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Diffstat (limited to 'lib/schemaupdater.php')
-rw-r--r-- | lib/schemaupdater.php | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/lib/schemaupdater.php b/lib/schemaupdater.php new file mode 100644 index 000000000..64f7c596d --- /dev/null +++ b/lib/schemaupdater.php @@ -0,0 +1,126 @@ +<?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 SchemaUpdater +{ + public function __construct($schema) + { + $this->schema = $schema; + $this->checksums = $this->getChecksums(); + } + + /** + * @param string $tableName + * @param array $tableDef + */ + public function register($tableName, array $tableDef) + { + $this->tables[$tableName] = $tableDef; + } + + /** + * Go ping em! + * + * @fixme handle tables that belong on different database servers...? + */ + public function checkSchema() + { + $checksums = $this->checksums; + foreach ($this->tables as $table => $def) { + $checksum = $this->checksum($def); + if (empty($checksums[$table])) { + common_log(LOG_DEBUG, "No previous schema_version for $table: updating to $checksum"); + } else if ($checksums[$table] == $checksum) { + common_log(LOG_DEBUG, "Last schema_version for $table up to date: $checksum"); + continue; + } else { + common_log(LOG_DEBUG, "Last schema_version for $table is {$checksums[$table]}: updating to $checksum"); + } + //$this->conn->query('BEGIN'); + $this->schema->ensureTable($table, $def); + $this->saveChecksum($table, $checksum); + //$this->conn->commit(); + } + } + + /** + * Calculate a checksum for this table definition array. + * + * @param array $def + * @return string + */ + public function checksum(array $def) + { + $flat = serialize($def); + return sha1($flat); + } + + /** + * Pull all known table checksums into an array for easy lookup. + * + * @return array: associative array of table names to checksum strings + */ + protected function getChecksums() + { + $checksums = array(); + + $sv = new Schema_version(); + $sv->find(); + while ($sv->fetch()) { + $checksums[$sv->table_name] = $sv->checksum; + } + + return $checksums; + } + + /** + * Save or update current available checksums. + * + * @param string $table + * @param string $checksum + */ + protected function saveChecksum($table, $checksum) + { + $sv = new Schema_version(); + $sv->table_name = $table; + $sv->checksum = $checksum; + $sv->modified = common_sql_now(); + if (isset($this->checksums[$table])) { + $sv->update(); + } else { + $sv->insert(); + } + $this->checksums[$table] = $checksum; + } +} |