Switch to a simpler progress bar library. I've been having trouble tracking
down a panic that seemed to affect the prior code; the new code is much
easier and uses far fewer async channels and things.
If we have some really tiny files, it's not worth compressing them. Among other things,
this will work around a bug in go-zopfli for 0- or 1-byte files.
Sometimes we might be asked to serve up a zero-length input file,
typically from some machine-generated CSS etc. We make some very
rudimentary guess about the content-type the caller wanted and skip the
mmap(2) call.
Since packing can be quite slow, it is nice to display progress to the
caller. We use the excellent github.com/vbauerster/mpb library to do so,
and add a bit of colour with github.com/logrusru/aurora.
Finally, augment the inspector and packer with a summary printer that
displays the overall file size/count, and compression ratio for each
compression type.
If a .svg file doesn't have a “<?xml…” prolog, then it would be detected as plain
text. Allow extension-based override of the content-type in this case.
Laurence Withers
Laurence Withers