htop/pcp/meters/memcache

#
# pcp-htop(1) configuration file - see pcp-htop(5)
#

[memcache]
caption = Memcache
description = Memcache Hits
hit.metric = sum(memcache.hits)
hit.color = green
miss.metric = sum(memcache.misses)
miss.color = blue
Add a new DynamicMeter class for runtime Meter extension This commit is based on exploratory work by Sohaib Mohamed. The end goal is two-fold - to support addition of Meters we build via configuration files for both the PCP platform and for scripts ( https://github.com/htop-dev/htop/issues/526 ) Here, we focus on generic code and the PCP support. A new class DynamicMeter is introduced - it uses the special case 'param' field handling that previously was used only by the CPUMeter, such that every runtime-configured Meter is given a unique identifier. Unlike with the CPUMeter this is used internally only. When reading/writing to htoprc instead of CPU(N) - where N is an integer param (CPU number) - we use the string name for each meter. For example, if we have a configuration for a DynamicMeter for some Redis metrics, we might read and write "Dynamic(redis)". This identifier is subsequently matched (back) up to the configuration file so we're able to re-create arbitrary user configurations. The PCP platform configuration file format is fairly simple. We expand configs from several directories, including the users homedir alongside htoprc (below htop/meters/) and also /etc/pcp/htop/meters. The format will be described via a new pcp-htop(5) man page, but its basically ini-style and each Meter has one or more metric expressions associated, as well as specifications for labels, color and so on via a dot separated notation for individual metrics within the Meter. A few initial sample configuration files are provided below ./pcp/meters that give the general idea. The PCP "derived" metric specification - see pmRegisterDerived(3) - is used as the syntax for specifying metrics in PCP DynamicMeters. 2021-06-23 07:44:56 +00:00			`#`
			`# pcp-htop(1) configuration file - see pcp-htop(5)`
			`#`

			`[memcache]`
			`caption = Memcache`
			`description = Memcache Hits`
			`hit.metric = sum(memcache.hits)`
			`hit.color = green`
			`miss.metric = sum(memcache.misses)`
			`miss.color = blue`