Merge commit 'f6d65'

# Conflicts:
#	skins/ArchLinux/ArchLinux.php

1 files changed, 412 insertions, 0 deletions

diff --git a/includes/api/ApiStashEdit.php b/includes/api/ApiStashEdit.php
new file mode 100644
index 00000000..c4b717c7
--- /dev/null
+++ b/includes/api/ApiStashEdit.php
@@ -0,0 +1,412 @@
+<?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;
+	}
+}