Ie161e0f was done in a hurry, and so didn't do things in the best ways.
This introduces a new "CachedBagOStuff" that transparently handles all
the logic that had been copy-pasted all over in Ie161e0f.
The differences between CachedBagOStuff and MultiWriteBagOStuff are:
* CachedBagOStuff supports only one "backend".
* There's a flag for writes to only go to the in-memory cache.
* The in-memory cache is always updated.
* Locks go to the backend cache (with MultiWriteBagOStuff, it would wind
up going to the HashBagOStuff used for the in-memory cache).
Change-Id: Iea494729bd2e8c6c5ab8facf4c241232e31e8215
* This can happen due to incr/add races. Use incrWithInit()
instead to handle such cases.
* Also made BagOStuff:incrWithInit() return the new value like incr().
Change-Id: I0e3b02a4cff7c20544a9db2eaabd3f61e5a470b1
Also consistently use self:: instead of BagOStuff:: for constants
referenced within the BagOStuff class.
Change-Id: I20fde9fa5cddcc9e92fa6a02b05dc7effa846742
For the sake of safety and correctness, the following BagOStuff::makeKey()
invocations should return distinct keys:
$cache->makeKey( 'ab:', 'cd' );
$cache->makeKey( 'ab', ':cd' );
That is not currently the case, because while we use ':' as a key path
separator, we don't escape ':' in the input supplied to makeKey(). So, make
BagOStuff::makeKeyInternal() URL-encode colons.
To prevent this from messing up the max. key length calculations, reproduce
this logic in MemcachedBagOStuff::makeKeyInternal(), in lieu of having the
method call its parent.
Change-Id: I83ea7e7336a1c9e64aa42284c2517089a736efe5
* This blocks on writing to all replicas
and returns false if any failed.
* This is useful if ChronologyProtector is to work across
domains by having the writes go everywhere so that later
reads will see them (and be local at the same time).
* Redundant doc comments were also removed.
Change-Id: I9ed098d563c64dba605e7809bc96731da3b3e79d
* Add a string `keyspace` member to BagOStuff instances. The default
implementation, meant for simple key/value stores, treats the key space
as a string prefix to prepend to keys. By default, its value is `local`,
but any instance created via ObjectCache::newFromParams() (or or one of
its callers) will have that default to $wgCachePrefix / wfWikiID().
* Add `makeKey` and `makeGlobalKey` methods to the base BagOStuff class.
These methods are not static to allow for BagOStuff types which require
a configured instance to know the underlying storage engine's key semantics.
* Make wfMemcKey() and wfGlobalCacheKey() delegate to these methods on the main
ObjectCache instance.
Change-Id: Ib7fc2f939be3decfa97f66af8c2431c51039905f
* Callers of get() no longer have to contend with
the annoying $casToken parameter, which is there
but totally unusable to non-BagOStuff code.
* The default get() now delegates to doGet(),
which callers must implement instead. They can
ignore the overhead of generating $casToken if
they do not implement cas(), which applies to
callers that use the stock merge(). If cas() is
used for merge(), then getWithToken() must be
implemented.
* Also add BagOStuff::READ_LATEST to mergeViaCas()
for sanity, as that missing before.
Likewise with mergeViaLock().
Change-Id: I4efce6a9ab4b1eadd2f161dff641004a7239c516
* This lets multiwrite backends upgrade cached items
to higher tiers using UPGRADE_TTL.
* This is useful for memcached/sql tiers or apc/memcached.
Change-Id: I34b30ce8b54f8de36429d48c80f6768aed310272
* This uses a non-blocking $wgMemc lock to reserve the user
name in question. This should prevent two threads from
reaching LOCK IN SHARE MODE and getting stuck on INSERT.
The lock is global to better cover auth plugins.
* This adds a BagOStuff::getScopedLock() convenience method.
It uses less queries than LockManager by being EX only.
* Avoid extra lock attempt in lock() in non-blocking mode.
* Removed (un)lock() HashBagOStuff overrides that made it
behave differently than other caches (wrt to re-entrance).
Bug: T106850
Change-Id: Iecf95206d712367f5d202f76ab0eaa9d7bdabf2b
* Previously it deleted the value it just cached due to a missing suffix,
which would lead to connection spam to get the new lag values.
Change-Id: I1040b2b87d3d4ddd7c368291cab87daf4227c2d0
This class handles caching across distance sites where purges
must reach both. It also aims to make purging more reliable in
the face of network glitches and node consistent hash ejection.
bug: T88492
Change-Id: I686811b3075bf22e2f4de45127e8461e54648ead
The base BagOStuff class and some of the implementations are
not dependent on MediaWiki and can be in the libs folder.
Change-Id: I299f9abb778abc65a70461a2aff3015c02a1f04d
2015-02-25 00:22:50 -08:00
Renamed from includes/objectcache/BagOStuff.php (Browse further)
