r3841 saveScript(): employ single-query update against a race condition

[racktables] / inc / database.php

<?php
/*
*
*  This file is a library of database access functions for RackTables.
*
*/

$SQLSchema = array
(
        'object' => array
        (
                'table' => 'RackObject',
                'columns' => array
                (
                        'id' => 'id',
                        'name' => 'name',
                        'label' => 'label',
                        'barcode' => 'barcode',
                        'asset_no' => 'asset_no',
                        'objtype_id' => 'objtype_id',
                        'rack_id' => '(select rack_id from RackSpace where object_id = id order by rack_id asc limit 1)',
                        'Rack_name' => '(select name from Rack where id = rack_id)',
                        'row_id' => '(select row_id from Rack where id = rack_id)',
                        'Row_name' => '(select name from RackRow where id = row_id)',
                        'has_problems' => 'has_problems',
                        'comment' => 'comment',
                        'nports' => '(SELECT COUNT(*) FROM Port WHERE object_id = RackObject.id)',
                        'runs8021Q' => '(SELECT 1 FROM VLANSwitch WHERE object_id = id LIMIT 1)',
                ),
                'keycolumn' => 'id',
                'ordcolumns' => array ('RackObject.name'),
        ),
        'user' => array
        (
                'table' => 'UserAccount',
                'columns' => array
                (
                        'user_id' => 'user_id',
                        'user_name' => 'user_name',
                        'user_password_hash' => 'user_password_hash',
                        'user_realname' => 'user_realname',
                ),
                'keycolumn' => 'user_id',
                'ordcolumns' => array ('UserAccount.user_name'),
        ),
        'ipv4net' => array
        (
                'table' => 'IPv4Network',
                'columns' => array
                (
                        'id' => 'id',
                        'ip' => 'INET_NTOA(IPv4Network.ip)',
                        'mask' => 'mask',
                        'name' => 'name',
                        'comment' => 'comment',
                        'parent_id' => '(SELECT id FROM IPv4Network AS subt WHERE IPv4Network.ip & (4294967295 >> (32 - subt.mask)) << (32 - subt.mask) = subt.ip and subt.mask < IPv4Network.mask ORDER BY subt.mask DESC limit 1)',
                        'vlanc' => '(SELECT COUNT(*) FROM VLANIPv4 WHERE ipv4net_id = id)',
                ),
                'keycolumn' => 'id',
                'ordcolumns' => array ('IPv4Network.ip', 'IPv4Network.mask'),
        ),
        'file' => array
        (
                'table' => 'File',
                'columns' => array
                (
                        'id' => 'id',
                        'name' => 'name',
                        'type' => 'type',
                        'size' => 'size',
                        'ctime' => 'ctime',
                        'mtime' => 'mtime',
                        'atime' => 'atime',
                        'comment' => 'comment',
                ),
                'keycolumn' => 'id',
                'ordcolumns' => array ('File.name'),
        ),
        'ipv4vs' => array
        (
                'table' => 'IPv4VS',
                'columns' => array
                (
                        'id' => 'id',
                        'vip' => 'INET_NTOA(vip)',
                        'vport' => 'vport',
                        'proto' => 'proto',
                        'name' => 'name',
                        'vsconfig' => 'vsconfig',
                        'rsconfig' => 'rsconfig',
                        'poolcount' => '(select count(vs_id) from IPv4LB where vs_id = id)',
                        'dname' => 'CONCAT_WS("/", CONCAT_WS(":", INET_NTOA(vip), vport), proto)',
                ),
                'keycolumn' => 'id',
                'ordcolumns' => array ('IPv4VS.vip', 'IPv4VS.proto', 'IPv4VS.vport'),
        ),
        'ipv4rspool' => array
        (
                'table' => 'IPv4RSPool',
                'columns' => array
                (
                        'id' => 'id',
                        'name' => 'name',
                        'refcnt' => '(select count(rspool_id) from IPv4LB where rspool_id = id)',
                        'rscount' => '(select count(rspool_id) from IPv4RS where rspool_id = IPv4RSPool.id)',
                        'vsconfig' => 'vsconfig',
                        'rsconfig' => 'rsconfig',
                ),
                'keycolumn' => 'id',
                'ordcolumns' => array ('IPv4RSPool.name', 'IPv4RSPool.id'),
        ),
        'rack' => array
        (
                'table' => 'Rack',
                'columns' => array
                (
                        'id' => 'id',
                        'name' => 'name',
                        'height' => 'height',
                        'comment' => 'comment',
                        'row_id' => 'row_id',
                        'row_name' => '(select name from RackRow where RackRow.id = row_id)',
                ),
                'keycolumn' => 'id',
                'ordcolumns' => array ('row_name', 'Rack.name'),
                'pidcolumn' => 'row_id',
        ),
);

$searchfunc = array
(
        'object' => array
        (
                'by_sticker' => 'getStickerSearchResults',
                'by_port' => 'getPortSearchResults',
                'by_attr' => 'getObjectAttrsSearchResults',
                'by_iface' => 'getObjectIfacesSearchResults',
                'by_nat' => 'getObjectNATSearchResults',
        ),
);

$tablemap_8021q = array
(
        'desired' => array
        (
                'pvm' => 'PortVLANMode',
                'pav' => 'PortAllowedVLAN',
                'pnv' => 'PortNativeVLAN',
        ),
        'cached' => array
        (
                'pvm' => 'CachedPVM',
                'pav' => 'CachedPAV',
                'pnv' => 'CachedPNV',
        ),
);

function escapeString ($value, $do_db_escape = FALSE)
{
        $ret = htmlspecialchars ($value, ENT_QUOTES, 'UTF-8');
        if ($do_db_escape)
        {
                global $dbxlink;
                $ret = substr ($dbxlink->quote ($ret), 1, -1);
        }
        return $ret;
}

// Return detailed information about one rack row.
function getRackRowInfo ($rackrow_id)
{
        $query =
                "select RackRow.id as id, RackRow.name as name, count(Rack.id) as count, " .
                "if(isnull(sum(Rack.height)),0,sum(Rack.height)) as sum " .
                "from RackRow left join Rack on Rack.row_id = RackRow.id " .
                "where RackRow.id = ? " .
                "group by RackRow.id";
        $result = usePreparedSelectBlade ($query, array ($rackrow_id));
        if ($row = $result->fetch (PDO::FETCH_ASSOC))
                return $row;
        else
                throw new EntityNotFoundException ('rackrow', $rackrow_id);
}

function getRackRows ()
{
        $result = usePreparedSelectBlade ('SELECT id, name FROM RackRow ORDER BY name');
        $rows = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $rows[$row['id']] = $row['name'];
        return $rows;
}

function commitAddRow($rackrow_name)
{
        return usePreparedInsertBlade ('RackRow', array ('name' => $rackrow_name));
}

function commitUpdateRow ($rackrow_id, $rackrow_name)
{
        return usePreparedExecuteBlade ('UPDATE RackRow SET name = ? WHERE id = ?', array ($rackrow_name, $rackrow_id));
}

function commitDeleteRow($rackrow_id)
{
        return usePreparedDeleteBlade ('RackRow', array ('id' => $rackrow_id));
}

// Return a simple object list w/o related information, so that the returned value
// can be directly used by printSelect(). An optional argument is the name of config
// option with constraint in RackCode.
function getNarrowObjectList ($varname = '')
{
        $wideList = listCells ('object');
        if (strlen ($varname) and strlen (getConfigVar ($varname)))
        {
                global $parseCache;
                if (!isset ($parseCache[$varname]))
                        $parseCache[$varname] = spotPayload (getConfigVar ($varname), 'SYNT_EXPR');
                if ($parseCache[$varname]['result'] != 'ACK')
                        return array();
                $wideList = filterCellList ($wideList, $parseCache[$varname]['load']);
        }
        $ret = array();
        foreach ($wideList as $cell)
                $ret[$cell['id']] = $cell['dname'];
        return $ret;
}

// For a given realm return a list of entity records, each with
// enough information for judgeCell() to execute.
function listCells ($realm, $parent_id = 0)
{
        if (!$parent_id)
        {
                global $entityCache;
                if (isset ($entityCache['complete'][$realm]))
                        return $entityCache['complete'][$realm];
        }
        global $SQLSchema;
        if (!isset ($SQLSchema[$realm]))
                throw new RealmNotFoundException ($realm);
        $SQLinfo = $SQLSchema[$realm];
        $qparams = array ($realm);
        $query = 'SELECT tag_id';
        foreach ($SQLinfo['columns'] as $alias => $expression)
                // Automatically prepend table name to each single column, but leave all others intact.
                $query .= ', ' . ($alias == $expression ? "${SQLinfo['table']}.${alias}" : "${expression} as ${alias}");
        $query .= " FROM ${SQLinfo['table']} LEFT JOIN TagStorage on entity_realm = ? and entity_id = ${SQLinfo['table']}.${SQLinfo['keycolumn']}";
        if (isset ($SQLinfo['pidcolumn']) and $parent_id)
        {
                $query .= " WHERE ${SQLinfo['table']}.${SQLinfo['pidcolumn']} = ?";
                $qparams[] = $parent_id;
        }
        $query .= " ORDER BY ";
        foreach ($SQLinfo['ordcolumns'] as $oc)
                $query .= "${oc}, ";
        $query .= " tag_id";
        $result = usePreparedSelectBlade ($query, $qparams);
        $ret = array();
        global $taglist;
        // Index returned result by the value of key column.
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $entity_id = $row[$SQLinfo['keycolumn']];
                // Init the first record anyway, but store tag only if there is one.
                if (!isset ($ret[$entity_id]))
                {
                        $ret[$entity_id] = array ('realm' => $realm);
                        foreach (array_keys ($SQLinfo['columns']) as $alias)
                                $ret[$entity_id][$alias] = $row[$alias];
                        $ret[$entity_id]['etags'] = array();
                        if ($row['tag_id'] != NULL && isset ($taglist[$row['tag_id']]))
                                $ret[$entity_id]['etags'][] = array
                                (
                                        'id' => $row['tag_id'],
                                        'tag' => $taglist[$row['tag_id']]['tag'],
                                        'parent_id' => $taglist[$row['tag_id']]['parent_id'],
                                );
                }
                elseif (isset ($taglist[$row['tag_id']]))
                        // Meeting existing key later is always more tags on existing list.
                        $ret[$entity_id]['etags'][] = array
                        (
                                'id' => $row['tag_id'],
                                'tag' => $taglist[$row['tag_id']]['tag'],
                                'parent_id' => $taglist[$row['tag_id']]['parent_id'],
                        );
        }
        // Add necessary finish to the list before returning it. Maintain caches.
        if (!$parent_id)
                unset ($entityCache['partial'][$realm]);
        foreach (array_keys ($ret) as $entity_id)
        {
                $ret[$entity_id]['etags'] = getExplicitTagsOnly ($ret[$entity_id]['etags']);
                $ret[$entity_id]['itags'] = getImplicitTags ($ret[$entity_id]['etags']);
                $ret[$entity_id]['atags'] = generateEntityAutoTags ($ret[$entity_id]);
                switch ($realm)
                {
                case 'object':
                        setDisplayedName ($ret[$entity_id]);
                        break;
                case 'ipv4net':
                        $ret[$entity_id]['ip_bin'] = ip2long ($ret[$entity_id]['ip']);
                        $ret[$entity_id]['mask_bin'] = binMaskFromDec ($ret[$entity_id]['mask']);
                        $ret[$entity_id]['mask_bin_inv'] = binInvMaskFromDec ($ret[$entity_id]['mask']);
                        $ret[$entity_id]['db_first'] = sprintf ('%u', 0x00000000 + $ret[$entity_id]['ip_bin'] & $ret[$entity_id]['mask_bin']);
                        $ret[$entity_id]['db_last'] = sprintf ('%u', 0x00000000 + $ret[$entity_id]['ip_bin'] | ($ret[$entity_id]['mask_bin_inv']));
                        break;
                default:
                        break;
                }
                if (!$parent_id)
                        $entityCache['complete'][$realm][$entity_id] = $ret[$entity_id];
                else
                        $entityCache['partial'][$realm][$entity_id] = $ret[$entity_id];
        }
        return $ret;
}

// Very much like listCells(), but return only one record requested (or NULL,
// if it does not exist).
function spotEntity ($realm, $id)
{
        global $entityCache;
        if (isset ($entityCache['complete'][$realm]))
        // Emphasize the absence of record, if listCells() has already been called.
                if (isset ($entityCache['complete'][$realm][$id]))
                        return $entityCache['complete'][$realm][$id];
                else
                        throw new EntityNotFoundException ($realm, $id);
        elseif (isset ($entityCache['partial'][$realm][$id]))
                return $entityCache['partial'][$realm][$id];
        global $SQLSchema;
        if (!isset ($SQLSchema[$realm]))
                throw new RealmNotFoundException ($realm);
        $SQLinfo = $SQLSchema[$realm];
        $query = 'SELECT tag_id';
        foreach ($SQLinfo['columns'] as $alias => $expression)
                // Automatically prepend table name to each single column, but leave all others intact.
                $query .= ', ' . ($alias == $expression ? "${SQLinfo['table']}.${alias}" : "${expression} as ${alias}");
        $query .= " FROM ${SQLinfo['table']} LEFT JOIN TagStorage on entity_realm = ? and entity_id = ${SQLinfo['table']}.${SQLinfo['keycolumn']}";
        $query .= " WHERE ${SQLinfo['table']}.${SQLinfo['keycolumn']} = ?";
        $query .= " ORDER BY tag_id";
        $result = usePreparedSelectBlade ($query, array ($realm, $id));
        $ret = array();
        global $taglist;
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                if (!isset ($ret['realm']))
                {
                        $ret = array ('realm' => $realm);
                        foreach (array_keys ($SQLinfo['columns']) as $alias)
                                $ret[$alias] = $row[$alias];
                        $ret['etags'] = array();
                        if ($row['tag_id'] != NULL && isset ($taglist[$row['tag_id']]))
                                $ret['etags'][] = array
                                (
                                        'id' => $row['tag_id'],
                                        'tag' => $taglist[$row['tag_id']]['tag'],
                                        'parent_id' => $taglist[$row['tag_id']]['parent_id'],
                                );
                }
                elseif (isset ($taglist[$row['tag_id']]))
                        $ret['etags'][] = array
                        (
                                'id' => $row['tag_id'],
                                'tag' => $taglist[$row['tag_id']]['tag'],
                                'parent_id' => $taglist[$row['tag_id']]['parent_id'],
                        );
        unset ($result);
        if (!isset ($ret['realm'])) // no rows were returned
                throw new EntityNotFoundException ($realm, $id);
        $ret['etags'] = getExplicitTagsOnly ($ret['etags']);
        $ret['itags'] = getImplicitTags ($ret['etags']);
        $ret['atags'] = generateEntityAutoTags ($ret);
        switch ($realm)
        {
        case 'object':
                setDisplayedName ($ret);
                break;
        case 'ipv4net':
                $ret['ip_bin'] = ip2long ($ret['ip']);
                $ret['mask_bin'] = binMaskFromDec ($ret['mask']);
                $ret['mask_bin_inv'] = binInvMaskFromDec ($ret['mask']);
                $ret['db_first'] = sprintf ('%u', 0x00000000 + $ret['ip_bin'] & $ret['mask_bin']);
                $ret['db_last'] = sprintf ('%u', 0x00000000 + $ret['ip_bin'] | ($ret['mask_bin_inv']));
                break;
        default:
                break;
        }
        $entityCache['partial'][$realm][$id] = $ret;
        return $ret;
}

// This function can be used with array_walk().
function amplifyCell (&$record, $dummy = NULL)
{
        switch ($record['realm'])
        {
        case 'object':
                $record['ports'] = getObjectPortsAndLinks ($record['id']);
                $record['ipv4'] = getObjectIPv4Allocations ($record['id']);
                $record['nat4'] = getNATv4ForObject ($record['id']);
                $record['ipv4rspools'] = getRSPoolsForObject ($record['id']);
                $record['files'] = getFilesOfEntity ($record['realm'], $record['id']);
                break;
        case 'file':
                $record['links'] = getFileLinks ($record['id']);
                break;
        case 'ipv4rspool':
                $record['lblist'] = array();
                $query = "select object_id, vs_id, lb.vsconfig, lb.rsconfig from " .
                        "IPv4LB as lb inner join IPv4VS as vs on lb.vs_id = vs.id " .
                        "where rspool_id = ? order by object_id, vip, vport";
                $result = usePreparedSelectBlade ($query, array ($record['id']));
                while ($row = $result->fetch (PDO::FETCH_ASSOC))
                        $record['lblist'][$row['object_id']][$row['vs_id']] = array
                        (
                                'rsconfig' => $row['rsconfig'],
                                'vsconfig' => $row['vsconfig'],
                        );
                unset ($result);
                $record['rslist'] = array();
                $query = "select id, inservice, inet_ntoa(rsip) as rsip, rsport, rsconfig from " .
                        "IPv4RS where rspool_id = ? order by IPv4RS.rsip, rsport";
                $result = usePreparedSelectBlade ($query, array ($record['id']));
                while ($row = $result->fetch (PDO::FETCH_ASSOC))
                        $record['rslist'][$row['id']] = array
                        (
                                'inservice' => $row['inservice'],
                                'rsip' => $row['rsip'],
                                'rsport' => $row['rsport'],
                                'rsconfig' => $row['rsconfig'],
                        );
                unset ($result);
                break;
        case 'ipv4vs':
                // Get the detailed composition of a particular virtual service, namely the list
                // of all pools, each shown with the list of objects servicing it. VS/RS configs
                // will be returned as well.
                $record['rspool'] = array();
                $query = "select pool.id, name, pool.vsconfig, pool.rsconfig, object_id, " .
                        "lb.vsconfig as lb_vsconfig, lb.rsconfig as lb_rsconfig from " .
                        "IPv4RSPool as pool left join IPv4LB as lb on pool.id = lb.rspool_id " .
                        "where vs_id = ? order by pool.name, object_id";
                $result = usePreparedSelectBlade ($query, array ($record['id']));
                while ($row = $result->fetch (PDO::FETCH_ASSOC))
                {
                        if (!isset ($record['rspool'][$row['id']]))
                                $record['rspool'][$row['id']] = array
                                (
                                        'name' => $row['name'],
                                        'vsconfig' => $row['vsconfig'],
                                        'rsconfig' => $row['rsconfig'],
                                        'lblist' => array(),
                                );
                        if ($row['object_id'] == NULL)
                                continue;
                        $record['rspool'][$row['id']]['lblist'][$row['object_id']] = array
                        (
                                'vsconfig' => $row['lb_vsconfig'],
                                'rsconfig' => $row['lb_rsconfig'],
                        );
                }
                unset ($result);
                break;
        case 'rack':
                $record['mountedObjects'] = array();
                // start with default rackspace
                for ($i = $record['height']; $i > 0; $i--)
                        for ($locidx = 0; $locidx < 3; $locidx++)
                                $record[$i][$locidx]['state'] = 'F';
                // load difference
                $query =
                        "select unit_no, atom, state, object_id " .
                        "from RackSpace where rack_id = ? and " .
                        "unit_no between 1 and ? order by unit_no";
                $result = usePreparedSelectBlade ($query, array ($record['id'], $record['height']));
                global $loclist;
                $mounted_objects = array();
                while ($row = $result->fetch (PDO::FETCH_ASSOC))
                {
                        $record[$row['unit_no']][$loclist[$row['atom']]]['state'] = $row['state'];
                        $record[$row['unit_no']][$loclist[$row['atom']]]['object_id'] = $row['object_id'];
                        if ($row['state'] == 'T' and $row['object_id'] != NULL)
                                $mounted_objects[$row['object_id']] = TRUE;
                }
                $record['mountedObjects'] = array_keys ($mounted_objects);
                unset ($result);
                break;
        case 'ipv4net':
                $record['8021q'] = getIPv4Network8021QBindings ($record['id']);
                break;
        default:
        }
}

function getObjectPortsAndLinks ($object_id)
{
        $query = "SELECT id, name, label, l2address, iif_id, (SELECT iif_name FROM PortInnerInterface WHERE id = iif_id) AS iif_name, " .
                "type AS oif_id, (SELECT dict_value FROM Dictionary WHERE dict_key = type) AS oif_name, reservation_comment " .
                "FROM Port WHERE object_id = ?";
        // list and decode all ports of the current object
        $result = usePreparedSelectBlade ($query, array ($object_id));
        $ret=array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $row['l2address'] = l2addressFromDatabase ($row['l2address']);
                $row['remote_id'] = NULL;
                $row['remote_name'] = NULL;
                $row['remote_object_id'] = NULL;
                $ret[] = $row;
        }
        unset ($result);
        // now find and decode remote ends for all locally terminated connections
        // FIXME: can't this data be extracted in one pass with sub-queries?
        foreach (array_keys ($ret) as $tmpkey)
        {
                $portid = $ret[$tmpkey]['id'];
                $remote_id = NULL;
                $query = "select porta, portb from Link where porta = ? or portb = ?";
                $result = usePreparedSelectBlade ($query, array ($portid, $portid));
                if ($row = $result->fetch (PDO::FETCH_ASSOC))
                {
                        if ($portid != $row['porta'])
                                $remote_id = $row['porta'];
                        elseif ($portid != $row['portb'])
                                $remote_id = $row['portb'];
                }
                unset ($result);
                if ($remote_id) // there's a remote end here
                {
                        $query = "SELECT name, object_id FROM Port WHERE id = ?";
                        $result = usePreparedSelectBlade ($query, array ($remote_id));
                        if ($row = $result->fetch (PDO::FETCH_ASSOC))
                        {
                                $ret[$tmpkey]['remote_name'] = $row['name'];
                                $ret[$tmpkey]['remote_object_id'] = $row['object_id'];
                        }
                        $ret[$tmpkey]['remote_id'] = $remote_id;
                        unset ($result);
                }
        }
        usort ($ret, 'sortByName');
        return $ret;
}

function commitAddRack ($name, $height = 0, $row_id = 0, $comment, $taglist)
{
        if ($row_id <= 0 or $height <= 0 or !strlen ($name))
                return FALSE;
        $result = usePreparedInsertBlade
        (
                'Rack',
                array
                (
                        'row_id' => $row_id,
                        'name' => $name,
                        'height' =>  $height,
                        'comment' => $comment
                )
        );
        $last_insert_id = lastInsertID();
        return (produceTagsForLastRecord ('rack', $taglist, $last_insert_id) == '') and recordHistory ('Rack', $last_insert_id);
}

function commitAddObject ($new_name, $new_label, $new_barcode, $new_type_id, $new_asset_no, $taglist = array())
{
        // Maintain UNIQUE INDEX for common names and asset tags by
        // filtering out empty strings (not NULLs).
        $result1 = usePreparedInsertBlade
        (
                'RackObject',
                array
                (
                        'name' => !strlen ($new_name) ? NULL : $new_name,
                        'label' => $new_label,
                        'barcode' => !strlen ($new_barcode) ? NULL : $new_barcode,
                        'objtype_id' => $new_type_id,
                        'asset_no' => !strlen ($new_asset_no) ? NULL : $new_asset_no,
                )
        );
        $last_insert_id = lastInsertID();
        // Do AutoPorts magic
        executeAutoPorts ($last_insert_id, $new_type_id);
        // Now tags...
        $error = produceTagsForLastRecord ('object', $taglist, $last_insert_id);

        recordHistory ('RackObject', $last_insert_id);

        return $last_insert_id;
}

function commitUpdateObject ($object_id = 0, $new_name = '', $new_label = '', $new_barcode = '', $new_type_id = 0, $new_has_problems = 'no', $new_asset_no = '', $new_comment = '')
{
        if ($new_type_id == 0)
                throw new InvalidArgException ('$new_type_id', $new_type_id);
        $ret = FALSE !== usePreparedExecuteBlade
        (
                'UPDATE RackObject SET name=?, label=?, barcode=?, objtype_id=?, has_problems=?, ' .
                'asset_no=?, comment=? WHERE id=?',
                array
                (
                        !strlen ($new_name) ? NULL : $new_name,
                        $new_label,
                        !strlen ($new_barcode) ? NULL : $new_barcode,
                        $new_type_id,
                        $new_has_problems,
                        !strlen ($new_asset_no) ? NULL : $new_asset_no,
                        $new_comment,
                        $object_id
                )
        );
        return $ret and recordHistory ('RackObject', $object_id);
}

// Remove file links related to the entity, but leave the entity and file(s) intact.
function releaseFiles ($entity_realm, $entity_id)
{
        usePreparedDeleteBlade ('FileLink', array ('entity_type' => $entity_realm, 'entity_id' => $entity_id));
}

// There are times when you want to delete all traces of an object
function commitDeleteObject ($object_id = 0)
{
        releaseFiles ('object', $object_id);
        destroyTagsForEntity ('object', $object_id);
        usePreparedDeleteBlade ('IPv4LB', array ('object_id' => $object_id));
        usePreparedDeleteBlade ('IPv4Allocation', array ('object_id' => $object_id));
        usePreparedDeleteBlade ('IPv4NAT', array ('object_id' => $object_id));
        usePreparedExecuteBlade ('DELETE FROM Atom WHERE molecule_id IN (SELECT new_molecule_id FROM MountOperation WHERE object_id = ?)', array ($object_id));
        usePreparedExecuteBlade ('DELETE FROM Molecule WHERE id IN (SELECT new_molecule_id FROM MountOperation WHERE object_id = ?)', array ($object_id));
        usePreparedDeleteBlade ('RackObject', array ('id' => $object_id));
        return '';
}

function commitDeleteRack($rack_id)
{
        releaseFiles ('rack', $rack_id);
        destroyTagsForEntity ('rack', $rack_id);
        usePreparedDeleteBlade ('RackSpace', array ('rack_id' => $rack_id));
        usePreparedDeleteBlade ('RackHistory', array ('id' => $rack_id));
        usePreparedDeleteBlade ('Rack', array ('id' => $rack_id));
        return TRUE;
}

function commitUpdateRack ($rack_id, $new_name, $new_height, $new_row_id, $new_comment)
{
        // Can't shrink a rack if rows being deleted contain mounted objects
        $check_result = usePreparedSelectBlade ('SELECT COUNT(*) AS count FROM RackSpace WHERE rack_id = ? AND unit_no > ?', array ($rack_id, $new_height));
        $check_row = $check_result->fetch (PDO::FETCH_ASSOC);
        unset ($check_result);
        if ($check_row['count'] > 0)
                throw new InvalidArgException ('new_height', $new_height, 'Cannot shrink rack, objects are still mounted there');

        usePreparedExecuteBlade
        (
                'UPDATE Rack SET name=?, height=?, comment=?, row_id=? WHERE id=?',
                array
                (
                        $new_name,
                        $new_height,
                        $new_comment,
                        $new_row_id,
                        $rack_id,
                )
        );
        return recordHistory ('Rack', $rack_id);
}

// This function accepts rack data returned by amplifyCell(), validates and applies changes
// supplied in $_REQUEST and returns resulting array. Only those changes are examined, which
// correspond to current rack ID.
// 1st arg is rackdata, 2nd arg is unchecked state, 3rd arg is checked state.
// If 4th arg is present, object_id fields will be updated accordingly to the new state.
// The function returns the modified rack upon success.
function processGridForm (&$rackData, $unchecked_state, $checked_state, $object_id = 0)
{
        global $loclist;
        $rack_id = $rackData['id'];
        $rack_name = $rackData['name'];
        $rackchanged = FALSE;
        for ($unit_no = $rackData['height']; $unit_no > 0; $unit_no--)
        {
                for ($locidx = 0; $locidx < 3; $locidx++)
                {
                        if ($rackData[$unit_no][$locidx]['enabled'] != TRUE)
                                continue;
                        // detect a change
                        $state = $rackData[$unit_no][$locidx]['state'];
                        if (isset ($_REQUEST["atom_${rack_id}_${unit_no}_${locidx}"]) and $_REQUEST["atom_${rack_id}_${unit_no}_${locidx}"] == 'on')
                                $newstate = $checked_state;
                        else
                                $newstate = $unchecked_state;
                        if ($state == $newstate)
                                continue;
                        $rackchanged = TRUE;
                        // and validate
                        $atom = $loclist[$locidx];
                        // The only changes allowed are those introduced by checkbox grid.
                        if
                        (
                                !($state == $checked_state && $newstate == $unchecked_state) &&
                                !($state == $unchecked_state && $newstate == $checked_state)
                        )
                                return array ('code' => 500, 'message' => "${rack_name}: Rack ID ${rack_id}, unit ${unit_no}, 'atom ${atom}', cannot change state from '${state}' to '${newstate}'");
                        // Here we avoid using ON DUPLICATE KEY UPDATE by first performing DELETE
                        // anyway and then looking for probable need of INSERT.
                        usePreparedDeleteBlade ('RackSpace', array ('rack_id' => $rack_id, 'unit_no' => $unit_no, 'atom' => $atom));
                        if ($newstate != 'F')
                                usePreparedInsertBlade ('RackSpace', array ('rack_id' => $rack_id, 'unit_no' => $unit_no, 'atom' => $atom, 'state' => $newstate));
                        if ($newstate == 'T' and $object_id != 0)
                        {
                                // At this point we already have a record in RackSpace.
                                $r = usePreparedExecuteBlade
                                (
                                        'UPDATE RackSpace SET object_id=? ' .
                                        'WHERE rack_id=? AND unit_no=? AND atom=?',
                                        array ($object_id, $rack_id, $unit_no, $atom)
                                );
                                if ($r === FALSE)
                                        return array ('code' => 500, 'message' => "${rack_name}: Rack ID ${rack_id}, unit ${unit_no}, atom '${atom}' failed to set object_id to '${object_id}'");
                                $rackData[$unit_no][$locidx]['object_id'] = $object_id;
                        }
                }
        }
        if ($rackchanged)
        {
                resetThumbCache ($rack_id);
                return array ('code' => 200, 'message' => "${rack_name}: All changes were successfully saved.");
        }
        else
                return array ('code' => 300, 'message' => "${rack_name}: No changes.");
}

// This function builds a list of rack-unit-atom records, which are assigned to
// the requested object.
function getMoleculeForObject ($object_id)
{
        $result = usePreparedSelectBlade
        (
                'SELECT rack_id, unit_no, atom FROM RackSpace ' .
                'WHERE state = "T" AND object_id = ? ORDER BY rack_id, unit_no, atom',
                array ($object_id)
        );
        return $result->fetchAll (PDO::FETCH_ASSOC);
}

// This function builds a list of rack-unit-atom records for requested molecule.
function getMolecule ($mid = 0)
{
        $result = usePreparedSelectBlade ('SELECT rack_id, unit_no, atom FROM Atom WHERE molecule_id = ?', array ($mid));
        return $result->fetchAll (PDO::FETCH_ASSOC);
}

// returns exactly what is's named after
function lastInsertID ()
{
        $result = usePreparedSelectBlade ('select last_insert_id()');
        $row = $result->fetch (PDO::FETCH_NUM);
        return $row[0];
}

// This function creates a new record in Molecule and number of linked
// R-U-A records in Atom.
function createMolecule ($molData)
{
        usePreparedExecuteBlade ('INSERT INTO Molecule VALUES()');
        $molecule_id = lastInsertID();
        foreach ($molData as $rua)
                usePreparedInsertBlade
                (
                        'Atom',
                        array
                        (
                                'molecule_id' => $molecule_id,
                                'rack_id' => $rua['rack_id'],
                                'unit_no' => $rua['unit_no'],
                                'atom' => $rua['atom'],
                        )
                );
        return $molecule_id;
}

// History logger. This function assumes certain table naming convention and
// column design:
// 1. History table name equals to dictionary table name plus 'History'.
// 2. History table must have the same row set (w/o keys) plus one row named
// 'ctime' of type 'timestamp'.
function recordHistory ($tableName, $orig_id)
{
        global $remote_username;
        return FALSE !== usePreparedExecuteBlade
        (
                "INSERT INTO ${tableName}History SELECT *, CURRENT_TIMESTAMP(), ? " .
                "FROM ${tableName} WHERE id=?",
                array ($remote_username, $orig_id)
        );
}

function getRackspaceHistory ()
{
        $result = usePreparedSelectBlade
        (
                "SELECT id as mo_id, object_id as ro_id, ctime, comment, user_name FROM " .
                "MountOperation ORDER BY ctime DESC"
        );
        return $result->fetchAll (PDO::FETCH_ASSOC);
}

// This function is used in renderRackspaceHistory()
function getOperationMolecules ($op_id = 0)
{
        $result = usePreparedSelectBlade ('SELECT old_molecule_id, new_molecule_id FROM MountOperation WHERE id = ?', array ($op_id));
        // We expect one row.
        $row = $result->fetch (PDO::FETCH_ASSOC);
        return array ($row['old_molecule_id'], $row['new_molecule_id']);
}

function getResidentRacksData ($object_id = 0, $fetch_rackdata = TRUE)
{
        $result = usePreparedSelectBlade ('SELECT DISTINCT rack_id FROM RackSpace WHERE object_id = ? ORDER BY rack_id', array ($object_id));
        $rows = $result->fetchAll (PDO::FETCH_NUM);
        unset ($result);
        $ret = array();
        foreach ($rows as $row)
        {
                if (!$fetch_rackdata)
                {
                        $ret[$row[0]] = $row[0];
                        continue;
                }
                $rackData = spotEntity ('rack', $row[0]);
                amplifyCell ($rackData);
                $ret[$row[0]] = $rackData;
        }
        return $ret;
}

function commitAddPort ($object_id = 0, $port_name, $port_type_id, $port_label, $port_l2address)
{
        if (NULL === ($db_l2address = l2addressForDatabase ($port_l2address)))
                return "Invalid L2 address ${port_l2address}";
        global $dbxlink;
        $dbxlink->exec ('LOCK TABLES Port WRITE');
        if (alreadyUsedL2Address ($db_l2address, $object_id))
        {
                $dbxlink->exec ('UNLOCK TABLES');
                return "address ${db_l2address} belongs to another object";
        }
        $matches = array();
        switch (1)
        {
        case preg_match ('/^([[:digit:]]+)-([[:digit:]]+)$/', $port_type_id, $matches):
                $iif_id = $matches[1];
                $oif_id = $matches[2];
                break;
        case preg_match ('/^([[:digit:]]+)$/', $port_type_id, $matches):
                $iif_id = 1;
                $oif_id = $matches[1];
                break;
        default:
                $dbxlink->exec ('UNLOCK TABLES');
                return "invalid port type id '${port_type_id}'";
        }
        $result = usePreparedInsertBlade
        (
                'Port',
                array
                (
                        'name' => $port_name,
                        'object_id' => $object_id,
                        'label' => $port_label,
                        'iif_id' => $iif_id,
                        'type' => $oif_id,
                        'l2address' => ($db_l2address === '') ? NULL : $db_l2address,
                )
        );
        $dbxlink->exec ('UNLOCK TABLES');
        if ($result)
                return '';
        else
                return 'SQL query failed';
}

// The fifth argument may be either explicit 'NULL' or some (already quoted by the upper layer)
// string value. In case it is omitted, we just assign it its current value.
// It would be nice to simplify this semantics later.
function commitUpdatePort ($object_id, $port_id, $port_name, $port_type_id, $port_label, $port_l2address, $port_reservation_comment)
{
        if (NULL === ($db_l2address = l2addressForDatabase ($port_l2address)))
                return "Invalid L2 address ${port_l2address}";
        global $dbxlink;
        $dbxlink->exec ('LOCK TABLES Port WRITE');
        if (alreadyUsedL2Address ($db_l2address, $object_id))
        {
                $dbxlink->exec ('UNLOCK TABLES');
                return "address ${db_l2address} belongs to another object";
        }
        $result = usePreparedExecuteBlade
        (
                'UPDATE Port SET name=?, type=?, label=?, reservation_comment=?, ' .
                'l2address=? WHERE id=? AND object_id=?',
                array
                (
                        $port_name,
                        $port_type_id,
                        $port_label,
                        mb_strlen ($port_reservation_comment) ? $port_reservation_comment : NULL,
                        ($db_l2address === '') ? NULL : $db_l2address,
                        $port_id,
                        $object_id
                )
        );
        $dbxlink->exec ('UNLOCK TABLES');
        if ($result == 1)
                return '';
        $errorInfo = $dbxlink->errorInfo();
        // We could update nothing.
        if ($errorInfo[0] == '00000')
                return '';
        return $errorInfo[2];
}

function delObjectPort ($port_id)
{
        if (usePreparedDeleteBlade ('Port', array ('id' => $port_id)) != TRUE)
                return __FUNCTION__ . ': usePreparedDeleteBlade() failed';
        return '';
}

function getAllIPv4Allocations ()
{
        $result = usePreparedSelectBlade
        (
                "select object_id as object_id, ".
                "RackObject.name as object_name, ".
                "IPv4Allocation.name as name, ".
                "INET_NTOA(ip) as ip ".
                "from IPv4Allocation join RackObject on id=object_id "
        );
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[] = $row;
        return $ret;
}

function linkPorts ($porta, $portb)
{
        if ($porta == $portb)
                throw new InvalidArgException ('porta/portb', $porta, "Ports can't be the same");
        if ($porta > $portb)
        {
                $tmp = $porta;
                $porta = $portb;
                $portb = $tmp;
        }
        $ret = FALSE !== usePreparedInsertBlade ('Link', array ('porta' => $porta, 'portb' => $portb));
        $ret = $ret and FALSE !== usePreparedExecuteBlade
        (
                'UPDATE Port SET reservation_comment=NULL WHERE id IN(?, ?)',
                array ($porta, $portb)
        );
        return $ret ? '' : 'query failed';
}

function unlinkPort ($port_id)
{
        usePreparedDeleteBlade ('Link', array ('porta' => $port_id, 'portb' => $port_id), 'OR');
        return '';
}

// Return all IPv4 addresses allocated to the objects. Attach detailed
// info about address to each alocation records. Index result by dotted-quad
// address.
function getObjectIPv4Allocations ($object_id = 0)
{
        $ret = array();
        $result = usePreparedSelectBlade
        (
                'SELECT name AS osif, type, inet_ntoa(ip) AS dottedquad FROM IPv4Allocation ' .
                'WHERE object_id = ? ORDER BY ip',
                array ($object_id)
        );
        // don't spawn a sub-query with unfetched buffer, it may fail
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['dottedquad']] = array ('osif' => $row['osif'], 'type' => $row['type']);
        unset ($result);
        foreach (array_keys ($ret) as $dottedquad)
                $ret[$dottedquad]['addrinfo'] = getIPv4Address ($dottedquad);
        return $ret;
}

// Return minimal IPv4 address, optionally with "ip" key set, if requested.
function constructIPv4Address ($dottedquad = NULL)
{
        $ret = array
        (
                'name' => '',
                'reserved' => 'no',
                'outpf' => array(),
                'inpf' => array(),
                'rslist' => array(),
                'allocs' => array(),
                'lblist' => array()
        );
        if ($dottedquad != NULL)
                $ret['ip'] = $dottedquad;
        return $ret;
}

// Check the range requested for meaningful IPv4 records, build them
// into a list and return. Return an empty list if nothing matched.
// Both arguments are expected in signed int32 form. The resulting list
// is keyed by uint32 form of each IP address, items aren't sorted.
// LATER: accept a list of pairs and build WHERE sub-expression accordingly
function scanIPv4Space ($pairlist)
{
        $ret = array();
        if (!count ($pairlist)) // this is normal for a network completely divided into smaller parts
                return $ret;
        // FIXME: this is a copy-and-paste prototype
        $or = '';
        $whereexpr1 = '(';
        $whereexpr2 = '(';
        $whereexpr3 = '(';
        $whereexpr4 = '(';
        $whereexpr5a = '(';
        $whereexpr5b = '(';
        $qparams = array();
        foreach ($pairlist as $tmp)
        {
                $db_first = sprintf ('%u', 0x00000000 + $tmp['i32_first']);
                $db_last = sprintf ('%u', 0x00000000 + $tmp['i32_last']);
                $whereexpr1 .= $or . "ip between ? and ?";
                $whereexpr2 .= $or . "ip between ? and ?";
                $whereexpr3 .= $or . "vip between ? and ?";
                $whereexpr4 .= $or . "rsip between ? and ?";
                $whereexpr5a .= $or . "remoteip between ? and ?";
                $whereexpr5b .= $or . "localip between ? and ?";
                $or = ' or ';
                $qparams[] = $db_first;
                $qparams[] = $db_last;
        }
        $whereexpr1 .= ')';
        $whereexpr2 .= ')';
        $whereexpr3 .= ')';
        $whereexpr4 .= ')';
        $whereexpr5a .= ')';
        $whereexpr5b .= ')';

        // 1. collect labels and reservations
        $query = "select INET_NTOA(ip) as ip, name, reserved from IPv4Address ".
                "where ${whereexpr1} and (reserved = 'yes' or name != '')";
        $result = usePreparedSelectBlade ($query, $qparams);
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $ip_bin = ip2long ($row['ip']);
                if (!isset ($ret[$ip_bin]))
                        $ret[$ip_bin] = constructIPv4Address ($row['ip']);
                $ret[$ip_bin]['name'] = $row['name'];
                $ret[$ip_bin]['reserved'] = $row['reserved'];
        }
        unset ($result);

        // 2. check for allocations
        $query =
                "select INET_NTOA(ip) as ip, object_id, name, type " .
                "from IPv4Allocation where ${whereexpr2} order by type";
        $result = usePreparedSelectBlade ($query, $qparams);
        // release DBX early to avoid issues with nested spotEntity() calls
        $allRows = $result->fetchAll (PDO::FETCH_ASSOC);
        unset ($result);
        foreach ($allRows as $row)
        {
                $ip_bin = ip2long ($row['ip']);
                if (!isset ($ret[$ip_bin]))
                        $ret[$ip_bin] = constructIPv4Address ($row['ip']);
                $oinfo = spotEntity ('object', $row['object_id']);
                $ret[$ip_bin]['allocs'][] = array
                (
                        'type' => $row['type'],
                        'name' => $row['name'],
                        'object_id' => $row['object_id'],
                        'object_name' => $oinfo['dname'],
                );
        }

        // 3. look for virtual services and related LB 
        $query = "select vs_id, inet_ntoa(vip) as ip, vport, proto, vs.name, object_id " .
                "from IPv4VS as vs inner join IPv4LB as lb on vs.id = lb.vs_id " .
                "where ${whereexpr3} order by vport, proto, object_id";
        $result = usePreparedSelectBlade ($query, $qparams);
        $allRows = $result->fetchAll (PDO::FETCH_ASSOC);
        unset ($result);
        foreach ($allRows as $row)
        {
                $ip_bin = ip2long ($row['ip']);
                if (!isset ($ret[$ip_bin]))
                        $ret[$ip_bin] = constructIPv4Address ($row['ip']);
                $oinfo = spotEntity ('object', $row['object_id']);
                $ret[$ip_bin]['lblist'][] = array
                (
                        'vport' => $row['vport'],
                        'proto' => $row['proto'],
                        'vs_id' => $row['vs_id'],
                        'name' => $row['name'],
                        'vip' => $row['ip'],
                        'object_id' => $row['object_id'],
                        'object_name' => $oinfo['dname'],
                );
        }

        // 4. don't forget about real servers along with pools
        $query = "select inet_ntoa(rsip) as ip, inservice, rsport, rspool_id, rsp.name as rspool_name from " .
                "IPv4RS as rs inner join IPv4RSPool as rsp on rs.rspool_id = rsp.id " .
                "where ${whereexpr4} " .
                "order by ip, rsport, rspool_id";
        $result = usePreparedSelectBlade ($query, $qparams);
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $ip_bin = ip2long ($row['ip']);
                if (!isset ($ret[$ip_bin]))
                        $ret[$ip_bin] = constructIPv4Address ($row['ip']);
                $tmp = array();
                foreach (array ('rspool_id', 'rsport', 'rspool_name', 'inservice') as $cname)
                        $tmp[$cname] = $row[$cname];
                $ret[$ip_bin]['rslist'][] = $tmp;
        }
        unset ($result);

        // 5. add NAT rules, part 1
        $query =
                "select " .
                "proto, " .
                "INET_NTOA(localip) as localip, " .
                "localport, " .
                "INET_NTOA(remoteip) as remoteip, " .
                "remoteport, " .
                "description " .
                "from IPv4NAT " .
                "where ${whereexpr5a} " .
                "order by localip, localport, remoteip, remoteport, proto";
        $result = usePreparedSelectBlade ($query, $qparams);
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $remoteip_bin = ip2long ($row['remoteip']);
                if (!isset ($ret[$remoteip_bin]))
                        $ret[$remoteip_bin] = constructIPv4Address ($row['remoteip']);
                $ret[$remoteip_bin]['inpf'][] = $row;
        }
        unset ($result);
        // 5. add NAT rules, part 2
        $query =
                "select " .
                "proto, " .
                "INET_NTOA(localip) as localip, " .
                "localport, " .
                "INET_NTOA(remoteip) as remoteip, " .
                "remoteport, " .
                "description " .
                "from IPv4NAT " .
                "where ${whereexpr5b} " .
                "order by localip, localport, remoteip, remoteport, proto";
        $result = usePreparedSelectBlade ($query, $qparams);
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $localip_bin = ip2long ($row['localip']);
                if (!isset ($ret[$localip_bin]))
                        $ret[$localip_bin] = constructIPv4Address ($row['localip']);
                $ret[$localip_bin]['outpf'][] = $row;
        }
        unset ($result);
        return $ret;
}

function getIPv4Address ($dottedquad = '')
{
        if ($dottedquad == '')
                throw new InvalidArgException ('$dottedquad', $dottedquad);
        $i32 = ip2long ($dottedquad); // signed 32 bit
        $scanres = scanIPv4Space (array (array ('i32_first' => $i32, 'i32_last' => $i32)));
        if (!isset ($scanres[$i32]))
                //$scanres[$i32] = constructIPv4Address ($dottedquad); // XXX: this should be verified to not break things
                return constructIPv4Address ($dottedquad);
        markupIPv4AddrList ($scanres);
        return $scanres[$i32];
}

function bindIpToObject ($ip = '', $object_id = 0, $name = '', $type = '')
{
        $result = usePreparedExecuteBlade
        (
                'INSERT INTO IPv4Allocation (ip, object_id, name, type) VALUES (INET_ATON(?), ?, ?, ?)',
                array ($ip, $object_id, $name, $type)
        );
        return $result ? '' : (__FUNCTION__ . '(): query failed');
}

// Return the id of the smallest IPv4 network containing the given IPv4 address
// or NULL, if nothing was found. When finding the covering network for
// another network, it is important to filter out matched records with longer
// masks (they aren't going to be the right pick).
function getIPv4AddressNetworkId ($dottedquad, $masklen = 32)
{
// N.B. To perform the same for IPv6 address and networks, some pre-requisites
// are necessary and a different query. IPv6 addresses are 128 bit long, which
// is too much for both PHP and MySQL data types. These values must be split
// into 4 32-byte long parts (b_u32_0, b_u32_1, b_u32_2, b_u32_3).
// Then each network must have its 128-bit netmask split same way and either
// stored right in its record or JOINed from decoder and accessible as m_u32_0,
// m_u32_1, m_u32_2, m_u32_3. After that the query to pick the smallest network
// covering the given address would look as follows:
// $query = 'select id from IPv6Network as n where ' .
// "(${b_u32_0} & n.m_u32_0 = n.b_u32_0) and " .
// "(${b_u32_1} & n.m_u32_1 = n.b_u32_1) and " .
// "(${b_u32_2} & n.m_u32_2 = n.b_u32_2) and " .
// "(${b_u32_3} & n.m_u32_3 = n.b_u32_3) and " .
// "mask < ${masklen} " .
// 'order by mask desc limit 1';

        $query = 'select id from IPv4Network where ' .
                "inet_aton(?) & (4294967295 >> (32 - mask)) << (32 - mask) = ip " .
                "and mask < ? " .
                'order by mask desc limit 1';
        $result = usePreparedSelectBlade ($query, array ($dottedquad, $masklen));
        if ($row = $result->fetch (PDO::FETCH_ASSOC))
                return $row['id'];
        return NULL;
}

function updateIPv4Network_real ($id = 0, $name = '', $comment = '')
{
        return usePreparedExecuteBlade ('UPDATE IPv4Network SET name = ?, comment = ? WHERE id = ?', array ($name, $comment, $id));
}

// This function is actually used not only to update, but also to create records,
// that's why ON DUPLICATE KEY UPDATE was replaced by DELETE-INSERT pair
// (MySQL 4.0 workaround).
function updateAddress ($ip = 0, $name = '', $reserved = 'no')
{
        usePreparedExecuteBlade ('DELETE FROM IPv4Address WHERE ip = INET_ATON(?)', array ($ip));
        // INSERT may appear not necessary.
        if ($name == '' and $reserved == 'no')
                return '';
        $ret = usePreparedExecuteBlade
        (
                'INSERT INTO IPv4Address (name, reserved, ip) VALUES (?, ?, INET_ATON(?))',
                array ($name, $reserved, $ip)
        );
        return $ret !== FALSE ? '' : (__FUNCTION__ . 'query failed');
}

function updateBond ($ip='', $object_id=0, $name='', $type='')
{
        return usePreparedExecuteBlade
        (
                'UPDATE IPv4Allocation SET name=?, type=? WHERE ip=INET_ATON(?) AND object_id=?',
                array ($name, $type, $ip, $object_id)
        );
}

function unbindIpFromObject ($ip='', $object_id=0)
{
        return usePreparedExecuteBlade
        (
                'DELETE FROM IPv4Allocation WHERE ip=INET_ATON(?) AND object_id=?',
                array ($ip, $object_id)
        );
}

function getIPv4PrefixSearchResult ($terms)
{
        $byname = getSearchResultByField
        (
                'IPv4Network',
                array ('id'),
                'name',
                $terms,
                'ip'
        );
        $ret = array();
        foreach ($byname as $row)
                $ret[] = spotEntity ('ipv4net', $row['id']);
        return $ret;
}

function getIPv4AddressSearchResult ($terms)
{
        $query = "select inet_ntoa(ip) as ip, name from IPv4Address where ";
        $or = '';
        $qparams = array();
        foreach (explode (' ', $terms) as $term)
        {
                $query .= $or . "name like ?";
                $or = ' or ';
                $qparams[] = "%${term}%";
        }
        $result = usePreparedSelectBlade ($query, $qparams);
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[] = $row;
        return $ret;
}

function getIPv4RSPoolSearchResult ($terms)
{
        $byname = getSearchResultByField
        (
                'IPv4RSPool',
                array ('id'),
                'name',
                $terms,
                'name'
        );
        $ret = array();
        foreach ($byname as $row)
                $ret[] = spotEntity ('ipv4rspool', $row['id']);
        return $ret;
}

function getIPv4VServiceSearchResult ($terms)
{
        $byname = getSearchResultByField
        (
                'IPv4VS',
                array ('id'),
                'name',
                $terms,
                'vip'
        );
        $ret = array();
        foreach ($byname as $row)
                $ret[] = spotEntity ('ipv4vs', $row['id']);
        return $ret;
}

function getAccountSearchResult ($terms)
{
        $byUsername = getSearchResultByField
        (
                'UserAccount',
                array ('user_id', 'user_name', 'user_realname'),
                'user_name',
                $terms,
                'user_name'
        );
        $byRealname = getSearchResultByField
        (
                'UserAccount',
                array ('user_id', 'user_name', 'user_realname'),
                'user_realname',
                $terms,
                'user_name'
        );
        // Filter out dupes.
        foreach ($byUsername as $res1)
                foreach (array_keys ($byRealname) as $key2)
                        if ($res1['user_id'] == $byRealname[$key2]['user_id'])
                        {
                                unset ($byRealname[$key2]);
                                continue 2;
                        }
        $ret = array_merge ($byUsername, $byRealname);
        // Set realm, so it's renderable.
        foreach (array_keys ($ret) as $key)
                $ret[$key]['realm'] = 'user';
        return $ret;
}

function getFileSearchResult ($terms)
{
        $byName = getSearchResultByField
        (
                'File',
                array ('id'),
                'name',
                $terms,
                'name'
        );
        $byComment = getSearchResultByField
        (
                'File',
                array ('id'),
                'comment',
                $terms,
                'name'
        );
        // Filter out dupes.
        foreach ($byName as $res1)
                foreach (array_keys ($byComment) as $key2)
                        if ($res1['id'] == $byComment[$key2]['id'])
                        {
                                unset ($byComment[$key2]);
                                continue 2;
                        }
        $ret = array();
        foreach (array_merge ($byName, $byComment) as $row)
                $ret[] = spotEntity ('file', $row['id']);
        return $ret;
}

function getRackSearchResult ($terms)
{
        $byName = getSearchResultByField
        (
                'Rack',
                array ('id'),
                'name',
                $terms,
                'name'
        );
        $byComment = getSearchResultByField
        (
                'Rack',
                array ('id'),
                'comment',
                $terms,
                'name'
        );
        // Filter out dupes.
        foreach ($byName as $res1)
                foreach (array_keys ($byComment) as $key2)
                        if ($res1['id'] == $byComment[$key2]['id'])
                        {
                                unset ($byComment[$key2]);
                                continue 2;
                        }
        $ret = array();
        foreach (array_merge ($byName, $byComment) as $row)
                $ret[] = spotEntity ('rack', $row['id']);
        return $ret;
}

function getSearchResultByField ($tname, $rcolumns, $scolumn, $terms, $ocolumn = '', $exactness = 0)
{
        $pfx = '';
        $query = 'select ';
        $qparams = array();
        foreach ($rcolumns as $col)
        {
                $query .= $pfx . $col;
                $pfx = ', ';
        }
        $pfx = '';
        $query .= " from ${tname} where ";
        foreach (explode (' ', $terms) as $term)
        {
                switch ($exactness)
                {
                case 2: // does this work as expected?
                        $query .= $pfx . "binary ${scolumn} = ?";
                        $qparams[] = $term;
                        break;
                case 1:
                        $query .= $pfx . "${scolumn} = ?";
                        $qparams[] = $term;
                        break;
                default:
                        $query .= $pfx . "${scolumn} like ?";
                        $qparams[] = "%${term}%";
                        break;
                }
                $pfx = ' or ';
        }
        if ($ocolumn != '')
                $query .= " order by ${ocolumn}";
        $result = usePreparedSelectBlade ($query, $qparams);
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[] = $row;
        return $ret;
}

function getObjectSearchResults ($what)
{
        $ret = array();
        global $searchfunc;
        foreach ($searchfunc['object'] as $method => $func)
                foreach ($func ($what) as $objRecord)
                {
                        $ret[$objRecord['id']]['id'] = $objRecord['id'];
                        $ret[$objRecord['id']][$method] = $objRecord[$method];
                }
        return $ret;
}

function getObjectAttrsSearchResults ($what)
{
        $ret = array();
        foreach (array ('name', 'label', 'asset_no', 'barcode') as $column)
        {
                $tmp = getSearchResultByField
                (
                        'RackObject',
                        array ('id'),
                        $column,
                        $what,
                        $column
                );
                foreach ($tmp as $row)
                {
                        $ret[$row['id']]['id'] = $row['id'];
                        $ret[$row['id']]['by_attr'][] = $column;
                }
        }
        return $ret;
}

// Look for EXACT value in stickers and return a list of pairs "object_id-attribute_id",
// which matched. A partilar object_id could be returned more, than once, if it has
// multiple matching stickers. Search is only performed on "string" attributes.
function getStickerSearchResults ($what, $exactness = 0)
{
        $stickers = getSearchResultByField
        (
                'AttributeValue',
                array ('object_id', 'attr_id'),
                'string_value',
                $what,
                'object_id',
                $exactness
        );
        $map = getAttrMap();
        $ret = array();
        foreach ($stickers as $sticker)
                if ($map[$sticker['attr_id']]['type'] == 'string')
                {
                        $ret[$sticker['object_id']]['id'] = $sticker['object_id'];
                        $ret[$sticker['object_id']]['by_sticker'][] = $sticker['attr_id'];
                }
        return $ret;
}

// search in port "reservation comment", "label" and "L2 address" columns
function getPortSearchResults ($what)
{
        $ret = array();
        $ports = getSearchResultByField
        (
                'Port',
                array ('object_id', 'id', 'reservation_comment'),
                'reservation_comment',
                $what,
                'object_id',
                0
        );
        foreach ($ports as $port)
        {
                $ret[$port['object_id']]['id'] = $port['object_id'];
                $ret[$port['object_id']]['by_port'][$port['id']] = $port['reservation_comment'];
        }
        $ports = getSearchResultByField
        (
                'Port',
                array ('object_id', 'id', 'label'),
                'label',
                $what,
                'object_id',
                0
        );
        foreach ($ports as $port)
        {
                $ret[$port['object_id']]['id'] = $port['object_id'];
                $ret[$port['object_id']]['by_port'][$port['id']] = $port['label'];
        }
        if (NULL === ($db_l2address = l2addressForDatabase ($what)))
                return $ret;
        $ports = getSearchResultByField
        (
                'Port',
                array ('object_id', 'id', 'l2address'),
                'l2address',
                $db_l2address,
                'object_id',
                2
        );
        foreach ($ports as $port)
        {
                $ret[$port['object_id']]['id'] = $port['object_id'];
                $ret[$port['object_id']]['by_port'][$port['id']] = $port['l2address'];
        }
        return $ret;
}

// search in IPv4 allocations
function getObjectIfacesSearchResults ($what)
{
        $ret = array();
        $ifaces = getSearchResultByField
        (
                'IPv4Allocation',
                array ('object_id', 'name'),
                'name',
                $what,
                'object_id'
        );
        foreach ($ifaces as $row)
        {
                $ret[$row['object_id']]['id'] = $row['object_id'];
                $ret[$row['object_id']]['by_iface'][] = $row['name'];
        }
        return $ret;
}

function getObjectNATSearchResults ($what)
{
        $ret = array();
        $ifaces = getSearchResultByField
        (
                'IPv4NAT',
                array ('object_id', 'description'),
                'description',
                $what,
                'object_id'
        );
        foreach ($ifaces as $row)
        {
                $ret[$row['object_id']]['id'] = $row['object_id'];
                $ret[$row['object_id']]['by_nat'][] = $row['description'];
        }
        return $ret;
}

// This function returns either port ID or NULL for specified arguments.
function getPortIDs ($object_id, $port_name)
{
        $ret = array();
        $result = usePreparedSelectBlade ('SELECT id FROM Port WHERE object_id = ? AND name = ?', array ($object_id, $port_name));
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[] = $row['id'];
        return $ret;
}

// Search in "FQDN" attribute only, and return object ID, when there is exactly
// one result found (and NULL in any other case).
function searchByMgmtHostname ($string)
{
        $result = usePreparedSelectBlade ('SELECT object_id FROM AttributeValue WHERE attr_id = 3 AND string_value = ? LIMIT 2', array ($string));
        $rows = $result->fetchAll (PDO::FETCH_NUM);
        if (count ($rows) != 1)
                return NULL;
        return $rows[0][0];
}

function commitCreateUserAccount ($username, $realname, $password)
{
        return usePreparedInsertBlade
        (
                'UserAccount',
                array
                (
                        'user_name' => $username,
                        'user_realname' => $realname,
                        'user_password_hash' => $password,
                )
        );
}

function commitUpdateUserAccount ($id, $new_username, $new_realname, $new_password)
{
        return usePreparedExecuteBlade
        (
                'UPDATE UserAccount SET user_name=?, user_realname=?, user_password_hash=? ' .
                'WHERE user_id=?',
                array ($new_username, $new_realname, $new_password, $id)
        );
}

// This function returns an array of all port type pairs from PortCompat table.
function getPortOIFCompat ()
{
        $query =
                "select type1, type2, d1.dict_value as type1name, d2.dict_value as type2name from " .
                "PortCompat as pc inner join Dictionary as d1 on pc.type1 = d1.dict_key " .
                "inner join Dictionary as d2 on pc.type2 = d2.dict_key " .
                'ORDER BY type1name, type2name';
        $result = usePreparedSelectBlade ($query);
        return $result->fetchAll (PDO::FETCH_ASSOC);
}

// Add a pair to the PortCompat table.
function commitSupplementPOIFC ($type1, $type2)
{
        if ($type1 <= 0)
                throw new InvalidArgException ('type1', $type1);
        if ($type2 <= 0)
                throw new InvalidArgException ('type2', $type2);
        return usePreparedInsertBlade
        (
                'PortCompat',
                array ('type1' => $type1, 'type2' => $type2)
        );
}

// Remove a pair from the PortCompat table.
function commitReducePOIFC ($type1, $type2)
{
        return usePreparedDeleteBlade ('PortCompat', array ('type1' => $type1, 'type2' => $type2));
}

function getDictStats ()
{
        $stock_chapters = array (1, 2, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28);
        $result = usePreparedSelectBlade
        (
                "select Chapter.id as chapter_no, Chapter.name as chapter_name, count(dict_key) as wc from " .
                "Chapter left join Dictionary on Chapter.id = Dictionary.chapter_id group by Chapter.id"
        );
        $tc = $tw = $uc = $uw = 0;
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $tc++;
                $tw += $row['wc'];;
                if (in_array ($row['chapter_no'], $stock_chapters))
                        continue;
                $uc++;
                $uw += $row['wc'];;
        }
        $result->closeCursor();
        unset ($result);
        $result = usePreparedSelectBlade
        (
                "select count(object_id) as attrc from RackObject as ro left join " .
                "AttributeValue as av on ro.id = av.object_id group by ro.id"
        );
        $to = $ta = $so = 0;
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $to++;
                if ($row['attrc'] != 0)
                {
                        $so++;
                        $ta += $row['attrc'];
                }
        }
        $result->closeCursor();
        $ret = array();
        $ret['Total chapters in dictionary'] = $tc;
        $ret['Total words in dictionary'] = $tw;
        $ret['User chapters'] = $uc;
        $ret['Words in user chapters'] = $uw;
        $ret['Total objects'] = $to;
        $ret['Objects with stickers'] = $so;
        $ret['Total stickers attached']  = $ta;
        return $ret;
}

function getIPv4Stats ()
{
        $ret = array();
        $subject = array();
        $subject[] = array ('q' => 'select count(id) from IPv4Network', 'txt' => 'Networks');
        $subject[] = array ('q' => 'select count(ip) from IPv4Address', 'txt' => 'Addresses commented/reserved');
        $subject[] = array ('q' => 'select count(ip) from IPv4Allocation', 'txt' => 'Addresses allocated');
        $subject[] = array ('q' => 'select count(*) from IPv4NAT', 'txt' => 'NAT rules');
        $subject[] = array ('q' => 'select count(id) from IPv4VS', 'txt' => 'Virtual services');
        $subject[] = array ('q' => 'select count(id) from IPv4RSPool', 'txt' => 'Real server pools');
        $subject[] = array ('q' => 'select count(id) from IPv4RS', 'txt' => 'Real servers');
        $subject[] = array ('q' => 'select count(distinct object_id) from IPv4LB', 'txt' => 'Load balancers');

        foreach ($subject as $item)
        {
                $result = usePreparedSelectBlade ($item['q']);
                $row = $result->fetch (PDO::FETCH_NUM);
                $ret[$item['txt']] = $row[0];
                $result->closeCursor();
                unset ($result);
        }
        return $ret;
}

function getRackspaceStats ()
{
        $ret = array();
        $subject = array();
        $subject[] = array ('q' => 'select count(*) from RackRow', 'txt' => 'Rack rows');
        $subject[] = array ('q' => 'select count(*) from Rack', 'txt' => 'Racks');
        $subject[] = array ('q' => 'select avg(height) from Rack', 'txt' => 'Average rack height');
        $subject[] = array ('q' => 'select sum(height) from Rack', 'txt' => 'Total rack units in field');

        foreach ($subject as $item)
        {
                $result = usePreparedSelectBlade ($item['q']);
                $row = $result->fetch (PDO::FETCH_NUM);
                $ret[$item['txt']] = !strlen ($row[0]) ? 0 : $row[0];
                $result->closeCursor();
                unset ($result);
        }
        return $ret;
}

/*

The following allows figuring out records in TagStorage, which refer to non-existing entities:

mysql> select entity_id from TagStorage left join Files on entity_id = id where entity_realm = 'file' and id is null;
mysql> select entity_id from TagStorage left join IPv4Network on entity_id = id where entity_realm = 'ipv4net' and id is null;
mysql> select entity_id from TagStorage left join RackObject on entity_id = id where entity_realm = 'object' and id is null;
mysql> select entity_id from TagStorage left join Rack on entity_id = id where entity_realm = 'rack' and id is null;
mysql> select entity_id from TagStorage left join IPv4VS on entity_id = id where entity_realm = 'ipv4vs' and id is null;
mysql> select entity_id from TagStorage left join IPv4RSPool on entity_id = id where entity_realm = 'ipv4rspool' and id is null;
mysql> select entity_id from TagStorage left join UserAccount on entity_id = user_id where entity_realm = 'user' and user_id is null;

Accordingly, these are the records, which refer to non-existent tags:

mysql> select tag_id from TagStorage left join TagTree on tag_id = id where id is null;

*/

// chapter_no is a must, see at @commitReduceDictionary() why
function commitUpdateDictionary ($chapter_no = 0, $dict_key = 0, $dict_value = '')
{
        return usePreparedExecuteBlade
        (
                'UPDATE Dictionary SET dict_value=? WHERE chapter_id=? AND dict_key=?',
                array ($dict_value, $chapter_no, $dict_key)
        );
}

function commitSupplementDictionary ($chapter_no = 0, $dict_value = '')
{
        if ($chapter_no <= 0)
                throw new InvalidArgException ('$chapter_no', $chapter_no);
        if (!strlen ($dict_value))
                throw new InvalidArgException ('$dict_value', $dict_value);
        return usePreparedInsertBlade
        (
                'Dictionary',
                array ('chapter_id' => $chapter_no, 'dict_value' => $dict_value)
        );
}

// Technically dict_key is enough to delete, but including chapter_id into
// WHERE clause makes sure, that the action actually happends for the same
// chapter, which authorization was granted for.
function commitReduceDictionary ($chapter_no = 0, $dict_key = 0)
{
        return usePreparedDeleteBlade ('Dictionary', array ('chapter_id' => $chapter_no, 'dict_key' => $dict_key));
}

function commitAddChapter ($chapter_name = '')
{
        if (!strlen ($chapter_name))
                throw new InvalidArgException ('$chapter_name', $chapter_name);
        return usePreparedInsertBlade
        (
                'Chapter',
                array ('name' => $chapter_name)
        );
}

function commitUpdateChapter ($chapter_no = 0, $chapter_name = '')
{
        if (!strlen ($chapter_name))
                throw new InvalidArgException ('$chapter_name', $chapter_name);
        return usePreparedExecuteBlade
        (
                'UPDATE Chapter SET name=? WHERE id=? AND sticky="no"',
                array ($chapter_name, $chapter_no)
        );
}

function commitDeleteChapter ($chapter_no = 0)
{
        return usePreparedDeleteBlade ('Chapter', array ('id' => $chapter_no, 'sticky' => 'no'));
}

// This is a dictionary accessor. We perform link rendering, so the user sees
// nice <select> drop-downs.
function readChapter ($chapter_id = 0, $style = '')
{
        $result = usePreparedSelectBlade
        (
                "select dict_key, dict_value from Dictionary " .
                "where chapter_id = ?",
                array ($chapter_id)
        );
        $chapter = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $chapter[$row['dict_key']] = $style == '' ? $row['dict_value'] : parseWikiLink ($row['dict_value'], $style);
        $result->closeCursor();
        // SQL ORDER BY had no sense, because we need to sort after link rendering, not before.
        asort ($chapter);
        return $chapter;
}

// Return refcounters for all given keys of the given chapter.
function getChapterRefc ($chapter_id, $keylist)
{
        $ret = array();
        foreach ($keylist as $key)
                $ret[$key] = 0;
        switch ($chapter_id)
        {
        case CHAP_OBJTYPE:
                // RackObjectType chapter is referenced by AttributeMap and RackObject tables
                $query = 'select dict_key as uint_value, (select count(*) from AttributeMap where objtype_id = dict_key) + ' .
                        "(select count(*) from RackObject where objtype_id = dict_key) as refcnt from Dictionary where chapter_id = ?";
                break;
        case CHAP_PORTTYPE:
                // PortOuterInterface chapter is referenced by PortCompat, PortInterfaceCompat and Port tables
                $query = 'select dict_key as uint_value, (select count(*) from PortCompat where type1 = dict_key or type2 = dict_key) + ' .
                        '(select count(*) from Port where type = dict_key) + (SELECT COUNT(*) FROM PortInterfaceCompat WHERE oif_id = dict_key) as refcnt ' .
                        "from Dictionary where chapter_id = ?";
                break;
        default:
                // Find the list of all assigned values of dictionary-addressed attributes, each with
                // chapter/word keyed reference counters.
                $query = "select uint_value, count(object_id) as refcnt " .
                        "from Attribute as a inner join AttributeMap as am on a.id = am.attr_id " .
                        "inner join AttributeValue as av on a.id = av.attr_id " .
                        "inner join Dictionary as d on am.chapter_id = d.chapter_id and av.uint_value = d.dict_key " .
                        "where a.type = 'dict' and am.chapter_id = ? group by uint_value";
                break;
        }
        $result = usePreparedSelectBlade ($query, array ($chapter_id));
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['uint_value']] = $row['refcnt'];
        return $ret;
}

// Return a list of all stickers with sticker map applied. Each sticker records will
// list all its ways on the map with refcnt set.
function getAttrMap ()
{
        $result = usePreparedSelectBlade
        (
                'SELECT id, type, name, chapter_id, (SELECT dict_value FROM Dictionary WHERE dict_key = objtype_id) '.
                'AS objtype_name, (SELECT name FROM Chapter WHERE id = chapter_id) ' .
                'AS chapter_name, objtype_id, (SELECT COUNT(object_id) FROM AttributeValue AS av INNER JOIN RackObject AS ro ' .
                'ON av.object_id = ro.id WHERE av.attr_id = Attribute.id AND ro.objtype_id = AttributeMap.objtype_id) ' .
                'AS refcnt FROM Attribute LEFT JOIN AttributeMap ON id = attr_id ORDER BY Attribute.name, objtype_name'
        );
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                if (!isset ($ret[$row['id']]))
                        $ret[$row['id']] = array
                        (
                                'id' => $row['id'],
                                'type' => $row['type'],
                                'name' => $row['name'],
                                'application' => array(),
                        );
                if ($row['objtype_id'] == '')
                        continue;
                $application = array
                (
                        'objtype_id' => $row['objtype_id'],
                        'refcnt' => $row['refcnt'],
                );
                if ($row['type'] == 'dict')
                {
                        $application['chapter_no'] = $row['chapter_id'];
                        $application['chapter_name'] = $row['chapter_name'];
                }
                $ret[$row['id']]['application'][] = $application;
        }
        return $ret;
}

function commitUpdateAttribute ($attr_id = 0, $attr_name = '')
{
        return usePreparedExecuteBlade ('UPDATE Attribute SET name=? WHERE id=?', array ($attr_name, $attr_id));
}

function commitAddAttribute ($attr_name = '', $attr_type = '')
{
        if (!strlen ($attr_name))
                throw new InvalidArgException ('$attr_name', $attr_name);
        switch ($attr_type)
        {
                case 'uint':
                case 'float':
                case 'string':
                case 'dict':
                        break;
                default:
                        throw new InvalidArgException ('$attr_type', $attr_type, 'Attribute type not supported');
        }
        return usePreparedInsertBlade
        (
                'Attribute',
                array ('name' => $attr_name, 'type' => $attr_type)
        );
}

function commitDeleteAttribute ($attr_id = 0)
{
        return usePreparedDeleteBlade ('Attribute', array ('id' => $attr_id));
}

// FIXME: don't store garbage in chapter_no for non-dictionary types.
function commitSupplementAttrMap ($attr_id = 0, $objtype_id = 0, $chapter_no = 0)
{
        if ($attr_id <= 0)
                throw new InvalidArgException ('$attr_id', $attr_id);
        if ($objtype_id <= 0)
                throw new InvalidArgException ('$objtype_id', $objtype_id);

        return usePreparedInsertBlade
        (
                'AttributeMap',
                array
                (
                        'attr_id' => $attr_id,
                        'objtype_id' => $objtype_id,
                        'chapter_id' => $chapter_no
                )
        );
}

function commitReduceAttrMap ($attr_id = 0, $objtype_id)
{
        return usePreparedDeleteBlade ('AttributeMap', array ('attr_id' => $attr_id, 'objtype_id' => $objtype_id));
}

// This function returns all optional attributes for requested object
// as an array of records. NULL is returned on error and empty array
// is returned, if there are no attributes found.
function getAttrValues ($object_id)
{
        $ret = array();
        $result = usePreparedSelectBlade
        (
                "select A.id as attr_id, A.name as attr_name, A.type as attr_type, C.name as chapter_name, " .
                "C.id as chapter_id, AV.uint_value, AV.float_value, AV.string_value, D.dict_value from " .
                "RackObject as RO inner join AttributeMap as AM on RO.objtype_id = AM.objtype_id " .
                "inner join Attribute as A on AM.attr_id = A.id " .
                "left join AttributeValue as AV on AV.attr_id = AM.attr_id and AV.object_id = RO.id " .
                "left join Dictionary as D on D.dict_key = AV.uint_value and AM.chapter_id = D.chapter_id " .
                "left join Chapter as C on AM.chapter_id = C.id " .
                "where RO.id = ? order by A.name, A.type",
                array ($object_id)
        );
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $record = array();
                $record['id'] = $row['attr_id'];
                $record['name'] = $row['attr_name'];
                $record['type'] = $row['attr_type'];
                switch ($row['attr_type'])
                {
                        case 'dict':
                                $record['chapter_id'] = $row['chapter_id'];
                                $record['chapter_name'] = $row['chapter_name'];
                                $record['key'] = $row['uint_value'];
                                // fall through
                        case 'uint':
                        case 'float':
                        case 'string':
                                $record['value'] = $row[$row['attr_type'] . '_value'];
                                $record['o_value'] = parseWikiLink ($record['value'], 'o');
                                $record['a_value'] = parseWikiLink ($record['value'], 'a');
                                break;
                        default:
                                $record['value'] = NULL;
                                break;
                }
                $ret[$row['attr_id']] = $record;
        }
        $result->closeCursor();
        return $ret;
}

function commitResetAttrValue ($object_id = 0, $attr_id = 0)
{
        return usePreparedDeleteBlade ('AttributeValue', array ('object_id' => $object_id, 'attr_id' => $attr_id));
}

function commitUpdateAttrValue ($object_id = 0, $attr_id = 0, $value = '')
{
        if ($object_id <= 0)
                throw new InvalidArgException ('$objtype_id', $objtype_id);
        if ($attr_id <= 0)
                throw new InvalidArgException ('$attr_id', $attr_id);
        if (!strlen ($value))
                return commitResetAttrValue ($object_id, $attr_id);
        $result = usePreparedSelectBlade ('select type as attr_type from Attribute where id = ?', array ($attr_id));
        $row = $result->fetch (PDO::FETCH_NUM);
        $attr_type = $row[0];
        unset ($result);
        switch ($attr_type)
        {
                case 'uint':
                case 'float':
                case 'string':
                        $column = $attr_type . '_value';
                        break;
                case 'dict':
                        $column = 'uint_value';
                        break;
                default:
                        throw new InvalidArgException ('$attr_type', $attr_type, 'Unknown attribute type found in object #'.$object_id.', attribute #'.$attr_id);
        }
        usePreparedDeleteBlade ('AttributeValue', array ('object_id' => $object_id, 'attr_id' => $attr_id));
        // We know $value isn't empty here.
        usePreparedInsertBlade
        (
                'AttributeValue',
                array
                (
                        $column => $value,
                        'object_id' => $object_id,
                        'attr_id' => $attr_id,
                )
        );
        return TRUE;
}

function commitUseupPort ($port_id = 0)
{
        return usePreparedExecuteBlade ('UPDATE Port SET reservation_comment=NULL WHERE id=?', array ($port_id));
}

function convertPDOException ($e)
{
        if ($e->getCode() != 23000)
                return $e;
        switch ($e->errorInfo[1])
        {
        case 1062:
                $text = 'such record already exists';
                break;
        case 1451:
        case 1452:
                $text = 'foreign key violation';
                break;
        default:
                $text = 'unknown error code ' . $e->errorInfo[1];
                break;
        }
        return new Exception ($text, E_DB_CONSTRAINT);
}

// This is a swiss-knife blade to insert a record into a table.
// The first argument is table name.
// The second argument is an array of "name" => "value" pairs.
function usePreparedInsertBlade ($tablename, $columns)
{
        global $dbxlink;
        $query = "INSERT INTO ${tablename} (" . implode (', ', array_keys ($columns));
        $query .= ') VALUES (' . implode (', ', array_fill (0, count ($columns), '?')) . ')';
        // Now the query should be as follows:
        // INSERT INTO table (c1, c2, c3) VALUES (?, ?, ?)
        try
        {
                $prepared = $dbxlink->prepare ($query);
                if (!$prepared->execute (array_values ($columns)))
                        return FALSE;
                return $prepared->rowCount() == 1;
        }
        catch (PDOException $e)
        {
                throw convertPDOException ($e);
        }
}

// This swiss-knife blade deletes any number of records from the specified table
// using the specified key names and values.
function usePreparedDeleteBlade ($tablename, $columns, $conjunction = 'AND')
{
        global $dbxlink;
        $conj = '';
        $query = "DELETE FROM ${tablename} WHERE ";
        foreach ($columns as $colname => $colvalue)
        {
                $query .= " ${conj} ${colname}=?";
                $conj = $conjunction;
        }
        try
        {
                $prepared = $dbxlink->prepare ($query);
                if (!$prepared->execute (array_values ($columns)))
                        return FALSE;
                return $prepared->rowCount(); // FALSE !== 0
        }
        catch (PDOException $e)
        {
                throw convertPDOException ($e);
        }
}

function usePreparedSelectBlade ($query, $args = array())
{
        global $dbxlink;
        $prepared = $dbxlink->prepare ($query);
        if (!$prepared->execute ($args))
                return FALSE;
        return $prepared;
}

// Prepare and execute the statement with parameters, then return number of
// rows affected (or FALSE in case of an error).
function usePreparedExecuteBlade ($query, $args = array())
{
        global $dbxlink;
        try
        {
                if (!$prepared = $dbxlink->prepare ($query))
                        return FALSE;
                if (!$prepared->execute ($args))
                        return FALSE;
                return $prepared->rowCount();
        }
        catch (PDOException $e)
        {
                throw convertPDOException ($e);
        }
}

function loadConfigCache ()
{
        $result = usePreparedSelectBlade ('SELECT varname, varvalue, vartype, is_hidden, emptyok, description, is_userdefined FROM Config ORDER BY varname');
        $cache = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $cache[$row['varname']] = $row;
        return $cache;
}

function loadUserConfigCache ($username = NULL)
{
        if (!strlen ($username))
                throw new InvalidArgException ('$username', $username);
        $result = usePreparedSelectBlade ('SELECT varname, varvalue FROM UserConfig WHERE user = ?', array ($username));
        $cache = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $cache[$row['varname']] = $row;
        return $cache;
}

function deleteUserConfigVar ($username = NULL, $varname = NULL)
{
        usePreparedDeleteBlade ('UserConfig', array ('varname' => $varname, 'user' => $username));
}

function storeUserConfigVar ($username = NULL, $varname = NULL, $varvalue = NULL)
{
        if (!strlen ($username))
                throw new InvalidArgException ('$username', $username);
        if (!strlen ($varname))
                throw new InvalidArgException ('$varname', $varname);
        if ($varvalue === NULL)
                throw new InvalidArgException ('$varvalue', $varvalue);
        return usePreparedExecuteBlade
        (
                'REPLACE UserConfig SET varvalue=?, varname=?, user=?',
                array ($varvalue, $varname, $username)
        );
}

// setConfigVar() is expected to perform all necessary filtering
function storeConfigVar ($varname = NULL, $varvalue = NULL)
{
        if ($varvalue === NULL)
                throw new InvalidArgException ('$varvalue', $varvalue);
        return usePreparedExecuteBlade
        (
                'UPDATE Config SET varvalue=? WHERE varname=?',
                array ($varvalue, $varname)
        );
}

// Database version detector. Should behave corretly on any
// working dataset a user might have.
function getDatabaseVersion ()
{
        $result = usePreparedSelectBlade ('SELECT varvalue FROM Config WHERE varname = "DB_VERSION" and vartype = "string"');
        if ($result == NULL)
        {
                global $dbxlink;
                $errorInfo = $dbxlink->errorInfo();
                if ($errorInfo[0] == '42S02') // ER_NO_SUCH_TABLE
                        return '0.14.4';
                die (__FUNCTION__ . ': SQL query #1 failed with error ' . $errorInfo[2]);
        }
        $rows = $result->fetchAll (PDO::FETCH_NUM);
        if (count ($rows) != 1 || !strlen ($rows[0][0]))
        {
                $result->closeCursor();
                die (__FUNCTION__ . ': Cannot guess database version. Config table is present, but DB_VERSION is missing or invalid. Giving up.');
        }
        $ret = $rows[0][0];
        $result->closeCursor();
        return $ret;
}

// Return an array of virtual services. For each of them list real server pools
// with their load balancers and other stats.
function getSLBSummary ()
{
        $result = usePreparedSelectBlade
        (
                'select vs.id as vsid, inet_ntoa(vip) as vip, vport, proto, vs.name, object_id, ' .
                'lb.rspool_id, pool.name as pool_name, count(rs.id) as rscount ' .
                'from IPv4VS as vs inner join IPv4LB as lb on vs.id = lb.vs_id ' .
                'inner join IPv4RSPool as pool on lb.rspool_id = pool.id ' .
                'left join IPv4RS as rs on rs.rspool_id = lb.rspool_id ' .
                'group by vs.id, object_id order by vs.vip, object_id'
        );
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $vsid = $row['vsid'];
                $object_id = $row['object_id'];
                if (!isset ($ret[$vsid]))
                {
                        $ret[$vsid] = array();
                        foreach (array ('vip', 'vport', 'proto', 'name') as $cname)
                                $ret[$vsid][$cname] = $row[$cname];
                        $ret[$vsid]['lblist'] = array();
                }
                // There's only one assigned RS pool possible for each LB-VS combination.
                $ret[$vsid]['lblist'][$row['object_id']] = array
                (
                        'id' => $row['rspool_id'],
                        'size' => $row['rscount'],
                        'name' => $row['pool_name']
                );
        }
        return $ret;
}

function addRStoRSPool ($pool_id = 0, $rsip = '', $rsport = 0, $inservice = 'no', $rsconfig = '')
{
        return usePreparedExecuteBlade
        (
                'INSERT INTO IPv4RS (rsip, rsport, rspool_id, inservice, rsconfig) VALUES (INET_ATON(?), ?, ?, ?, ?)',
                array
                (
                        $rsip,
                        (!strlen ($rsport) or $rsport === 0) ? NULL : $rsport,
                        $pool_id,
                        $inservice == 'yes' ? 'yes' : 'no',
                        !strlen ($rsconfig) ? NULL : $rsconfig
                )
        );
}

function commitCreateVS ($vip = '', $vport = 0, $proto = '', $name = '', $vsconfig, $rsconfig, $taglist = array())
{
        if (!strlen ($vip))
                throw new InvalidArgException ('$vip', $vip);
        if ($vport <= 0)
                throw new InvalidArgException ('$vport', $vport);
        if (!strlen ($proto))
                throw new InvalidArgException ('$proto', $proto);
        if (FALSE === usePreparedExecuteBlade
        (
                'INSERT INTO IPv4VS (vip, vport, proto, name, vsconfig, rsconfig) VALUES (INET_ATON(?), ?, ?, ?, ?, ?)',
                array
                (
                        $vip,
                        $vport,
                        $proto,
                        !strlen ($name) ? NULL : $name,
                        !strlen ($vsconfig) ? NULL : $vsconfig,
                        !strlen ($rsconfig) ? NULL : $rsconfig,
                )
        ))
                return __FUNCTION__ . ': SQL insertion failed';
        return produceTagsForLastRecord ('ipv4vs', $taglist);
}

function addLBtoRSPool ($pool_id = 0, $object_id = 0, $vs_id = 0, $vsconfig = '', $rsconfig = '')
{
        return usePreparedInsertBlade
        (
                'IPv4LB',
                array
                (
                        'object_id' => $object_id,
                        'rspool_id' => $pool_id,
                        'vs_id' => $vs_id,
                        'vsconfig' => (!strlen ($vsconfig) ? NULL : $vsconfig),
                        'rsconfig' => (!strlen ($rsconfig) ? NULL : $rsconfig)
                )
        );
}

function commitDeleteRS ($id = 0)
{
        return usePreparedDeleteBlade ('IPv4RS', array ('id' => $id));
}

function commitDeleteVS ($id = 0)
{
        releaseFiles ('ipv4vs', $id);
        return FALSE !== usePreparedDeleteBlade ('IPv4VS', array ('id' => $id)) && FALSE !== destroyTagsForEntity ('ipv4vs', $id);
}

function commitDeleteLB ($object_id = 0, $pool_id = 0, $vs_id = 0)
{
        return usePreparedDeleteBlade ('IPv4LB', array ('object_id' => $object_id, 'rspool_id' => $pool_id, 'vs_id' => $vs_id));
}

function commitUpdateRS ($rsid = 0, $rsip = '', $rsport = 0, $rsconfig = '')
{
        if (long2ip (ip2long ($rsip)) !== $rsip)
                throw new InvalidArgException ('$rsip', $rsip);
        return usePreparedExecuteBlade
        (
                'UPDATE IPv4RS SET rsip=INET_ATON(?), rsport=?, rsconfig=? WHERE id=?',
                array
                (
                        $rsip,
                        (!strlen ($rsport) or $rsport === 0) ? NULL : $rsport,
                        !strlen ($rsconfig) ? NULL : $rsconfig,
                        $rsid,
                )
        );
}

function commitUpdateLB ($object_id = 0, $pool_id = 0, $vs_id = 0, $vsconfig = '', $rsconfig = '')
{
        return usePreparedExecuteBlade
        (
                'UPDATE IPv4LB SET vsconfig=?, rsconfig=? WHERE object_id=? AND rspool_id=? AND vs_id=?',
                array
                (
                        !strlen ($vsconfig) ? NULL : $vsconfig,
                        !strlen ($rsconfig) ? NULL : $rsconfig,
                        $object_id,
                        $pool_id,
                        $vs_id,
                )
        );
}

function commitUpdateVS ($vsid = 0, $vip = '', $vport = 0, $proto = '', $name = '', $vsconfig = '', $rsconfig = '')
{
        if (!strlen ($vip))
                throw new InvalidArgException ('$vip', $vip);
        if ($vport <= 0)
                throw new InvalidArgException ('$vport', $vport);
        if (!strlen ($proto))
                throw new InvalidArgException ('$proto', $proto);
        return usePreparedExecuteBlade
        (
                'UPDATE IPv4VS SET vip=INET_ATON(?), vport=?, proto=?, name=?, vsconfig=?, rsconfig=? WHERE id=?',
                array
                (
                        $vip,
                        $vport,
                        $proto,
                        !strlen ($name) ? NULL : $name,
                        !strlen ($vsconfig) ? NULL : $vsconfig,
                        !strlen ($rsconfig) ? NULL : $rsconfig,
                        $vsid,
                )
        );
}

function loadThumbCache ($rack_id = 0)
{
        $ret = NULL;
        $result = usePreparedSelectBlade ("SELECT thumb_data FROM Rack WHERE id = ? AND thumb_data IS NOT NULL", array ($rack_id));
        $row = $result->fetch (PDO::FETCH_ASSOC);
        if ($row)
                $ret = base64_decode ($row['thumb_data']);
        return $ret;
}

function saveThumbCache ($rack_id = 0, $cache = NULL)
{
        if ($cache == NULL)
                throw new InvalidArgException ('$cache', $cache);
        usePreparedExecuteBlade ('UPDATE Rack SET thumb_data=? WHERE id=?', array (base64_encode ($cache), $rack_id));
}

function resetThumbCache ($rack_id = 0)
{
        usePreparedExecuteBlade ('UPDATE Rack SET thumb_data=NULL WHERE id=?', array ($rack_id));
}

// Return the list of attached RS pools for the given object. As long as we have
// the LB-VS UNIQUE in IPv4LB table, it is Ok to key returned records
// by vs_id, because there will be only one RS pool listed for each VS of the
// current object.
function getRSPoolsForObject ($object_id = 0)
{
        $result = usePreparedSelectBlade
        (
                'select vs_id, inet_ntoa(vip) as vip, vport, proto, vs.name, pool.id as pool_id, ' .
                'pool.name as pool_name, count(rsip) as rscount, lb.vsconfig, lb.rsconfig from ' .
                'IPv4LB as lb inner join IPv4RSPool as pool on lb.rspool_id = pool.id ' .
                'inner join IPv4VS as vs on lb.vs_id = vs.id ' .
                'left join IPv4RS as rs on lb.rspool_id = rs.rspool_id ' .
                'where lb.object_id = ? ' .
                'group by lb.rspool_id, lb.vs_id order by vs.vip, vport, proto, pool.name',
                array ($object_id)
        );
        $ret = array ();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                foreach (array ('vip', 'vport', 'proto', 'name', 'pool_id', 'pool_name', 'rscount', 'vsconfig', 'rsconfig') as $cname)
                        $ret[$row['vs_id']][$cname] = $row[$cname];
        return $ret;
}

function commitCreateRSPool ($name = '', $vsconfig = '', $rsconfig = '', $taglist = array())
{
        if (!strlen ($name))
                throw new InvalidArgException ('$name', $name);
        if (!usePreparedInsertBlade
        (
                'IPv4RSPool',
                array
                (
                        'name' => (!strlen ($name) ? NULL : $name),
                        'vsconfig' => (!strlen ($vsconfig) ? NULL : $vsconfig),
                        'rsconfig' => (!strlen ($rsconfig) ? NULL : $rsconfig)
                )
        ))
                return __FUNCTION__ . ': SQL insertion failed';
        return produceTagsForLastRecord ('ipv4rspool', $taglist);
}

function commitDeleteRSPool ($pool_id = 0)
{
        releaseFiles ('ipv4rspool', $pool_id);
        return usePreparedDeleteBlade ('IPv4RSPool', array ('id' => $pool_id)) && destroyTagsForEntity ('ipv4rspool', $pool_id);
}

function commitUpdateRSPool ($pool_id = 0, $name = '', $vsconfig = '', $rsconfig = '')
{
        return usePreparedExecuteBlade
        (
                'UPDATE IPv4RSPool SET name=?, vsconfig=?, rsconfig=? WHERE id=?',
                array
                (
                        !strlen ($name) ? NULL : $name,
                        !strlen ($vsconfig) ? NULL : $vsconfig,
                        !strlen ($rsconfig) ? NULL : $rsconfig,
                        $pool_id,
                )
        );
}

function getRSList ()
{
        $result = usePreparedSelectBlade
        (
                "select id, inservice, inet_ntoa(rsip) as rsip, rsport, rspool_id, rsconfig " .
                "from IPv4RS order by rspool_id, IPv4RS.rsip, rsport"
        );
        $ret = array ();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                foreach (array ('inservice', 'rsip', 'rsport', 'rspool_id', 'rsconfig') as $cname)
                        $ret[$row['id']][$cname] = $row[$cname];
        return $ret;
}

// Return the list of all currently configured load balancers with their pool count.
function getLBList ()
{
        $result = usePreparedSelectBlade
        (
                "select object_id, count(rspool_id) as poolcount " .
                "from IPv4LB group by object_id order by object_id"
        );
        $ret = array ();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['object_id']] = $row['poolcount'];
        return $ret;
}

// For the given object return: its vsconfig/rsconfig; the list of RS pools
// attached (each with vsconfig/rsconfig in turn), each with the list of
// virtual services terminating the pool. Each pool also lists all real
// servers with rsconfig.
function getSLBConfig ($object_id)
{
        $ret = array();
        $result = usePreparedSelectBlade
        (
                'select vs_id, inet_ntoa(vip) as vip, vport, proto, vs.name as vs_name, ' .
                'vs.vsconfig as vs_vsconfig, vs.rsconfig as vs_rsconfig, ' .
                'lb.vsconfig as lb_vsconfig, lb.rsconfig as lb_rsconfig, pool.id as pool_id, pool.name as pool_name, ' .
                'pool.vsconfig as pool_vsconfig, pool.rsconfig as pool_rsconfig, ' .
                'rs.id as rs_id, inet_ntoa(rsip) as rsip, rsport, rs.rsconfig as rs_rsconfig from ' .
                'IPv4LB as lb inner join IPv4RSPool as pool on lb.rspool_id = pool.id ' .
                'inner join IPv4VS as vs on lb.vs_id = vs.id ' .
                'inner join IPv4RS as rs on lb.rspool_id = rs.rspool_id ' .
                "where lb.object_id = ? and rs.inservice = 'yes' " .
                "order by vs.vip, vport, proto, pool.name, rs.rsip, rs.rsport",
                array ($object_id)
        );
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $vs_id = $row['vs_id'];
                if (!isset ($ret[$vs_id]))
                {
                        foreach (array ('vip', 'vport', 'proto', 'vs_name', 'vs_vsconfig', 'vs_rsconfig', 'lb_vsconfig', 'lb_rsconfig', 'pool_vsconfig', 'pool_rsconfig', 'pool_id', 'pool_name') as $c)
                                $ret[$vs_id][$c] = $row[$c];
                        $ret[$vs_id]['rslist'] = array();
                }
                foreach (array ('rsip', 'rsport', 'rs_rsconfig') as $c)
                        $ret[$vs_id]['rslist'][$row['rs_id']][$c] = $row[$c];
        }
        return $ret;
}

function commitSetInService ($rs_id = 0, $inservice = '')
{
        if (!strlen ($inservice))
                throw new InvalidArgException ('$inservice', $inservice);
        return usePreparedExecuteBlade ('UPDATE IPv4RS SET inservice=? WHERE id=?', array ($inservice, $rs_id));
}

function executeAutoPorts ($object_id = 0, $type_id = 0)
{
        if ($object_id == 0)
                throw new InvalidArgException ('$object_id', $object_id);
        if ($type_id == 0)
                throw new InvalidArgException ('$type_id', $type_id);
        $ret = TRUE;
        foreach (getAutoPorts ($type_id) as $autoport)
                $ret = $ret and '' == commitAddPort ($object_id, $autoport['name'], $autoport['type'], '', '');
        return $ret;
}

// Return only implicitly listed tags, the rest of the chain will be
// generated/deducted later at higher levels.
// Result is a chain: randomly indexed taginfo list.
function loadEntityTags ($entity_realm = '', $entity_id = 0)
{
        $ret = array();
        $result = usePreparedSelectBlade
        (
                "select tt.id, tag from " .
                "TagStorage as ts inner join TagTree as tt on ts.tag_id = tt.id " .
                "where entity_realm = ? and entity_id = ? " .
                "order by tt.tag",
                array ($entity_realm, $entity_id)
        );
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['id']] = $row;
        return getExplicitTagsOnly ($ret);
}

// Return a tag chain with all DB tags on it.
function getTagList ()
{
        $ret = array();
        $result = usePreparedSelectBlade
        (
                "select id, parent_id, tag, entity_realm as realm, count(entity_id) as refcnt " .
                "from TagTree left join TagStorage on id = tag_id " .
                "group by id, entity_realm order by tag"
        );
        // Collation index. The resulting rows are ordered according to default collation,
        // which is utf8_general_ci for UTF-8.
        $ci = 0;
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                if (!isset ($ret[$row['id']]))
                        $ret[$row['id']] = array
                        (
                                'id' => $row['id'],
                                'tag' => $row['tag'],
                                'ci' => $ci++,
                                'parent_id' => $row['parent_id'],
                                'refcnt' => array ('total' => 0)
                        );
                if ($row['realm'])
                {
                        $ret[$row['id']]['refcnt'][$row['realm']] = $row['refcnt'];
                        $ret[$row['id']]['refcnt']['total'] += $row['refcnt'];
                }
        }
        return $ret;
}

function commitCreateTag ($tagname = '', $parent_id = 0)
{
        if ($tagname == '')
                throw new InvalidArgException ('tagname', $tagname);
        return usePreparedInsertBlade
        (
                'TagTree',
                array
                (
                        'tag' => $tagname,
                        'parent_id' => $parent_id
                )
        );
}

function commitDestroyTag ($tagid = 0)
{
        if (usePreparedDeleteBlade ('TagTree', array ('id' => $tagid)))
                return '';
        return 'usePreparedDeleteBlade() failed in ' . __FUNCTION__;
}

function commitUpdateTag ($tag_id, $tag_name, $parent_id)
{
        return usePreparedExecuteBlade
        (
                'UPDATE TagTree SET tag=?, parent_id=? WHERE id=?',
                array
                (
                        $tag_name,
                        $parent_id == 0 ? NULL : $parent_id,
                        $tag_id,
                )
        );
}

// Drop the whole chain stored.
function destroyTagsForEntity ($entity_realm, $entity_id)
{
        return usePreparedDeleteBlade ('TagStorage', array ('entity_realm' => $entity_realm, 'entity_id' => $entity_id));
}

// Drop only one record. This operation doesn't involve retossing other tags, unlike when adding.
// FIXME: this function could be used by 3rd-party scripts, dismiss it at some later point,
// but not now.
function deleteTagForEntity ($entity_realm, $entity_id, $tag_id)
{
        return usePreparedDeleteBlade ('TagStorage', array ('entity_realm' => $entity_realm, 'entity_id' => $entity_id, 'tag_id' => $tag_id));
}

// Push a record into TagStorage unconditionally.
function addTagForEntity ($realm = '', $entity_id, $tag_id)
{
        if (!in_array ($realm, array ('file', 'ipv4net', 'ipv4vs', 'ipv4rspool', 'object', 'rack', 'user')))
                return FALSE;
        return usePreparedInsertBlade
        (
                'TagStorage',
                array
                (
                        'entity_realm' => $realm,
                        'entity_id' => $entity_id,
                        'tag_id' => $tag_id,
                )
        );
}

// Add records into TagStorage, if this makes sense (IOW, they don't appear
// on the implicit list already). Then remove any other records, which
// appear on the "implicit" side of the chain. This will make sure,
// that both the tag base is still minimal and all requested tags appear on
// the resulting tag chain.
// Return TRUE, if any changes were committed.
function rebuildTagChainForEntity ($realm, $entity_id, $extrachain = array())
{
        // Put the current explicit sub-chain into a buffer and merge all tags from
        // the extra chain, which aren't there yet.
        $newchain = $oldchain = loadEntityTags ($realm, $entity_id);
        foreach ($extrachain as $extratag)
                if (!tagOnChain ($extratag, $newchain))
                        $newchain[] = $extratag;
        // Then minimize the working buffer and check if it differs from the original
        // chain we started with. If it is so, save the work and signal the upper layer.
        $newchain = getExplicitTagsOnly ($newchain);
        if (tagChainCmp ($oldchain, $newchain))
        {
                destroyTagsForEntity ($realm, $entity_id);
                foreach ($newchain as $taginfo)
                        addTagForEntity ($realm, $entity_id, $taginfo['id']);
                return TRUE;
        }
        return FALSE;
}

// Presume, that the target record has no tags attached.
function produceTagsForLastRecord ($realm, $tagidlist, $last_insert_id = 0)
{
        if (!count ($tagidlist))
                return '';
        if (!$last_insert_id)
                $last_insert_id = lastInsertID();
        $errcount = 0;
        foreach (getExplicitTagsOnly (buildTagChainFromIds ($tagidlist)) as $taginfo)
                if (addTagForEntity ($realm, $last_insert_id, $taginfo['id']) == FALSE)
                        $errcount++;    
        if (!$errcount)
                return '';
        else
                return "Experienced ${errcount} errors adding tags in realm '${realm}' for entity ID == ${last_insert_id}";
}

function createIPv4Prefix ($range = '', $name = '', $is_bcast = FALSE, $taglist = array())
{
        // $range is in x.x.x.x/x format, split into ip/mask vars
        $rangeArray = explode('/', $range);
        if (count ($rangeArray) != 2)
                return "Invalid IPv4 prefix '${range}'";
        $ip = $rangeArray[0];
        $mask = $rangeArray[1];

        if (!strlen ($ip) or !strlen ($mask))
                return "Invalid IPv4 prefix '${range}'";
        $ipL = ip2long($ip);
        $maskL = ip2long($mask);
        if ($ipL == -1 || $ipL === FALSE)
                return 'Bad IPv4 address';
        if ($mask < 32 && $mask > 0)
                $maskL = $mask;
        else
        {
                $maskB = decbin($maskL);
                if (strlen($maskB)!=32)
                        return 'Invalid netmask';
                $ones=0;
                $zeroes=FALSE;
                foreach( str_split ($maskB) as $digit)
                {
                        if ($digit == '0')
                                $zeroes = TRUE;
                        if ($digit == '1')
                        {
                                $ones++;
                                if ($zeroes == TRUE)
                                        return 'Invalid netmask';
                        }
                }
                $maskL = $ones;
        }
        $binmask = binMaskFromDec($maskL);
        $ipL = $ipL & $binmask;
        $result = usePreparedInsertBlade
        (
                'IPv4Network',
                array
                (
                        'ip' => sprintf ('%u', $ipL),
                        'mask' => $maskL,
                        'name' => $name
                )
        );
        if ($result != TRUE)
                return "Could not add ${range} (already exists?).";

        if ($is_bcast and $maskL < 31)
        {
                $network_addr = long2ip ($ipL);
                $broadcast_addr = long2ip ($ipL | binInvMaskFromDec ($maskL));
                updateAddress ($network_addr, 'network', 'yes');
                updateAddress ($broadcast_addr, 'broadcast', 'yes');
        }
        return produceTagsForLastRecord ('ipv4net', $taglist);
}

// FIXME: This function doesn't wipe relevant records from IPv4Address table.
function destroyIPv4Prefix ($id = 0)
{
        releaseFiles ('ipv4net', $id);
        if (FALSE === usePreparedDeleteBlade ('IPv4Network', array ('id' => $id)))
                return __FUNCTION__ . ': SQL query #1 failed';
        if (FALSE === destroyTagsForEntity ('ipv4net', $id))
                return __FUNCTION__ . ': SQL query #2 failed';
        return '';
}

function loadScript ($name)
{
        $result = usePreparedSelectBlade ("select script_text from Script where script_name = ?", array ($name));
        $row = $result->fetch (PDO::FETCH_NUM);
        if ($row !== FALSE)
                return $row[0];
        else
                return NULL;
}

function saveScript ($name = '', $text)
{
        if (!strlen ($name))
                throw new InvalidArgException ('$name', $name);
        return usePreparedExecuteBlade
        (
                'INSERT INTO Script (script_name, script_text) VALUES (?, ?) ' .
                'ON DUPLICATE KEY UPDATE script_text=?',
                array ($name, $text, $text)
        );
}

function newPortForwarding ($object_id, $localip, $localport, $remoteip, $remoteport, $proto, $description)
{
        if (NULL === getIPv4AddressNetworkId ($localip))
                return "$localip: Non existant ip";
        if (NULL === getIPv4AddressNetworkId ($remoteip))
                return "$remoteip: Non existant ip";
        if ( ($localport <= 0) or ($localport >= 65536) )
                return "$localport: invaild port";
        if ( ($remoteport <= 0) or ($remoteport >= 65536) )
                return "$remoteport: invaild port";

        $result = usePreparedExecuteBlade
        (
                'INSERT INTO IPv4NAT (object_id, localip, remoteip, localport, remoteport, proto, description) ' .
                'VALUES (?, INET_ATON(?), INET_ATON(?), ?, ?, ?, ?)',
                array
                (
                        $object_id,
                        $localip,
                        $remoteip,
                        $localport,
                        $remoteport,
                        $proto,
                        $description,
                )
        );
        return $result !== FALSE ? '' : (__FUNCTION__ . '(): failed to insert the rule');
}

function deletePortForwarding ($object_id, $localip, $localport, $remoteip, $remoteport, $proto)
{
        return usePreparedExecuteBlade
        (
                'DELETE FROM IPv4NAT WHERE object_id=? AND localip=INET_ATON(?) AND ' .
                'remoteip=INET_ATON(?) AND localport=? AND remoteport=? AND proto=?',
                array ($object_id, $localip, $remoteip, $localport, $remoteport, $proto)
        );
}

function updatePortForwarding ($object_id, $localip, $localport, $remoteip, $remoteport, $proto, $description)
{
        return usePreparedExecuteBlade
        (
                'UPDATE IPv4NAT SET description=? WHERE object_id=? AND localip=INET_ATON(?) AND remoteip=INET_ATON(?) ' .
                'AND localport=? AND remoteport=? AND proto=?',
                array ($description, $object_id, $localip, $remoteip, $localport, $remoteport, $proto)
        );
}

function getNATv4ForObject ($object_id)
{
        $ret = array();
        $ret['out'] = array();
        $ret['in'] = array();
        $result = usePreparedSelectBlade
        (
                "select ".
                "proto, ".
                "INET_NTOA(localip) as localip, ".
                "localport, ".
                "INET_NTOA(remoteip) as remoteip, ".
                "remoteport, ".
                "ipa1.name as local_addr_name, " .
                "ipa2.name as remote_addr_name, " .
                "description ".
                "from IPv4NAT ".
                "left join IPv4Address as ipa1 on IPv4NAT.localip = ipa1.ip " .
                "left join IPv4Address as ipa2 on IPv4NAT.remoteip = ipa2.ip " .
                "where object_id=? ".
                "order by localip, localport, proto, remoteip, remoteport",
                array ($object_id)
        );
        $count=0;
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                foreach (array ('proto', 'localport', 'localip', 'remoteport', 'remoteip', 'description', 'local_addr_name', 'remote_addr_name') as $cname)
                        $ret['out'][$count][$cname] = $row[$cname];
                $count++;
        }
        unset ($result);

        $result = usePreparedSelectBlade
        (
                "select ".
                "proto, ".
                "INET_NTOA(localip) as localip, ".
                "localport, ".
                "INET_NTOA(remoteip) as remoteip, ".
                "remoteport, ".
                "IPv4NAT.object_id as object_id, ".
                "RackObject.name as object_name, ".
                "description ".
                "from ((IPv4NAT join IPv4Allocation on remoteip=IPv4Allocation.ip) join RackObject on IPv4NAT.object_id=RackObject.id) ".
                "where IPv4Allocation.object_id=? ".
                "order by remoteip, remoteport, proto, localip, localport",
                array ($object_id)
        );
        $count=0;
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                foreach (array ('proto', 'localport', 'localip', 'remoteport', 'remoteip', 'object_id', 'object_name', 'description') as $cname)
                        $ret['in'][$count][$cname] = $row[$cname];
                $count++;
        }
        return $ret;
}

// Return a list of files, which are not linked to the specified record. This list
// will be used by printSelect().
function getAllUnlinkedFiles ($entity_type = NULL, $entity_id = 0)
{
        $query = usePreparedSelectBlade
        (
                'SELECT id, name FROM File ' .
                'WHERE id NOT IN (SELECT file_id FROM FileLink WHERE entity_type = ? AND entity_id = ?) ' .
                'ORDER BY name, id',
                array ($entity_type, $entity_id)
        );
        $ret=array();
        while ($row = $query->fetch (PDO::FETCH_ASSOC))
                $ret[$row['id']] = $row['name'];
        return $ret;
}

// FIXME: return a standard cell list, so upper layer can iterate over
// it conveniently.
function getFilesOfEntity ($entity_type = NULL, $entity_id = 0)
{
        $query = usePreparedSelectBlade
        (
                'SELECT FileLink.file_id, FileLink.id AS link_id, name, type, size, ctime, mtime, atime, comment ' .
                'FROM FileLink LEFT JOIN File ON FileLink.file_id = File.id ' .
                'WHERE FileLink.entity_type = ? AND FileLink.entity_id = ? ORDER BY name',
                array ($entity_type, $entity_id)
        );
        $ret = array();
        while ($row = $query->fetch (PDO::FETCH_ASSOC))
                $ret[$row['file_id']] = array (
                        'id' => $row['file_id'],
                        'link_id' => $row['link_id'],
                        'name' => $row['name'],
                        'type' => $row['type'],
                        'size' => $row['size'],
                        'ctime' => $row['ctime'],
                        'mtime' => $row['mtime'],
                        'atime' => $row['atime'],
                        'comment' => $row['comment'],
                );
        return $ret;
}

function getFile ($file_id = 0)
{
        $query = usePreparedSelectBlade
        (
                'SELECT id, name, type, size, ctime, mtime, atime, contents, comment ' .
                'FROM File WHERE id = ?',
                array ($file_id)
        );
        if (($row = $query->fetch (PDO::FETCH_ASSOC)) == NULL)
        {
                showWarning ('Query succeeded, but returned no data', __FUNCTION__);
                $ret = NULL;
        }
        else
        {
                $ret = array();
                $ret['id'] = $row['id'];
                $ret['name'] = $row['name'];
                $ret['type'] = $row['type'];
                $ret['size'] = $row['size'];
                $ret['ctime'] = $row['ctime'];
                $ret['mtime'] = $row['mtime'];
                $ret['atime'] = $row['atime'];
                $ret['contents'] = $row['contents'];
                $ret['comment'] = $row['comment'];
                $query->closeCursor();

                // Someone accessed this file, update atime
                usePreparedExecuteBlade ('UPDATE File SET atime = ? WHERE id = ?', array (date ('YmdHis'), $file_id));
        }
        return $ret;
}

function getFileLinks ($file_id = 0)
{
        $query = usePreparedSelectBlade
        (
                'SELECT id, file_id, entity_type, entity_id FROM FileLink ' .
                'WHERE file_id = ? ORDER BY entity_type, entity_id',
                array ($file_id)
        );
        $rows = $query->fetchAll (PDO::FETCH_ASSOC);
        $ret = array();
        foreach ($rows as $row)
        {
                // get info of the parent
                switch ($row['entity_type'])
                {
                        case 'ipv4net':
                                $page = 'ipv4net';
                                $id_name = 'id';
                                $parent = spotEntity ($row['entity_type'], $row['entity_id']);
                                $name = sprintf("%s (%s/%s)", $parent['name'], $parent['ip'], $parent['mask']);
                                break;
                        case 'ipv4rspool':
                                $page = 'ipv4rspool';
                                $id_name = 'pool_id';
                                $parent = spotEntity ($row['entity_type'], $row['entity_id']);
                                $name = $parent['name'];
                                break;
                        case 'ipv4vs':
                                $page = 'ipv4vs';
                                $id_name = 'vs_id';
                                $parent = spotEntity ($row['entity_type'], $row['entity_id']);
                                $name = $parent['name'];
                                break;
                        case 'object':
                                $page = 'object';
                                $id_name = 'object_id';
                                $parent = spotEntity ($row['entity_type'], $row['entity_id']);
                                $name = $parent['dname'];
                                break;
                        case 'rack':
                                $page = 'rack';
                                $id_name = 'rack_id';
                                $parent = spotEntity ($row['entity_type'], $row['entity_id']);
                                $name = $parent['name'];
                                break;
                        case 'user':
                                $page = 'user';
                                $id_name = 'user_id';
                                $parent = spotEntity ($row['entity_type'], $row['entity_id']);
                                $name = $parent['user_name'];
                                break;
                }

                // name needs to have some value for hrefs to work
        if (!strlen ($name))
                        $name = sprintf("[Unnamed %s]", formatEntityName($row['entity_type']));

                $ret[$row['id']] = array(
                                'page' => $page,
                                'id_name' => $id_name,
                                'entity_type' => $row['entity_type'],
                                'entity_id' => $row['entity_id'],
                                'name' => $name
                );
        }
        return $ret;
}

function getFileStats ()
{
        $result = usePreparedSelectBlade ('SELECT entity_type, COUNT(*) AS count FROM FileLink GROUP BY entity_type');
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                if ($row['count'] > 0)
                        $ret["Links in realm '${row['entity_type']}'"] = $row['count'];
        unset ($result);

        // Find number of files without any linkage
        $result = usePreparedSelectBlade
        (
                'SELECT COUNT(*) ' .
                'FROM File ' .
                'WHERE id NOT IN (SELECT file_id FROM FileLink)'
        );
        $ret["Unattached files"] = $result->fetchColumn ();
        unset ($result);

        // Find total number of files
        $result = usePreparedSelectBlade ('SELECT COUNT(*) FROM File');
        $ret["Total files"] = $result->fetchColumn ();

        return $ret;
}

function commitAddFile ($name, $type, $size, $contents, $comment)
{
        $now = date('YmdHis');

        global $dbxlink;
        $query  = $dbxlink->prepare('INSERT INTO File (name, type, size, ctime, mtime, atime, contents, comment) VALUES (?, ?, ?, ?, ?, ?, ?, ?)');
        $query->bindParam(1, $name);
        $query->bindParam(2, $type);
        $query->bindParam(3, $size);
        $query->bindParam(4, $now);
        $query->bindParam(5, $now);
        $query->bindParam(6, $now);
        $query->bindParam(7, $contents, PDO::PARAM_LOB);
        $query->bindParam(8, $comment);
        try
        {
                return $query->execute();
        }
        catch (PDOException $e)
        {
                throw convertPDOException ($e);
        }
}

function commitLinkFile ($file_id, $entity_type, $entity_id)
{
        return usePreparedExecuteBlade
        (
                'INSERT INTO FileLink (file_id, entity_type, entity_id) VALUES (?, ?, ?)',
                array ($file_id, $entity_type, $entity_id)
        );
}

function commitReplaceFile ($file_id = 0, $contents)
{
        global $dbxlink;
        $query = $dbxlink->prepare('UPDATE File SET mtime = NOW(), contents = ?, size = LENGTH(contents) WHERE id = ?');
        $query->bindParam(1, $contents, PDO::PARAM_LOB);
        $query->bindParam(2, $file_id);

        try
        {
                return $query->execute();
        }
        catch (PDOException $e)
        {
                throw convertPDOException ($e);
        }
}

function commitUpdateFile ($file_id = 0, $new_name = '', $new_type = '', $new_comment = '')
{
        if (!strlen ($new_name))
                throw new InvalidArgException ('$new_name', $new_name);
        if (!strlen ($new_type))
                throw new InvalidArgException ('$new_type', $new_type);
        return usePreparedExecuteBlade
        (
                'UPDATE File SET name = ?, type = ?, comment = ? WHERE id = ?',
                array ($new_name, $new_type, $new_comment, $file_id)
        );
}

function commitUnlinkFile ($link_id)
{
        if (usePreparedDeleteBlade ('FileLink', array ('id' => $link_id)) === FALSE)
                return __FUNCTION__ . '(): query failed';
        return '';
}

function commitDeleteFile ($file_id)
{
        destroyTagsForEntity ('file', $file_id);
        if (usePreparedDeleteBlade ('File', array ('id' => $file_id)) === FALSE)
                return __FUNCTION__ . '(): query failed';
        return '';
}

function getChapterList ()
{
        $ret = array();
        $result = usePreparedSelectBlade
        (
                'SELECT id, sticky, name, count(chapter_id) as wordc ' .
                'FROM Chapter LEFT JOIN Dictionary ON Chapter.id = chapter_id ' .
                'GROUP BY id ORDER BY name'
        );
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['id']] = $row;
        return $ret;
}

// Return file id by file name.
function findFileByName ($filename)
{
        $query = usePreparedSelectBlade ('SELECT id FROM File WHERE name = ?', array ($filename));
        if (($row = $query->fetch (PDO::FETCH_ASSOC)))
                return $row['id'];

        return NULL;
}

function acquireLDAPCache ($form_username, $password_hash, $expiry = 0)
{
        global $dbxlink;
        $dbxlink->beginTransaction();
        $result = usePreparedSelectBlade
        (
                'SELECT TIMESTAMPDIFF(SECOND, first_success, now()) AS success_age, ' .
                'TIMESTAMPDIFF(SECOND, last_retry, now()) AS retry_age, displayed_name, memberof ' .
                'FROM LDAPCache WHERE presented_username = ? AND successful_hash = ? ' .
                'HAVING success_age < ? FOR UPDATE',
                array ($form_username, $password_hash, $expiry)
        );
        if ($row = $result->fetch (PDO::FETCH_ASSOC))
        {
                $row['memberof'] = unserialize (base64_decode ($row['memberof']));
                return $row;
        }
        return NULL;
}

function releaseLDAPCache ()
{
        global $dbxlink;
        $dbxlink->commit();
}

// This actually changes only last_retry.
function touchLDAPCacheRecord ($form_username)
{
        return usePreparedExecuteBlade ('UPDATE LDAPCache SET last_retry=NOW() WHERE presented_username=?', array ($form_username));
}

function replaceLDAPCacheRecord ($form_username, $password_hash, $dname, $memberof)
{
        deleteLDAPCacheRecord ($form_username);
        usePreparedInsertBlade ('LDAPCache',
                array
                (
                        'presented_username' => $form_username,
                        'successful_hash' => $password_hash,
                        'displayed_name' => $dname,
                        'memberof' => base64_encode (serialize ($memberof)),
                )
        );
}

function deleteLDAPCacheRecord ($form_username)
{
        return usePreparedDeleteBlade ('LDAPCache', array ('presented_username' => $form_username));
}

// Age all records older, than cache_expiry seconds, and all records made in future.
// Calling this function w/o argument purges the whole LDAP cache.
function discardLDAPCache ($maxage = 0)
{
        return usePreparedExecuteBlade ('DELETE from LDAPCache WHERE TIMESTAMPDIFF(SECOND, first_success, NOW()) >= ? or NOW() < first_success', array ($maxage));
}

function getUserIDByUsername ($username)
{
        $result = usePreparedSelectBlade ('SELECT user_id FROM UserAccount WHeRE user_name = ?', array ($username));
        if ($row = $result->fetch (PDO::FETCH_ASSOC))
                return $row['user_id'];
        return NULL;
}

// Return TRUE, if the given address is assigned to a port of any object
// except the current object. Using this function as a constraint makes
// it possible to reuse L2 addresses within one object, yet keeping them
// universally unique on the other hand.
function alreadyUsedL2Address ($address, $my_object_id)
{
        $result = usePreparedSelectBlade
        (
                'SELECT COUNT(*) FROM Port WHERE BINARY l2address = ? AND object_id != ?',
                array ($address, $my_object_id)
        );
        $row = $result->fetch (PDO::FETCH_NUM);
        return $row[0] != 0;
}

function getPortInterfaceCompat()
{
        $result = usePreparedSelectBlade
        (
                'SELECT iif_id, iif_name, oif_id, dict_value AS oif_name ' .
                'FROM PortInterfaceCompat INNER JOIN PortInnerInterface ON id = iif_id ' .
                'INNER JOIN Dictionary ON dict_key = oif_id ' .
                'ORDER BY iif_name, oif_name'
        );
        return $result->fetchAll (PDO::FETCH_ASSOC);
}

// Return a set of options for a plain SELECT. These options include the current
// OIF of the given port and all OIFs of its permanent IIF.
function getExistingPortTypeOptions ($port_id)
{
        $result = usePreparedSelectBlade
        (
                'SELECT oif_id, dict_value AS oif_name ' .
                'FROM PortInterfaceCompat INNER JOIN Dictionary ON oif_id = dict_key ' .
                'WHERE iif_id = (SELECT iif_id FROM Port WHERE id = ?) ' .
                'ORDER BY oif_name',
                array ($port_id)
        );
        $ret = array();
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['oif_id']] = $row['oif_name'];
        return $ret;
}

function getPortIIFOptions()
{
        $ret = array();
        $result = usePreparedSelectBlade ('SELECT id, iif_name FROM PortInnerInterface ORDER BY iif_name');
        while ($row = $result->fetch (PDO::FETCH_ASSOC))
                $ret[$row['id']] = $row['iif_name'];
        return $ret;
}

function commitSupplementPIC ($iif_id, $oif_id)
{
        return usePreparedInsertBlade
        (
                'PortInterfaceCompat',
                array ('iif_id' => $iif_id, 'oif_id' => $oif_id)
        );
}

function commitReducePIC ($iif_id, $oif_id)
{
        return usePreparedDeleteBlade ('PortInterfaceCompat', array ('iif_id' => $iif_id, 'oif_id' => $oif_id));
}

function getPortIIFStats ($args)
{
        $result = usePreparedSelectBlade
        (
                'SELECT dict_value AS title, COUNT(id) AS max, ' .
                'COUNT(reservation_comment) + ' .
                'SUM((SELECT COUNT(*) FROM Link WHERE id IN (porta, portb))) AS current ' .