Speed up Build-Process of WiX-Installer

Question

For my Wix project I am harvesting 4 directories, via the pre-build-event of visual studio, which will result in about 160mb of data, and about 220 files, but the build process tooks very long.

How can i speed that process up? I have one embedded media.cab file which will hold all the files. Is it the size or the amount of files that will slow the process down? Or is it the harvesting with the heat tool in the pre-build-event? Would it be faster with the HeatDirectory element?

Anyone made some experience with speeding this up?

Answer 1

For us, the vast majority of the time was spent invoking light (for the linking phase).

light is very slow at compressing cabinets. Changing the DefaultCompressionLevel in the .wixproj from high to mszip (or low or none) helps a lot. However, our build was still too slow.

It turns out that light handles cabinets independently, and automatically links them on multiple threads by default. To take advantage of this parallelism, you need to generate multiple cabinets. In our .wxs Product element, we had the following that placed everything in a single cabinet:

<MediaTemplate EmbedCab="yes" />

It turns out you can use the MaximumUncompressedMediaSize attribute to declare the threshold (in MB) at which you want files to be automatically sharded into different .cab files:

<MediaTemplate EmbedCab="yes" MaximumUncompressedMediaSize="2" />

Now light was much faster, even with high compression, but still not fast enough for incremental builds (where only a few files change).

Back in the .wixproj, we can use the following to set up a cabinet cache, which is ideal for incremental builds where few files change and most cabinets don't need to be regenerated:

<CabinetCachePath>$(OutputPath)cabcache\</CabinetCachePath>
<ReuseCabinetCache>True</ReuseCabinetCache>

Suppressing validation also gives a nice speedup (light.exe spends about a third of its time validating the .msi by default). We activate this for debug builds:

<SuppressValidation>True</SuppressValidation>

With these changes, our final (incremental) build went from over a minute to a few seconds for a 32 MB .msi output, and a full rebuild stayed well under a minute, even with the high compression level.