On Jul 21, 2009, at 6:27 AM, Adam Murdoch wrote:
Steve Appling wrote:
I have been trying to make use of the new onlyIf method to optimize
our large build. OnlyIf seemed liked a very useful approach in the
abstract, but is proving to be more of a challenge in a real
project. It was useful for a few tasks (like jar.onlyIf
{ compile.didWork || processResources.didWork }), but not for some
of the more expensive ones. The Test task, in particular, has been
frustrating.
I tried the somewhat too simple:
test.onlyIf { compile.didWork || testCompile.didWork ||
processTestResources.didWork }
This does exactly what it says, it only runs the tests if new code
was compiled or the test resources changed and this seemed great at
first glance. When I tried this on our real project, however, I
was disappointed. What this will do is to cause the test task for
a module to be run only once. If it fails and the developer does
not correct it, then the next time the build is run the test will
be skipped. This gives the false impression that everything is
correct when it is not. To be useful, I think this also needs some
type of state information about whether the tests passed last time,
but this is getting more complicated than I originally envisioned.
A general solution to this problem is going to have to remember
whether a task has completed or failed to execute. It is also going
to have to consider the output artifacts of the task (and do a
better job with the input artifacts). I think it is reasonable for
Gradle to maintain this state, provided we do so in a general-
purpose way.
For example, this is something that the OptimisationHelper could
expose, that the onlyIf clause can make use of if it cares:
test.onlyIf { compile.didWork || ... || !completedSuccessfully }
Why not provide the completedSuccessfully (possibly with a different
name) as a task property? As a first implementation we could have a
file (somewhere in .gradle) for each task being executed. This file
just contains true/false at the moment. False is returned if the file
contains false or the file does not exists.
As soon as we have multiple source dir/test source dir roots, we need
our new SourceSet abstraction to get the necessary conditions for the
onlyIf.
- Hans
--
Hans Dockter
Gradle Project Manager
http://www.gradle.org
---------------------------------------------------------------------
To unsubscribe from this list, please visit:
http://xircles.codehaus.org/manage_email
