And deprecated aliases for the the no namespaced classes.
ReplicatedBagOStuff that already is deprecated isn't moved.
Bug: T353458
Change-Id: Ie01962517e5b53e59b9721e9996d4f1ea95abb51
== Background
Most of this was introduced in commit 5c335f9d77 (I1eb897c2cea3f5b7).
The original motivation was:
* Ensure wrappers like MultiWriteBagOStuff naturally do the right
thing. In practice, makeKey() results are interchangeable, with
the most contrained one (Memcached) also generally used as the first
tier. However, this is not intuitive and may change in the future.
To make it more intuitive, the default implemention became known
as "generic", with proxyCall() responsible for decoding these,
and then re-encoding them with makeKey() from the respective
underlying BagOStuff. This meant that MultiWriteBag would no longer
use the result of the Memcached-formatted cache key and pass it
to SqlBagOStuff.
* Allow extraction of the key group from a given key cache,
for use in statistics.
Both motivations remains valid and addressed after this refactor.
== Change
* Remove boilerplate and indirection around makeKey from a dozen
classes. E.g. copy-paste stubs for makeKey, makeKeyInternal, and
convertGenericKey.
Instead, let BagOStuff::makeKey and ::makeKeyInternal hold the
defaults. I believe this makes the logic easier to find, understand,
and refer to.
The three non-default implementations (Memcached, WinCache, Sql)
now naturally reflect what they are in terms of business logic,
they are a method override.
Introduce a single boolean requireConvertGenericKey() to let the
three non-default implementations signal their need to convert
keys before use.
* Further improve internal consistently of BagOStuff::makeKeyInternal.
The logic of genericKeyFromComponents() was moved up into
BagOStuff::makeKeyInternal. As a result of caling this directly
from BagOStuff::makeKey(), this code now sees $keyspace and $components
as separate arguments. To keep the behaviour the same, we would
have to either unshift $keyspace into $components, or duplicate
the strtr() call to escape it.
Instead, excempt keyspace from escaping. This matches how the most
commonly used BagOStuff implementations (MemcachedBag, and SqlBag)
already worked for 10+ years, thus this does not introduce any new
responsibility on callers. In particular, keyspace (not key group)
is set by MediaWiki core in service wiring to the wiki ID, and so
is not the concern of individual callers anyway.
* Docs: Explain in proxyCall() why this indirection and complexity
exists. It lets wrapping classes decode and re-encode keys.
* Docs: Explain the cross-wiki and local-wiki semantics of makeKey
and makeKeyGlobal, and centralise this and other important docs
about this method in the place with the most eye balls where it is
most likely seen and discovered, namely BagOStuff::makeKey.
Remove partial docs from other places in favour of references to this one.
Previously, there was no particular reason to follow `@see IStoreKeyEncoder`
much less to know that it holds critical that communicate the
responsibility to limit the key group to 48 chars.
* Docs: Consistently refer to the first component as the "key group",
thus unifying what was known as "key class", "collection",
"key collection name", or "collection name".
The term "key group" seems to be what is used by developers in
conversations for this concept, matching WMF on-boarding docs and
WMF's Grafana dashboard for WANObjectCache.
Change-Id: I6b3167cac824d8bd8773bc66c386f41e4d380021
Some subclasses, like APCUBagOStuff, use the whole cache value itself
as the CAS token. Previously, in such cases, an error would be thrown
when the key held a PHP object, and the comparison would fail if the
key held an array that contained an object.
Make RedisBagOStuff and HashBagOStuff return null CAS tokens if the
value is false, to match other subclasses.
Make WinCacheBagOStuff CAS tokens distinguish int and digit strings.
Change-Id: I797f036e53aae7a4fdcb8586fbd4ebdbd7e8bae3
All callers in Wikimedia gerrit repos have since been migrated to
incrWithInit(), which is usually what is desired and is easier to
implement in various backends. Newer memcached versions of the
memcached protocol even support auto-initializing increments
(including an initial TTL) via the 'ma' command. The incr()/decr()
methods currently bloat the interface and subclasses (often with
slow and buggy implementations). These methods are also hard to
implement in a multi-DC store (either extremely slow or racey)
even though callers might assume they handle high concurrency.
Also, force each MediumSpecificBagOStuff subclass to implement
incrWithInit() instead of having some rely on the base method
In mcc.php, add incrWithInit() and simplify parameters, making
it possible to test non-memcached backends.
Change-Id: I53c9c2c839a1e71d5c104913fea0680c30d11108
The apcu_* methods do not accept unix timestamps as expiry values.
Previously, if a unix timestamp, one hour in the future, was passed to
APCUBagOStuff::set(), then the apcu value was set to expire a number of
seconds in the future equal to that unix timestamp (e.g. many years).
Instead, convert absolute expirations to relative expirations (TTLs).
This logic uses the same function as RedisBagOStuff.
Bug: T286260
Change-Id: I6df484eaaed81fa4741a7de1e633e682362ffb85
This is micro-optimization of closure code to avoid binding the closure
to $this where it is not needed.
Created by I25a17fb22b6b669e817317a0f45051ae9c608208
Change-Id: I0ffc6200f6c6693d78a3151cb8cea7dce7c21653
This saves a few bytes in the response size and make it easy
for memcached proxies to distinguish key fetches that are part
of check-and-set cycles from those that are not.
MediumSpecificBagOStuff now requires PASS_BY_REF to fetch CAS
tokens. BagOStuff::merge() and WinCacheBagOStuff::doCas() are
the only callers that need this mode.
Bug: T257003
Change-Id: If91963f58adc4cda94f6d634ee0252a479a0fc5e
This can be used by WANObjectCache or statsd metrics to estimate
the size of objects and network commands without having to do an
extra serialization round.
Change-Id: I7b1b787bba39a21e2e04262e77ee7ae24e88f8ca
Make the default $init value for incrWithInit() be $value.
This is far less suprising and also makes the operation
easier to replicate without conflicts.
Make decr() definitions more explicit since various cache
drivers do not handle negative incr() values (e.g. memcached).
Change-Id: I2b8d642656cc91c841abbd7a55d97eba101b027a
Add MediumSpecificBagOStuff::getValueOrSegmentList() helper method.
Also:
* Use $keysMissing variable correctly in CachedBagOStuff::getMulti()
to avoid extra overhead.
* Optimize mergeViaCas() when the current value matches the new one.
Change-Id: I5c4bd74379bc459216ac0278150ce3aecff3b851
Allow integers to so that incr() and other cases work. This class
now passes all the unit tests again.
Change-Id: Ie7aae36180472a0e913fb8275bccee3fbc6fe7d9
Use it for ApiStashEdit so that large PaserOutput can be stored.
Add flag to allow for value segmentation on set() in BagOStuff.
Also add a flag for immediate deletion of segments on delete().
BagOStuff now has base serialize()/unserialize() methods.
Bug: T204742
Change-Id: I0667a02612526d8ddfd91d5de48b6faa78bd1ab5
Do not hold WinCache locks during merge() callbacks, as that
could be seconds of being blocked (and some callers do not
expect indefinite blocking). Make merge() use the CAS method
which only uses wincache_lock() after callback runs in very
tight getWithToken()/set() cycle.
Make incr() use wincache_lock() since it also is very tight
doGet()/set() cycle with negligable work in between.
Change-Id: I0dde6f62c7e3d4a802470c181570ad4353d0e6ea
This makes it consistent with set() and merge(). Also, one subclass
was already using the field in this manner.
Clean up the code related to WRITE_SYNC in SqlBagOStuff.
Change-Id: I0fb84f4475311889507d3ef98afd4476fb81174f
WinCache incr function adds a number to the value of a key, but
in the process loses the Time To Live of the cache entry. This
fixes such bug.
Bug: T211914
Change-Id: I02889e63b95188b8d5123a9788a020ca3aa7d1b1
Adds MD5 hashing to the generation of keys for WinCache. This
fixes the issue of keys (e.g. sub-headings) longer than 150
characters.
Bug: T210794
Change-Id: Ieabf6b014a0660198077a23760a05564bf268535
I was bored. What? Don't look at me that way.
I mostly targetted mixed tabs and spaces, but others were not spared.
Note that some of the whitespace changes are inside HTML output,
extended regexps or SQL snippets.
Change-Id: Ie206cc946459f6befcfc2d520e35ad3ea3c0f1e0
Mostly places which immediately had a:
if ( !is_callable( $callback ) ) {
throw new Exception(...);
}
check at the beginning of the function.
Change-Id: Ia78663b2231629010816bd1cda8814b996968d1d
* 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
* 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
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/WinCacheBagOStuff.php (Browse further)
