Zen Garden

Python threads in action

2012-02-12T16:50:00.000-08:00

Simple port proxy in python

Seems like there's a lot of python out there telling you how to use threads, and none of it actually shows you how to do it.

Here's an example that extends "Thread" and also makes use of the Thread(target = XXX) functionality.


import nark
import socket
from threading import Thread
from ICacheService import *
from IFetchService import *

class SoapCachedItem(Thread):
  """ Single proxy entry. """

  def __init__(self, remoteHost, remotePort, localPort, localDir):
    Thread.__init__(self)

    self.remoteHost = remoteHost
    self.remotePort = remotePort
    self.localPort = localPort
    self.localDir = localDir

    register = nark.Register.get()
    container = register.instance(nark.Container)
    self.cache = container.resolve(ICacheService)
    self.fetcher = container.resolve(IFetchService)
    self.log = register.instance(nark.Log)

    self.dead = False

  def __respond(self, request):
    """ Look for a cached response; if none, fetch one. """
    rtn = self.cache.respond(self.localDir, request)
    if not rtn:
      rtn = self.fetcher.respond(self.remoteHost, self.remotePort, request)
      self.cache.store(self.localDir, request, rtn)
    return rtn

  def run(self):
    """ Run a mini server """
    s = socket.socket()
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind(('', self.localPort))
    s.listen(1)
    s.settimeout(1)
    self.log.trace("Listening on local port: " + str(self.localPort))
    while not self.dead:
      try:
        t,_ = s.accept();
        Thread(target = self.__handle, args = (self, t)).start()
      except:
        pass #timeout
    self.log.trace("Stopping server on port: " + str(self.localPort))

  @classmethod
  def __handle(type, self, s):
    """ Handle in incoming thread """
    try:
      request = s.recv(4096)
      self.log.trace(request)
      response = self.__respond(request)
      s.send(response)
      s.close()
      self.dead = True
    except Exception, e:
      self.log.error("Error processing request:", e)
      self.dead = True

Notice how we have to decorate __handle() with @classmethod, otherwise the arguments passed into it will be incorrect.

NB. Obviously this is only a fragment and wont possibly compile without the extra classes and things. :P

ABCMeta vs. throw NotImplementedError

2012-01-26T17:36:00.000-08:00

ABCMeta vs. throw NotImplementedError

Ever wondered what the difference between using the ABC module in python and just throwing an error when a base function isn't present is? Actually, it pretty obvious once you do it...


from abc import ABCMeta, abstractmethod

class Base1(object):
  def requiredCall(self, x):
    raise NotImplementedError()

class Base2(object):
  __metaclass__ = ABCMeta  
  @abstractmethod
  def requiredCall(self, x):
    return

class Impl1(Base1):
  pass

class Impl2(Base2):
  pass

try:
  i1 = Impl1()
except:
  print("Unable to create Impl1")
  
try:
  i2 = Impl2()
except:
  print("Unable to create Impl2")

The answer? Tada~ You can create an instance of Impl1 without any errors, and will only discover the problem when you try to use it; on the other hand, trying to create an instance of Impl2 will result in an exception.

Extremely handy~

Logical OR in bash programming.

2010-10-11T20:11:00.000-07:00

Why do none of the guides to bash programming explain how to do a logical OR?

Spent ages trying to figure this one, so here we go, the basic syntax is:

if [ Expression ] || [ Expression]; then
fi

For example, checking if you have one or two command line arguments:

if [ `expr $# == 1` == 1 ] || [ `expr $# == 2` == 1 ]; then
echo "OK";
fi

Tada!

Programming guide fail! :P

Php + GWT in Dev mode

2010-05-18T18:20:00.000-07:00

One of the things that's been annoying me recently with GWT is that although it's an awesome toy, it's really had to develop with anything that doesn't use a java backend.

So, for example, say you have an awesome GWT app, but you want to use some client side services in php or ruby. Sure, you can write it all up, document it, do the GWT app and then do the php backend as separate steps... but, you lose all the power of the GWT environment debugging tools and the wonderful google plugin for eclipse that makes bug fixing so much easier.

What I didn't realize is that you can use the java implementation of these languages inside the dev environment to develop your backend applications.

Once you're done you have to go back and check they work normally under a native implementation (instead of the java implementation) but jython, jruby and quercus will get you up and running the dev environment right away. Very nice.

Specifically for php, you just need to add this to your web.xml:


  <servlet>
    <servlet-name>Quercus Servlet</servlet-name>
    <servlet-class>com.caucho.quercus.servlet.QuercusServlet</servlet-class>
    <init-param>
      <param-name>script-encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
    <init-param>
      <param-name>ini-file</param-name>
      <param-value>WEB-INF/php.ini</param-value>
    </init-param>
  </servlet>

...and, add inject-16.jar, javamail-141.jar and resin.jar from the quercus download to your download path.

http://www.caucho.com/resin-3.0/quercus/

Then stick your php in the war directory and point your gwt ajax calls at the php scripts. :)

Teehee~

2010-04-28T01:57:00.000-07:00

Care of http://www.mikematas.com/.

Telescopes? Hell yes.

2010-04-27T22:00:00.000-07:00

http://blogs.discovermagazine.com/badastronomy/2010/04/27/amazing-shuttle-picture/

Nice. This guy managed to snap a photo of the ISS with just a telescope and a digital camera. Sooooo cool. :)

Operator please...?

2010-04-26T23:50:00.003-07:00

Never been such a fan of operator please, but I quite enjoy this new one, 'Back and Forth'. [ Listen ]

There goes Heineken again: Men with Talent

2010-04-26T23:50:00.001-07:00

http://ettf.net/archives/14129
nice.

Conversations about taichi late at night...

2010-04-05T03:27:00.000-07:00

So late last night we were standing around in the chilly night air, talking about taichi and drinking tawny port. Well... I was drinking port anyway.

Totally awesome night, I'm so sad I didn't get any pictures of the fairy lights up inside the tent. Note to self: next time, make sure phone is charged before going out...

Tomorrow, a new layout for the zen garden; this one is starting to feel a little stale now I think.

Meanwhile, I leave you with this wonderful picture from the Swancon Masquerade (src).

Hopefully no one managed to catch any pictures of me that evening...

Zen Gardens are Tricky...

2010-03-23T05:04:00.000-07:00

So I've updated my website to put this blog inline on the page, instead of my twitter feed, because it seems a little more appropriate.

Also, this way I can comment on particularly tasteful garden rakings, such as this one:

This is a my second attempt at a single-pass-raking, where the entire zen garden is done in a single continuous motion. Unfortunately as I ranked outward from the center stones (as you're supposed to; the lines in the sand supposedly akin to the ripple of a pebble cast into a pond), the edges ended up a little messily. I'll have to plan ahead a little bit better next time...

Secret handsake machine

2010-01-07T19:35:00.000-08:00

Have to give it to these guys, they made a very cool toy:
http://amandapeyton.com/mas834/

Check out the video too; super frikking awesome.

ShakeOnIt Demo from David Cranor on Vimeo.

Man... we need to stop using swipe cards immediately and shift to this technology for user recognition... ;)

No fair~

2010-01-04T20:28:00.001-08:00

Wow, these guys look like that have way toooo much fun at work. Sigh~
http://giantsparrow.com/blog/

I'm sure it's not all playing with paint in the sunshine.

surely...

Unit Tests in GWT

2010-01-01T22:49:00.000-08:00

Wow, the google tutorial about how to make unit tests in GWT using the eclipse plugin is strangely unhelpful.

It's actually very easy...

1) Create a test for your class.

package com.hax.gwt.client.events;

import com.google.gwt.junit.client.GWTTestCase;

public class ActionTest extends GWTTestCase {
    
    @Override
    public String getModuleName() {
        return("com.hax.gwt.Libs");
    }
    
    public void testSample() {
        Action a = new Action();
        assertEquals("OK", a.sample());
    }
}

2) Create a test suite.

package com.hax.gwt.client.events;

import junit.framework.Test;
import junit.framework.TestSuite;
import com.google.gwt.junit.tools.GWTTestSuite;

public class eventsTestSuite extends GWTTestSuite {
    public static Test suite() {
        TestSuite suite = new TestSuite("Tests for: com.hax.gwt.client.events");
        suite.addTestSuite(ActionTest.class);
        return suite;
    }
}

3) Use the 'run as GWT unit test' on the test suite.

:D! Note that getModuleName() should return a reference to an xml definition for a web application; it doesn't have to do anything, but that's the profile that is used to launch the client side unit tests.

jSnow Mods

2009-12-22T20:11:00.000-08:00

Christmas is the perfect time for a bit of random snowflake action on the website, and jSnow (http://www.DuMmWiaM.com/jSnow) is an awesome little GPL jquery plugin to help with that.

There are a couple of bugs tho, which I've fixed and GPL being great, here's the full source of the code post-mod.

Changes:

- Unpacked (why was it ever packed? O_o)

- Now automatically replaces .png with .gif for IE6, IE7.

- Scrollbar doesn't go crazy in firefox.

- zIndex works properly in IE6.

To use it;

   $(function() {  
     $().jSnow({  
       flakes : 25,  
       flakeCode : [  
         "/img/jsnow/snow.1.png",  
         "/img/jsnow/snow.1.png",  
         "/img/jsnow/snow.2.png",  
         "/img/jsnow/snow.3.png",  
         "/img/jsnow/snow.4.png",  
         "/img/jsnow/snow.5.png",  
         "/img/jsnow/snow.6.png",  
         "/img/jsnow/snow.5.png",  
         "/img/jsnow/snow.7.png",  
         "/img/jsnow/snow.7.png"  
       ],  
       fallingSpeedMax : 2,  
       fallingSpeedMin : 0,  
       zIndex : 65535,  
       interval : 30  
     });  
   });

Notice how some of the images are repeated? That's handy for increasing the frequency of some types of snow flakes.

And, here's the source:

 // jSnow, a jQuery Plugin v1.1.mod1  
 // Licensed under GPL licenses.  
 // Copyright (C) 2009 Nikos "DuMmWiaM" Kontis, dummwiam@gmail.com  
 // http://www.DuMmWiaM.com/jSnow  
 // Modified 2009~  
 (function ($) {  
   $.fn.jSnow = function (h) {  
     var j = $.extend({},  
     $.fn.jSnow.defaults, h);  
     var k, WIN_HEIGHT;  
     setWaH();  
     var l = j.flakes;  
     var m = j.flakeCode;  
     var n = j.flakeColor;  
     var o = j.flakeMinSize;  
     var p = j.flakeMaxSize;  
     var q = j.fallingSpeedMin;  
     var r = j.fallingSpeedMax;  
     var s = j.interval;  
     var t = j.zIndex;  
     var useGif = false;  
     if ($.browser.msie && (parseFloat($.browser.version) < 8))  
       useGif = true;  
     if ($.browser.msie && (parseFloat($.browser.version) < 8) && t == "auto")  
       t = 0;  
     var u = $("<div \/>");  
     u.css({  
       width: k + "px",  
       height: 1,  
       display: "block",  
       overflow: "visible",  
       position: "absolute",  
       top: $("html").scrollTop() + 1 + "px",  
       left: "1px",  
       zIndex: t  
     });  
     $("body").prepend(u).css({  
       height: "100%"  
     });  
     $("html").css({  
       "overflow-y": "scroll",  
       "overflow-x": "hidden"  
     });    var v = Array();  
     generateFlake(l, false);  
     setInterval(animateFlakes, s);  
     window.onresize = setWaH;  
     function setWaH() {  
       k = $('body').width();  
       WIN_HEIGHT = window.innerHeight || document.documentElement.clientHeight  
       WIN_HEIGHT -= 50;  
     };  
     window.onscroll = function () {  
       u.css({  
         top: $("html").scrollTop() + "px"  
       })  
     };  
     function generateFlake(a, b) {  
       a = a || 1;  
       b = b || false;  
       var i = 0;  
       for (i = 0; i < a; i++) {  
         var c = $("<span \/>");  
         var d = o + Math.floor(Math.random() * p);  
         var e = m[Math.floor(Math.random() * m.length)];  
         if (e.indexOf(".gif") != -1 || e.indexOf(".png") != -1) {  
           var f = new Image();  
           if (useGif)  
             e = e.replace("png", "gif");  
           f.src = e;  
           e = "<img src='" + e + "' alt='jSnowFlake'>"  
         }  
         c.html(e).css({  
           color: n[Math.floor(Math.random() * n.length)],  
           fontSize: d + "px",  
           display: "block",  
           position: "absolute",  
           cursor: "default",  
           "z-index": t  
         });  
         $(u).append(c);  
         f_left = Math.floor(Math.random() * (k - c.width() - 50)) + 25;  
         f_top = (b) ? -1 * c.height() : Math.floor(Math.random() * (WIN_HEIGHT - 50));  
         var g = Math.floor(Math.random() * 90);  
         jQuery.data(c, "posData", {  
           top: f_top,  
           left: f_left,  
           rad: Math.random() * 50,  
           i: Math.ceil(q + Math.random() * (r - q)),  
           swingRange: g  
         });  
         c.css({  
           top: f_top + "px",  
           left: f_left + "px"  
         });  
         v.push(c)  
       }  
     };  
     function animateFlakes() {  
       var i = 0;  
       for (i = v.length - 1; i >= 0; i--) {  
         var f = v[i];  
         var a = jQuery.data(f, "posData");  
         a.top += a.i;  
         var b = Number();  
         b = Math.cos((a.rad / 180) * Math.PI);  
         a.rad += 2;  
         var X = a.left - b * a.swingRange;  
         f.css({  
           top: a.top + "px",  
           left: X + "px"  
         });  
         if (a.top > WIN_HEIGHT) {  
           jQuery.removeData(f);  
           f.remove();  
           v.splice(i, 1);  
           generateFlake(1, true)  
         }  
       }  
     };  
     return this  
   };  
   $.fn.jSnow.defaults = {  
     flakes: 30,  
     fallingSpeedMin: 1,  
     fallingSpeedMax: 3,  
     flakeMaxSize: 20,  
     flakeMinSize: 10,  
     flakeCode: ["&bull;"],  
     flakeColor: ["#fff"],  
     zIndex: "auto",  
     interval: 50  
   }  
 })(jQuery);

Mortal Combat Coffee?

2009-12-15T19:12:00.000-08:00

Dragon coffee! Wow, this is the most awesome thing I've seen in ages~

I wish the local coffee place here made coffee like this... *sigh*

cred: link.