diff options
Diffstat (limited to 'lib/schema.php')
| -rw-r--r-- | lib/schema.php | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/lib/schema.php b/lib/schema.php new file mode 100644 index 000000000..8c8f5e9ff --- /dev/null +++ b/lib/schema.php @@ -0,0 +1,445 @@ +<?php +/** + * StatusNet, the distributed open-source microblogging tool + * + * Database schema utilities + * + * PHP version 5 + * + * LICENCE: This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * @category Database + * @package StatusNet + * @author Evan Prodromou <evan@status.net> + * @copyright 2009 StatusNet, Inc. + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0 + * @link http://status.net/ + */ + +if (!defined('STATUSNET')) { + exit(1); +} + +/** + * Class representing the database schema + * + * A class representing the database schema. Can be used to + * manipulate the schema -- especially for plugins and upgrade + * utilities. + * + * @category Database + * @package StatusNet + * @author Evan Prodromou <evan@status.net> + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0 + * @link http://status.net/ + */ + +class Schema +{ + static $_single = null; + protected $conn = null; + + protected function __construct() + { + // XXX: there should be an easier way to do this. + $user = new User(); + $this->conn = $user->getDatabaseConnection(); + $user->free(); + unset($user); + } + + static function get() + { + if (empty(self::$_single)) { + self::$_single = new Schema(); + } + return self::$_single; + } + + public function getTableDef($name) + { + $res =& $this->conn->query('DESCRIBE ' . $name); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + $td = new TableDef(); + + $td->name = $name; + $td->columns = array(); + + $row = array(); + + while ($res->fetchInto($row, DB_FETCHMODE_ASSOC)) { + + $cd = new ColumnDef(); + + $cd->name = $row['Field']; + + $packed = $row['Type']; + + if (preg_match('/^(\w+)\((\d+)\)$/', $packed, $match)) { + $cd->type = $match[1]; + $cd->size = $match[2]; + } else { + $cd->type = $packed; + } + + $cd->nullable = ($row['Null'] == 'YES') ? true : false; + $cd->key = $row['Key']; + $cd->default = $row['Default']; + $cd->extra = $row['Extra']; + + $td->columns[] = $cd; + } + + return $td; + } + + public function getColumnDef($table, $column) + { + $td = $this->getTableDef($table); + + foreach ($td->columns as $cd) { + if ($cd->name == $column) { + return $cd; + } + } + + return null; + } + + public function getIndexDef($table, $index) + { + return null; + } + + public function createTable($name, $columns, $indices=null) + { + $uniques = array(); + $primary = array(); + $indices = array(); + + $sql = "CREATE TABLE $name (\n"; + + for ($i = 0; $i < count($columns); $i++) { + + $cd =& $columns[$i]; + + if ($i > 0) { + $sql .= ",\n"; + } + + $sql .= $this->_columnSql($cd); + + switch ($cd->key) { + case 'UNI': + $uniques[] = $cd->name; + break; + case 'PRI': + $primary[] = $cd->name; + break; + case 'MUL': + $indices[] = $cd->name; + break; + } + } + + if (count($primary) > 0) { // it really should be... + $sql .= ",\nconstraint primary key (" . implode(',', $primary) . ")"; + } + + foreach ($uniques as $u) { + $sql .= ",\nunique index {$name}_{$u}_idx ($u)"; + } + + foreach ($indices as $i) { + $sql .= ",\nindex {$name}_{$i}_idx ($i)"; + } + + $sql .= "); "; + + common_debug($sql); + + $res =& $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function dropTable($name) + { + $res =& $this->conn->query("DROP TABLE $name"); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function createIndex($table, $columnNames, $name = null) + { + if (!is_array($columnNames)) { + $columnNames = array($columnNames); + } + + if (empty($name)) { + $name = "$table_".implode("_", $columnNames)."_idx"; + } + + $res =& $this->conn->query("ALTER TABLE $table ADD INDEX $name (".implode(",", $columnNames).")"); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function dropIndex($table, $name) + { + $res =& $this->conn->query("ALTER TABLE $table DROP INDEX $name"); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function addColumn($table, $columndef) + { + $sql = "ALTER TABLE $table ADD COLUMN " . $this->_columnSql($columndef); + + $res =& $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function modifyColumn($table, $columndef) + { + $sql = "ALTER TABLE $table MODIFY COLUMN " . $this->_columnSql($columndef); + + $res =& $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function dropColumn($table, $columnName) + { + $sql = "ALTER TABLE $table DROP COLUMN $columnName"; + + $res =& $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + public function ensureTable($tableName, $columns, $indices=null) + { + // XXX: DB engine portability -> toilet + + try { + $td = $this->getTableDef($tableName); + } catch (Exception $e) { + if (preg_match('/no such table/', $e->getMessage())) { + return $this->createTable($tableName, $columns, $indices); + } else { + throw $e; + } + } + + $cur = $this->_names($td->columns); + $new = $this->_names($columns); + + $toadd = array_diff($new, $cur); + $todrop = array_diff($cur, $new); + + $same = array_intersect($new, $cur); + + $tomod = array(); + + foreach ($same as $m) { + $curCol = $this->_byName($td->columns, $m); + $newCol = $this->_byName($columns, $m); + + if (!$newCol->equals($curCol)) { + $tomod[] = $newCol->name; + } + } + + if (count($toadd) + count($todrop) + count($tomod) == 0) { + // nothing to do + return true; + } + + // For efficiency, we want this all in one + // query, instead of using our methods. + + $phrase = array(); + + foreach ($toadd as $columnName) { + $cd = $this->_byName($columns, $columnName); + $phrase[] = 'ADD COLUMN ' . $this->_columnSql($cd); + } + + foreach ($todrop as $columnName) { + $phrase[] = 'DROP COLUMN ' . $columnName; + } + + foreach ($tomod as $columnName) { + $cd = $this->_byName($columns, $columnName); + $phrase[] = 'MODIFY COLUMN ' . $this->_columnSql($cd); + } + + $sql = 'ALTER TABLE ' . $tableName . ' ' . implode(', ', $phrase); + + $res =& $this->conn->query($sql); + + if (PEAR::isError($res)) { + throw new Exception($res->getMessage()); + } + + return true; + } + + function _names($cds) + { + $names = array(); + + foreach ($cds as $cd) { + $names[] = $cd->name; + } + + return $names; + } + + function _byName($cds, $name) + { + foreach ($cds as $cd) { + if ($cd->name == $name) { + return $cd; + } + } + + return null; + } + + function _columnSql($cd) + { + $sql = "{$cd->name} "; + + if (!empty($cd->size)) { + $sql .= "{$cd->type}({$cd->size}) "; + } else { + $sql .= "{$cd->type} "; + } + + if (!empty($cd->default)) { + $sql .= "default {$cd->default} "; + } else { + $sql .= ($cd->nullable) ? "null " : "not null "; + } + + return $sql; + } +} + +class TableDef +{ + public $name; + public $columns; +} + +class ColumnDef +{ + public $name; + public $type; + public $size; + public $nullable; + public $key; + public $default; + public $extra; + + function __construct($name=null, $type=null, $size=null, + $nullable=true, $key=null, $default=null, + $extra=null) { + $this->name = strtolower($name); + $this->type = strtolower($type); + $this->size = $size+0; + $this->nullable = $nullable; + $this->key = $key; + $this->default = $default; + $this->extra = $extra; + } + + function equals($other) + { + return ($this->name == $other->name && + $this->_typeMatch($other) && + $this->_defaultMatch($other) && + $this->_nullMatch($other) && + $this->key == $other->key); + } + + function _typeMatch($other) + { + switch ($this->type) { + case 'integer': + case 'int': + return ($other->type == 'integer' || + $other->type == 'int'); + break; + default: + return ($this->type == $other->type && + $this->size == $other->size); + } + } + + function _defaultMatch($other) + { + return ((is_null($this->default) && is_null($other->default)) || + ($this->default == $other->default)); + } + + function _nullMatch($other) + { + return ((!is_null($this->default) && !is_null($other->default) && + $this->default == $other->default) || + ($this->nullable == $other->nullable)); + } +} + +class IndexDef +{ + public $name; + public $table; + public $columns; +} |