Smalltalk with James Robertson

I've been building BottomFeeder without RTP for awhile now, but until I started looking at build automation for this new job, I hadn't fully automated it. That's something I've done now, and one thing that I really like about the process I use is the predictability.

With RTP, if you let it scan and strip, you're never really sure what it took out. Oh, sure, there's a report it generates, and you can go through that - but it's not easy to digest. Instead, I have a script that pulls out a set of named packages - this is one of the advantages to the newer releases of VW, btw - having defined blobs of code that have structure not only makes loading easier, it makes unloading easier. Here's what I have my script do:

"Unload the debugger and other tools"
(Store.Registry pundleNamed: 'Tools-Debugger')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].
(Store.Registry pundleNamed: 'Tools-Refactoring Browser')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].
(Store.Registry pundleNamed: 'Tools-Parcel Manager')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].
(Store.Registry pundleNamed: 'Tools-Changes')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].
(Store.Registry pundleNamed: 'Tools-File Browser')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].
(Store.Registry pundleNamed: 'UIPainter')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].
(Store.Registry pundleNamed: 'StoreForPostgreSQL')  ifNotNil: [:pundle |
	pundle leafItems do: [:each | each markNotModified].
	[pundle markNotModified; unloadFromImage] on: Warning do: [:ex | ex
	resume: true]].

The handler block allows the script to proceed if anything odd happens; I should probably be logging those events. The larger point is this: I know exactly what got pulled, and, more importantly - what didn't. Unless you're really careful (and you have to be careful every time code has changed), RTP will strip code from your application. That's usually safe, but if you use constructed message sends for any reason (good or bad), you can get smacked. I think this approach is vastly safer.

I've posted before on how I put the image into a runtime state, but it's worth going over again:

• Have a subclass of UserApplication. Specify your prereq subsystems, and implement #main. In that method, start your application. It'll get called when it's safe to do so at startup, based on the prereqs you specified
• Execute the following code after you do whatever other image prep is necessary:

"set up logging and exception handling"
DeploymentOptionsSystem current startInRuntime: true.
Notifier current: RuntimePackager.RuntimeEmergencyNotifier.
RuntimePackager.RuntimeManager errorLogPath: 'error.log'.
Notifier logToFile: true.
"set up runtime state"
UI.WindowManager noWindowBlock: [:windowManager | ].
stream := WriteStream on: String new.
stream nextPutAll: 'changeRequest'; cr; cr; tab.
stream nextPutAll: '^true'.
VisualLauncher compile: stream contents.
VisualLauncher allInstances do: [:each | each closeAndUnschedule.  each release].
ObjectMemory garbageCollect.
Workbook allInstances do: [:each | each closeRequest].
(Delay forSeconds: 20) wait.
Parcel searchPathModel value: (List with: (PortableFilename named: '.')).
SourceFileManager default discardSources.

"Now save the image such that this file doesn't get looked for at startup"
[ObjectMemory permSaveAs: runtime' thenQuit: false] fork.
[(Delay forSeconds: 25) wait.
RuntimeSystem isRuntime ifFalse: [ObjectMemory quit]] fork.

I actually use some of the RTP infrastructure (the runtime exception handler and logging) - I just don't use it to create the image. It's a pretty simple process, and once you have the script created, it's easy to have a "one button click" UI drive it - from another image

You would think that getting the version comment for a package or bundle you've published to Store would be simple - there's a method called #versionComment right there in Pundle - but you would be mistaken. No, that's not the comment you type into the text field when you publish.

Why do I care? Well, as part of my build automation work, I'm generating a small report, and part of that report involves pulling out the comment for a published package. That takes more work to get at than you might think:

pkg := (Store.Package withName: 'PkgNameHere' version: 'versionStringHere') first.
blessing := (Blessing 
				blessingsForRecordID: pkg  primaryKey
				type: pkg  typeStringForBlessing) first.
comment := blessing getCommentString.

Just tracing Store code to figure that out was painful; the comparison tool Version Browser doesn't make it obvious. Then there's the whole head scratching nature of "why isn't there a method that does this for me in Pundle?" Anyway, that does the job I wanted, and now I have that bit of my reporting task handled.

I'll be at StS 2011, giving a talk on Smalltalk on the server side, focusing on cloud services. I still need to register - as I write this, the STIC website (where the registration page lives) is down though. I'll get to it when the site pops back online :)

The next podcast on the schedule will involve a look at where Instantiations is taking VA Smalltalk. Dave Buck and I will be talking to Mike Taylor, President and CEO of the company. If you have anything you would like us to ask Mike, email me before 5 PM EST today. The podcast will be out on Sunday, as per our regular schedule.

Before you can even get to building a runtime image from a clean base image, you have to get to the point where yoiu can build a clean development image from a clean base image. That was today's first challenge.

On any long lived project, things pile up if no one has been doing clean builds, and this one was no different. It wasn't bad - I only ran into one issue that needed resolving: four methods in one package were being invoked (via package initialization code), but those methods were defined in a package that hadn't loaded yet.

To back up a bit, the entire project here is in a "master bundle" - you load that, and you get everything (either in the bundle or via pre-reqs). Over the last little while, builds have only been done on top of previous development images, so no one spotted this issue. I cleaned that up, and then everything came in easily.

Next up was trying to save the bundle out as a parcel (I'd like to be able to build into an image without Store present). Now I ran into the second check: a bunch of external interfaces were defined with optimization level #debug, and parcels can't be saved with that setting. So... another bunch of small changes and bam - I had a parcel out on disk.

Now comes the fun part - one of the pre-reqs is all of the patch sets that Cincom support sends out (boy, would this be simpler if they just shipped new versions of the owning packages, but I digress). That stuff can't be saved (at least in VW 7.6) as a parcel, because they all contain overrides. So... I just filed that out. Since it's all patches on the base system, I can just set that up to load last and I shouldn't run into problems.

Thus far, I have the system loading cleanly from a base visual.im, which is progress. From there, I can move along to the next few steps and see if I can get a runtime build. Fingers crossed :)