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+<?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;
+}