It is going to be a busy year this year. Some highlights below. If you are in San Francisco note that the Lightning Talks and Javabloggers meetup are tomorrow.

Community One (Monday)

We are running a Lightning Talk session at Community One (12noon I think). I’m one of the speakers, my title is “You suck at webapps” (or will be if I can finish it between now and then). It should be fun. Be there, or … be one of the less square people in SF at the moment.

Javabloggers meetup (Monday night)

Atlassian is sponsoring the Javabloggers meetup at Thirsty Bear downtown San Francisco after CommunityOne. Free beer from 7:30pm proudly sponsored by Atlassian.

Pimp Your Build (Thursday TS-5596)

Conor and I are speaking at JavaOne on Thursday 4:10pm. “Pimp My Build: 10 Ways to Make Your Build Rock”. Come along, you’ll learn a little, cry a little, and come away feeling full of hope.

Atlassian Booth (Pavillion)

I’ll be at the Atlassian booth, come say hello, watch a demo and get an awesome t-shirt.

They are “the Oscars of our industry” which — for better or for worse — is about right. But I still I have a fondness for the Jolt awards. The first time I saw the awards in Dr Dobbs Journal, I remember thinking how nice it was that this caffeinated beverage company targets us sleep-deprived code monkeys, and gets us enough to award us for our deeds. And fondness for the Jolt awards certainly has something to do with my fondness for Dr Dobbs Journal.

I’ve poured a lot of code into FishEye over the years. And we are still working quite hard at improving it, so it is sometimes hard to keep at the top of the stack the fact that a lot of people use it and think it is awesome. When non-nerds ask me what I do I give a standard response of “I develop tools for other software developers”, which most people seem to grok reasonably easily. This response took me a few years to refine and means such lines of conversation quickly get to the point where a change of subject is needed (to the relief of both parties). Conversations with other nerds run a little different. We can either be rather evasive, or overly detailed — seeing a fellow nerd’s face gloss over is a bad sign. It is a balancing act that I don’t always get right. But now, if someone’s curiosity matches my current grandiosity, I might just say:

I’ve won a Jolt.

10:49:42 PM spud: it’s finally being pooped out http://paulgraham.com/arc0.html
10:52:58 PM michael: @spud: gentlemen, start your parentheses!
10:59:10 PM spud: “Arc only supports Ascii. I realize that supporting only Ascii is uninternational to a point that’s almost offensive … But the kind of people who would be offended by that wouldn’t like Arc anyway.” Well, now I don’t like it… shesh!
11:00:23 PM adrian: Ewwww.
11:00:37 PM conor: too full of himself
11:00:49 PM spud: that’s paul g all over
11:01:11 PM spud: I like the direction erlang went, it doesn’t have a char type, just uses lists of ints
11:01:17 PM conor: probably only 7bit ASCII
11:01:27 PM * adrian likes the name Erlang.
11:01:39 PM conor: Having done traffic engineering, I find it difficult to use a language called Erlang
11:01:48 PM spud: ?
11:02:10 PM adrian: Erlang is the unit of measurement of telecommunications traffic.
11:03:28 PM adrian: 1 erlang = 100% occupancy
11:02:57 PM spud: wow didn’t know that
11:03:07 PM michael: so it’s for stupid mono-lingual programmers writing software for other stupid mono-lingual programmers without funny accents in their names? please!
11:03:57 PM spud: I’ll wait for Erlang 2.0 then
11:04:02 PM peter: Riley (read any 2 yearold) = 2 erlang
11:04:09 PM conor: I’m a .5 Erlang developer
11:04:11 PM spud: @peter lol
11:05:49 PM spud: meh fuck lisp
11:06:18 PM spud: that took 16 mins

Atlassian has a rich and vibrant technical culture — the internal blogs are pure bliss. And there is always room for a bit of fun, which lead to the following little video blog:

Talking Nerdy

(Apologies if the sound is a little off. It’s not too bad considering it was all done with the movie-mode on my digital camera.)

Today, Atlassian acquired Cenqua. More details here.

Kinda seems surreal typing that in. But without a doubt exciting. Certainly seems surreal that I’ll be moving to Sydney, but that is real exciting too.

Not much more to say than that at the moment, other than it is full steam ahead on making FishEye, Crucible and Clover kick more arse than ever before. And looking forward to catching up with a lot of the Sydney crowd.

Apache httpd serves static content out of its DocumentRoot :

DocumentRoot /usr/local/apache/htdocs
<Directory /usr/local/apache/htdocs>
  Order allow,deny
  Allow from all
</Directory>

The contents of that location in the filesystem might look like:

/usr/local/apache/htdocs/index.php
/usr/local/apache/htdocs/images/a.png
/usr/local/apache/htdocs/images/b.png
/usr/local/apache/htdocs/images/c.png

And to a web browser, the site looks like:

/index.php
/images/a.png
/images/b.png
/images/c.png

All very vanilla. But sometimes you want to be able to store the site in two parallel and overlapping directories in the filesystem, without changing the way it is presented to the browser.

/usr/local/apache/htdocs/index.php
/usr/local/apache/htdocs/images/a.png
/home/matt/alt_htdocs/images/b.png
/home/matt/alt_htdocs/images/c.png

If you don’t have parallel or overlapping requirements, then Alias is your friend. If you do, read on.

The Hack

Do this:

DocumentRoot /usr/local/apache/htdocs
<Directory /usr/local/apache/htdocs>
  Order allow,deny
  Allow from all
</Directory>

RewriteEngine on

RewriteCond "/home/matt/alt_htdocs%{REQUEST_URI}" -f [OR]
RewriteCond “/home/matt/alt_htdocs%{REQUEST_URI}” -d
RewriteRule ^/?(.*)$ /home/matt/alt_htdocs/$1 [L]

<Directory /home/matt/alt_htdocs>
  Order allow,deny
  Allow from all
</Directory>

If you don’t want to serve directories from the alternate docroot (Options +Indexes) then you don’t need the RewriteCond with the -d. Remove it and the [OR] from the previous line.

If you want to add a restriction to the alternate docroot, for example only allow the images directory, then put that in your regex:

RewriteCond "/home/matt/alt_htdocs%{REQUEST_URI}" -f [OR]
RewriteCond “/home/matt/alt_htdocs%{REQUEST_URI}” -d
RewriteRule ^/?(images/.+)$ /home/matt/alt_htdocs/$1 [L]

If you want three or four or five alternate docroots, just copy-and-paste the three rewrite lines as necessary. And remember you may need a <Directory> section for each location.

How it works

If you see a file or directory in the alternate docroot, then serve it. Otherwise: DocumentRoot.

The RewriteConds look into the alternate docroot, and checks if a file (-f) or directory (-d) exists under there that matches the REQUEST_URI, which is something like /index.php or /images/b.png.

If either/both of the RewriteConds match, then the RewriteRule runs. If its regex matches, then we give Apache the explicit filesystem path it should serve. If no such rules match, then the DocumentRoot comes into play.

In some situations (if you are doing further rewrites) then you may not want the [L], which instructs mod_rewrite to run no further rules for this request.

Untested

Today is the first day I’ve used this hack, so YMMV. But it seems to work very well for static files. Preliminary testing also indicates it works for .php files (in both the normal and alternate docroot). I doubt it would work if trying to include one .php into another across docroots.

The Use Case

Why would anyone, or even myself, find this useful?

Websites tend to end up like my son’s food at the end of dinner: all mushed up into a claggy mess. You may be running a couple of PHP apps, a couple of your own apps, in addition to a bunch of static files. And you may care about permalinks. And sometimes all these things overlap in the filesystem.

One solution is to copy everything into the one docroot. When it comes time to upgrade a component, you have to selectively pull out the old bits and dump in the new bits, without overwriting everything else. That sucks, and is why I always hate upgrading my WordPress instance.

The other solution is to put each component in its own directory. Upgrading a component is then the graceful process of deleting a directory and replacing it with new content. Separate directories can also have differing permissions, so that they can be edited by different people or programs.

If your components don’t overlap, then vanilla rewrites or Aliases work very well. Otherwise this hack may come in handy.

Further work

I’m sure this could be done much more easily with a custom module, in the vein of VirtualDocumentRoot. Ideally it would be nice to say (with options for specifying priority):

DocumentRoot /usr/local/apache/htdocs
AltDocumentRoot /home/matt/alt_htdocs

It would be also nice to be able to support parallel-overlapping views in the filesystem proper. A kind of “mount” that presented a view of several parallel directories.

Day Two (Wednesday)

(I didn’t have my camera with me this day.)

A good day at the booth. I had a couple of Technical Sessions on my schedule, but it was a busy day on the floor.

The Java Posse was walking around interviewing the vendors, I’m sure it is going to be a very interesting podcast. They stopped by our booth, so listen in to that podcast if you want to find out what code-coverage our Clover product achieves.

The first event of the evening was the Adobe party, at the poolroom in Jillian’s (in the Metronone). Open bar, good food, lots of nerds, pool tables. What more could you want. Joe Nuxoll taught us how to play “cut throat”, which is an awesome 3-player (or 3 teams of 2) game. Kind of a cross between billiards, Risk and Diplomacy.

Next was the Google party, and while at a much swisher location, didn’t quite achieve the same vibe. But full of interesting people. I spent a lot of the night chatting with this very nice chap from the Google-mobile team in London.

Day ended around 3pm after a quick trip to Loui’s Diner for some pancakes.

Day Three (Thursday)

(I didn’t have my camera this day either… perhaps a good thing.)

This was the last day on the booth. Didn’t get to any technical session but spoke to a heap of interesting punters. In previous years, I was a reasonably dedicated schwag hunter, but there are only so many flashing buttons and mouse-pads that you need. I picked up a Duke plush doll, and a couple of Sun mugs with funny phrases on them (the details of which allude me right now, blame it on the timezone shift). One of the coolest schwag items (beside our own t-shirts, of course, of which we ran out earlier that day) was a cool blue/pink ball (from Terracotta I think). It was blue, and if you threw it up it would kind of turn inside out and when you caught it it would have turned pink. I suppose you had to be there.

Later that afternoon we decided to organize what will hopefully become the Inaugural Cenqua Just-In-Time JavaOne party. To protect the innocent, and perhaps not so innocent, I won’t go into too much details about who we managed to drag along. Let’s just say it involved a little obfuscation. There were some abstractions in the design that definitely did not leak, no matter how hard we looked.

The day ended again around 3pm, with another trip to Loui’s. Well, for some of us it ended at 3pm: some were still arriving back at the hotel when I was getting up for the General Session on day 4.

Day Four (Friday)

The last day. Fighting a hangover that was much smaller than it deserved to be, I headed out for the “Toy Show” General Session. This was pretty fun, and like each year James makes a great host. (I should really try getting to the other General Sessions and Keynotes next year.)

The show started with a set of “tycho” (spelling?) drummers, which was really fun.

Roman Sholopsk showed the “DTrace Light” / “DLight” visualizer. This would actually be really really useful if dtrace ran on something other than Solaris.

Tor Norbye a gave “mashup” presentation showing off the new Netbeans. I can’t say that the refactorings and tools on show in Netbeans were anything I hadn’t seen before in IntelliJ IDEA, aside perhaps from the great JRuby support. Tor’s style and presentation was top notch: even though he talked fast, clicked around the screen fast, and presented a lot of dense information, I was always able to grok what he was saying and as I then started to wonder about how you would do X, he started showing how to do X. A very cohesive and coherent and grokkable presentation.

There was a demo of the Blu-Ray technology: the whole menu-system jobbie in Blu-Ray is a Java derivative. Very impressive actually.

A couple of guys from Cinegistics showed an app for use when setting up video shots. Plug your HD camera into a laptop, and this (almost 100%) Java Swing app shows the scene, can highlight light/audio problems etc. The most impressive thing was that all the number crunching was done in Java. I have seen a few things at JavaOne that I wouldn’t have given credit as implementable in Java.

Those Java-enabled robots made an appearance. They are very cute, I went and checked out their booth the previous day. This following robotic arm was able of achieving rapid movements in access of 10g. All in RealTime Java. Impressive.

They “flew” in (suspended from wires) Paul Perrone’s remote helicopter, which has a 3D laser imaging system on the bottom. It was able to take these great 1000-scan-per-second 3D linear maps of the stage, with James and Paul lying on the floor. All the imaging and stability processing was done in RT Java. I think that’s great.

After a trip to the Pork Shop for breakfast, and Ritual Roasters for coffee, I headed back to JavaOne for Martin Odersky’s Scala talk.

Scala is very, very interesting.

And that, as they say, is the end. Another great JavaOne.

In typical form, we managed to setup our booth (above) and demos just moments before the Exhibitor’s Pavilion opened. The first day on the floor is always a killer: 11:30am to 8:30pm. I was wise and kept up my sustenance over that period; an apple for breakfast and an Oreo for lunch.

It was my turn to be the media whore today. Lucky I had had a shave. First up was an interview with SYSCON-TV http://soa.sys-con.com/read/372918.htm (the title is a little OT, and I’m pretty sure I didn’t use any of those exact words, but the gist is right). I was also interviewed by Frank and Bill for an Artima podcast. They both ask great questions and it was a lot of fun chatting to them.

Against one of the far wall in the Pavilion is one of those Sun datacenters-in-a-cargo-box thingies on the back of a huge semi trailer. High candy value, I’ll try and take some internal photos tomorrow.

I managed to sneak away from the Cenqua booth to go see Neal Grafter’s Closure technical session. He does a lot of pointing.

Neal’s explanation of his Closure proposal is thorough and clear. I got up and asked him a question during the Q&A, but managed to completely dilute my real question with qualifications. I’ll try and write more about that later, if I can get my head together.

At the end of the day I hit the Closure and Java Posse BOFs. The Closure BOF ended up as mostly a re-cap of the previous technical session. The Posse’s BOF was great, though not all of us found it enthralling as others:

After that some of the people at the Posse BOF went to the pub for a few well-desereved coldies.

phew now starts Day Two…

Tor found a few bugs in Netbean’s doco-popup support, which was funny for us and no doubt useful for him.

The JRuby presentation was structured very well, which couldn’t really be said for Gosling’s “Netbeans Toys” segment that came next.

Gosling was his usual self: excited yet monotone, and not giving anyone an inch. I suppose it is a hard task to come up with an interesting “toy” story involving Netbeans, and none of the presenters were up to the challenge. There were about 8 too many class diagrams in the RDF presentation (and, wtf, between alt-tabbing windows I could see his Inbox unread count; it went from 2800 one minute to 2934 the next). The JMF guy was dropping frames like there was no tomorrow. The best effort was put in by Bob Beasley and his D.O.R.K. device. I give the man full credits for showmanship, and those SunSpot jobbies look pretty cool.

Tomorrow: JavaOne day one. 9 hours on my feet, hopefully I’ll get to the Closure Technical session during the day, and the Closure and Java Posse BOFs in the evening. The Java Puzzlers TS will be a stretch-goal.