On 17/04/2013, at 8:08 PM, Rene Groeschke <gra...@breskeby.com> wrote:
> Hey, > there is a story in the according spec "Fix up-to-date issues on copy tasks". > Does this include porting the Copy task to use this incremental feature where > possible? Not really. The use case in the spec is more about making copy and friends correct rather than fast. I've added some more stuff to the spec to remind us to make copy incremental. > > Especially when dealing with lot of resources this can make a big difference. > > cheers, > René > > -- > Join me at the Gradle Summit 2013, June 13th and 14th in Santa Clara, CA: > http://www.gradlesummit.com > > Rene Groeschke > Principal Engineer, > Gradleware Inc. - Gradle Training, Support, Consulting > rene.groesc...@gradleware.com > http://gradleware.com > > > > Daz DeBoer wrote: >> G'day >> >> Now in master is a pretty cool new feature: you can now implement an >> 'incremental' task that is informed about exactly which input files >> have changed when the task is out of date. >> This is very useful for something like a C++ compile task, as it means >> that only the changed files need to be recompiled, rather than the >> entire set of inputs. >> >> I've got a 'draft' DSL functioning, and would appreciate any feedback >> you guys have. Here's a sample: >> >> class IncrementalSync extends DefaultTask { >> @InputFiles >> def FileCollection src >> >> @OutputDirectory >> def File destination >> >> @TaskAction >> void execute(TaskInputChanges inputs) { >> if (inputs.allOutOfDate) { >> FileUtils.forceDelete(destination) >> } >> >> inputs.outOfDate({ >> FileUtils.copyFile(change.file, targetFile(change.file)) >> } as Action) >> .removed({ >> FileUtils.forceDelete(targetFile(change.file)) >> } as Action) >> .process() >> } >> >> def targetFile(def inputFile) { >> new File(destination, change.file.name) >> } >> } >> >> Notes: >> 1. The way to implement an incremental task is to add a >> TaskInputChanges parameter to your @TaskAction method. This must be a >> typed parameter, and currently TaskInputChanges is the only parameter >> type we support (but there are plans to add more, like >> TaskOutputChanges). The reason for using a typed parameter is that >> this is the way the task tells us what it wants: I thought about an >> annotated parameter, but it seems kind of pointless when the >> annotation would imply the type anyway. (Perhaps we can add an >> annotation-based marker at a later stage, if it helps). >> >> 2. There are 2 discrete ways we report incremental changes: >> - If the _only_ change to the task execution state is changed input >> files, then TaskInputChanges.allOutOfDate() will be false, and only >> the added/changed/removed files will be notified to the >> TaskInputChanges.outOfDate() and .removed() actions. >> - In the case of non-file changes to task inputs (properties, task >> class) and changes to task output files, then Gradle will consider all >> input files to be out of date. In this case, >> TaskInputChanges.allOutOfDate() will be true, and every input file >> will be reported to the TaskInputChanges.outOfDate() action. >> >> 4. The reason for the chained action methods combined with a final >> process() method is that this allows us to stream changed inputs in >> any order, and does not require us to persist these changes for a >> subsequent method call. This is a little awkward, but doesn't force us >> to jump through hoops. We could implement a more discrete API on top, >> but it may be less efficient. >> >> 5. I haven't yet got any DSL magic applied to the TaskInputChanges >> instance, so using a closure directly isn't (yet) possible. Not sure >> how important that is for this DSL, or how tricky it will be to add. >> >> You can read more about the plans here: >> https://github.com/gradle/gradle/blob/master/design-docs/incremental-build.md >> Next steps for incremental tasks include providing access to changed >> outputs and properties (in the case a task can handle these more >> efficiently), automatically cleaning up stale outputs, and fixing some >> bugs around the incremental nature of Copy tasks (and others). >> >> -- >> Darrell (Daz) DeBoer >> Principal Engineer, Gradleware >> http://www.gradleware.com >> Join us at the Gradle Summit 2013, June 13th and 14th in Santa Clara, >> CA: http://www.gradlesummit.com >> >> --------------------------------------------------------------------- >> To unsubscribe from this list, please visit: >> >> http://xircles.codehaus.org/manage_email >> >> > > > --------------------------------------------------------------------- > To unsubscribe from this list, please visit: > > http://xircles.codehaus.org/manage_email > > -- Adam Murdoch Gradle Co-founder http://www.gradle.org VP of Engineering, Gradleware Inc. - Gradle Training, Support, Consulting http://www.gradleware.com Join us at the Gradle Summit 2013, June 13th and 14th in Santa Clara, CA: http://www.gradlesummit.com
