DatabaseError.php

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<?php
class DBError extends MWException {
    public $db;
 
    function __construct( DatabaseBase $db = null, $error ) {
        $this->db = $db;
        parent::__construct( $error );
    }
}
 
class DBExpectedError extends DBError {
    function getText() {
        global $wgShowDBErrorBacktrace;
 
        $s = $this->getTextContent() . "\n";
 
        if ( $wgShowDBErrorBacktrace ) {
            $s .= "Backtrace:\n" . $this->getTraceAsString() . "\n";
        }
 
        return $s;
    }
 
    function getHTML() {
        global $wgShowDBErrorBacktrace;
 
        $s = $this->getHTMLContent();
 
        if ( $wgShowDBErrorBacktrace ) {
            $s .= '<p>Backtrace:</p><pre>' . htmlspecialchars( $this->getTraceAsString() ) . '</pre>';
        }
 
        return $s;
    }
 
    function getPageTitle() {
        return $this->msg( 'databaseerror', 'Database error' );
    }
 
    protected function getTextContent() {
        return $this->getMessage();
    }
 
    protected function getHTMLContent() {
        return '<p>' . nl2br( htmlspecialchars( $this->getTextContent() ) ) . '</p>';
    }
}
 
class DBConnectionError extends DBExpectedError {
    public $error;
 
    function __construct( DatabaseBase $db = null, $error = 'unknown error' ) {
        $msg = 'DB connection error';
 
        if ( trim( $error ) != '' ) {
            $msg .= ": $error";
        } elseif ( $db ) {
            $error = $this->db->getServer();
        }
 
        parent::__construct( $db, $msg );
        $this->error = $error;
    }
 
    function useOutputPage() {
        // Not likely to work
        return false;
    }
 
    function msg( $key, $fallback /*[, params...] */ ) {
        $args = array_slice( func_get_args(), 2 );
 
        if ( $this->useMessageCache() ) {
            return wfMessage( $key, $args )->useDatabase( false )->text();
        } else {
            return wfMsgReplaceArgs( $fallback, $args );
        }
    }
 
    function isLoggable() {
        // Don't send to the exception log, already in dberror log
        return false;
    }
 
    function getHTML() {
        global $wgShowDBErrorBacktrace, $wgShowHostnames, $wgShowSQLErrors;
 
        $sorry = htmlspecialchars( $this->msg(
            'dberr-problems',
            'Sorry! This site is experiencing technical difficulties.'
        ) );
        $again = htmlspecialchars( $this->msg(
            'dberr-again',
            'Try waiting a few minutes and reloading.'
        ) );
 
        if ( $wgShowHostnames || $wgShowSQLErrors ) {
            $info = str_replace(
                '$1', Html::element( 'span', [ 'dir' => 'ltr' ], $this->error ),
                htmlspecialchars( $this->msg( 'dberr-info', '(Cannot access the database: $1)' ) )
            );
        } else {
            $info = htmlspecialchars( $this->msg(
                'dberr-info-hidden',
                '(Cannot access the database)'
            ) );
        }
 
        # No database access
        MessageCache::singleton()->disable();
 
        $html = "<h1>$sorry</h1><p>$again</p><p><small>$info</small></p>";
 
        if ( $wgShowDBErrorBacktrace ) {
            $html .= '<p>Backtrace:</p><pre>' . htmlspecialchars( $this->getTraceAsString() ) . '</pre>';
        }
 
        $html .= '<hr />';
 
        return $html;
    }
 
    protected function getTextContent() {
        global $wgShowHostnames, $wgShowSQLErrors;
 
        if ( $wgShowHostnames || $wgShowSQLErrors ) {
            return $this->getMessage();
        } else {
            return 'DB connection error';
        }
    }
 
    public function reportHTML() {
        global $wgUseFileCache;
 
        // Check whether we can serve a file-cached copy of the page with the error underneath
        if ( $wgUseFileCache ) {
            try {
                $cache = $this->fileCachedPage();
                // Cached version on file system?
                if ( $cache !== null ) {
                    // Hack: extend the body for error messages
                    $cache = str_replace( [ '</html>', '</body>' ], '', $cache );
                    // Add cache notice...
                    $cache .= '<div style="border:1px solid #ffd0d0;padding:1em;">' .
                        htmlspecialchars( $this->msg( 'dberr-cachederror',
                            'This is a cached copy of the requested page, and may not be up to date.' ) ) .
                        '</div>';
 
                    // Output cached page with notices on bottom and re-close body
                    echo "{$cache}<hr />{$this->getHTML()}</body></html>";
 
                    return;
                }
            } catch ( Exception $e ) {
                // Do nothing, just use the default page
            }
        }
 
        // We can't, cough and die in the usual fashion
        parent::reportHTML();
    }
 
    private function fileCachedPage() {
        $context = RequestContext::getMain();
 
        if ( $context->getOutput()->isDisabled() ) {
            // Done already?
            return '';
        }
 
        if ( $context->getTitle() ) {
            // Use the main context's title if we managed to set it
            $t = $context->getTitle()->getPrefixedDBkey();
        } else {
            // Fallback to the raw title URL param. We can't use the Title
            // class is it may hit the interwiki table and give a DB error.
            // We may get a cache miss due to not sanitizing the title though.
            $t = str_replace( ' ', '_', $context->getRequest()->getVal( 'title' ) );
            if ( $t == '' ) { // fallback to main page
                $t = Title::newFromText(
                    $this->msg( 'mainpage', 'Main Page' ) )->getPrefixedDBkey();
            }
        }
 
        $cache = new HTMLFileCache( $t, 'view' );
        if ( $cache->isCached() ) {
            return $cache->fetchText();
        } else {
            return '';
        }
    }
}
 
class DBQueryError extends DBExpectedError {
    public $error, $errno, $sql, $fname;
 
    function __construct( DatabaseBase $db, $error, $errno, $sql, $fname ) {
        if ( $db->wasConnectionError( $errno ) ) {
            $message = "A connection error occured. \n" .
                "Query: $sql\n" .
                "Function: $fname\n" .
                "Error: $errno $error\n";
        } else {
            $message = "A database error has occurred. Did you forget to run " .
                "maintenance/update.php after upgrading?  See: " .
                "https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script\n" .
                "Query: $sql\n" .
                "Function: $fname\n" .
                "Error: $errno $error\n";
        }
        parent::__construct( $db, $message );
 
        $this->error = $error;
        $this->errno = $errno;
        $this->sql = $sql;
        $this->fname = $fname;
    }
 
    function getPageTitle() {
        return $this->msg( 'databaseerror', 'Database error' );
    }
 
    protected function getHTMLContent() {
        $key = 'databaseerror-text';
        $s = Html::element( 'p', [], $this->msg( $key, $this->getFallbackMessage( $key ) ) );
 
        $details = $this->getTechnicalDetails();
        if ( $details ) {
            $s .= '<ul>';
            foreach ( $details as $key => $detail ) {
                $s .= str_replace(
                    '$1', call_user_func_array( 'Html::element', $detail ),
                    Html::element( 'li', [],
                        $this->msg( $key, $this->getFallbackMessage( $key ) )
                    )
                );
            }
            $s .= '</ul>';
        }
 
        return $s;
    }
 
    protected function getTextContent() {
        $key = 'databaseerror-textcl';
        $s = $this->msg( $key, $this->getFallbackMessage( $key ) ) . "\n";
 
        foreach ( $this->getTechnicalDetails() as $key => $detail ) {
            $s .= $this->msg( $key, $this->getFallbackMessage( $key ), $detail[2] ) . "\n";
        }
 
        return $s;
    }
 
    protected function getTechnicalDetails() {
        global $wgShowHostnames, $wgShowSQLErrors;
 
        $attribs = [ 'dir' => 'ltr' ];
        $details = [];
 
        if ( $wgShowSQLErrors ) {
            $details['databaseerror-query'] = [
                'div', [ 'class' => 'mw-code' ] + $attribs, $this->sql ];
        }
 
        if ( $wgShowHostnames || $wgShowSQLErrors ) {
            $errorMessage = $this->errno . ' ' . $this->error;
            $details['databaseerror-function'] = [ 'code', $attribs, $this->fname ];
            $details['databaseerror-error'] = [ 'samp', $attribs, $errorMessage ];
        }
 
        return $details;
    }
 
    private function getFallbackMessage( $key ) {
        $messages = [
            'databaseerror-text' => 'A database query error has occurred.
This may indicate a bug in the software.',
            'databaseerror-textcl' => 'A database query error has occurred.',
            'databaseerror-query' => 'Query: $1',
            'databaseerror-function' => 'Function: $1',
            'databaseerror-error' => 'Error: $1',
        ];
 
        return $messages[$key];
    }
}
 
class DBUnexpectedError extends DBError {
}
 
class DBReadOnlyError extends DBExpectedError {
    function getPageTitle() {
        return $this->msg( 'readonly', 'Database is locked' );
    }
}
 
class DBTransactionError extends DBExpectedError {
}