Current File : //data/www_bck/varak.net_bck/havranipapuce.varak.net/includes/api/ApiStashEdit.php
<?php
/**
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @author Aaron Schulz
*/
/**
* Prepare and edit in shared cache so that it can be reused on edit
*
* This endpoint can be called via AJAX as the user focuses on the edit
* summary box. By the time of submission, the parse may have already
* finished, and can be immediately used on page save. Certain parser
* functions like {{REVISIONID}} or {{CURRENTTIME}} may cause the cache
* to not be used on edit. Template and files used are check for changes
* since the output was generated. The cache TTL is also kept low for sanity.
*
* @ingroup API
* @since 1.25
*/
class ApiStashEdit extends ApiBase {
const ERROR_NONE = 'stashed';
const ERROR_PARSE = 'error_parse';
const ERROR_CACHE = 'error_cache';
const ERROR_UNCACHEABLE = 'uncacheable';
public function execute() {
global $wgMemc;
$user = $this->getUser();
$params = $this->extractRequestParams();
$page = $this->getTitleOrPageId( $params );
$title = $page->getTitle();
if ( !ContentHandler::getForModelID( $params['contentmodel'] )
->isSupportedFormat( $params['contentformat'] )
) {
$this->dieUsage( "Unsupported content model/format", 'badmodelformat' );
}
// Trim and fix newlines so the key SHA1's match (see RequestContext::getText())
$text = rtrim( str_replace( "\r\n", "\n", $params['text'] ) );
$textContent = ContentHandler::makeContent(
$text, $title, $params['contentmodel'], $params['contentformat'] );
$page = WikiPage::factory( $title );
if ( $page->exists() ) {
// Page exists: get the merged content with the proposed change
$baseRev = Revision::newFromPageId( $page->getId(), $params['baserevid'] );
if ( !$baseRev ) {
$this->dieUsage( "No revision ID {$params['baserevid']}", 'missingrev' );
}
$currentRev = $page->getRevision();
if ( !$currentRev ) {
$this->dieUsage( "No current revision of page ID {$page->getId()}", 'missingrev' );
}
// Merge in the new version of the section to get the proposed version
$editContent = $page->replaceSectionAtRev(
$params['section'],
$textContent,
$params['sectiontitle'],
$baseRev->getId()
);
if ( !$editContent ) {
$this->dieUsage( "Could not merge updated section.", 'replacefailed' );
}
if ( $currentRev->getId() == $baseRev->getId() ) {
// Base revision was still the latest; nothing to merge
$content = $editContent;
} else {
// Merge the edit into the current version
$baseContent = $baseRev->getContent();
$currentContent = $currentRev->getContent();
if ( !$baseContent || !$currentContent ) {
$this->dieUsage( "Missing content for page ID {$page->getId()}", 'missingrev' );
}
$handler = ContentHandler::getForModelID( $baseContent->getModel() );
$content = $handler->merge3( $baseContent, $editContent, $currentContent );
}
} else {
// New pages: use the user-provided content model
$content = $textContent;
}
if ( !$content ) { // merge3() failed
$this->getResult()->addValue( null,
$this->getModuleName(), array( 'status' => 'editconflict' ) );
return;
}
// The user will abort the AJAX request by pressing "save", so ignore that
ignore_user_abort( true );
// Get a key based on the source text, format, and user preferences
$key = self::getStashKey( $title, $content, $user );
// De-duplicate requests on the same key
if ( $user->pingLimiter( 'stashedit' ) ) {
$status = 'ratelimited';
} elseif ( $wgMemc->lock( $key, 0, 30 ) ) {
$unlocker = new ScopedCallback( function() use ( $key ) {
global $wgMemc;
$wgMemc->unlock( $key );
} );
$status = self::parseAndStash( $page, $content, $user );
} else {
$status = 'busy';
}
$this->getResult()->addValue( null, $this->getModuleName(), array( 'status' => $status ) );
}
/**
* @param WikiPage $page
* @param Content $content
* @param User $user
* @return integer ApiStashEdit::ERROR_* constant
* @since 1.25
*/
public static function parseAndStash( WikiPage $page, Content $content, User $user ) {
global $wgMemc;
$format = $content->getDefaultFormat();
$editInfo = $page->prepareContentForEdit( $content, null, $user, $format, false );
if ( $editInfo && $editInfo->output ) {
$key = self::getStashKey( $page->getTitle(), $content, $user );
list( $stashInfo, $ttl ) = self::buildStashValue(
$editInfo->pstContent, $editInfo->output, $editInfo->timestamp
);
if ( $stashInfo ) {
$ok = $wgMemc->set( $key, $stashInfo, $ttl );
if ( $ok ) {
wfDebugLog( 'StashEdit', "Cached parser output for key '$key'." );
return self::ERROR_NONE;
} else {
wfDebugLog( 'StashEdit', "Failed to cache parser output for key '$key'." );
return self::ERROR_CACHE;
}
} else {
wfDebugLog( 'StashEdit', "Uncacheable parser output for key '$key'." );
return self::ERROR_UNCACHEABLE;
}
}
return self::ERROR_PARSE;
}
/**
* Attempt to cache PST content and corresponding parser output in passing
*
* This method can be called when the output was already generated for other
* reasons. Parsing should not be done just to call this method, however.
* $pstOpts must be that of the user doing the edit preview. If $pOpts does
* not match the options of WikiPage::makeParserOptions( 'canonical' ), this
* will do nothing. Provided the values are cacheable, they will be stored
* in memcached so that final edit submission might make use of them.
*
* @param Article|WikiPage $page Page title
* @param Content $content Proposed page content
* @param Content $pstContent The result of preSaveTransform() on $content
* @param ParserOutput $pOut The result of getParserOutput() on $pstContent
* @param ParserOptions $pstOpts Options for $pstContent (MUST be for prospective author)
* @param ParserOptions $pOpts Options for $pOut
* @param string $timestamp TS_MW timestamp of parser output generation
* @return bool Success
*/
public static function stashEditFromPreview(
Page $page, Content $content, Content $pstContent, ParserOutput $pOut,
ParserOptions $pstOpts, ParserOptions $pOpts, $timestamp
) {
global $wgMemc;
// getIsPreview() controls parser function behavior that references things
// like user/revision that don't exists yet. The user/text should already
// be set correctly by callers, just double check the preview flag.
if ( !$pOpts->getIsPreview() ) {
return false; // sanity
} elseif ( $pOpts->getIsSectionPreview() ) {
return false; // short-circuit (need the full content)
}
// PST parser options are for the user (handles signatures, etc...)
$user = $pstOpts->getUser();
// Get a key based on the source text, format, and user preferences
$key = self::getStashKey( $page->getTitle(), $content, $user );
// Parser output options must match cannonical options.
// Treat some options as matching that are different but don't matter.
$canonicalPOpts = $page->makeParserOptions( 'canonical' );
$canonicalPOpts->setIsPreview( true ); // force match
$canonicalPOpts->setTimestamp( $pOpts->getTimestamp() ); // force match
if ( !$pOpts->matches( $canonicalPOpts ) ) {
wfDebugLog( 'StashEdit', "Uncacheable preview output for key '$key' (options)." );
return false;
}
// Build a value to cache with a proper TTL
list( $stashInfo, $ttl ) = self::buildStashValue( $pstContent, $pOut, $timestamp );
if ( !$stashInfo ) {
wfDebugLog( 'StashEdit', "Uncacheable parser output for key '$key' (rev/TTL)." );
return false;
}
$ok = $wgMemc->set( $key, $stashInfo, $ttl );
if ( !$ok ) {
wfDebugLog( 'StashEdit', "Failed to cache preview parser output for key '$key'." );
} else {
wfDebugLog( 'StashEdit', "Cached preview output for key '$key'." );
}
return $ok;
}
/**
* Check that a prepared edit is in cache and still up-to-date
*
* This method blocks if the prepared edit is already being rendered,
* waiting until rendering finishes before doing final validity checks.
*
* The cache is rejected if template or file changes are detected.
* Note that foreign template or file transclusions are not checked.
*
* The result is a map (pstContent,output,timestamp) with fields
* extracted directly from WikiPage::prepareContentForEdit().
*
* @param Title $title
* @param Content $content
* @param User $user User to get parser options from
* @return stdClass|bool Returns false on cache miss
*/
public static function checkCache( Title $title, Content $content, User $user ) {
global $wgMemc;
$key = self::getStashKey( $title, $content, $user );
$editInfo = $wgMemc->get( $key );
if ( !is_object( $editInfo ) ) {
$start = microtime( true );
// We ignore user aborts and keep parsing. Block on any prior parsing
// so as to use it's results and make use of the time spent parsing.
if ( $wgMemc->lock( $key, 30, 30 ) ) {
$editInfo = $wgMemc->get( $key );
$wgMemc->unlock( $key );
}
$sec = microtime( true ) - $start;
if ( $sec > .01 ) {
wfDebugLog( 'StashEdit', "Waited $sec seconds on '$key'." );
}
}
if ( !is_object( $editInfo ) || !$editInfo->output ) {
wfDebugLog( 'StashEdit', "No cache value for key '$key'." );
return false;
}
$time = wfTimestamp( TS_UNIX, $editInfo->output->getTimestamp() );
if ( ( time() - $time ) <= 3 ) {
wfDebugLog( 'StashEdit', "Timestamp-based cache hit for key '$key'." );
return $editInfo; // assume nothing changed
}
$dbr = wfGetDB( DB_SLAVE );
// Check that no templates used in the output changed...
$cWhr = array(); // conditions to find changes/creations
$dWhr = array(); // conditions to find deletions
foreach ( $editInfo->output->getTemplateIds() as $ns => $stuff ) {
foreach ( $stuff as $dbkey => $revId ) {
$cWhr[] = array( 'page_namespace' => $ns, 'page_title' => $dbkey,
'page_latest != ' . intval( $revId ) );
$dWhr[] = array( 'page_namespace' => $ns, 'page_title' => $dbkey );
}
}
$change = $dbr->selectField( 'page', '1', $dbr->makeList( $cWhr, LIST_OR ), __METHOD__ );
$n = $dbr->selectField( 'page', 'COUNT(*)', $dbr->makeList( $dWhr, LIST_OR ), __METHOD__ );
if ( $change || $n != count( $dWhr ) ) {
wfDebugLog( 'StashEdit', "Stale cache for key '$key'; template changed." );
return false;
}
// Check that no files used in the output changed...
$cWhr = array(); // conditions to find changes/creations
$dWhr = array(); // conditions to find deletions
foreach ( $editInfo->output->getFileSearchOptions() as $name => $options ) {
$cWhr[] = array( 'img_name' => $dbkey,
'img_sha1 != ' . $dbr->addQuotes( strval( $options['sha1'] ) ) );
$dWhr[] = array( 'img_name' => $dbkey );
}
$change = $dbr->selectField( 'image', '1', $dbr->makeList( $cWhr, LIST_OR ), __METHOD__ );
$n = $dbr->selectField( 'image', 'COUNT(*)', $dbr->makeList( $dWhr, LIST_OR ), __METHOD__ );
if ( $change || $n != count( $dWhr ) ) {
wfDebugLog( 'StashEdit', "Stale cache for key '$key'; file changed." );
return false;
}
wfDebugLog( 'StashEdit', "Cache hit for key '$key'." );
return $editInfo;
}
/**
* Get the temporary prepared edit stash key for a user
*
* This key can be used for caching prepared edits provided:
* - a) The $user was used for PST options
* - b) The parser output was made from the PST using cannonical matching options
*
* @param Title $title
* @param Content $content
* @param User $user User to get parser options from
* @return string
*/
protected static function getStashKey( Title $title, Content $content, User $user ) {
$hash = sha1( implode( ':', array(
$content->getModel(),
$content->getDefaultFormat(),
sha1( $content->serialize( $content->getDefaultFormat() ) ),
$user->getId() ?: md5( $user->getName() ), // account for user parser options
$user->getId() ? $user->getTouched() : '-' // handle preference change races
) ) );
return wfMemcKey( 'prepared-edit', md5( $title->getPrefixedDBkey() ), $hash );
}
/**
* Build a value to store in memcached based on the PST content and parser output
*
* This makes a simple version of WikiPage::prepareContentForEdit() as stash info
*
* @param Content $pstContent
* @param ParserOutput $parserOutput
* @param string $timestamp TS_MW
* @return array (stash info array, TTL in seconds) or (null, 0)
*/
protected static function buildStashValue(
Content $pstContent, ParserOutput $parserOutput, $timestamp
) {
// If an item is renewed, mind the cache TTL determined by config and parser functions
$since = time() - wfTimestamp( TS_UNIX, $parserOutput->getTimestamp() );
$ttl = min( $parserOutput->getCacheExpiry() - $since, 5 * 60 );
if ( $ttl > 0 && !$parserOutput->getFlag( 'vary-revision' ) ) {
// Only store what is actually needed
$stashInfo = (object)array(
'pstContent' => $pstContent,
'output' => $parserOutput,
'timestamp' => $timestamp
);
return array( $stashInfo, $ttl );
}
return array( null, 0 );
}
public function getAllowedParams() {
return array(
'title' => array(
ApiBase::PARAM_TYPE => 'string',
ApiBase::PARAM_REQUIRED => true
),
'section' => array(
ApiBase::PARAM_TYPE => 'string',
),
'sectiontitle' => array(
ApiBase::PARAM_TYPE => 'string'
),
'text' => array(
ApiBase::PARAM_TYPE => 'string',
ApiBase::PARAM_REQUIRED => true
),
'contentmodel' => array(
ApiBase::PARAM_TYPE => ContentHandler::getContentModels(),
ApiBase::PARAM_REQUIRED => true
),
'contentformat' => array(
ApiBase::PARAM_TYPE => ContentHandler::getAllContentFormats(),
ApiBase::PARAM_REQUIRED => true
),
'baserevid' => array(
ApiBase::PARAM_TYPE => 'integer',
ApiBase::PARAM_REQUIRED => true
)
);
}
function needsToken() {
return 'csrf';
}
function mustBePosted() {
return true;
}
function isInternal() {
return true;
}
}
Mini Shell