Named return variables should only be used to describe the returned type
further, e.g. `err error` doesn't add any new information and is just
stutter.
Removed all global types that were unnecessary, and refactored to use constructor-created values and inline values instead of globals.
Signed-Off-By: Joe Handzik <joseph.t.handzik@hpe.com>
This patch makes stylistic changes to error strings, unexports method names by lower casing them, removes unused dataSetMetric, and adds copyright/licence information.
Signed-Off-By: Corey Stewart <stewa169@purdue.edu>
It is tested on FreeBSD 10.2-RELEASE and Linux (ZFS on Linux 0.6.5.4).
On FreeBSD, Solaris, etc. ZFS metrics are exposed through sysctls.
ZFS on Linux exposes the same metrics through procfs `/proc/spl/...`.
In addition to sysctl metrics, 'computed metrics' are exposed by
the collector, which are based on several sysctl values.
There is some conditional logic involved in computing these metrics
which cannot be easily mapped to PromQL.
Not all 92 ARC sysctls are exposed right now but this can be changed
with one additional LOC each.
