MediaWiki  1.28.1
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1 <?php
27 # Obsolete aliases
28 define( 'DB_SLAVE', -1 );
34 define( 'LIST_COMMA', IDatabase::LIST_COMMA );
35 define( 'LIST_AND', IDatabase::LIST_AND );
36 define( 'LIST_SET', IDatabase::LIST_SET );
37 define( 'LIST_NAMES', IDatabase::LIST_NAMES );
38 define( 'LIST_OR', IDatabase::LIST_OR );
44 define( 'NS_MEDIA', -2 );
45 define( 'NS_SPECIAL', -1 );
56 define( 'NS_MAIN', 0 );
57 define( 'NS_TALK', 1 );
58 define( 'NS_USER', 2 );
59 define( 'NS_USER_TALK', 3 );
60 define( 'NS_PROJECT', 4 );
61 define( 'NS_PROJECT_TALK', 5 );
62 define( 'NS_FILE', 6 );
63 define( 'NS_FILE_TALK', 7 );
64 define( 'NS_MEDIAWIKI', 8 );
65 define( 'NS_MEDIAWIKI_TALK', 9 );
66 define( 'NS_TEMPLATE', 10 );
67 define( 'NS_TEMPLATE_TALK', 11 );
68 define( 'NS_HELP', 12 );
69 define( 'NS_HELP_TALK', 13 );
70 define( 'NS_CATEGORY', 14 );
71 define( 'NS_CATEGORY_TALK', 15 );
83 define( 'NS_IMAGE', NS_FILE );
87 define( 'NS_IMAGE_TALK', NS_FILE_TALK );
93 define( 'CACHE_ANYTHING', -1 ); // Use anything, as long as it works
94 define( 'CACHE_NONE', 0 ); // Do not cache
95 define( 'CACHE_DB', 1 ); // Store cache objects in the DB
96 define( 'CACHE_MEMCACHED', 2 ); // MemCached, must specify servers in $wgMemCacheServers
97 define( 'CACHE_ACCEL', 3 ); // APC, XCache or WinCache
100 require_once __DIR__ . '/libs/mime/defines.php';
105 define( 'AV_NO_VIRUS', 0 ); # scan ok, no virus found
106 define( 'AV_VIRUS_FOUND', 1 ); # virus found!
107 define( 'AV_SCAN_ABORTED', -1 ); # scan aborted, the file is probably immune
108 define( 'AV_SCAN_FAILED', false ); # scan failed (scanner not found or error in scanner)
116 define( 'ALF_PRELOAD_LINKS', 1 ); // unused
117 define( 'ALF_PRELOAD_EXISTENCE', 2 ); // unused
118 define( 'ALF_NO_LINK_LOCK', 4 ); // unused
119 define( 'ALF_NO_BLOCK_LOCK', 8 ); // unused
126 define( 'MW_DATE_DEFAULT', 'default' );
127 define( 'MW_DATE_MDY', 'mdy' );
128 define( 'MW_DATE_DMY', 'dmy' );
129 define( 'MW_DATE_YMD', 'ymd' );
130 define( 'MW_DATE_ISO', 'ISO 8601' );
136 define( 'RC_EDIT', 0 );
137 define( 'RC_NEW', 1 );
138 define( 'RC_LOG', 3 );
139 define( 'RC_EXTERNAL', 5 );
140 define( 'RC_CATEGORIZE', 6 );
146 define( 'EDIT_NEW', 1 );
147 define( 'EDIT_UPDATE', 2 );
148 define( 'EDIT_MINOR', 4 );
149 define( 'EDIT_SUPPRESS_RC', 8 );
150 define( 'EDIT_FORCE_BOT', 16 );
151 define( 'EDIT_DEFER_UPDATES', 32 ); // Unused since 1.27
152 define( 'EDIT_AUTOSUMMARY', 64 );
153 define( 'EDIT_INTERNAL', 128 );
159 require_once __DIR__ . '/libs/rdbms/defines.php';
164 require_once __DIR__ . '/compat/normal/UtfNormalDefines.php';
188 define( 'OT_HTML', 1 );
189 define( 'OT_WIKI', 2 );
190 define( 'OT_PREPROCESS', 3 );
191 define( 'OT_MSG', 3 ); // b/c alias for OT_PREPROCESS
192 define( 'OT_PLAIN', 4 );
201 define( 'SFH_NO_HASH', 1 );
202 define( 'SFH_OBJECT_ARGS', 2 );
209 define( 'APCOND_EDITCOUNT', 1 );
210 define( 'APCOND_AGE', 2 );
211 define( 'APCOND_EMAILCONFIRMED', 3 );
212 define( 'APCOND_INGROUPS', 4 );
213 define( 'APCOND_ISIP', 5 );
214 define( 'APCOND_IPINRANGE', 6 );
215 define( 'APCOND_AGE_FROM_EDIT', 7 );
216 define( 'APCOND_BLOCKED', 8 );
217 define( 'APCOND_ISBOT', 9 );
223 define( 'PROTO_HTTP', 'http://' );
224 define( 'PROTO_HTTPS', 'https://' );
225 define( 'PROTO_RELATIVE', '//' );
226 define( 'PROTO_CURRENT', null );
227 define( 'PROTO_CANONICAL', 1 );
228 define( 'PROTO_INTERNAL', 2 );
239 define( 'CONTENT_MODEL_WIKITEXT', 'wikitext' );
240 define( 'CONTENT_MODEL_JAVASCRIPT', 'javascript' );
241 define( 'CONTENT_MODEL_CSS', 'css' );
242 define( 'CONTENT_MODEL_TEXT', 'text' );
243 define( 'CONTENT_MODEL_JSON', 'json' );
253 // wikitext
254 define( 'CONTENT_FORMAT_WIKITEXT', 'text/x-wiki' );
255 // for js pages
256 define( 'CONTENT_FORMAT_JAVASCRIPT', 'text/javascript' );
257 // for css pages
258 define( 'CONTENT_FORMAT_CSS', 'text/css' );
259 // for future use, e.g. with some plain-html messages.
260 define( 'CONTENT_FORMAT_TEXT', 'text/plain' );
261 // for future use, e.g. with some plain-html messages.
262 define( 'CONTENT_FORMAT_HTML', 'text/html' );
263 // for future use with the api and for extensions
264 define( 'CONTENT_FORMAT_SERIALIZED', 'application/vnd.php.serialized' );
265 // for future use with the api, and for use by extensions
266 define( 'CONTENT_FORMAT_JSON', 'application/json' );
267 // for future use with the api, and for use by extensions
268 define( 'CONTENT_FORMAT_XML', 'application/xml' );
274 define( 'SHELL_MAX_ARG_STRLEN', '100000' );
#define the
table suitable for use with IDatabase::select()
We use the convention $dbr for read and $dbw for write to help you keep track of whether the database object is a the world will explode Or to be a subsequent write query which succeeded on the master may fail when replicated to the slave due to a unique key collision Replication on the slave will stop and it may take hours to repair the database and get it back online Setting read_only in my cnf on the slave will avoid this but given the dire we prefer to have as many checks as possible We provide a but the wrapper functions like please read the documentation for except in special pages derived from QueryPage It s a common pitfall for new developers to submit code containing SQL queries which examine huge numbers of rows Remember that COUNT * is(N), counting rows in atable is like counting beans in a bucket.------------------------------------------------------------------------Replication------------------------------------------------------------------------The largest installation of MediaWiki, Wikimedia, uses a large set ofslave MySQL servers replicating writes made to a master MySQL server.Itis important to understand the issues associated with this setup if youwant to write code destined for Wikipedia.It's often the case that the best algorithm to use for a given taskdepends on whether or not replication is in use.Due to our unabashedWikipedia-centrism, we often just use the replication-friendly version, but if you like, you can use wfGetLB() ->getServerCount() > 1 tocheck to see if replication is in use.===Lag===Lag primarily occurs when large write queries are sent to the master.Writes on the master are executed in parallel, but they are executed inserial when they are replicated to the slaves.The master writes thequery to the binlog when the transaction is committed.The slaves pollthe binlog and start executing the query as soon as it appears.They canservice reads while they are performing a write query, but will not readanything more from the binlog and thus will perform no more writes.Thismeans that if the write query runs for a long time, the slaves will lagbehind the master for the time it takes for the write query to complete.Lag can be exacerbated by high read load.MediaWiki's load balancer willstop sending reads to a slave when it is lagged by more than 30 seconds.If the load ratios are set incorrectly, or if there is too much loadgenerally, this may lead to a slave permanently hovering around 30seconds lag.If all slaves are lagged by more than 30 seconds, MediaWiki will stopwriting to the database.All edits and other write operations will berefused, with an error returned to the user.This gives the slaves achance to catch up.Before we had this mechanism, the slaves wouldregularly lag by several minutes, making review of recent editsdifficult.In addition to this, MediaWiki attempts to ensure that the user seesevents occurring on the wiki in chronological order.A few seconds of lagcan be tolerated, as long as the user sees a consistent picture fromsubsequent requests.This is done by saving the master binlog positionin the session, and then at the start of each request, waiting for theslave to catch up to that position before doing any reads from it.Ifthis wait times out, reads are allowed anyway, but the request isconsidered to be in"lagged slave mode".Lagged slave mode can bechecked by calling wfGetLB() ->getLaggedSlaveMode().The onlypractical consequence at present is a warning displayed in the pagefooter.===Lag avoidance===To avoid excessive lag, queries which write large numbers of rows shouldbe split up, generally to write one row at a time.Multi-row INSERT...SELECT queries are the worst offenders should be avoided altogether.Instead do the select first and then the insert.===Working with lag===Despite our best efforts, it's not practical to guarantee a low-lagenvironment.Lag will usually be less than one second, but mayoccasionally be up to 30 seconds.For scalability, it's very importantto keep load on the master low, so simply sending all your queries tothe master is not the answer.So when you have a genuine need forup-to-date data, the following approach is advised:1) Do a quick query to the master for a sequence number or timestamp 2) Run the full query on the slave and check if it matches the data you gotfrom the master 3) If it doesn't, run the full query on the masterTo avoid swamping the master every time the slaves lag, use of thisapproach should be kept to a minimum.In most cases you should just readfrom the slave and let the user deal with the delay.------------------------------------------------------------------------Lock contention------------------------------------------------------------------------Due to the high write rate on Wikipedia(and some other wikis), MediaWiki developers need to be very careful to structure their writesto avoid long-lasting locks.By default, MediaWiki opens a transactionat the first query, and commits it before the output is sent.Locks willbe held from the time when the query is done until the commit.So youcan reduce lock time by doing as much processing as possible before youdo your write queries.Often this approach is not good enough, and it becomes necessary toenclose small groups of queries in their own transaction.Use thefollowing syntax:$dbw=wfGetDB(DB_MASTER
Definition: Defines.php:37
null for the local wiki Added in
Definition: hooks.txt:1555
Apache License January http
We ve cleaned up the code here by removing clumps of infrequently used code and moving them off somewhere else It s much easier for someone working with this code to see what s _really_ going and make changes or fix bugs In we can take all the code that deals with the little used title reversing we can concentrate it all in an extension file
Definition: hooks.txt:93
const LIST_AND
Definition: Defines.php:35
Definition: Defines.php:34
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such and we might be restricted by PHP settings such as safe mode or open_basedir We cannot assume that the software even has read access anywhere useful Many shared hosts run all users web applications under the same so they can t rely on Unix and must forbid reads to even standard directories like tmp lest users read each others files We cannot assume that the user has the ability to install or run any programs not written as web accessible PHP scripts Since anything that works on cheap shared hosting will work if you have shell or root access MediaWiki s design is based around catering to the lowest common denominator Although we support higher end setups as the way many things work by default is tailored toward shared hosting These defaults are unconventional from the point of view of normal(non-web) applications--they might conflict with distributors'policies
const NS_FILE
Definition: Defines.php:62
Definition: Defines.php:63
const LIST_SET
Definition: Defines.php:36
this hook is for auditing only RecentChangesLinked and Watchlist RecentChangesLinked and Watchlist e g Watchlist removed from all revisions and log entries to which it was applied This gives extensions a chance to take it off their books as the deletion has already been partly carried out by this point or something similar the user will be unable to create the tag set and then return false from the hook function Ensure you consume the ChangeTagAfterDelete hook to carry out custom deletion actions as context called by AbstractContent::getParserOutput May be used to override the normal model specific rendering of page content as context as context the output can only depend on parameters provided to this hook not on global state indicating whether full HTML should be generated If generation of HTML may be but other information should still be present in the ParserOutput object to manipulate or replace but no entry for that model exists in $wgContentHandlers if desired whether it is OK to use $contentModel on $title Handler functions that modify $ok should generally return false to prevent further hooks from further modifying $ok inclusive false for true for descending in case the handler function wants to provide a converted Content object Note that $result getContentModel() must return $toModel. 'CustomEditor'$rcid is used in generating this variable which contains information about the new such as the revision s whether the revision was marked as a minor edit or not
Definition: hooks.txt:1156
const LIST_OR
Definition: Defines.php:38
design txt This is a brief overview of the new design More thorough and up to date information is available on the documentation wiki at https
Definition: design.txt:12