[WIP] Memcached

[marc-mabe]

• removed dependency to Zend\Validator
• allow to share one memcached resource over different adapter instances
• instantiate the memcached resource on first use
• init list of servers and lib options only on instantiating the memcached resource
• allow different format to configure servers:
  • array list: array(array([, [, ]][, ...]))
  • array assoc: array(array('host' => [, 'port' => [, 'weight' => ]][, ...]))
  • string list: array(':?weight='[, ...])
  • string separated: ':?weight=[, ...]'

[weierophinney]

This is not good -- it's an API change. I'm okay with adding a method, but not with removing one.

[weierophinney]

All suggestions were incorporated during merge. I re-added the listener for "option", but have it now only caring about "namespace"; this fixed two failing unit tests. Additionally, I'd discovered that the default server had been removed, so I reinstated that as well, this time within MemcachedOptions.

[marc-mabe]

Hi @weierophinney

Thank you for review and corrections.
But saw some problems with it but couldn't fix it all because of stress at work and now I'm sick :(
(Sry if I didn't communicate)

1. addServer: The event option should be triggered on changing an option but currently doesn't for servers and if it will be implemented it would for every server instead of only once for all.
2. Noted in Missing expiration parameter for "setItem" on Cache adapters #2760 it must be possible to share the same memcached resource over different adapter instances but than there are always servers and lib options configured. It's than would add the default configured server or the servers have to be configured twice and would be added twice.
3. Similar as 2.
   It must be possible to share the same memcached instances but use different namespaces.
   • I would like to implement the namespace support manually and let it be independent of Memcached::OPT_PREFIX_KEY (It wasn't ready)

Any thoughts ?

[weierophinney]

@marc-mabe :

1. I attached the option listener directly to the memcached resource, which means it should affect all servers (as servers are attached to the memcached resource, and they cannot be changed once the resource is initialized). As such, I think this is working correctly now.
2. I think that if you use the same memcached resource over different adapter instances, you're asking for problems, unless you know that the exact same configuration will work.
3. Same thing -- different namespaces will lead to liklihood of collisions. My inclination is that this is a YAGNI situation. (That said, the liklihood of namespace issues should be moot, as if you provide the namespace in an operation, the listener will be triggered, and thus change the namespace for that operation.)