Export.php 40.3 KB
Newer Older
Hamza Arfaoui's avatar
Hamza Arfaoui committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101
<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
 * function for the main export logic
 *
 * @package PhpMyAdmin
 */
namespace PhpMyAdmin;

use PhpMyAdmin\Core;
use PhpMyAdmin\Encoding;
use PhpMyAdmin\Message;
use PhpMyAdmin\Plugins;
use PhpMyAdmin\Plugins\ExportPlugin;
use PhpMyAdmin\Sanitize;
use PhpMyAdmin\Table;
use PhpMyAdmin\Url;
use PhpMyAdmin\Util;
use PhpMyAdmin\ZipExtension;

/**
 * PhpMyAdmin\Export class
 *
 * @package PhpMyAdmin
 */
class Export
{
    /**
     * Sets a session variable upon a possible fatal error during export
     *
     * @return void
     */
    public static function shutdown()
    {
        $error = error_get_last();
        if ($error != null && mb_strpos($error['message'], "execution time")) {
            //set session variable to check if there was error while exporting
            $_SESSION['pma_export_error'] = $error['message'];
        }
    }

    /**
     * Detect ob_gzhandler
     *
     * @return bool
     */
    public static function isGzHandlerEnabled()
    {
        return in_array('ob_gzhandler', ob_list_handlers());
    }

    /**
     * Detect whether gzencode is needed; it might not be needed if
     * the server is already compressing by itself
     *
     * @return bool Whether gzencode is needed
     */
    public static function gzencodeNeeded()
    {
        /*
         * We should gzencode only if the function exists
         * but we don't want to compress twice, therefore
         * gzencode only if transparent compression is not enabled
         * and gz compression was not asked via $cfg['OBGzip']
         * but transparent compression does not apply when saving to server
         */
        $chromeAndGreaterThan43 = PMA_USR_BROWSER_AGENT == 'CHROME'
            && PMA_USR_BROWSER_VER >= 43; // see bug #4942

        if (function_exists('gzencode')
            && ((! ini_get('zlib.output_compression')
            && ! self::isGzHandlerEnabled())
            || $GLOBALS['save_on_server']
            || $chromeAndGreaterThan43)
        ) {
            return true;
        }

        return false;
    }

    /**
     * Output handler for all exports, if needed buffering, it stores data into
     * $dump_buffer, otherwise it prints them out.
     *
     * @param string $line the insert statement
     *
     * @return bool Whether output succeeded
     */
    public static function outputHandler($line)
    {
        global $time_start, $dump_buffer, $dump_buffer_len, $save_filename;

        // Kanji encoding convert feature
        if ($GLOBALS['output_kanji_conversion']) {
            $line = Encoding::kanjiStrConv(
                $line,
                $GLOBALS['knjenc'],
                isset($GLOBALS['xkana']) ? $GLOBALS['xkana'] : ''
            );
        }

        // If we have to buffer data, we will perform everything at once at the end
        if ($GLOBALS['buffer_needed']) {

            $dump_buffer .= $line;
            if ($GLOBALS['onfly_compression']) {

                $dump_buffer_len += strlen($line);

                if ($dump_buffer_len > $GLOBALS['memory_limit']) {
                    if ($GLOBALS['output_charset_conversion']) {
                        $dump_buffer = Encoding::convertString(
                            'utf-8',
                            $GLOBALS['charset'],
                            $dump_buffer
                        );
                    }
                    if ($GLOBALS['compression'] == 'gzip'
                        && self::gzencodeNeeded()
                    ) {
                        // as a gzipped file
                        // without the optional parameter level because it bugs
                        $dump_buffer = gzencode($dump_buffer);
                    }
                    if ($GLOBALS['save_on_server']) {
                        $write_result = @fwrite($GLOBALS['file_handle'], $dump_buffer);
                        // Here, use strlen rather than mb_strlen to get the length
                        // in bytes to compare against the number of bytes written.
                        if ($write_result != strlen($dump_buffer)) {
                            $GLOBALS['message'] = Message::error(
                                __('Insufficient space to save the file %s.')
                            );
                            $GLOBALS['message']->addParam($save_filename);
                            return false;
                        }
                    } else {
                        echo $dump_buffer;
                    }
                    $dump_buffer = '';
                    $dump_buffer_len = 0;
                }
            } else {
                $time_now = time();
                if ($time_start >= $time_now + 30) {
                    $time_start = $time_now;
                    header('X-pmaPing: Pong');
                } // end if
            }
        } else {
            if ($GLOBALS['asfile']) {
                if ($GLOBALS['output_charset_conversion']) {
                    $line = Encoding::convertString(
                        'utf-8',
                        $GLOBALS['charset'],
                        $line
                    );
                }
                if ($GLOBALS['save_on_server'] && mb_strlen($line) > 0) {
                    $write_result = @fwrite($GLOBALS['file_handle'], $line);
                    // Here, use strlen rather than mb_strlen to get the length
                    // in bytes to compare against the number of bytes written.
                    if (! $write_result
                        || $write_result != strlen($line)
                    ) {
                        $GLOBALS['message'] = Message::error(
                            __('Insufficient space to save the file %s.')
                        );
                        $GLOBALS['message']->addParam($save_filename);
                        return false;
                    }
                    $time_now = time();
                    if ($time_start >= $time_now + 30) {
                        $time_start = $time_now;
                        header('X-pmaPing: Pong');
                    } // end if
                } else {
                    // We export as file - output normally
                    echo $line;
                }
            } else {
                // We export as html - replace special chars
                echo htmlspecialchars($line);
            }
        }
        return true;
    } // end of the 'self::outputHandler()' function

    /**
     * Returns HTML containing the footer for a displayed export
     *
     * @param string $back_button   the link for going Back
     * @param string $refreshButton the link for refreshing page
     *
     * @return string $html the HTML output
     */
    public static function getHtmlForDisplayedExportFooter($back_button, $refreshButton)
    {
        /**
         * Close the html tags and add the footers for on-screen export
         */
        $html = '</textarea>'
            . '    </form>'
            . '<br />'
            // bottom back button
            . $back_button
            . $refreshButton
            . '</div>'
            . '<script type="text/javascript">' . "\n"
            . '//<![CDATA[' . "\n"
            . 'var $body = $("body");' . "\n"
            . '$("#textSQLDUMP")' . "\n"
            . '.width($body.width() - 50)' . "\n"
            . '.height($body.height() - 100);' . "\n"
            . '//]]>' . "\n"
            . '</script>' . "\n";
        return $html;
    }

    /**
     * Computes the memory limit for export
     *
     * @return int $memory_limit the memory limit
     */
    public static function getMemoryLimit()
    {
        $memory_limit = trim(ini_get('memory_limit'));
        $memory_limit_num = (int)substr($memory_limit, 0, -1);
        $lowerLastChar = strtolower(substr($memory_limit, -1));
        // 2 MB as default
        if (empty($memory_limit) || '-1' == $memory_limit) {
            $memory_limit = 2 * 1024 * 1024;
        } elseif ($lowerLastChar == 'm') {
            $memory_limit = $memory_limit_num * 1024 * 1024;
        } elseif ($lowerLastChar == 'k') {
            $memory_limit = $memory_limit_num * 1024;
        } elseif ($lowerLastChar == 'g') {
            $memory_limit = $memory_limit_num * 1024 * 1024 * 1024;
        } else {
            $memory_limit = (int)$memory_limit;
        }

        // Some of memory is needed for other things and as threshold.
        // During export I had allocated (see memory_get_usage function)
        // approx 1.2MB so this comes from that.
        if ($memory_limit > 1500000) {
            $memory_limit -= 1500000;
        }

        // Some memory is needed for compression, assume 1/3
        $memory_limit /= 8;
        return $memory_limit;
    }

    /**
     * Return the filename and MIME type for export file
     *
     * @param string       $export_type       type of export
     * @param string       $remember_template whether to remember template
     * @param ExportPlugin $export_plugin     the export plugin
     * @param string       $compression       compression asked
     * @param string       $filename_template the filename template
     *
     * @return string[] the filename template and mime type
     */
    public static function getFilenameAndMimetype(
        $export_type, $remember_template, $export_plugin, $compression,
        $filename_template
    ) {
        if ($export_type == 'server') {
            if (! empty($remember_template)) {
                $GLOBALS['PMA_Config']->setUserValue(
                    'pma_server_filename_template',
                    'Export/file_template_server',
                    $filename_template
                );
            }
        } elseif ($export_type == 'database') {
            if (! empty($remember_template)) {
                $GLOBALS['PMA_Config']->setUserValue(
                    'pma_db_filename_template',
                    'Export/file_template_database',
                    $filename_template
                );
            }
        } else {
            if (! empty($remember_template)) {
                $GLOBALS['PMA_Config']->setUserValue(
                    'pma_table_filename_template',
                    'Export/file_template_table',
                    $filename_template
                );
            }
        }
        $filename = Util::expandUserString($filename_template);
        // remove dots in filename (coming from either the template or already
        // part of the filename) to avoid a remote code execution vulnerability
        $filename = Sanitize::sanitizeFilename($filename, $replaceDots = true);

        // Grab basic dump extension and mime type
        // Check if the user already added extension;
        // get the substring where the extension would be if it was included
        $extension_start_pos = mb_strlen($filename) - mb_strlen(
            $export_plugin->getProperties()->getExtension()
        ) - 1;
        $user_extension = mb_substr(
            $filename, $extension_start_pos, mb_strlen($filename)
        );
        $required_extension = "." . $export_plugin->getProperties()->getExtension();
        if (mb_strtolower($user_extension) != $required_extension) {
            $filename  .= $required_extension;
        }
        $mime_type  = $export_plugin->getProperties()->getMimeType();

        // If dump is going to be compressed, set correct mime_type and add
        // compression to extension
        if ($compression == 'gzip') {
            $filename  .= '.gz';
            $mime_type = 'application/x-gzip';
        } elseif ($compression == 'zip') {
            $filename  .= '.zip';
            $mime_type = 'application/zip';
        }
        return array($filename, $mime_type);
    }

    /**
     * Open the export file
     *
     * @param string  $filename     the export filename
     * @param boolean $quick_export whether it's a quick export or not
     *
     * @return array the full save filename, possible message and the file handle
     */
    public static function openFile($filename, $quick_export)
    {
        $file_handle = null;
        $message = '';
        $doNotSaveItOver = true;

        if(isset($_POST['quick_export_onserver_overwrite'])) {
            $doNotSaveItOver = $_POST['quick_export_onserver_overwrite'] != 'saveitover';
        }

        $save_filename = Util::userDir($GLOBALS['cfg']['SaveDir'])
            . preg_replace('@[/\\\\]@', '_', $filename);

        if (@file_exists($save_filename)
            && ((! $quick_export && empty($_POST['onserver_overwrite']))
            || ($quick_export
            && $doNotSaveItOver))
        ) {
            $message = Message::error(
                __(
                    'File %s already exists on server, '
                    . 'change filename or check overwrite option.'
                )
            );
            $message->addParam($save_filename);
        } elseif (@is_file($save_filename) && ! @is_writable($save_filename)) {
            $message = Message::error(
                __(
                    'The web server does not have permission '
                    . 'to save the file %s.'
                )
            );
            $message->addParam($save_filename);
        } elseif (! $file_handle = @fopen($save_filename, 'w')) {
            $message = Message::error(
                __(
                    'The web server does not have permission '
                    . 'to save the file %s.'
                )
            );
            $message->addParam($save_filename);
        }
        return array($save_filename, $message, $file_handle);
    }

    /**
     * Close the export file
     *
     * @param resource $file_handle   the export file handle
     * @param string   $dump_buffer   the current dump buffer
     * @param string   $save_filename the export filename
     *
     * @return Message $message a message object (or empty string)
     */
    public static function closeFile($file_handle, $dump_buffer, $save_filename)
    {
        $write_result = @fwrite($file_handle, $dump_buffer);
        fclose($file_handle);
        // Here, use strlen rather than mb_strlen to get the length
        // in bytes to compare against the number of bytes written.
        if (strlen($dump_buffer) > 0
            && (! $write_result || $write_result != strlen($dump_buffer))
        ) {
            $message = new Message(
                __('Insufficient space to save the file %s.'),
                Message::ERROR,
                array($save_filename)
            );
        } else {
            $message = new Message(
                __('Dump has been saved to file %s.'),
                Message::SUCCESS,
                array($save_filename)
            );
        }
        return $message;
    }

    /**
     * Compress the export buffer
     *
     * @param array|string $dump_buffer the current dump buffer
     * @param string       $compression the compression mode
     * @param string       $filename    the filename
     *
     * @return object $message a message object (or empty string)
     */
    public static function compress($dump_buffer, $compression, $filename)
    {
        if ($compression == 'zip' && function_exists('gzcompress')) {
            $zipExtension = new ZipExtension();
            $filename = substr($filename, 0, -4); // remove extension (.zip)
            $dump_buffer = $zipExtension->createFile($dump_buffer, $filename);
        } elseif ($compression == 'gzip' && self::gzencodeNeeded()) {
            // without the optional parameter level because it bugs
            $dump_buffer = gzencode($dump_buffer);
        }
        return $dump_buffer;
    }

    /**
     * Saves the dump_buffer for a particular table in an array
     * Used in separate files export
     *
     * @param string  $object_name the name of current object to be stored
     * @param boolean $append      optional boolean to append to an existing index or not
     *
     * @return void
     */
    public static function saveObjectInBuffer($object_name, $append = false)
    {

        global $dump_buffer_objects, $dump_buffer, $dump_buffer_len;

        if (! empty($dump_buffer)) {
            if ($append && isset($dump_buffer_objects[$object_name])) {
                $dump_buffer_objects[$object_name] .= $dump_buffer;
            } else {
                $dump_buffer_objects[$object_name] = $dump_buffer;
            }
        }

        // Re - initialize
        $dump_buffer = '';
        $dump_buffer_len = 0;

    }

    /**
     * Returns HTML containing the header for a displayed export
     *
     * @param string $export_type the export type
     * @param string $db          the database name
     * @param string $table       the table name
     *
     * @return string[] the generated HTML and back button
     */
    public static function getHtmlForDisplayedExportHeader($export_type, $db, $table)
    {
        $html = '<div>';

        /**
         * Displays a back button with all the $_POST data in the URL
         * (store in a variable to also display after the textarea)
         */
        $back_button = '<p id="export_back_button">[ <a href="';
        if ($export_type == 'server') {
            $back_button .= 'server_export.php" data-post="' . Url::getCommon([], '');
        } elseif ($export_type == 'database') {
            $back_button .= 'db_export.php" data-post="' . Url::getCommon(array('db' => $db), '');
        } else {
            $back_button .= 'tbl_export.php" data-post="' . Url::getCommon(
                array(
                    'db' => $db, 'table' => $table
                ), ''
            );
        }

        // Convert the multiple select elements from an array to a string
        if ($export_type == 'database') {
            $structOrDataForced = empty($_POST['structure_or_data_forced']);
            if ($structOrDataForced && ! isset($_POST['table_structure'])) {
                $_POST['table_structure'] = [];
            }
            if ($structOrDataForced && ! isset($_POST['table_data'])) {
                $_POST['table_data'] = [];
            }
        }

        foreach ($_POST as $name => $value) {
            if (!is_array($value)) {
                $back_button .= '&amp;' . urlencode($name) . '=' . urlencode($value);
            }
        }
        $back_button .= '&amp;repopulate=1">' . __('Back') . '</a> ]</p>';
        $html .= '<br />';
        $html .= $back_button;
        $refreshButton = '<form id="export_refresh_form" method="POST" action="export.php" class="disableAjax">';
        $refreshButton .= '[ <a class="disableAjax" onclick="$(this).parent().submit()">'. __('Refresh') .'</a> ]';
        foreach($_POST as $name => $value) {
            if (is_array($value)) {
                foreach($value as $val) {
                    $refreshButton .= '<input type="hidden" name="' . htmlentities((string) $name) . '[]" value="' . htmlentities((string) $val) . '">';
                }
            }
            else {
                $refreshButton .= '<input type="hidden" name="' . htmlentities((string) $name) . '" value="' . htmlentities((string) $value) . '">';
            }
        }
        $refreshButton .= '</form>';
        $html .= $refreshButton
            . '<br />'
            . '<form name="nofunction">'
            . '<textarea name="sqldump" cols="50" rows="30" '
            . 'id="textSQLDUMP" wrap="OFF">';

        return array($html, $back_button, $refreshButton);
    }

    /**
     * Export at the server level
     *
     * @param string       $db_select       the selected databases to export
     * @param string       $whatStrucOrData structure or data or both
     * @param ExportPlugin $export_plugin   the selected export plugin
     * @param string       $crlf            end of line character(s)
     * @param string       $err_url         the URL in case of error
     * @param string       $export_type     the export type
     * @param bool         $do_relation     whether to export relation info
     * @param bool         $do_comments     whether to add comments
     * @param bool         $do_mime         whether to add MIME info
     * @param bool         $do_dates        whether to add dates
     * @param array        $aliases         alias information for db/table/column
     * @param string       $separate_files  whether it is a separate-files export
     *
     * @return void
     */
    public static function exportServer(
        $db_select, $whatStrucOrData, $export_plugin, $crlf, $err_url,
        $export_type, $do_relation, $do_comments, $do_mime, $do_dates,
        array $aliases, $separate_files
    ) {
        if (! empty($db_select)) {
            $tmp_select = implode($db_select, '|');
            $tmp_select = '|' . $tmp_select . '|';
        }
        // Walk over databases
        foreach ($GLOBALS['dblist']->databases as $current_db) {
            if (isset($tmp_select)
                && mb_strpos(' ' . $tmp_select, '|' . $current_db . '|')
            ) {
                $tables = $GLOBALS['dbi']->getTables($current_db);
                self::exportDatabase(
                    $current_db, $tables, $whatStrucOrData, $tables, $tables,
                    $export_plugin, $crlf, $err_url, $export_type, $do_relation,
                    $do_comments, $do_mime, $do_dates, $aliases,
                    $separate_files == 'database' ? $separate_files : ''
                );
                if ($separate_files == 'server') {
                    self::saveObjectInBuffer($current_db);
                }
            }
        } // end foreach database
    }

    /**
     * Export at the database level
     *
     * @param string       $db              the database to export
     * @param array        $tables          the tables to export
     * @param string       $whatStrucOrData structure or data or both
     * @param array        $table_structure whether to export structure for each table
     * @param array        $table_data      whether to export data for each table
     * @param ExportPlugin $export_plugin   the selected export plugin
     * @param string       $crlf            end of line character(s)
     * @param string       $err_url         the URL in case of error
     * @param string       $export_type     the export type
     * @param bool         $do_relation     whether to export relation info
     * @param bool         $do_comments     whether to add comments
     * @param bool         $do_mime         whether to add MIME info
     * @param bool         $do_dates        whether to add dates
     * @param array        $aliases         Alias information for db/table/column
     * @param string       $separate_files  whether it is a separate-files export
     *
     * @return void
     */
    public static function exportDatabase(
        $db, array $tables, $whatStrucOrData, array $table_structure, array $table_data,
        $export_plugin, $crlf, $err_url, $export_type, $do_relation,
        $do_comments, $do_mime, $do_dates, array $aliases, $separate_files
    ) {
        $db_alias = !empty($aliases[$db]['alias'])
            ? $aliases[$db]['alias'] : '';

        if (! $export_plugin->exportDBHeader($db, $db_alias)) {
            return;
        }
        if (! $export_plugin->exportDBCreate($db, $export_type, $db_alias)) {
            return;
        }
        if ($separate_files == 'database') {
            self::saveObjectInBuffer('database', true);
        }

        if (($GLOBALS['sql_structure_or_data'] == 'structure'
            || $GLOBALS['sql_structure_or_data'] == 'structure_and_data')
            && isset($GLOBALS['sql_procedure_function'])
        ) {
            $export_plugin->exportRoutines($db, $aliases);

            if ($separate_files == 'database') {
                self::saveObjectInBuffer('routines');
            }
        }

        $views = array();

        foreach ($tables as $table) {
            $_table = new Table($table, $db);
            // if this is a view, collect it for later;
            // views must be exported after the tables
            $is_view = $_table->isView();
            if ($is_view) {
                $views[] = $table;
            }
            if (($whatStrucOrData == 'structure'
                || $whatStrucOrData == 'structure_and_data')
                && in_array($table, $table_structure)
            ) {
                // for a view, export a stand-in definition of the table
                // to resolve view dependencies (only when it's a single-file export)
                if ($is_view) {
                    if ($separate_files == ''
                        && isset($GLOBALS['sql_create_view'])
                        && ! $export_plugin->exportStructure(
                            $db, $table, $crlf, $err_url, 'stand_in',
                            $export_type, $do_relation, $do_comments,
                            $do_mime, $do_dates, $aliases
                        )
                    ) {
                        break;
                    }
                } elseif (isset($GLOBALS['sql_create_table'])) {

                    $table_size = $GLOBALS['maxsize'];
                    // Checking if the maximum table size constrain has been set
                    // And if that constrain is a valid number or not
                    if ($table_size !== '' && is_numeric($table_size)) {
                        // This obtains the current table's size
                        $query = 'SELECT data_length + index_length
                              from information_schema.TABLES
                              WHERE table_schema = "' . $GLOBALS['dbi']->escapeString($db) . '"
                              AND table_name = "' . $GLOBALS['dbi']->escapeString($table) . '"';

                        $size = $GLOBALS['dbi']->fetchValue($query);
                        //Converting the size to MB
                        $size = ($size / 1024) / 1024;
                        if ($size > $table_size) {
                            continue;
                        }
                    }

                    if (! $export_plugin->exportStructure(
                        $db, $table, $crlf, $err_url, 'create_table',
                        $export_type, $do_relation, $do_comments,
                        $do_mime, $do_dates, $aliases
                    )) {
                        break;
                    }

                }

            }
            // if this is a view or a merge table, don't export data
            if (($whatStrucOrData == 'data' || $whatStrucOrData == 'structure_and_data')
                && in_array($table, $table_data)
                && ! ($is_view)
            ) {
                $tableObj = new Table($table, $db);
                $nonGeneratedCols = $tableObj->getNonGeneratedColumns(true);

                $local_query  = 'SELECT ' . implode(', ', $nonGeneratedCols)
                    .  ' FROM ' . Util::backquote($db)
                    . '.' . Util::backquote($table);

                if (! $export_plugin->exportData(
                    $db, $table, $crlf, $err_url, $local_query, $aliases
                )) {
                    break;
                }
            }

            // this buffer was filled, we save it and go to the next one
            if ($separate_files == 'database') {
                self::saveObjectInBuffer('table_' . $table);
            }

            // now export the triggers (needs to be done after the data because
            // triggers can modify already imported tables)
            if (isset($GLOBALS['sql_create_trigger']) && ($whatStrucOrData == 'structure'
                || $whatStrucOrData == 'structure_and_data')
                && in_array($table, $table_structure)
            ) {
                if (! $export_plugin->exportStructure(
                    $db, $table, $crlf, $err_url, 'triggers',
                    $export_type, $do_relation, $do_comments,
                    $do_mime, $do_dates, $aliases
                )) {
                    break;
                }

                if ($separate_files == 'database') {
                    self::saveObjectInBuffer('table_' . $table, true);
                }
            }

        }

        if (isset($GLOBALS['sql_create_view'])) {

            foreach ($views as $view) {
                // no data export for a view
                if ($whatStrucOrData == 'structure'
                    || $whatStrucOrData == 'structure_and_data'
                ) {
                    if (! $export_plugin->exportStructure(
                        $db, $view, $crlf, $err_url, 'create_view',
                        $export_type, $do_relation, $do_comments,
                        $do_mime, $do_dates, $aliases
                    )) {
                        break;
                    }

                    if ($separate_files == 'database') {
                        self::saveObjectInBuffer('view_' . $view);
                    }
                }
            }

        }

        if (! $export_plugin->exportDBFooter($db)) {
            return;
        }

        // export metadata related to this db
        if (isset($GLOBALS['sql_metadata'])) {
            // Types of metadata to export.
            // In the future these can be allowed to be selected by the user
            $metadataTypes = self::getMetadataTypes();
            $export_plugin->exportMetadata($db, $tables, $metadataTypes);

            if ($separate_files == 'database') {
                self::saveObjectInBuffer('metadata');
            }
        }

        if ($separate_files == 'database') {
            self::saveObjectInBuffer('extra');
        }

        if (($GLOBALS['sql_structure_or_data'] == 'structure'
            || $GLOBALS['sql_structure_or_data'] == 'structure_and_data')
            && isset($GLOBALS['sql_procedure_function'])
        ) {
            $export_plugin->exportEvents($db);

            if ($separate_files == 'database') {
                self::saveObjectInBuffer('events');
            }
        }
    }

    /**
     * Export at the table level
     *
     * @param string       $db              the database to export
     * @param string       $table           the table to export
     * @param string       $whatStrucOrData structure or data or both
     * @param ExportPlugin $export_plugin   the selected export plugin
     * @param string       $crlf            end of line character(s)
     * @param string       $err_url         the URL in case of error
     * @param string       $export_type     the export type
     * @param bool         $do_relation     whether to export relation info
     * @param bool         $do_comments     whether to add comments
     * @param bool         $do_mime         whether to add MIME info
     * @param bool         $do_dates        whether to add dates
     * @param string       $allrows         whether "dump all rows" was ticked
     * @param string       $limit_to        upper limit
     * @param string       $limit_from      starting limit
     * @param string       $sql_query       query for which exporting is requested
     * @param array        $aliases         Alias information for db/table/column
     *
     * @return void
     */
    public static function exportTable(
        $db, $table, $whatStrucOrData, $export_plugin, $crlf, $err_url,
        $export_type, $do_relation, $do_comments, $do_mime, $do_dates,
        $allrows, $limit_to, $limit_from, $sql_query, array $aliases
    ) {
        $db_alias = !empty($aliases[$db]['alias'])
            ? $aliases[$db]['alias'] : '';
        if (! $export_plugin->exportDBHeader($db, $db_alias)) {
            return;
        }
        if (isset($allrows)
            && $allrows == '0'
            && $limit_to > 0
            && $limit_from >= 0
        ) {
            $add_query  = ' LIMIT '
                        . (($limit_from > 0) ? $limit_from . ', ' : '')
                        . $limit_to;
        } else {
            $add_query  = '';
        }

        $_table = new Table($table, $db);
        $is_view = $_table->isView();
        if ($whatStrucOrData == 'structure'
            || $whatStrucOrData == 'structure_and_data'
        ) {

            if ($is_view) {

                if (isset($GLOBALS['sql_create_view'])) {
                    if (! $export_plugin->exportStructure(
                        $db, $table, $crlf, $err_url, 'create_view',
                        $export_type, $do_relation, $do_comments,
                        $do_mime, $do_dates, $aliases
                    )) {
                        return;
                    }
                }

            } elseif (isset($GLOBALS['sql_create_table'])) {

                if (! $export_plugin->exportStructure(
                    $db, $table, $crlf, $err_url, 'create_table',
                    $export_type, $do_relation, $do_comments,
                    $do_mime, $do_dates, $aliases
                )) {
                    return;
                }

            }

        }
        // If this is an export of a single view, we have to export data;
        // for example, a PDF report
        // if it is a merge table, no data is exported
        if ($whatStrucOrData == 'data'
            || $whatStrucOrData == 'structure_and_data'
        ) {
            if (! empty($sql_query)) {
                // only preg_replace if needed
                if (! empty($add_query)) {
                    // remove trailing semicolon before adding a LIMIT
                    $sql_query = preg_replace('%;\s*$%', '', $sql_query);
                }
                $local_query = $sql_query . $add_query;
                $GLOBALS['dbi']->selectDb($db);
            } else {
                // Data is exported only for Non-generated columns
                $tableObj = new Table($table, $db);
                $nonGeneratedCols = $tableObj->getNonGeneratedColumns(true);

                $local_query  = 'SELECT ' . implode(', ', $nonGeneratedCols)
                    .  ' FROM ' . Util::backquote($db)
                    . '.' . Util::backquote($table) . $add_query;
            }
            if (! $export_plugin->exportData(
                $db, $table, $crlf, $err_url, $local_query, $aliases
            )) {
                return;
            }
        }
        // now export the triggers (needs to be done after the data because
        // triggers can modify already imported tables)
        if (isset($GLOBALS['sql_create_trigger']) && ($whatStrucOrData == 'structure'
            || $whatStrucOrData == 'structure_and_data')
        ) {
            if (! $export_plugin->exportStructure(
                $db, $table, $crlf, $err_url, 'triggers',
                $export_type, $do_relation, $do_comments,
                $do_mime, $do_dates, $aliases
            )) {
                return;
            }
        }
        if (! $export_plugin->exportDBFooter($db)) {
            return;
        }

        if (isset($GLOBALS['sql_metadata'])) {
            // Types of metadata to export.
            // In the future these can be allowed to be selected by the user
            $metadataTypes = self::getMetadataTypes();
            $export_plugin->exportMetadata($db, $table, $metadataTypes);
        }
    }

    /**
     * Loads correct page after doing export
     *
     * @param string $db          the database name
     * @param string $table       the table name
     * @param string $export_type Export type
     *
     * @return void
     */
    public static function showPage($db, $table, $export_type)
    {
        global $cfg;
        if ($export_type == 'server') {
            $active_page = 'server_export.php';
            include_once 'server_export.php';
        } elseif ($export_type == 'database') {
            $active_page = 'db_export.php';
            include_once 'db_export.php';
        } else {
            $active_page = 'tbl_export.php';
            include_once 'tbl_export.php';
        }
        exit();
    }

    /**
     * Merge two alias arrays, if array1 and array2 have
     * conflicting alias then array2 value is used if it
     * is non empty otherwise array1 value.
     *
     * @param array $aliases1 first array of aliases
     * @param array $aliases2 second array of aliases
     *
     * @return array resultant merged aliases info
     */
    public static function mergeAliases(array $aliases1, array $aliases2)
    {
        // First do a recursive array merge
        // on aliases arrays.
        $aliases = array_merge_recursive($aliases1, $aliases2);
        // Now, resolve conflicts in aliases, if any
        foreach ($aliases as $db_name => $db) {
            // If alias key is an array then
            // it is a merge conflict.
            if (isset($db['alias']) && is_array($db['alias'])) {
                $val1 = $db['alias'][0];
                $val2 = $db['alias'][1];
                // Use aliases2 alias if non empty
                $aliases[$db_name]['alias']
                    = empty($val2) ? $val1 : $val2;
            }
            if (!isset($db['tables'])) {
                continue;
            }
            foreach ($db['tables'] as $tbl_name => $tbl) {
                if (isset($tbl['alias']) && is_array($tbl['alias'])) {
                    $val1 = $tbl['alias'][0];
                    $val2 = $tbl['alias'][1];
                    // Use aliases2 alias if non empty
                    $aliases[$db_name]['tables'][$tbl_name]['alias']
                        = empty($val2) ? $val1 : $val2;
                }
                if (!isset($tbl['columns'])) {
                    continue;
                }
                foreach ($tbl['columns'] as  $col => $col_as) {
                    if (isset($col_as) && is_array($col_as)) {
                        $val1 = $col_as[0];
                        $val2 = $col_as[1];
                        // Use aliases2 alias if non empty
                        $aliases[$db_name]['tables'][$tbl_name]['columns'][$col]
                            = empty($val2) ? $val1 : $val2;
                    }
                };
            };
        }
        return $aliases;
    }

    /**
     * Locks tables
     *
     * @param string $db       database name
     * @param array  $tables   list of table names
     * @param string $lockType lock type; "[LOW_PRIORITY] WRITE" or "READ [LOCAL]"
     *
     * @return mixed result of the query
     */
    public static function lockTables($db, array $tables, $lockType = "WRITE")
    {
        $locks = array();
        foreach ($tables as $table) {
            $locks[] = Util::backquote($db) . "."
                . Util::backquote($table) . " " . $lockType;
        }

        $sql = "LOCK TABLES " . implode(", ", $locks);
        return $GLOBALS['dbi']->tryQuery($sql);
    }

    /**
     * Releases table locks
     *
     * @return mixed result of the query
     */
    public static function unlockTables()
    {
        return $GLOBALS['dbi']->tryQuery("UNLOCK TABLES");
    }

    /**
     * Returns all the metadata types that can be exported with a database or a table
     *
     * @return string[] metadata types.
     */
    public static function getMetadataTypes()
    {
        return array(
            'column_info',
            'table_uiprefs',
            'tracking',
            'bookmark',
            'relation',
            'table_coords',
            'pdf_pages',
            'savedsearches',
            'central_columns',
            'export_templates',
        );
    }

    /**
     * Returns the checked clause, depending on the presence of key in array
     *
     * @param string $key   the key to look for
     * @param array  $array array to verify
     *
     * @return string the checked clause
     */
    public static function getCheckedClause($key, array $array)
    {
        if (in_array($key, $array)) {
            return ' checked="checked"';
        }

        return '';
    }

    /**
     * get all the export options and verify
     * call and include the appropriate Schema Class depending on $export_type
     *
     * @param string $export_type format of the export
     *
     * @return void
     */
    public static function processExportSchema($export_type)
    {
        /**
         * default is PDF, otherwise validate it's only letters a-z
         */
        if (! isset($export_type) || ! preg_match('/^[a-zA-Z]+$/', $export_type)) {
            $export_type = 'pdf';
        }

        // sanitize this parameter which will be used below in a file inclusion
        $export_type = Core::securePath($export_type);

        // get the specific plugin
        /* @var $export_plugin SchemaPlugin */
        $export_plugin = Plugins::getPlugin(
            "schema",
            $export_type,
            'libraries/classes/Plugins/Schema/'
        );

        // Check schema export type
        if (! isset($export_plugin)) {
            Core::fatalError(__('Bad type!'));
        }

        $GLOBALS['dbi']->selectDb($_POST['db']);
        $export_plugin->exportSchema($_POST['db']);
    }
}