There's really not a great way to map individual levels to each
compression library, so this just adds a new type that will invoke the
three relevant levels for each library used. This could be improved in
the future.
This replaces the parallel gzip with the boring gzip from Go's standard
lib. The main motivations for doing this are:
1) Reduce runtime memory requirements
2) shed some external dependencies
There's obviously a trade-off with compression speed/time (as seen
below), but I feel like it's a worthwhile trade-off.
Note that there's likely very little impact to boot performance wrt
extracting these archives, the compression levels are similar.
Measured on a Shift 6mq, which is a very fast phone...
** compress/gzip:
User time (seconds): 1.81
System time (seconds): 0.38
Percent of CPU this job got: 104%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:02.09
Maximum resident set size (kbytes): 62024
-rw-r--r-- 1 clayton clayton 6.1M Sep 20 17:20 initramfs
-rw-r--r-- 1 clayton clayton 2.5M Sep 20 17:20 initramfs-extra
** pgzip:
User time (seconds): 1.19
System time (seconds): 0.48
Percent of CPU this job got: 159%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.05
Maximum resident set size (kbytes): 109952
-rw-r--r-- 1 clayton clayton 6.8M Sep 20 17:20 initramfs
-rw-r--r-- 1 clayton clayton 2.8M Sep 20 17:20 initramfs-extra
inspired by: https://gitlab.com/postmarketOS/pmaports/-/issues/1704
Checking for the app is unnecessary, since the cmd.Run later will fail
if it doesn't exist. This allows dropping the dependency on misc.Exists.
There's also no reason to print that the command failed, just return the
error.
This new style is a little more verbose (having to manually set return
code on error..), but at least it offers a chance to improve the
printing of errors a little more.
This greatly reduces the chance accidentally adding dependencies to the
other (currently unused) variables later on. Getting away from depending
on deviceinfo has a lot of benefits, but mainly it helps offload
device-specific boot configuration to boot-deploy. Handling those
complexities in a shell script is often nicer.
Also, reducing the need to handle variables that contain lists means
that this app doesn't have to worry about how to merge/handle multiple
versions of those. That might be useful later if mkinitfs has to read
deviceinfo config from multiple deviceinfo files.
For example, trying to figure out how to merge these two things is...
ehhh...
a_modules_initfs="abc bar banana bazz"
b_modules_initfs="foo bar bazz bar2 guava"
This is kinda janky, passing both a list of modules and a directory path
is just because we support modules in deviceinfo and in directory file
lists... Maybe one day we can move away from having modules in the
deviceinfo...
