The sbt project load made a number of relatively inefficient
transformations of scala collecitons. I went through and found the slow
parts during project loading and made my best attempt at fixing them.
The most significant changes I made were in places using IMap. An IMap
is more or less a wrapper around an immutable Map. It can be much faster
to construct an IMap by creating a java mutable hashmap, wrapping it a
scala Map that delegates to the underlying java hashmap (with a copy on
write if the map is modified) and constructing the IMap from the wrapped
map. It was also in many cases to parallelize some transformations
wherever the order didn't matter.
After applying all of these changes, I found that loading the sbt
project took generally between 8.5 and 9 seconds on my laptop. With
1.3.13, it hovered around 11.5 seconds. I saw a similar speedup in zinc.
The biggest specific improvement was that generating the compiled map
dropped from between 3.5-4 seconds to pretty consistently being around
1.5 seconds.
The continuous command recompiles the setting graph into a CompiledMap
data structure so that it can determine which files it needs to
transitively monitor during watch. Generating the CompiledMap can be
very slow for large projects (5 seconds or so on my computer in the sbt
project) and this startup cost is paid every time the user enters a
watch with `~`. To avoid this, we can cache the compile map that is
generated during the initial settings evaluation.
The only real drawback I can see is that the compiled map is guaranteed
to remain in memory so long as the BuildStructure instance that holds it
is alive. Given the performance benefit, this seems like a worthwhile
tradeoff.
This implements Selective functor for `Either[A, B]` "task" (`Initialize[Task[Either[A, B]]]`).
The selective functor allows an encoding of if-expression:
```
def ifS[A](
x: Def.Initialize[Task[Boolean]]
)(t: Def.Initialize[Task[A]])(e: Def.Initialize[Task[A]]): Def.Initialize[Task[A]]
```
The benefit of this approach is that task dependencies are still visible to inspect command.
To demonstrate [-Yno-lub](http://eed3si9n.com/stricter-scala-with-ynolub), this shows the code changes that removes lubing (Not all subprojects are done).
After I made the changes, I switched the Scala back to normal 2.12.10.
During akka startup, addLocal was caused twice and prior to this change,
it took roughly 200ms per call on my computer. After this change, it
took about 100ms.
I was seeing a number of compiler warnings about the type parameter
Scope:
Settings.scala:55:12: type parameter Scope defined in trait Init shadows class Scope defined in package util. You may want to rename your type parameter, or possibly remove it.
I'm not sure why I wasn't seeing these before, but the fix is simple.
While the AnyLeft and AnyRight types are necessary to make the extension
class work, I don't want to leak the AnyLeft or AnyRight traits into the
public api. It wasn't neceessary to annotate `some`, but it's good
practice to annotate anything public anyway.
Fixessbt/sbt#1812
This adds unified slash syntax for both sbt shell and the build.sbt DSL.
Instead of the current `<project-id>/config:intask::key`,
this adds `<project-id>/<config-ident>/intask/key` where <config-ident> is the Scala identifier notation for the configurations like `Compile` and `Test`.
This also adds a series of implicits called `SlashSyntax` that adds `/` operators to project refererences, configuration, and keys such that the same syntax works in build.sbt.
These examples work for both from the shell and in build.sbt.
Global / cancelable
ThisBuild / scalaVersion
Test / test
root / Compile / compile / scalacOptions
ProjectRef(uri("file:/xxx/helloworld/"),"root")/Compile/scalacOptions
Zero / Zero / name
The inspect command now outputs something that can be copy-pasted:
> inspect compile
[info] Task: sbt.inc.Analysis
[info] Description:
[info] Compiles sources.
[info] Provided by:
[info] ProjectRef(uri("file:/xxx/helloworld/"),"root")/Compile/compile
[info] Defined at:
[info] (sbt.Defaults) Defaults.scala:326
[info] Dependencies:
[info] Compile/manipulateBytecode
[info] Compile/incCompileSetup
[info] Reverse dependencies:
[info] Compile/printWarnings
[info] Compile/products
[info] Compile/discoveredSbtPlugins
[info] Compile/discoveredMainClasses
[info] Delegates:
[info] Compile/compile
[info] compile
[info] ThisBuild/Compile/compile
[info] ThisBuild/compile
[info] Zero/Compile/compile
[info] Global/compile
[info] Related:
[info] Test/compile
Ref #3282
We used to wrap InputStream so it will inject Thread.sleep, which then allows the thread to be cancelled, emulating a non-blocking readLine. This trick doesn't seem to work for Windows.
For non-Cygwin, actually just removing the wrapping does the job, but I couldn't get it to work for Cygwin.
To test, run some command via network, and then type `show name` into the terminal. On Cygwin, it will not respond.
Ethan Atkins
eugene yokota
nigredo-tori
Dale Wijnand
Josh Soref
xuwei-k
Ethan Atkins
Dale Wijnand
Simon Schäfer