I'd like to add a "persistent state" directory with a hard-coded default, config directive and API equivalent to the runtimdir in config.layout, DefaultRuntimeDir directive and ap_runtime_dir_relative(). The "runtime" directory is used for transient state which disappears and can be deleted once the server is stopped. This can be safely stored in tmpfs or even created & deleted on the fly. A "persistent state" directory would be for data which is expected to persist across restarts.
Example users are the mod_dav_fs lock database, mod_md's MD data store. With an API & default, these can have hard-coded default paths so the modules work without needing configuration. The proxy cache root could count here too. Any thoughts/objections? I'm not sure about naming, maybe simply: DefaultStateDir -- ap_state_dir_relative() and use "statedir" in config.layout since localstatedir is already used and is typically set to /var or $prefix. For Linux/FHS type layouts, statedir could be set to e.g. /var/lib/httpd and for layouts like "Apache", maybe $prefix/state or something like that would be fine. Regards, Joe
