Convert vmstat to use libxo

[• rodrigc]

Summary

Update patch from Juniper which converts vmstat to use libxo.

Test Plan

Ran the following:

vmstat -a -i
vmstat -f
vmstat -o
vmstat -m
vmstat -P
vmstat -a -i --libxo json | python2.7 -mjson.tool
vmstat -f --libxo json | python2.7 -mjson.tool
vmstat -o --libxo json | python2.7 -mjson.tool
vmstat -m --libxo json | python2.7 -mjson.tool
vmstat -P --libxo json | python2.7 -mjson.tool

[allanjude]

Please add a xo_version() somewhere before the start of the output

[• rodrigc]

Use xo_set_version()

[allanjude]

vmstat.c

671 ↗

(On Diff #9494)

xo_attr doesn't really apply to JSON
rather than that, you can do: {:name/encoded version/text version}

so:

snprintf(fmt, sizeof(fmt), "{:%s/%%ju/%%s}", name);
xo_emit(fmt, (uintmax_t) val, size, buf);

805 ↗

(On Diff #9494)

%1d %1d %1d became %1d %ld %ld (one one one, became one ell ell), was that indentional?

Any time the 'width' of the output is limited, you should use have an 'encoding' format version that is not limited

for example: xo_emit("{:name/%16s}", string);

should be: xo_emit("{:name/%s/%16s}", string, string);

so the xml/json version is not truncated (or padded), but the text version is

822 ↗

(On Diff #9494)

fixed width number

886 ↗

(On Diff #9494)

did you mean to add a literal dollar sign here?

989 ↗

(On Diff #9494)

you could tag the 'usec' as the units, but probably not worth it

1380 ↗

(On Diff #9494)

%-%s is meant to have a * isn't it?

[• rodrigc]

Regarding xo_attr(), yes you are right that it applies to XML and not JSON. That part of the patch is from Juniper's original patch,
and Juniper relies more heavily on XML for some of their stuff, so I would rather leave that part of the patch in for them.

[op]

head/usr.bin/vmstat/vmstat.c

809

Are these %1d -> %ld conversion here intended?

1514

Why not {T:LIMIT/%-20s} and similar here, as in line 1654 or vica-versa?