I was thinking about a couple of the slower MSBuild tasks:
- `Javac`
- `CompileToDalvik`
One thing I noticed here was that `Javac` outputs a `classes.zip`
file, and `CompileToDalvik` consumes it. It also looked like we are
using `CompressionMethod.Default` as you would expect.
So why should we compress this file at all? It seemed that was work we
could just skip and things would work fine? Presumably `dx.jar` can
work with an uncompressed `classes.zip` file faster than a compressed
one?
So I made the following changes:
- Added an option to pass in the `CompressionMethod` in `ZipArchiveEx`
- Used `CompressionMethod.Store` for creating `classes.zip`
The results on a File | New Xamarin.Forms app looked great!
Before:
     3443 ms  Javac                                      1 calls
    11545 ms  CompileToDalvik                            1 calls
After:
     3338 ms  Javac                                      1 calls
    10535 ms  CompileToDalvik                            1 calls
I did a `Clean` before running the `SignAndroidPackage` target on
these builds.
These savings seem pretty good! The only drawback being we use more
disk space in `$(IntermediateOutputPath)`.