It's Time for Carbon Apps to Support RTF on the Clipboard

I don't know when the 'styl' resource was defined, but I do know it is very, very old. For those not in the know, back in the days of the Mac II, if you wanted to copy and paste bold/italic/underlined/colored/text from your application to another, you put both a 'TEXT' Handle on the clipboard, and a Handle filled with individual style records (the 'styl' flavor), with each record corresponding to a range of the raw text in the 'TEXT' resource. You could even put in foreign words and phrases by switching to lets say a Japanese font. This was what was done in 1987, it was what was done in 1997, and it is what most Carbon apps still do in 2007. I fired up iTunes Friday, copied something from a dialog, and looked at what was on the clipboard: a 'TEXT' resource and a 'styl' resource.

Well, what's wrong with it?

Here is an individual style record from TextEdit.h:
struct ScrpSTElement {
long scrpStartChar;
short scrpHeight;
short scrpAscent;
short scrpFont;
StyleField scrpFace;
short scrpSize;
RGBColor scrpColor;
};
And here are the things you can put in a StyleField:
normal = 0,
bold = 1,
italic = 2,
underline = 4,
outline = 8,
shadow = 0x10,
condense = 0x20,
extend = 0x40
What's wrong?

• No superscript or subscript, not even one level. Try pasting data from a scientific app to MS Word. H⁺₂SO₄^-2 becomes H+2SO4-2.
• It takes an old fashioned QuickDraw font ID, not an ATSUI ID, so it may be difficult to map to the fonts you're actually using.
• No paragraph alignment information. You can have any justification you want as long as it's left.
• Text encoding is by necessity implied by the QuickDraw font encoding.
• The OS has to go through and endian swap every element before pasting across Rosetta.

So what is the alternative?

There is nothing preventing you from supporting the 'RTF ' (Rich Text Format) flavor on the clipboard. It's a Microsoft invention, so you know Word will like it, and it satisfies all the problems I enumerated above. Plus, it's the favored flavor of any Cocoa application, so your text should be more accurately transferred to newer applications.

It's just a matter of implementing it. As I was already mixing in Cocoa into my Carbon application, I built up an NSAttributedString, extracted the string's content using the RTFFromRange:documentAttributes message and stored that raw data in a Handle. When I, inversely, wanted to paste, I extracted styled text information from an NSAttributedString created from the data in an RTF Handle. I did it all in a day for my application. (Sorry, can't share the code.) This has the added advantage of using the exact RTF flavor Cocoa applications get for free.

Alternatively, you could pretty easily create simple RTF documents from scratch using the description of the format in O'Reilly's RTF Pocket Guide. Parsing such documents looks to be a lot harder, but doable, just ignore the tags you aren't interested in.

I could hardly be happier with the result. My users will be getting a nice little present come the next release, and I'm one step closer to expunging the last bit of QuickDraw from my application. If you are maintaining a Carbon application which has anything but the simplest text formatting requirements, do your users a favor and look into supporting the 'RTF ' clipboard flavor.
[Entry has been edited for content since first publication]

The Freedom of EV-DO

My dad is an interesting, and smart guy. He left retail banking 20 years ago to start a software company in his basement, then transitioned into brokering the sale of small planes. And for much of that 20 years, he's sat in that basement, making sales call after sales call. I can't estimate how many thousands of times he's told a prospect to check "w w w dot global dash air dot com." As his phone, his computer and his dial-up Internet connection were in that basement, and he couldn't afford to be away from them, the basement became a prison of sorts.


And then a piece of technology came along to change this. He bought a Dell laptop (a Dell Inspiron E1405), and more importantly, he signed up for Sprint wireless broadband and bought a Sprint Mobile Broadband USB Modem. Suddenly, when combined with a healthy number of cell phone minutes, his business was located not in his basement, but wherever he happened to be. He could visit his friends in West Virginia and Florida. He could spend a week in my basement. He could even hang out with my mom while she was watching grandbabies all over the greater Twin Cities area. Technology has set him free.


And the EVDO modem is faster, even in Dad's rural basement, than his soon-to-be-cancelled dialup. He could stop waiting for the phone company to bring DSL one more mile out of town.


This is the sort of thing technology should be doing all the time. As an engineer, I am always on the lookout for ways to improve the lives of my users. The EVDO engineers at Sprint and elsewhere have markedly improved the lives of my Dad and others like him. It's why a lot of us got into engineering in the first place. Congratulations and thanks to them.

Netscape Plugin Development in XCode

A desperate Google searcher emailed me today asking about getting together an XCode project for a Netscape style plugin. Since this, apparently, is not well known, there is a NetscapeMoviePlugin project in the standard set of examples installed with your developer tools.


/Developer/Examples/WebKit/NetscapeMoviePlugIn/


One thing I would not recommend is using any of the QuickTime API calls in that plugin, they are laughably out of date. Nor was it obvious, to me, how you add things like JavaScript properties. But it is a start for an XCode project.

And I won't get started on what a sorry state of affairs that something so archaic as Netscape plugins are still used to add functionality to Mac browsers.

Building WebKit on OS X when you have Qt installed

I ran into trouble building WebKit (Safari) on my MacBook. When I entered the command to build it
% WebKit/WebKitTools/Scripts/build-webkit --debug
the build script immediately started complaining about qmake not understanding the "-r" option. This seemed really strange to me as I hadn't thought Safari was a Qt application; it certainly looks much better than any Qt application I've ever seen on the Mac, and I've written 3. It turns out that Safari is not a Qt application but the build script does look for the QTDIR environment variable and will try to build a Qt version if it finds that variable. [Thanks to Mark Rowe on the WebKit team for this information].

So the solution to my problem was to temporarily undefine QTDIR.

% echo $QTDIR
% unsetenv QTDIR
% WebKit/WebKitTools/Scripts/build-webkit --debug


Netscape Style Browser Plugin Development on OS X

If you are creating or maintaining Netscape style browser plugins on the Mac, you must get the nightly build of the open source version of Safari from WebKit.org. As someone who occasionally has been reduced to doing printfs to the system log in order to debug plugins remotely on a 10.3 box, it is luxurious having a debug build of the host application. Just follow the instructions for compiling a debug version and debugging it from XCode; if you have everything setup correctly you can debug the application and the plugin at the same time. Total setup time of less than an hour. It's fantastic.

I've tried to compile Firefox from source (using Visual Studio under Windows) and it was nearly impossible to get a debug build up and running. Actually, I don't know if it is nearly impossible or simply impossible since I gave up after a couple of days. Creating a Safari debug environment is a snap by comparison.

And the WebKit team is unbelievably responsive to bugs you find in WebKit itself. I've reported 2 problems over the last week and both were solved by the next day.

Chroma Keying BMP files in OS X

I've been contracted by Train Player International to help port their TrackLayer model railroad design software to OS X. It has been going quite well, and I'm grateful the proprietor, Jim, has allowed me to apply my theories of cross-platform development, and create a first class Cocoa application. But it is a work in progress, and there are both bugs and unimplemented features.

Regardless of its fragile state, Jim sent our development version out to select users for feedback and to prove it isn't completely vaporous. And feedback we got. Some of it positive, some negative, but the one thing everybody hated was the launch time; it was abysmal on older hardware and not particularly peppy even on my MacBook. I will not tolerate intolerable performance in any app I write, so I've made it my first priority to fix.

It didn't take long to track down the culprit, the reason TrackLayer was taking 13 seconds to launch on my MacBook. I was pre-loading 83 small image files representing train car tops and sides. These files were 24 bit BMP files with neither masks nor alpha channels; they were chroma keyed--a color was set aside to represent blank space--and my code was responsible for converting it to an a form with an alpha channel which could be composited with other images. Here's an example file of the same format:


My code replaced the pink area with transparency. The problem was with my original code to manipulate BMP images. I had even written a comment to myself to say it would be slow and inappropriate for heavy use. The major problem is that NSImages are not easily manipulated; their API is extremely limited in that regard. Basically, there is colorAtX:Y and setColor:atX:y which I had been using to change the chroma key color one pixel at a time:

// don't do this, it is slow
NSColor* clearColor = [NSColor clearColor];
int width = (int)originalSize.width;
int height = (int)originalSize.height;

NSBitmapImageRep *repWithAlpha = [[[NSBitmapImageRep alloc]
initWithBitmapDataPlanes:NULL
pixelsWide:width
pixelsHigh:height
bitsPerSample:8
samplesPerPixel:4
hasAlpha:YES
isPlanar:NO
colorSpaceName:NSCalibratedRGBColorSpace
bytesPerRow:0
bitsPerPixel:32] autorelease];

for(int x=0; x < width; x++)
{
for(int y=0; y < height; y++)
{
NSColor* originalColor = [(NSBitmapImageRep*)anImageRep colorAtX:x y:y];
if([originalColor isEqual:chromaColor])
{
[repWithAlpha setColor:clearColor atX:x y:y];
}
else
{
[repWithAlpha setColor:originalColor atX:x y:y];
}
}
}

It's slow just looking at it, what with the creation of an NSColor object for each pixel. And I needed to come up with something much faster. The problem is there is not a lot of documentation on doing what I want with either NSImages or CGImageRefs. There was this short section of the Quartz 2D Programming Guide, which recommends using the CGImageCreateWithMaskingColors function new to OS X 10.4, but isn't very clear on its use, and that's why I'm writing this blog entry to clear it up.

In order to create a masked image from my BMP, I had to:

• Create an NSImage from the BMP file
• Use colorAtX:y to get the color at the top left corner which I assume is the chroma key
• Ask Quicktime to create a CGImageRef from the file
• Use CGImageCreateWithMaskingColors to create a masked copy
• Convert the CGImageRef to the NSImage I can use

That's right, I create 4 separate versions of the image to get what I need. And it is still more than 10x as fast as the original.


NSColor* chromaColor = [(NSBitmapImageRep*)anImageRep colorAtX:0 y:0];

size_t bitsPerComponent = ::CGImageGetBitsPerComponent(originalImage);
float maxComponent = float((int)1 < < bitsPerComponent)-1.0;
float redF = rintf([chromaColor redComponent]*maxComponent);
float greenF = rintf([chromaColor greenComponent]*maxComponent);
float blueF = rintf([chromaColor blueComponent]*maxComponent);

const float maskingMinMax[] = { redF, redF, greenF, greenF, blueF, blueF };
CGImageRef maskedImage = ::CGImageCreateWithMaskingColors(originalImage, maskingMinMax);


Using this new code dropped the launch times on my MacBook from 13 seconds to under 2; pretty peppy.

I've put together a sample project: ChromaKeyTester.dmg which contains all the code for this, so I hope you Google searchers found what you sought. This only works with the variety of BMPs I needed to open, but it could be made more general.


[UPDATE]
I received an e-mail from a coder with evidently more experience than I at manipulating images in Cocoa. He made a number of suggestions, none of which I found worthwhile pursuing because I'm just not going to get my launch times much faster. I've gotten the launch time on my MacBook down to 1.5 seconds (and this is the worst case, where an image populated document is automatically re-opened, forcing the main thread to wait for the image loading thread to complete). Even if his conversion methods took zero time they could not push the launch time below 0.9 seconds. I realize 0.6 seconds on my MacBook might be 1.2 seconds on a PowerBook G4, but still, it's fast enough.

Still, other programmers might have a more dire need for squeezing performance, so here are a summary of his suggestions with my parenthetical reasons for rejecting them:

• Use a reasonable format like PNG instead of BMP (Can't do this for backwards compatibility. That was the first thing I asked.)
• Skip the reading top/left corner for chroma key color step. (Can't, different images use different colors.)
• My method leaves traces of the chroma key in the anti-aliasing (Sorry, that's just the test image. The actual production images are hand tweaked pixel by pixel with no anti-aliasing. And I could always expand the range of colors masked by CGImageCreateWithMaskingColors. )
• Do the conversion with a Quartz Composer script. (This is a cool idea, but sounds complicated to setup, and could you really load the Quartz Composer framework and execute a script in less than 0.3 seconds or so? Maybe, the Quartz Composer application launches in less than a second, and can merrily load and display my BMPs at a rate limited 60 fps and 7% rendering load.)
• Use a NSCIImageRep--which is a Cocoa wrapper around a Core Image Image. (I had not been aware of this very useful looking object, and this seems the most practical suggestion. If I have the time for extra speed tuning, I will explore this.)
• Get some C or C++ BMP reading code and read and convert the raw data myself. (This would have to be a big win performance wise for me to have to deal with the vagaries of the BMP format myself. And there would be no guarantee of a big win, as Apple's converter code is presumably optimized for Altivec or SSE3 or whatever.)

I will remind myself to read up on using NSCIImageRep and the Core Image framework. It sounds extremely useful.

[Another Update: Turns out there is code in Apple's examples for dealing with converting arbitrary bitmap formats to a reference format: either RGBA integer, or RGBA float. This is in the Tableau example for the Accelerate framework. Look for the message "constructIntegerReferenceImage". You can easily refactor this code to run through the reference image buffer and do your chroma keying before taking the step to create an NSBitmapImageRep].

Upgrading a 4GB iPod Mini to 8GB

I've been watching the DealRAM prices for 8GB Compact Flash modules. My intent has been to upgrade my wife's 4GB Pink iPod Mini which has sentimental value to me (in addition to having what I consider the perfect form for music playing). Well, the price of a solid state Transcend 8GB 120x speed compact module (model # TS8GCF120) just dipped to $100 at one of my favorite vendors: newegg.com, and it became time to pull the trigger. (It's actually become cheaper since I bought mine.)

There are plenty of instructions on the Web for surgically replacing an iPod's hard drive. I went with this instructional video. The only difference was the thinner form of the compact flash module. Also, I had to determine which way to plug the old drive's cable into the CF module. The trick is to look at the rail guides on the sides of the old MicroDrive, compare them with the rail guides on the CF module and plug the cable in maintaining orientation. Also, I reused the blue rubber bumper from the old drive to keep the new module from rattling around. I also took the opportunity to install a new battery.

As for performance, it seems to be working fine. It filled up with 6GB of data over FireWire in a reasonable amount of time (sorry, didn't time it, maybe 20 minutes). It just has a lot more space.

[post was updated for minor fact correction]

[Update: The upgraded iPod has been working fine for 10 months. Today, I installed a 2nd card, a Transcend TS8GCF133, into my own 6GB Silver iPod Mini. The original Microdrive failed and it was either upgrading or trashing. Seems to work just fine.]

Replacement Nipples (for the ThinkPad)

My wife has an X23 series model 2662 IBM ThinkPad. For years, she's avoided using the TrackPoint pointing device embedded in the keyboard as the standard rounded one was extremely abrasive and worn. She'd always attach an external mouse or (after meeting me) a trackball, or when in need using a piece of tissue to protect her finger. Well, dutiful husband that I am, I finally bothered to do a Google search if there was some replacement nipple or eraser tip for her model.

I was happy to find that Lenovo sells an inexpensive ThinkPlus TrackPoint Cap Collection. So for $10 shipped, I bought a variety of replacement caps, and she likes the wide flat type with the rim. Much more comfortable.

MythFrontend and HDHomeRun Wireless on a MacBook

[Update: check out Signal GH, an iPhone utility for monitoring the signal quality of an HDHomerun].

I've been running the MythTV Frontend for Intel OS X several hours a week for the last month. This is on my original MacBook (1.83GHz Core Duo, 2GB RAM) connected wirelessly via a 802.11g router to the basement MythTV server. I'm typically on the couch in the TV room upstairs, or on the bed in the basement; 30 feet from the wireless hub at most.

Performance has been good, and I've been happy with it, but it does lock up if you quit the application directly from Live TV mode. It's an odd sort of lock up in that the video keeps playing, but the beach ball of death cursor indicates the GUI itself is locked. So I'll command-tab out and force quit the application. Of course, the audio is nothing compared to the 5.1 speakers on the actual MythTV, but I have been known to watch even such sound intense shows as 24 on the MacBook, too lazy to watch it properly. Occasional flickers could be wireless instability, noise on the antenna, other processes grabbing the MacBook CPU or packets lost in Ethernet. It's hard to say.

I had worried whether my Ethernet network was up to the task of carrying 2 HD streams down from the HDHomeRun in the network closet to the MythTV (both the PC and the HDHomeRun are 100Base-T, the routers are 1000Base-T and the wiring is Cat-6) while simultaneously streaming a 3rd stream back up the same Ethernet cable to the wireless hub in the network closet. But, this works surprisingly well. I do like to give Live TV a couple seconds of buffer to give it a chance for error.

The GUI actually works better than the Linux version on my desktop, where I long ago lost the overlay GUI in TV mode. On the Mac, I actually see the Paused/Play time HUD window when I pause playback. Interlacing is not as good though.

In preparation for writing this blog entry, I put the MythTV frontend into a small window mode, and I'm just noticing it mirrors the video content in the OS X Dock. This is probably a bad idea, and a waste of cycles. I know it's cool and all, in a 2001 sort of way, but not that cool. Also, the UI for changing the window size is completely lame: holding down the right arrow key while it counts up to 480 horizontal pixels when I have a perfect good 4, 8 and 0 keys is unforgivable.

In summary, MythFrontend for OS X is nice to have, and I'm glad network and computer hardware is finally up to the task of this kind of high bandwidth application.

Be careful with your CFBundleVersion

This post is along the way of a reminder to myself should I ever have to figure out how my application's plist has caused the Launch Services manager to act strangely.

If you accidently setup your CFBundleVersion element badly, by for example, putting it in quotes, you will end up with the Launch Services database treating it as if it had a version of zero. You can see this clearly by running the lsregister utility:
/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -dump

[Update: lsregister has moved in Leopard:
/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -dump
]

Static Libraries dependent upon static libraries in XCode

Just a helpful hint to try and prevent your wasting time like we did at my day job. We have a large C++ application which has several different levels (Standard, Pro, Ultra....). So to speed compilation and linking, we put large chunks of code common to all the levels into separately compiled static libraries. Thus, we only have to compile that code once every time we build all the applications, resulting in a massive time savings.

Unfortunately, this was not working under XCode as when we linked in our libraries, there was always some symbol or other which was not available, and we ended up putting large amounts of code into the main project and compiling it for each application level (making our build process at least twice as long as it should have been).

My boss finally got so sick of this he spent a couple days tracking down the problem, and it was that our static libraries were dependent upon other static libraries, but those libraries were not linked in until the application as a whole was linked. Somehow, this confused the XCode linker (ld) and it ended up missing symbols. The trick was to link the other sub-dependent libraries into the libraries static libraries and not directly from the main project.

I know the above is confusing. Here's a more graphical description.
(Before)

• Main Project


• Static Library 1 Project (needs Static Library 2 & 3)


• Static Library 2 Project


• Static Library 3 Project

(Now)

• Main Project


• Static Library 1 Project (needs Static Library 2 & 3)


• Static Library 2 Project


• Static Library 3 Project

HDHomeRun - Networked HDTV Tuner

[Update: check out Signal GH, an iPhone utility for monitoring the signal quality of an HDHomerun].

I have a PCHDTV 3000 PCI card in the Dell Dimension which serves as my MythTV. Since DVB drivers became part of the standard Fedora install, it has been problem-free. But, it doesn't meet all of my needs.

First, there are occasions when the broadcast networks show 2 or even 3 good shows at once. I'd like to be able to catch these rare alignments, but my PCHDTV can only record one show at once. I could buy another, but that would be the last open PCI slot in the Dimension, and what if I wanted to expand internal storage later with an SATA card? Second, the MythTV was banished to the basement for excessive noise, which means it is about 80 feet of RG6 cable from the main antenna splitter in the second bedroom, meaning it is getting less signal, and noisier signal than an upstairs device. Third, to be useful, the MythTV has to be on all the time, which means draining a minimum of $9/month of electricity. Fourth, I've never been able to figure how to access a PCHDTV card with non-root level privileges; I'm sure it's possible, I just can't figure it out, which means I run the mythtv backend as root. This is frowned upon.

Then, I came across the HDHomeRun networked digital TV tuner (both ATSC and QAM). This simultaneously overcomes all 4 problems with the PCHDTV.

• It has 2 tuners.
• It doesn't use up a PCI slot.
• It can be located as close to the antenna as I like.
• It can be accessed via any user account with network access.
• I can access the data stream directly from my MacBook, albeit kludgily, even when my MythTV is off. [Update: It is no longer cludgy on the Mac. You can buy an HDHomerun bundled with El Gato's slick EyeTV application.]

It does cost more than a PCHDTV, but less than two.

I held out for a while, but I finally ordered one. It came Wednesday. I've been happy.

MythTV 0.20 has built in support for this device. However, be warned that you have to open your firewall to its traffic. If you try to run mythtv-setup and you can't get it to scan for channels. Maybe it's your firewall.

I was amazed by how well my MythTV box pumped massive amounts of data. At one time, I simultaneously recorded 3 HD programs over the air--2 over Ethernet from the HDHomeRun, and 1 via the PCHDTV--while watching a recording of Day Break from the night before, and it was smooth as silk. There have been a lot of improvements in MythTV over the last year; I don't think it could have taken all this back then on my aging hardware.

Lately, whenever I buy new hardware, I measure it's electrical usage. There is a hidden cost to every gadget we buy. According to my Kill-A-Watt, my HDHomeRun draws 6 Watts at all times, whether capturing or not [Update: I've heard that subsequent revisions (those you would buy new today) use less power] . A low power mode while awaiting network commands would be nice, but the usage isn't bad compared to the 90 Watts the MythTV box draws. So it's less than a dollar a month to power it. However low the power, it does get a little warm, and I worry about it's life span, but time will tell.

In order to control the device from my Mac, I downloaded the hdhomerun_config source code from the Silicon Dust Forum. It was a simple matter to create an XCode project and compile the command line tool for Mac OS X, and I could then use the instructions for using VLC to watch TV directly from the device on my MacBook. Entering a series of obscure command line commands is much too klunky, and I hope VLC will absorb these functions, but it did work and looked great on the 13.3 inch screen.

Dell 2005FPW with the LG LST-3510A HDTV receiver

I have a two year old Dell 20.1" widescreen LCD display (2005FPW). I also have three LG LST-3510A HDTV receiver/DVD players. Just so any Googlers might be curious, yes you can watch HDTV on your DVI capable LCD monitor and this receiver. No, you can't watch upconverted DVDs, at least not with the firmware in this particular 3510A (1.93), it gives me a warning about needing a HDCP connection and refuses to play. HDTV is a little distorted, as the 2005FPW is not a true 16:9 monitor (closer to 16:10), but it looks fine driven at 720p.

I like the 3510A as an HDTV receiver. I bought this particular unit for $49 shipped via an eBay auction, The low price due to the description saying it couldn't play DVDs well. Well, guess what? I don't care. It's a sensitive, reliable, flexible HDTV tuner and that is what matters to me. I can hook it up with DVI, VGA or component connectors to any number of display devices. Plus, it has both coax and optical digital audio connectors. I got another one cheap (not as cheap) with the preferred 1.91 firmware because the seller didn't know how to get it out of Spanish menu mode.

Here's its manual.

As is typical, neither eBay units came with remotes. Luckily, my third unit has a remote. Also, you can get most (not all, the DVD arrow keys are wrong) of the functionality from a cheap One-For-All remote. The One-For-All even has the codes for a proper fast forward/reverse on the DVD player, which the original remote does not have. Even the Harmony remote database has a few holes, so I'm glad to have at least one master remote.

Actually, I have little clue how people choose the proper eBay price for one of these things. I just saw an auction close for $58+shipping on a unit which was clearly marked as broken and being sold for salvage/repair. But it did come with a remote.

I don't really need 3 HDTV receivers. This third one is a family gift.

XCode debugger exited with status (1)

All of a sudden an XCode project which I was sharing with a collaborator refused to be debugged. The debugger was evidently exiting unexpectedly with "exited with status (1)" message. 

It took a long while to figure this out, but the project had been modified by my collaborator to hard code ppc generation. There were 3 such references in the project file. Had to change that to get the debugger to work again.

How not to use the boost singleton class

This is an odd and frustrating warning I was seeing while using the templated singleton class which comes with the boost C++ libraries while compiling under Visual Studio 2005. I used the following code to define a class which would be controlling a thread. It worked, but I was scared by the warning.



template< class T > class MySingleton : public boost::detail::thread::singleton < T >
{
};

class MyPayloadThread : public MySingleton< class MyPayload >
{

};



1>c:\src\hdrs\MySingleton.h(133) : warning C4624: 'MySingleton < T > ' : destructor could not be generated because a base class destructor is inaccessible
1> with
1> [
1> T=MyPayload
1> ]
1> c:\src\MySingleton.cpp(16) : see reference to class template instantiation 'MySingleTon < T > ' being compiled
1> with
1> [
1> T=MyPayload
1> ]


I did a lot of googling and couldn't find a direct answer to how I was supposed to give access to the singleton's private destructor. Then I had an epiphany about how I was supposed to use this class. The proper usage is:


typedef boost::detail::thread::singleton < class MyPayload > MyPayloadThread;

In retrospect, it's obvious that I couldn't sub-class singleton, I had to make use of it as a pure template.

New version of Remote Remote GH for MythTV

Just posted some fixes I did over the last several hours in a new release.

Blogger Dashboard Widget

Google has a bunch of Dashboard Widgets out today. Just testing to see how that works.

Setting up a Cheap Version Control Server for XCode

If you program, you need a version control system. We've all heard it, we all know it. But it's a trouble to setup and a pain in the pocketbook to dedicate a server, and even if you have a used computer free for the asking, it's still going to take up space and $10/month for electricity.

Because of a collaborative project, I felt an acute need for a version control system. My collaborator and I were spending much too much time stepping on each other's code trying to maintain a collection of source files via diffs and hand editing. So Sunday morning, I woke up with the resolve to set up a system.

My first thought was just to run a version control system on the Linux box I use for MythTV, but I've been rebooting into Windows XP every couple days to play Madden 06, and during the summer, when nothing much is on TV, I often turn it off to save energy. So it wouldn't be an ideal situation.

I thought of posts I've read about hacking NAS boxen to run Linux and a quick bit of googling came up with the consensus winner, the Linksys Storage Link for USB 2.0 Disk Drives NSLU2. This is a really cheap ($80), amazingly small, embedded Linux computer with 100 Base-T ethernet and 2 USB 2.0 ports. Plus it has an active development community of hackers extending what it can do.


I also decided to use a popular open source version control system Subversion (svn), if for no other reason that it isn't CVS, which I hate, or Perforce, which hates me.

Disclaimer: I am not a Linux expert. I am a decent Mac coder and software designer. You could very easily end up with a $80 paper weight, and not a good paper weight at that. Be careful.

Setting up the NSLU2

I am not going to go deep into setting up an NSLU2. I used the Unslung firmware, the instructions which came with the firmware, and the NSLU2-Linux HowTo.

Some important warnings about the process: test out the NSLU2 before modifying it. Bring it up in its unhacked form. Have it format your drive as EXT3. Make sure it works. Mount the shared volume on your Mac, copy some files, etc. The ethernet on the first unit I bought failed moments before I was going to flash its firmware, saving me from returning it modified. Think about your needs when it comes to hardware, I had a 60GB notebook drive in a compact USB 2.0 case lying on my desk; the capacity is fine for running a version control system, it's low power (it's actually powered by the two USB ports in the NSLU2), and I already had it. I used a cable tie to attach it to the NSLU2, and it became one, very portable solution. My Kill-A-Watt says the NSLU2 and the hard drive together draw 4W idling (9VA).



[Update:
One thing I didn't take into account while setting this up is spinning the drive down to save noise and wear. According to this page, this is problematic and should be looked into before settling on a drive. I'm sitting at my desk 3 feet from the NSLU2 and I can definitely hear a bit of sandy whirl coming from the drive. Of course, the beauty of a server is that I can store it anywhere with an ethernet port and a electrical socket, like next to the upstairs router.]

[Update: I replaced the 2.5 inch drive with a standard 3.5 inch external USB drive, and that has been going strong for 2 years now. Having said that, I should look into backing it up.]

Use the NSLU2 web interface to give yourself an account with the same name as your account on your Mac. This will make ssh'ing into the unit just a bit easier. In the text below, I will use "jim" as a user name.

Again using the web interface, Give the NSLU2 a static IP address in the range used by your router, for example 192.168.0.21 if your router uses 192.168.0.x IP addresses which is common.

Change the password for the admin account to something more secure.

Also make a group for all the collaborators of your project. Add yourself and the collaborator accounts to this group. This can all be done from the web interface. Make sure to give all these new accounts their own private folder.

At this point, you should have installed the new firmware, "unslung" Linux from running embedded to running off the USB 2.0 hard drive and been able to telnet into the box (Enable telnet from the web interface), and know your root password. Your NSLU2 is not going back to its old self, it's married to its hard drive.

I'm going to take over with the instructions.

Installing OpenSSH.

• Telnet as root into the NSLU2 and install the OpenSSH package.

#ipgk update
#ipkg install unslung-feeds
#ipkg update
#ipkg install openssh

• Reboot (unplug the NSLU2, plug it back in, push the on button, wait)
• Turn Telnet back on via the Web Interface.
• Telnet into the NSLU2
• Edit the ssh server configuration file at /opt/etc/openssh/sshd_config (I used #sudo vi /opt/etc/openssh/sshd_config)


...
#LoginGraceTime 2m
PermitRootLogin no
#StrictModes no
MaxAuthTries 6
RSAAuthentication no
PubkeyAuthentication yes
AuthorizedKeysFile %h/.ssh/authorized_keys
...

• If you like the bash shell, then
  #ipkg install bash
• Make sure your user account is setup to take you to your home directory with your favorite shell by editting /etc/passwd

jim:sc0MOzL8dVGa6:2003:501::sc3B6pVbVCgxc:/dev/null
to
jim:sc0MOzL8dVGa6:2000:501::/jim/:/opt/bin/bash

• Edit /opt/etc/init.d/S40sshd by changing

/opt/sbin/sshd
to
/opt/sbin/sshd -f /opt/etc/openssh/sshd_config

• Restart the NSLU2

So at this time, you should be able to ssh into the NSLU2 via a command like: ssh jim@192.168.0.21 Confirm this is so, and if not remember that you can probably get back in via telnet. A point about what we have done. We disabled ssh as root because hackers might get lucky guessing your root password. My /var/log/messages file is filled with miscreants trying to get in as root.

Setting up public/private keys

Y
[Update: I had had outdated instructions for setting up certificate based login here. OS X Leopard makes it much easier. Instructions Here.]

At this time, you should be able to ssh into your server without being asked for a password or passphrase as long as you are running SSH Agent. Now it's time to install svn.

Setting up the svn server

Subversion is a version control system. Version control systems are complex and have a high learning curve. Subversion is complex and has a high learning curve. There is a free O'Reilly book which covers its usage pretty well. At least read the Getting Started Chapter.

• Install the svn package


#ipkg install svn

• Copy the directory tree of the project for which you are starting source control onto the NSLU2 (let's say in /tmp/myproject)[Update: don't copy the build directory]
• If you haven't already, create a directory for your project.
• Make sure that your project group has access to this new directory.
• Import the project under the control of svn


#mkdir /MyProject
#chown jim:myprojectgroup /MyProject
#cd /MyProject
#svnadmin create /MyProject
#svn import /tmp/myproject file:///MyProject/myproject -m "initial import"

At this time you should have a project under version control. You just need to be able to access it from your Mac.

Setting up the svn client on the Mac

[Update: Try to install the same version of subversion on your Mac as you do on the NSLU2. I had trouble with version 1.4 on the Mac and 1.3.2 on the NSLU2.
svn --version
]
Here are two ways to install Subversion:

1) Go this page on apple.com.

2) Install Fink and use Fink Commander to keep installing packages until svn-client and svn-shlibs are listed as current. I found that fink balked at compiling all the pre-requisite libraries, but I could install those from binary and finally get svn itself to compile. It will take a while to compile.

At this point, you should have the svn client installed in your /sw/bin/ directory and be ready to checkout your project.

Checking out your project

• Create a clean directory into which you want to check out your project.
• Open up a Terminal window and cd into the newly created directory.

$svn checkout svn+ssh://192.168.0.21/MyProject This is where it was important that you use the same user name for both the NSLU2 and your Mac. Notice I didn't have to specify "jim@". It was all implied.

At this point, you should have your project checked out onto your Mac.

Setting up XCode

• Open up the XCode project file in your checked out project directory.
• In the Groups And Files panel, choose the topmost blue project icon.
• Right click on the project; select Get Info
• In the General tab, choose Subversion as the SCM System
• In the General tab, click the Edit... button. Enter /sw/bin/svn
• In the General tab, click Enable SCM.

At this point, you should be able to commit changes, revert changes, and other basic source control functions from XCode's SCM menu.

Allowing outside collaborators access to the svn server

Obviously, a big part of source control is allowing outside collaborators access to your code. That's one of the big reasons we've gone to the trouble of using the ssh tunneling method for accessing the svn server. It should allow safer access to your network. But people outside your local area network will need to locate the NSLU2 from the Internet.

To do this, you will have to have a router which supports DynDNS. I have a previous blog entry about setting up a DynDNS account. In addition to the setup there, you will have to have your router redirect port 22 (ssh) traffic to the NSLU2. Do not do this until you are satisfied you are secure; it's a jungle out there.

Also, your collaborators will have to setup their own DSA public/private keys for their own accounts on the NSLU2. An easy way to download their private key is via CyberDuck. I had initially recommended the old standby Fugu, but I didn't have a Universal binary version of Fugu and when I looked for one, found a lot of positive feedback for CyberDuck. Just be sure to choose the SFTP option for the new connection.


At this point, you should have a network setup where a collaborator could checkout your project using a command like:
$svn checkout svn+ssh://mydomain.homeip.net/MyProject

Good luck, and sorry if I missed anything.

Throwing RAM at XCode Linking

In my day job, I spend a lot of time compiling and linking a fairly large commercial C++ application. My PowerBook G4 was not up to the task of compiling the whole thing in a reasonable time, although I could distribute the compilation to two G5 desktops when I was at work. But this did not help when I worked from home, nor did it help with linking. And no, zero-link never seems to work for me.


So I bought a MacBook, and home compiles are now peppy. But linking is still fairly slow, especially if I'm running my normal selection of apps, and I rarely compile the whole application, but I have to re-link it every time I want to test a change. I ran the Utility Monitor utility while linking and I was shocked to see that linking, which drags my whole computer down to a crawl, was only using 10% of the CPU; it was crawling because even in 1GB of RAM, linking caused a horrible virtual memory paging thrash. Well, one of the nice things about a MacBook is it is upgradeable to 2GB.


I first measured my linking speed on my 1GB 1.83GHz MacBook with a 5400 rpm SATA 120GB Momentus hard drive. It actually wasn't too bad, linking my work application in an average of 150 seconds. If it was like that all the time, I might not have seen the need to upgrade my memory, but adding applications running concurrently makes linking time progressively worse. Launching Safari, iTunes, and iPhoto and doing light browsing while the link completes, bumps it up to 197 seconds, adding Skype to the mix increases the time to 248 seconds. (150/197/248)


Then I upgraded the RAM to 1.5 GB and the times improved markedly. (91/110/102)


Then I upgraded the RAM to 2.0 GB and the times really got fast. (39/54/61).




I noticed that as the times got quicker, the fraction of the CPU taken up by the linker (ld) went up. At 1GB of RAM, ld was using at most 14% of the CPU, at 2GB, it was up to 50%. It wasn't spending all it's time paging out. In fact, Activity Monitor
showed only 7 page outs after my testing versus hundreds of thousands of page outs after the 1GB testing.


You might have noticed, I didn't mention the size of my application. That is because, the size of my application is irrelevant to you. The point is, I was having slow linking, and upgrading my memory capacity improved my linking speed by around 4x for an investment of $165 (shipped) in name brand RAM. If you are having a slow linking problem, maybe you will get similar results; but you will have to measure to find out.


My brother Joe also has a RAM hungry program he relies upon, Parallels Desktop, and he tells me that bumping his MacBook to 2GB made it the fastest Windows XP computer he's ever used. (And that's with one core tied behind its back.)

Windmill vs. New Refrigerator

Must resist urge to use the word tilting


I recently bought a Kill A Watt energy consumption measuring device, and have become an enthusiast for saving electrical power. Several co-workers have borrowed it and now have a better understanding of how they can conserve power.


In the course of my evangelism, I fell into a conversation with a co-worker who planned to buy and install a windmill on his property in New Hampshire. He feels this is a good way to both save resources and money. I asked him how much electricty he could generate, and he replied that his measurements indicated he could generate an average of 450 Watts. At $0.15 per kWh, this would be around $45 a month in energy. I asked him how much a windmill costs: $4000. How long would it last: 30 years with little maintenance.


By way of comparison, I had lent my Kill-A-Watt to another fellow, who reported back that his 15+ year old refrigerator was using $45 a month in energy. My refrigerator uses $12 a month in electricity, so this person could save $33 a month if he were only to buy as efficient a refrigerator as mine. Checking online, indicates a refrigerator should last for 15 years, and a top rated model (by Consumer Reports) such as the Whirlpool ET1FHTXMQ costs $750.


So the question is: If I had $4000 should I get a new refrigerator, or a windmill? (this thought experiment does not take into account subsidies, inflation or taxes). Interest income calculated using this online calculator.

Scenario 1 (buy windmill)
Initial investment account balance: $0
Return on energy generated: $45/month
Investment account balance after 30 years (assuming 8% return):$67513


Scenario 2: (buy $750 refrigerator and replace it again in 15 years)
Initial investment account balance: $3250
Return on energy saved: $33/month
Investment account balance after 30 years (assuming 8% return):$82571


Scenario 3: (buy neither)
Initial investment account balance: $4000
Investment account balance after 30 years (assuming 8% return):$43743


So, from a purely monetary point of view, investing in a new refrigerator is better than buying a windmill if your old refrigerator needs replacing. And if you have both an old refrigerator and an old dehumidifier, I suspect you will end up saving as much energy as a windmill generates at a fraction of the price. The guy with the bad refrigerator was also spending $60 per month on dehumidification.


The amazing thing for me is that the 50+% return you can get from buying a new refrigerator makes it such an incredibly good deal if your old refrigerator is inefficient. (Over 15 years you save $6000 in energy costs, which if invested at 8% would yield $11,500) Obviously, not everyone has such an old clunker as my co-worker. Your mileage may vary, but I highly recommend getting a Kill-A-Watt and finding out.