clean_old_shadow_links.php

<?php
error_reporting(E_ALL);
if ((php_sapi_name() != 'cli')) {
    trigger_error("\nYou can only run this script from the command line.\n", E_USER_ERROR);
}

$options = getopt('m:s:p:d:');

if (empty($options)) {
    print_usage();
    exit;
}

if (!isset($options['m']) || !is_dir($options['m'])) {
    echo "\nYou need to supply the path to the System Root as the argument of -m option.
Run the script without argument to see its usage.\n\n";
    exit;
}

require_once $options['m'].'/core/include/init.inc';

// If -d option is used, do not check for other options
if (isset($options['d'])) {
    if (is_file($options['d'])) {
        delete_old_shadow_links($options['d']);
    } else {
        echo "\nYou need to supply the path to the PHP file as the argument of -d option.
Run the script without argument to see its usage.\n\n";
    }
    exit;
}

// Get old shadow links
$old_links = get_old_shadow_links();

// If there are no old shadow links, print a message and quit
if (empty($old_links)) {
    echo "\nThere are no old shadow links in the system.\n\n";
    exit;
}

// Print old shadow links
print_links($old_links);

// If the options -s, -p and -d are not used at all, print a message to remind the user
if (!isset($options['s']) && !isset($options['p'])) {
    echo '
You will need to run this script with -s or -p option to save the shadow links to files
and -d option to delete the shadow links stored in the output file generated by -p option.
(You have to use an SQL client like psql to execute the SQL statements generated by -s option)

';
} else {
    // Save SQL statements to file
    if (isset($options['s'])) {
        save_sql_statements($old_links, $options['s']);
    }
    
    // Save shadow links as array to a file
    if (isset($options['p'])) {
        save_linkid_array($old_links, $options['p']);
    }
}


function delete_old_shadow_links($file)
{
    // Require the file to get the $linkids array
    require $file;
    
    // Check if $linkids array is defined
    if (!isset($linkids) || !is_array($linkids)) {
        echo "\nERROR: The file $file is not in a correct format.\n\n";
        return;
    }
    
    // Split the array into chunks of 100 elements
    $chunks = array_chunk($linkids, 100);
    
    // Declare total deleted links variable
    $total_deleted_links = 0;
    
    // Delete the old shadow links
    $GLOBALS['SQ_SYSTEM']->changeDatabaseConnection('db2');
    $GLOBALS['SQ_SYSTEM']->doTransaction('BEGIN');
    
    try {
        foreach ($chunks as $chunk) {
            $delete_linkids = Array();
            foreach ($chunk as $linkid) {
                $delete_linkids[] = MatrixDAL::quote($linkid);
            }
            
            $sql = 'DELETE FROM sq_shdw_ast_lnk WHERE linkid IN ('.implode(',', $delete_linkids).')';
            $deleted_rows = MatrixDAL::executeSql($sql);
            $total_deleted_links += $deleted_rows;
        }
        
    } catch (DALException $e) {
        $GLOBALS['SQ_SYSTEM']->doTransaction('ROLLBACK');
        $GLOBALS['SQ_SYSTEM']->restoreDatabaseConnection();
        throw new Exception('Can not delete old shadow links due to the DB error: '.$e->getMessage());
    }
    
    $GLOBALS['SQ_SYSTEM']->doTransaction('COMMIT');
    $GLOBALS['SQ_SYSTEM']->restoreDatabaseConnection();
    
    echo "\n$total_deleted_links old shadow link(s) from $file were deleted successfully.\n\n";
    
}//end delete_old_shadow_links()


function save_linkid_array($links, $file)
{
    // Create a big PHP string with comments in it
    $linkids = Array();
    foreach ($links as $link) {
        $linkids[] = "'".$link['linkid']."', /* link_type=".$link['link_type']
                     .", majorid=".$link['majorid'].", minorid=".$link['minorid']
                     ." */";
    }
    
    $php = '<?php
    $linkids = Array(
'.implode("\n", $linkids).'
                    );
?>
';
    
    // Save the PHP string to file
    if (file_put_contents($file, $php) === FALSE) {
        echo "\nERROR: Can not write PHP array to $file\n\n";
    } else {
        echo "\nThe PHP array to delete the old shadow links are saved to $file\n\n";
    }
    
}//end save_linkid_array()


function save_sql_statements($links, $file)
{
    // Create a big SQL string with comments in it
    $sql = '';
    foreach ($links as $link) {
        $sql .= 'DELETE FROM sq_shdw_ast_lnk WHERE linkid='.MatrixDAL::quote($link['linkid'])
                .'; -- link_type='.$link['link_type'].', majorid='.$link['majorid']
                .', minorid='.$link['minorid']."\n";
    }
    
    // Save the SQL string to file
    if (file_put_contents($file, $sql) === FALSE) {
        echo "\nERROR: Can not write SQL statements to $file\n\n";
    } else {
        echo "\nThe SQL statements to delete the old shadow links are saved to $file\n\n";
    }
    
}//end save_sql_statements()


function print_links($links)
{
    echo "\nList of old shadow links:\n\n";
    // Create row format
    $row_format = "%7s |%5s |%8s | %-55s\n";
    $row_delimiter_format = "%'-7s-+%'-5s-+%'-8s-+%'-55s-\n";
    
    // Print the header
    printf($row_format, 'linkid', 'type', 'majorid', 'minorid');
    printf($row_delimiter_format, '', '', '', '');
    
    // Print the links
    foreach ($links as $link) {
        printf($row_format, $link['linkid'], $link['link_type'], $link['majorid'], $link['minorid']);
    }
    
    echo "(Number of links: ".count($links).")\n";
    
}//end print_links()


function get_old_shadow_links()
{
    // Get all shadow links
    $GLOBALS['SQ_SYSTEM']->changeDatabaseConnection('db');
    
    $sql = 'SELECT linkid, link_type, majorid, minorid FROM sq_shdw_ast_lnk ORDER BY majorid, link_type, linkid';
    $links = MatrixDAL::executeSqlAll($sql);
    
    $GLOBALS['SQ_SYSTEM']->restoreDatabaseConnection();
    
    // Search for old shadow links
    $am = $GLOBALS['SQ_SYSTEM']->am;
    $old_links = Array();
    foreach ($links as $link) {
        $shadow_assetid = $link['minorid'];
        $id_parts = explode(':', $shadow_assetid);
        if (isset($id_parts[1])) {
            $bridge_id = $id_parts[0];
            $bridge = $am->getAsset($bridge_id, '', FALSE);
            if (is_null($bridge) || !method_exists($bridge, 'getAsset')) {
                $old_links[] = $link;
            } else {
                //getAsset() from bridge directly so we can set the fourth param $return_null to TRUE so we don't get dummy assets.
                $shadow_asset = $bridge->getAsset($shadow_assetid, '', FALSE, TRUE);
                if (is_null($shadow_asset)) $old_links[] = $link;
            }
        } 
    }
    
    return $old_links;
    
}//end get_old_shadow_links()


function print_usage()
{
    $usage = '
This script is used to clean the old shadow links whose minor shadow assets are
no longer valid because their bridges can not find them anymore.
Usage:
          php clean_old_shadow_links.php [OPTION]
          
Options list:
    -m    Required. This option requires an argument which is the Matrix System Root.
    -s    Optional. This option requires a file path to save the SQL statements to.
    -p    Optional. This option requires a file path to save the PHP array to.
    -d    Optional. This option requires the path of a PHP file generated by
          the -p option to delete old shadow links from the database.

Example:
    List the old shadow links:
          php scripts/clean_old_shadow_links.php -m $PWD

    Save the SQL statements to delete old shadow links to file:
          php scripts/clean_old_shadow_links.php -m $PWD -s delete_shd_links.sql

    Save the shadow links under PHP array format:
          php scripts/clean_old_shadow_links.php -m $PWD -p old_shadow_links.inc

    Delete the shadow links in the PHP file:
          php scripts/clean_old_shadow_links.php -m $PWD -d old_shadow_links.inc


';
    echo $usage;
    
}//end print_usage()


?>