There was a TODO to make this code more legible. I still think it's
somewhat ugly, but it does read _slightly_ better as a switch statement.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
By avoiding lots of small string allocations and reallocations when
appending to the output buffer, we can get a pretty decent performance
improvement (~6x for strings that do not require escaping, and ~2x for
most other multi-byte utf8 strings).
goos: linux
goarch: amd64
pkg: github.com/vbatts/go-mtree/pkg/govis
cpu: AMD Ryzen 7 7840U w/ Radeon 780M Graphics
│ before │ after │
│ sec/op │ sec/op vs base │
Vis/NoChange-16 2372.5n ± 2% 379.1n ± 1% -84.02% (p=0.000 n=10)
Vis/Binary-16 2.104µ ± 8% 1.319µ ± 8% -37.35% (p=0.000 n=10)
Vis/ASCII-16 2070.0n ± 1% 737.3n ± 0% -64.38% (p=0.000 n=10)
Vis/German-16 3.380µ ± 1% 1.181µ ± 2% -65.04% (p=0.000 n=10)
Vis/Russian-16 10.927µ ± 2% 5.293µ ± 2% -51.56% (p=0.000 n=10)
Vis/Japanese-16 7.489µ ± 1% 3.990µ ± 0% -46.72% (p=0.000 n=10)
geomean 3.767µ 1.447µ -61.58%
In theory we could get more performance if switch away from fmt.Sprintf,
but the %.N handling would be a little annoying to implement and so we
can punt on that for now.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This code was written before %w was added to Go, and there were a fair
few mistakes in the copy-pasted error code.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
govis is a reimplementation of vis(3) and unvis(3) specifically made to
be unicode aware. It was specifically rewritten to replace cvis and the
other go vis reimplementation we have in go-mtree.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
