IXR_Message::parse()

45    function parse()46    {47        if ( ! function_exists( 'xml_parser_create' ) ) {48            trigger_error( __( "PHP's XML extension is not available. Please contact your hosting provider to enable PHP's XML extension." ) );49            return false;50        }51 52        // first remove the XML declaration53        // merged from WP #10698 - this method avoids the RAM usage of preg_replace on very large messages54        $header = preg_replace( '/<\?xml.*?\?'.'>/s', '', substr( $this->message, 0, 100 ), 1 );55        $this->message = trim( substr_replace( $this->message, $header, 0, 100 ) );56        if ( '' == $this->message ) {57            return false;58        }59 60        // Then remove the DOCTYPE61        $header = preg_replace( '/^<!DOCTYPE[^>]*+>/i', '', substr( $this->message, 0, 200 ), 1 );62        $this->message = trim( substr_replace( $this->message, $header, 0, 200 ) );63        if ( '' == $this->message ) {64            return false;65        }66 67        // Check that the root tag is valid68        $root_tag = substr( $this->message, 0, strcspn( substr( $this->message, 0, 20 ), "> \t\r\n" ) );69        if ( '<!DOCTYPE' === strtoupper( $root_tag ) ) {70            return false;71        }72        if ( ! in_array( $root_tag, array( '<methodCall', '<methodResponse', '<fault' ) ) ) {73            return false;74        }75 76        // Bail if there are too many elements to parse77        $element_limit = 30000;78        if ( function_exists( 'apply_filters' ) ) {79            /**80             * Filters the number of elements to parse in an XML-RPC response.81             *82             * @since 4.0.083             *84             * @param int $element_limit Default elements limit.85             */86            $element_limit = apply_filters( 'xmlrpc_element_limit', $element_limit );87        }88        if ( $element_limit && 2 * $element_limit < substr_count( $this->message, '<' ) ) {89            return false;90        }91 92        $this->_parser = xml_parser_create();93        // Set XML parser to take the case of tags in to account94        xml_parser_set_option($this->_parser, XML_OPTION_CASE_FOLDING, false);95        // Set XML parser callback functions96        xml_set_element_handler($this->_parser, array($this, 'tag_open'), array($this, 'tag_close'));97        xml_set_character_data_handler($this->_parser, array($this, 'cdata'));98 99        // 256Kb, parse in chunks to avoid the RAM usage on very large messages100        $chunk_size = 262144;101 102        /**103         * Filters the chunk size that can be used to parse an XML-RPC response message.104         *105         * @since 4.4.0106         *107         * @param int $chunk_size Chunk size to parse in bytes.108         */109        $chunk_size = apply_filters( 'xmlrpc_chunk_parsing_size', $chunk_size );110 111        $final = false;112 113        do {114            if (strlen($this->message) <= $chunk_size) {115                $final = true;116            }117 118            $part = substr($this->message, 0, $chunk_size);119            $this->message = substr($this->message, $chunk_size);120 121            if (!xml_parse($this->_parser, $part, $final)) {122                if (PHP_VERSION_ID < 80000) { // xml_parser_free() has no effect as of PHP 8.0.123                    xml_parser_free($this->_parser);124                }