : 'index', }), ('portal.kb', { 'display_name' : 'KB', 'url_name' : 'kb_index', }), ('portal.provision', { 'display_name' : 'Provision', 'url_name' : 'provision_index', }), ) INSTALLED_APPS = SILENT_APPS + tuple(map(lambda x: x[0], SHOWN_APPS)) /pre/blockquote We build the ttINSTALLED_APPS/tt tuple that Django expects out of the silent and shown apps, although I imagine a few Python purists are wishing me dead for the map lambda construct. My excellent defence is a good grounding in functional programming. When my site supports Python 3000 and its pythonisations of these kind of concepts, I'll rewrite it.P So ttSHOWN_APPS/tt is a tuple of tuples containing application paths and dictionaries with their parameters. In particular, each shown application can have a ttdisplay_name/tt and a tturl_name/tt. The latter relates to a named URL in the URLs definition, so you then need to make sure that your index pages are listed in your application's tturls.py/tt file as:P blockquotepre url(r'^$', 'kb.views.vIndex', name = 'kb_index'), /pre/blockquote Note the 'name' parameter there, and the use of the tturl()/tt constructor function.p You then need a 'context processor' to set up the information that can go to your template. This is a piece of code that gets called before the template gets compiled - it takes the request context and returns a dictionary which is added to the dictionary going to the template. At the moment mine is the file ttapp_name_context.py/tt:P blockquotepre from django.conf import settings from django.core.urlresolvers import reverse def app_names(request): Get the current application name and the list of all installed applications. dict = {} app_list = [] project_name = None for app, info in settings.SHOWN_APPS: if '.' in app: name = app.split('.')[1] # remove project name else: name = app project_name = name app_data = { 'name' : name, } # Display name - override or title from name if 'display_name' in info: app_data['display_name'] = info['display_name'] else: app_data['display_name'] = name.title() # URL name - override or derive from name if 'url_name' in info: app_data['url'] = reverse(info['url_name']) else: app_data['url'] = reverse(name + '_index') app_list.append(app_data) dict['app_names'] = app_list app_name = request.META['PATH_INFO'].split('/')[1] if app_name == '': app_name = project_name dict['this_app'] = app_name return dict /pre/blockquote Note the use of ttreverse/tt. This takes a URL name and returns the actual defined URL for that name. This locks in with the named URL in the tturls.py/tt snippet. This is the Don't Repeat Yourself principle once again: you've already defined how that URL looks in your tturls.py/tt, and you just look it up from there. Seriously, if you're not using reverse and ttget_absolute_url()/tt in your Django templates, stop now and go and fix your code.P We also try to do the Django thing of not needing to override behaviour that is already more or less correct. So we get display names that are title-cased from their application name, and URL names which are the application name with '_index' appended. You now need to include this context processor in the list of template context processors that are called for every page. You do this by using the ttTEMPLATE_CONTEXT_PROCESSORS/tt setting; unfortunately, if this isn't listed (and it isn't by default) then you get a set of four very useful context processors that you don't want to miss, so you have to include them all explicitly if you override this setting. So in your ttsettings.py/tt file you need to further add: blockquotepre TEMPLATE_CONTEXT_PROCESSORS = ( django.core.context_processors.auth, django.core.context_processors.debug, django.core.context_processors.i18n, django.core.context_processors.media, portal.app_name_context.app_names, ) /pre/blockquote The most inconvenient part of the whole lot is that you now have to use a specific subclass of the Context class in every template you render in order to get these context processors working. You need to do this anyway if you're writing a site that uses permissions, so there is good justification for doing it. For every ttrender_to_response/tt call you make, you now have to add a third argument - a RequestContext object. These calls will now look like:p blockquotepre return render_to_response('template_file.html', { # dictionary of stuff to pass to the template }, context_instance=RequestContext(request)) /pre/blockquote The last line is the one that's essentially new.P Finally, you have to get your template to show it! This looks like: blockquotepre lt;ulgt;{% for app in app_names %} lt;ligt;lt;a class={% ifequal app.name this_app %}menu_selected{% else %}menu{% endifequal %} href={{ app.url }}gt;{{ app.display_name }}lt;/agt;lt;/ligt; {% endfor %}lt;/ulgt; /pre/blockquote With the apprporiate amount of CSS styles, you now get a list of applications with the current one selected, and whenever you add an application this will automatically change to include that new application. Yes, of course, the solution may be more complicated in the short term - but the long term benefits quite make up for it in my opinion. And (again in my opinion) we haven't done anything that is too outrageous or made
Cue high speed tape recorder sound effect

Posted: October 28th, 2008, 6:55am CET

For the more technically minded, here is a brief synopsis of my criticisms of the Clean Feed 'initiative', sent in a letter to Senator Stephen Conroy:P blockquote ol li1% false positive rate is way too high to be usable./li li75% slower is too low to be usable, and the faster filters have a higher false positive rate./li liIt only blocks standard web traffic, not file sharing, chat or other protocols./li liIf you filter HTTPS, you cripple the financial system of internet shopping, banking, and personal information (e.g. tax returns)./li liIf the Government ignores who's requesting filtered content, then those wishing to circumvent it can keep on looking with no punishment. If the Government does record who requests filtered content, then even ASIO will have a hard time searching through the mountain of false positives./li liWe already have filtering solutions for those that want it, at no cost./li liMandatory filtering leads to state-run censorship and gives an in for the Big Media Corporations to 'protect their assets' by blocking anything they like./li liThe whole thing is morally indefensible: it doesn't prevent a majority of online abuse such as chat bullying or file trading, and it relies on the tired old 'think of the children' argument which is beneath contempt./li liPeople who assume that their children are safe under such as system and therefore do not use other protection mechanisms such as watching their children or providing appropriate support are living in a false sense of security./li /ol Instead, the Government should either put the money toward the National Broadband Network programme, or run their own ISP with the clean feed technology to compete with the regular ISPs.P Regards, Paul.P /blockquote I urge every Australian to write to Senator Conroy and/or their local Member of Parliament on this issue - it is one we cannot afford to be complacent about!
Hacking the LCA registration process for fun and, er, fun

Posted: October 13th, 2008, 11:38pm CEST

With the way tickets went for A href=http://www.linux.conf.au/Linux Conf AU/A this year gone, and getting paid today, I decided to get my registration in early. Once again I noted they had continued the fine tradition of having a random silly message per registrant. Once again I decided to hack it to make it say what I wanted it to say.P Needless to say they raised the bar this year. Up until 2007 it was just a hidden field in the form. In 2008 they added a checksum - this delayed me a good five minutes while I worked out how they'd generated it. This year they've upped the ante, including both a different checksum and adding a salt to it. Another five minute's playing with ttbash/tt revealed the exact combination of timestamp, delimiter, and phrase necessary to get a correct checksum. span style=color: white; background-color: white;I am also made of cheese./spanP Naturally, don't bother A href=mailto:paulway@mabula.netemailing me/a to find out how I did it; the fun is in the discovery!
Look Out Eddie Van Halen

Posted: October 9th, 2008, 5:18am CEST

Back in the days when Icehouse was in, Crowded House was big and I was getting deeply hooked into Yello, I had a Roland Juno 6. It was my Dad's, but I played it a fair bit. One of the leaders in the analog synthesis days between full-on knob-for-everything setups like the Moog and the start of MIDI and digital control, it is still legendary for producing huge bass lines and stunning synth leads. Then our house burned down and took the Juno with it, and though I often thought of getting another synthesizer I never did.P Until now. It started with playing the piano at friends and relatives houses; then Kate suggested I could accompany her violin playing. As I got more into LMMS I started realising that having a keyboard to record lines and work out notes and melodies on was going to be very useful. So I did some research and found the Roland Juno G, which sat between the full-on knob tweaking of Nords and Moogs (all digital, now, of course, but still faithfully emulating the analogue sound synthesis process), the 'play the demo song' integrated-speaker cheap synthesizer market, and the 'it has 4096 patches, all pianos' professional keyboard. This may sound like a no man's land, but the market segment is for people who want a range of instruments, the ability to fiddle with how they sound, and don't need heavy 'piano-action' keys. Unfortunately, they don't make the Juno G anymore.P Fortunately, it's successor is the Juno Stage, which is basically version 2 - all the features of the G but without the confusion between it and the Juno D. You get knobs to control attack and release, low and high frequency rolloff, and cutoff and resonance of the filter - which you can twiddle on the fly. It comes with 1024 different patches, a variety of modes including split keyboard (SuperSaw on the left and piano on the right is a favourite) and lots of nice features that I haven't truly discovered yet. So I bought it, brought it home, and started practicing again.P Gradually my fingers are warming up again, playing scales and old tunes I used to know. But what has amazed me is the amount of pure inspiration I'm getting from the sounds. A new patch will make me start writing new melodies out of thin air, and when I find that some presets consist of an arpeggio and drum rhythm on the left hand, new mystical tunes will flow out of my right hand and almost amaze me in the process. That and the joy of working out the chord progressions (the title of this post is a nod to the classic synth line of 'Jump' by Van Halen - I hit the first two chords (C, F in my playing) and then had to figure out the next (B) later by experimentation - I don't know what the actual song used but it's easiest to play on G, C, and F) for songs I remember. Playing the Doctor Who theme or the theme to Axel F or Fletch (yay Harold Faltermeyer) is always a blast, and it all came right back to me.P So I'm now doing regular practice of my own devising, before I seek out someone to teach me how to play more. I'll report how I go plugging it into the computer (yay USB MIDI interface) in another post.
Perl threaded database query processing

Posted: October 9th, 2008, 5:11am CEST

In my work I've recently had to implement several pieces of code which follow this basic pattern:P ol liRetrieve data from the database/li liProcess data/li liStore data somewhere./li /ol Because of Perl DBI's habit (on the systems I've used) of grabbing all the data from the database into memory before actually giving it to the caller, and because that data can often get large enough to get my process swapping or killed, what this usually turns into is:P ol liGet a list of 'grouping' items (e.g. days, months, IP addresses, etc.)/li liFor each item in that group: ol liRetrieve data from the database for that item. liProcess data/li liStore data somewhere./li /ol /ol This runs into an unfortunate problem when the database server you're talking to takes a noticeable time to process your query - the whole thing slows down hugely. A typical slowdown I've seen is in the order of 500% - and both the database and the client processors are mostly idle during that time, as each query has to be individually fetched, processed, dumped back to the client, and then processed. It suffers the same problem if the time to process each group of data is significant - by the time you've got back to fetching the next group, the database has gone off and done other things and needs to get its disk heads back in the right place for your data.P These days we have processors capable of doing multiple things at the same time, and so it would be nice if the client could be processing rows at the same time as it's also requesting more data from the database. This is where Perl's a href=http://perldoc.perl.org/threads.htmlttthreads/tt/a and a href=http://perldoc.perl.org/Thread/Queue.htmlttThread::Queue/tt/a libraries come in. It seems to me to be a generalisable task, so I'm sharing my first attempt at doing this in a generalisable way here. My main subroutine is:P pre ###################################### sub Thread_Process { ###################################### # We take one query which returns a list of items, a query which # returns other rows based on each of those items, and a function # which processes those rows. We then run the processor function # in parallel to the fetching process to utilise the connection # to the database and keep the local processor active. # Requirements: # The item query must be executed and ready to return rows. It # can return any number of fields. # The rows query must be ready to be executed, and will be # executed with the row_args_ref and then the items from each # row in the item query in turn (as arrays). # The function takes as its last argument the Thread::Queue object # that data will be passed through. It must know exactly how # many items it will take from each row, and that should match # the number of items returned in the query. For reasons as yet # unclear, we can't pass references of any kind on the queue, # so we pass the fields in each row as single scalars. Any # arguments that it needs should be given in fn_args_ref. It # should exit on receiving an undef. my ($items_qry, $rows_qry, $row_args_ref, $fn_ref, $fn_args_aref) = @_; my ($items_aref) = $items_qry-fetchall_arrayref; unless (ref $items_aref eq 'ARRAY') { carp Warning: got no rows from item query\n; return 0; } my $queue = Thread::Queue-new(); my $thread = threads-create($fn_ref, @$fn_args_aref, $queue); foreach my $item_aref (@$items_aref) { $rows_qry-execute(@$row_args_ref, @$item_aref); while (my $aref = $rows_qry-fetchrow_arrayref) { $queue-enqueue(@$aref); } } $queue-enqueue(undef); $thread-join(); return scalar @$items_aref; } /pre A sample caller function would be:p pre sub Send_mail_to_everyone { my ($mail_handler, $template, $start_date, $end_date); my $servers_qry = $dbh-prepare( 'select distinct mail_server from addresses' .' where birth_date between ? and ? and current = true', ); my $args_ref = [$start_date, $end_date]; $servers-execute(@$args_ref); my $email_qry = $dbh-prepare( 'select user_name, server, full_name, birth_date' .' from addresses' .' where birth_date between ? and ? and server = ?' .' and current = true' ); my $mailer_sub = sub { my ($queue) = @_; while (defined my $user_name = $queue-dequeue) { my $server = $queue-dequeue; my $full_name = $queue-dequeue; my $birth_date = $queue-dequeue; my $email_body = sprintf $template , $username, $server, $full_name, $birth_date; $mail_handler-send($user_name@$server, body = $email_body); } }; # Here most of the work gets done. Thread_Process($servers_qry, $email_qry, $args_ref, $mailer_sub, []); } /pre Of course, this is somewhat of a contrived example, and gives you little in the way of feedback or error handling. But it's an example of how to use the ttThread_Process/tt subroutine. The mailer subroutine gets its tt$mail_hander/tt and tt$template/tt from being within the ttSend_mail_to_everyone/tt routine.P There are two problems I've discovered so far. The first is that trying to do any kind of database operation within the subroutine doesn't work, because the database handle needs to be cloned. On the systems I've tested this on, unfortunately, tt$dbh-clone/tt seems to be a no-op and the DBI engine complains that a different thread is using the database handle. I've tried passing tt$dbh-clone/tt to the handler function, and doing the clone inside the handler function, but they change nothing.P More annoying is the fact that the memory used by the process continues to rise even if the number of outstanding rows is constant or dropping. I haven't traced this down, and haven't really the time now, but it seems to be related to the Thread::Queue object - I've tested variations of my handler routine that reuse existing memory rather than doing ttundef @array/tt and ttpush @array, $data/tt in the handler, and this changes little.P What I don't know yet is whether either to package this up as a Perl module and start being a maintainer or whether it's too trivial or not generalised enough to be useful for anyone but me.
Anonymous Earpieces

Posted: October 9th, 2008, 5:11am CEST

I bought a Stereo Headset Kit at Landmark Computers in Braddon the other day. This consists of a pair of wireless headphones, a bluetooth dongle that functions as a stereo encoder, a CD, a USB cable, a charger and some basic instructions. It's almost impossible to find out exactly who made this - there's no actual brand on the box or devices and the only identifiable branding is of the USB connection software. The software does have a Linux version available but (almost inevitably) it isn't supplied - the disk is really Windows-only.P The dongle has a switch that allows it to function in either USB or Audio mode. In USB mode it is a fully-featured USB Bluetooth dongle - plugging it into my Fedora 9 install allowed me to see all nearby Bluetooth phones, computers and the headset. I haven't tried to see if I can get it to function as a Bluetooth audio device, but PulseAudio does apparently provide this. In Audio mode, it encodes input from the headphone jack on the dongle and sends it to the paired headset. This allows you to use other devices such as computers, phones and music players that don't have Bluetooth capability.P The headset supports the A2DP profile, which basically supports (reasonable quality) stereo audio over Bluetooth. The quality and the stereo separation are quite good and, although it might not be up to full studio monitoring quality, it is easily capable of delivering good quality audio for everyday use. It also supports the headset profile for phones that don't have A2DP capability, but the headphones don't have a microphone so you can't use it as a full headset.P The headphones are comfortable even after a couple of hours of use. They sit around the back of the head, and even for people who have a large skull (such as myself) they don't press in uncomfortably. They can also fold to be flat so they can easily fit in a pocket when not in use. The right speaker has a volume up/down control, a skip forward/back control (for phones that support such control) and a main button that can be used to turn the unit off and on and put it in pairing mode.P These are not a cheap device, at around $110. However, they are cheaper than many of the brand-name devices and are more comfortable than the BlueAnt X5s that I tried a while back. The larger speaker gives them a better bass response than smaller earphones and the lack of cord prevents all sorts of tangles and trip-ups. As someone who seems prone to turning away from the computer and pulling the earphones out of my ears by accident (and force), that's a good thing.P The major downside so far has been that, while they give perfectly good stereo audio between the encoder dongle and the headphones, the other two devices I've tried both have bizarre and annoying behaviour that makes them nearly unusuable. My phone, a Nokia 5310 XpressMusic easily capable of A2DP, will drop them down from A2DP to Headset protocol, detectable as a flat mono signal, and then eventually (in three tests) drop them altogether, often getting wedged on the song being played back (a different song each time which has played normally otherwise, so that wasn't the problem). This wedges the headphones too, requiring a little press of the hidden reset button with a handy bent paperclip. Don't have one to hand? Too bad. (Note to young players - the little hole beneath the reset button is actually to seal the rubber protector in place, and should not be poked into unless you want to put a damaging hole in the speaker diaphragm. And you don't.)P The computer was even worse. I got the laptop bluetooth working with the instructions at a href=http://fedoraforum.org/forum/showthread.php?t=190468http://fedoraforum.org/forum/showthread.php?t=190468/a and it all came through nicely. For two minutes. Then it went to Insanely Loud Mode. Once I'd dialled back all the settings in PulseAudio (which, for reasons as yet unclear, muted the audio completely at 60% main volume or 40% RhythmBox volume) it was listenable, although you could tell there was hard clipping going on somewhere before the volume reduction stage (audible as a 'crackliness' to the sound). Then, two minutes later, it dropped back to completely inaudible, and only by turning all the volumes up again did anything come out. Two minutes later it cycled back to insanely loud and kept doing this as long as I was prepared to put up with it. Adjusting the volume on the headset seemed to do little, although when I later connected it to my phone for a second test the volume on the headset was turned up very loud, and changing the volume on the headset altered the volume on the phone. So I assume that something in PulseAudio was 'helpfully' adjusting the volume, for reasons as yet unclear.P I haven't tested it with anything else that outputs A2DP via Bluetooth, so I haven't any other benchmarks to work against. But so far this is a device that works perfectly with its own adapter and appallingly with everything else; not a trait that endears it to me.
Words For The Next Decade

Posted: September 9th, 2008, 2:54am CEST

I had a realisation last night that there's a new word that I suspect will be entering the news lexicon soon. That word isp ddbEnviropath/b/dd dtAn benviropath/b is a person or company who has a warped or distorted view of how to treat the environment, most commonly seeing it simply as something to exploit without consequence. Just as a sociopath cares little about their effect on society, and a psychopath cares little for their effect on people's psychologies, an enviropath cares little about their effect on the environment in the course of doing what they want./dtp The Urban Dictionary, which I won't link to here, has an alternate definition which basically is a derogatory term for someone too obsessed with the environment. I don't think this is using the i-pathy/i suffix - meaning a href=http://www.hospitalhelp.co.uk/general/operation_terminology.html'suffering or disease'/a - correctly; but then I'm sure the Urban Dictionary doesn't really care.P What it comes down to, for me, is that I believe that there are people and companies whose view point on the Earth and the natural world is that it is simply there for exploitation. They seem to believe that we can not just keep on doing what we've been doing, but actually find new ways to exploit the world, and the consequences simply don't apply to them. In this, my basic stance is completely the opposite - I believe it's time to do everything we possibly can to save the planet we live in. I also side with my dad's line of reasoning on this, in that I can afford to be wrong, but they can't.
Go to the Courts

Posted: August 26th, 2008, 8:57am CEST

There is a state in playing a href=http://en.wikipedia.org/wiki/Go_(board_game)Go/a where one recognises that a move might seem to give one a small gain in pieces now but gives more power to ones opponent in the long run. While I still struggle with this, and the larger question of 'what should I play so that I ido/i gain advantage over my opponent in the long run' is one I still find exceptionally difficult to grasp, I have at least started to recognise that getting a single eye now may actually give my opponent a double eye later.P It occurs to me, albeit as a layman with little knowledge of the real processes of law in and out of the courts, that there is a common pattern to high-profile law cases. If the objective is for A to win over B, then it is:P ol liA sues B and wins/li liB appeals against the judgement, brings in new arguments and wins./li liA appeals against that decision in the high court, brings in the full arsenal, and wins./li /ol B has lost because they have no higher court to appeal to. B has also lost because it has let itself be put in this position.P So what's odd in the whole Nine versus IceTV is that Nine has done this:P ol liNine sues IceTV and iloses/i/li liNine appeals against the judgement, brings in new arguments and wins./li liIceTV appeals against that decision in the high court.../li /ol Substituting Nine for B and IceTV for A in the pattern, therefore, means that it has allowed itself to be snookered by IceTV. Not only that, but the a href=http://www.austlii.edu.au/au/cases/cth/FCAFC/2008/71.htmlappeal decision/a, in my (again completely layman) view, were rather skewed: calling Nine's last minute channel changes 'creative input' is a rather large stretch, whereas calling them 'bungles' is probably nearer the mark. Then arguing that those changes then become not mere facts (that can be copied) but are promoted to copyrightable material is to call anything that a human being has any input into a creative process. It's easy to come up with counter-examples - copying numbers from a book, or assembling cars - but what may be more important is that this works in IceTV's favour, in that by the same rule IceTV are then putting creative input into the schedule and are therefore also making a creative work which is distinct from Nine's schedule by that very fact.P I'm sure the legal minefield starts well back at the start of that previous paragraph, and so I defer to Kim Weatherall and other experts, but when courts start handing down legal judgements that imply that almost any information is copywritable by someone makes the whole existence of facts in the public domain highly tenuous. Can someone copyright my name? My address? Do I somehow own a copyright to my particular choice of phone number and address that means that Telstra owes me money every time they print a phone book? (Note here that when it came to moving house most recently, I was given the choice of a couple of numbers by Telstra and I chose the one I liked - therefore, it wasn't Telstra's creative input that determined my phone number, it was mine.) If someone uses the word PaulWay in a way that I don't like, and I've been using it since 1992 and therefore have 15 years of established usage to back it up (again, having chosen that name creatively), can I sue them for copyright infringement without ever having to register it as a trademark? And if it's a copyright infringement, do I get those penalties that the APRA and ACA and so forth have fought for - penalties that are much worse than if it was just a defamation or trademark infringement case? Can you go to prison for creating a post-it note that copies your bus timetable or a person's phone number?P Yes, I know, it's all wild speculation. But this whole judgement feels completely at odds with how people really think about facts and raw information. While I respect the old style of directory compilation, to me it still doesn't equate to a monopoly on the information so collected. The whole sweat of the brow protection - that the labour itself makes it enough to be protected - doesn't wash with me, especially in a world where facts, information, opinions and news wash over us almost continually.P Anyway, back to my point. I think that Nine has, in their attempt to get their way in the short term, actually meant that IceTV will triumph in the end. By presenting a case based on such a skewed interpretation of the Australian copyright laws as they apply to facts and information, they've opened it up to the High Court leaning in the opposite direction and blowing Nine out of the water (and, I'd say, causing a considerable re-evaluation of the Desktop Systems vs Telstra case).
Tougher recycling

Posted: August 22nd, 2008, 10:01am CEST

At the moment, recycling is by and large a voluntary affair. We private citizens mostly have recycling bins, and a reasonable proportion of the populace put the correct stuff in them. Companies and Government too are catching on, with recycling bins appearing in tea rooms and beside desks and photocopiers. I've even been bringing my own compost bin into work, and that's been getting a reasonable quantity of scraps in it.P However, it seems to me that there are two barriers to this being a much more wide-spread and profitable industry. The first is that in many places it's difficult to know exactly what can be recycled. In many instances, things which can be recycled aren't marked with the appropriate symbols, or the bins which take the recycling aren't marked to say what exactly they can take. As another example, if you move house in Melbourne (for example) what you can actually put in your recycling bin, as well as its size, can vary dramatically. In my view, people will tend to be conservative and not put things in the recycling bin which could be recycled in case they can't, instead of the more optimistic opposite approach.P But it seems to me that this is a minor concern compared with the fundamental problem, which is illustrated in my first sentence. The fact that it's completely voluntary, combined with the complete absence of any feedback regarding whether you're doing the right thing or not, means that the wasters out there have absolutely no incentive to change. They can keep on throwing their cans, cardboard, plastic boxes and bottles and paper into the garbage and it will keep on being merrily taken away and put into landfill, and they never have to lift a finger to change.P As a case in point, I noticed on the way into my work that there is a large skip outside the deliveries entrance. It's being used because there are building renovations going on and the scrap material is going into the bin. It was quite easy for me to see that there were may cardboard boxes and metal wall divisions, all of which could be easily recycled. While I know that a couple of the waste skip hire companies in Canberra do actually send all their rubbish through the a href=http://www.skipbins.com/actrcc.htmrecycling centre/a here, I'll bet three to one that the majority of skip hire companies in most other capital cities in Australia don't do this. Canberra has an aggressive No Waste by 2010 policy, but how the ACT Government intends to get that last 10% fixed in the sixteen months remaining is beyond me.P Imagine, for a moment, random house bin inspections. A note in your letterbox gives you a score of how good you are at recycling, and what things you may have missed. Houses with good scores might receive a discount on their rates, and houses at the bottom end might recieve fines (to compensate). A follow-up with the worst offenders in a week or two might find other ways that the household could reduce their waste, energy use and costs. A similar scheme for companies would be easy to implement, and for businesses that have a lot of variety in their waste types - restaurants and builders, for example - might be linked up with other programmes (such as worm farms for spoilt food waste or recycled building supplies resellers) to help them reduce their waste output or get it going to the best use available.P The one great flaw in this plan, however, is that Governments have tried to avoid any confrontation with the public - any situation where they have to tell people to change their ways for the good of society. There are obvious exceptions, but the key difference I see between this kind of recycling enforcement and a programme to get dangerous cars off the road or to curb violent behaviour is that the latter things break laws and are 'provably' dangerous to other people. On soft issues like good parenting, good recycling or good social responsibility, the Government has heard the NIMBY and Nanny State lobbyists and realised that it's much easier to get people to do something if opposition can be branded as somehow bad. It's much easier to get people to give up their civil liberties and freedoms if you can say that anyone who wants to walk around taking pictures of arbitrary places (for example) must be a terrorist.P Ahem. Got carried away there.P Anyway, the other side to this is for state, territory and federal Governments to make sure that they aren't providing unnecessary subsidies to industries that are deliberately wasting resources. If these companies can't see the writing on the wall when it comes to climate change, then should we really be propping them up? Lobbyists from the coal power industry love to say how other methods of power generation aren't profitable, while conveniently overlooking the hundreds of millions of dollars in funding that they get from the Government to shore up their own 'we-can't-do-any-better' behaviour.P Capitalism gone right, on the other hand, looks like a href=http://www.skipbins.com/aboutus.htmACT Skip Bins/a. Other companies might whinge and moan that they can't possibly recycle everything as it costs too much. Then ACT Skip Bins not only goes and does it, but then makes money from the recycled materials as well.P But despite this, I still end up thinking that there are a lot of people and companies who not only just don't care but don't have to. And until they get hit in the hip pocket, they won't care either.
Error Message Hell

Posted: August 20th, 2008, 8:13am CEST

If there's one thing anyone that works with computers hates, it's an error message that is misleading or vague. Syntax Error, Bad Command Or File Name, General Protection Fault, and so forth have haunted us for ages; kernel panics, strange reboots, devices that just don't seem to be recognised by the system, and programs mysteriously disappearing likewise. The trend has been to give people more information, and preferably a way to understand what they need to do to fix the problem.P I blog this because I've just been struggling with a problem in Django for the last day or so, and after much experimentation I've finally discovered what the error really means. Django, being written in Python, of course comes with huge backtraces, verbose error messages, and neat formatting of all the data in the hopes that it will give you more to work with when solving your problem. Unfortunately, this error message was both wrong - in that the error it was complaining about was not actually correct - and misleading - in that the real cause of the error was something else entirely.P Django has a tturls.py/tt file which defines a set of regular expressions for URLs, and the appropriate action to take when receiving each one. So you can set up ttr'/poll/(?Ppoll_id\d+)'/tt as a URL, and it will call the associated view's method and pass the parameter ttpoll_id/tt to be whatever the URL contained. In the spirit of Don't Repeat Yourself, you can also name this URL, for example:P tturl(r'/poll/(?Ppoll_id\d+)', 'view_poll', name = 'poll_view_one')/ttP And then in your templates you can say:P ttlt;a href={{ url poll_view_one poll_id=poll.id }}gt;{{ poll.name }}lt;/agt;/ttP Django will then find the URL with that name, feed the poll ID in at the appropriate place in the expression, and there you are - you don't have to go rewriting all your links when your site structure changes. This, to me, is a great idea.P The problem was that Django was reporting that Reverse for 'portal.address_new_in_street' not found. when it was clearly listed in a clearly working tturls.py/tt file. Finally, I started playing around with the expression, experimenting with what would work and what wouldn't in the expression. In this case, the pattern was:P ttnew/in/(?Psuburb_id\d+)/(?Pstreet[A-Za-z .'-]+)/ttP When I changed this to:P ttnew/in/(?Psuburb_id.+)/(?Pstreet.+)/ttP It suddenly came good. And then I discovered that the the thing being fed into the 'suburb_id' was not a number, but a string. So what that error message really means is The pattern you tried to use didn't match because of format differences between the parameters and the regular expression. Maybe it means that you can have several patterns with the same name that will try to match based on the first such pattern that does so. But until then, I'll remember this; and hopefully someone else trying to figure out this problem won't butt their head against a wall for a day like I did.
Django 101

Posted: July 29th, 2008, 5:53am CEST

At work I've started working on a portal written in Python using the Django framework. And I have to say I'm pretty impressed. Django does large quantities of magic to make mothe model data accessible, the templating language is pretty spiffy (it's about on a par with ClearSilver, which I'm more familiar with - each has bits that the other doesn't do), and the views and url mapping handling is nice too. I can see this as being a very attractive platform to get into in the future - I'm already considering writing my Set Dance Music Database in it just to see what it can do.P So how do I feel as a Perl programmer writing Python? Pretty good too. There are obvious differences, and traps for new players, but the fact that I can dive into something and fairly quickly be fixing bugs and implementing new features is pretty nice too. Overall, I think that once you get beyond the relatively trivial details of the structure of the code and how variables work and so on, what really makes languages strong is their libraries and interfaces, and this to me is where Perl stands out with its overwhelmingly successfull CPAN and Python, while slightly less organised from what I've seen so far, still has a similar level of power.P About the only criticism I have is the way the command line option processing is implemented - Python has tried one way (getopt) which is clearly thinking just like a C programmer, and another (optparse) which is more object oriented but is hugely cumbersome to use in its attempt to be flexible. Neither of these hold a candle to Perl's GetOpt::Long module.
No good title

Posted: July 25th, 2008, 1:22pm CEST

History has been revised. Thank you.
The lost limericks list

Posted: July 15th, 2008, 1:51am CEST

After that post, I thought I'd just check which category I'd put my previous limericks in. To my horror, I discovered that I hadn't blogged them at all, but had (merely) posted them to the Linux Australia list. So I rescued them and posted them here for posterity.P blockquote That wonderful man Andrew Tridgellbr Over SaMBa keeps permanent vigil.br SMB, it is said,br He decodes in his head,br And CIFS 2 will some day bear his sigil./blockquote blockquote The great LGuest programmer Rusty,br Is virtually never seen dusty.br He eats 16K pages,br And has done so for ages,br Yet his moustache is clean and not crusty./blockquote blockquote That marvellous girl Pia Waughbr Is certainly hard to ignore.br With her leet ninja moves,br Open Source just improves -br All Linux Australians show awe!/blockquote
The Wireless Jonathan Oxer

Posted: July 15th, 2008, 1:50am CEST

After the three limericks I wrote about Tridge, Pia and Rusty, the conversation came up on #linux-aus about whether I could make a similar epgiram for Jon Oxer, former Linux Australia president, front-line hardware hacker and all-round good guy. It took me two months, but in an email to Jon I finally cracked it, packing much more into the rhyme than I originally thought would be possible:P blockquote The wireless Jonathan Oxer,br Waves his hand and his front door unloxer.br A remote-control loo,br And home theatre too -br If you as me, his whole house just roxor!/blockquote Who's next, I wonder?P blockquote We tune to podcasting James Purser,br Long known as a rhymer and verser.br With his darling wife Karinbr They are not known as barren:br Three children now stare at their cursor./blockquote Steve Walsh, however, is going to take a bit more thinking about.P Send your suggestions of who should be next under the pen to a href=mailto:paulway#64;mabula.netpaulway#64;mabula.net/a
Censorship, mine and yours

Posted: July 10th, 2008, 12:50am CEST

A couple of days ago I missed a couple of phone calls from one of Kate's family. When I finally got back to her it was to find out that she'd objected to me putting photos of her daughters (my nieces through Kate) on the internet, and blogging about her and her family. The photos I can vaguely understand - I had already put another bunch of photos from another family outing under a password-protected part of the gallery, but this group - which only features one photo of her eldest daughter - hadn't gone under that stricture yet. They are now.
There are two things that gall me about this incident. The first is that she has not actually seen what I had on my blog or my gallery - they don't have access to the internet at home and she uses it at her part time work only sparingly. She was prepared to accuse me of some nameless terror against her children, some breaking of trust, based purely on what her brother had (inadvertently) reported to her. He, it should be said, takes much the same attitude - that any personal details including photographs can be somehow used against you in the future. Again, he hasn't read through my blog to see whether I am actually discreet or not - I think I am - but is prepared to just put the blanket statement down and say that I shouldn't write about them or post pictures of them.
The second thing that galls me here is what I refer to as "somehow used against you" and "nameless terror". It's just basic paranoia combined with ignorance. They have no actual idea of the threats that are out there or whether the above disclosures of information are in any way likely to lead to any real danger, but they're going to shut me up and tell me off just in case. It doesn't satisfy them, either, because they only come up with some more prepostorous "nameless terror" that might befall their children or themselves because of the next imagined problem.
In Kate's sister's defence, apparently friends of theirs have had some acrimonious fall-out with photos of daughters being posted on the internet. And I can well understand that Kate's sister may not want to divulge too many details of this family to protect whatever privacy they have left. But this is all sounding like yet another "friend of a friend" story. From what little detail I have I would propose that this family was in much more danger from their own members knowing each other's phone numbers, bank account details, and whereabouts - a bunch of photos on the internet is hardly the great threat that it sounds.
From what I know - and, to borrow a phrase overused a couple of nights ago for entirely different reasons, I am prepared to change my belief if sufficient proof otherwise is provided - there has been no case of people dangerous to children being found with photos of random children from the internet in perfectly ordinary situations. The paedophile rings that I've heard busted have traded photos exclusively within their own group and they are photos taken by them of children "in their power". In other words, my photos of Kate's nieces are hardly a danger to them or their family.
It's not unlike the recent kerfuffle over Bill Henson's photos - although his photos are (in my opinion) much more controversial, they are still hardly likely to be the subject of or cause any paedophilic behaviour. But the masses, uneducated in the actual threats and their likelihood, are prepared to go on making wild accusations in order to assuage their latest paranoid fantasy.
I've had my name, birthday and post office box on my website for years. There has never been any problem caused by that. No-one has ever used it to steal my identity, no-one has ever sent me unsolicited post, and no trouble has ever been caused by it. On the other hand, I just got a phishing spam the other day asking for my username, password and date of birth, and I'm sure that there are uneducated idiots out there that would thoughtlessly respond despite the email's obvious lack of personal identification and simple spelling and grammar mistakes. Which is the greater threat? Which should we be realistically guarding against?
It would be petty of me - but quite apposite - to reciprocate by telling them, if they ever ask me to help get them set up on the internet, to tell them that I've never seen how they use the internet but since they are obviously unaware of the dangers of spam and viruses I'd better make sure they never use the internet just in case.
New Job, Same Old Business

Posted: July 2nd, 2008, 2:29am CEST

I've just started work on Monday at my new employer, a href=http://www.transact.com.auTransACT/A, a fibre and copper communications provider in (as the name implies) the Australian Capital Territory. I've read through the employee handbook, done all the financial documentation, been given a computer and installed Fedora 9 on it. The majority of the team here use Mac Minis as their desktop machines, because there's a high requirement to use Unix commands to manage the network infrastructure. Of course, we still have to hook into the Microsoft Windows support infrastructure, but that's hardly a challenge these days.P The reason I mention this is because TransACT and its parent company ActewAGL are featured on Microsoft Australia's a href=http://www.microsoft.com/australia/windowsserversystem/getthefacts/default.mspxGet The Facts/a pages as some kind of 'shining example' of a company that Wave[d] Goodbye To Linux and somehow saved money. The Ifacts/I are radically different, even from the small sample I've seen so far. All the network infrastructure, from the set top boxes to the DHCP servers to the encryption server for the IPTV, run on some kind of Unix - Debian Linux seems to be the predominate flavour. Microsoft's case study is really just a small part of TransACT and ActewAGL's business, and it's hardly waved goodbye to Linux in the organisation.

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