gnu-social/lib/mysqlschema.php

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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 MysqlSchema extends Schema
{
static $_single = null;
protected $conn = null;
/**
* Main public entry point. Use this to get
* the singleton object.
*
* @return Schema the (single) Schema object
*/
static function get()
{
if (empty(self::$_single)) {
self::$_single = new Schema();
}
return self::$_single;
}
/**
* Returns a TableDef object for the table
* in the schema with the given name.
*
* Throws an exception if the table is not found.
*
* @param string $name Name of the table to get
*
* @return TableDef tabledef for that table.
* @throws SchemaTableMissingException
*/
public function getTableDef($name)
{
$query = "SELECT * FROM INFORMATION_SCHEMA.COLUMNS " .
"WHERE TABLE_SCHEMA='%s' AND TABLE_NAME='%s'";
$schema = $this->conn->dsn['database'];
$sql = sprintf($query, $schema, $name);
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
if ($res->numRows() == 0) {
$res->free();
throw new SchemaTableMissingException("No such table: $name");
}
$td = new TableDef();
$td->name = $name;
$td->columns = array();
$row = array();
while ($res->fetchInto($row, DB_FETCHMODE_ASSOC)) {
$cd = new ColumnDef();
$cd->name = $row['COLUMN_NAME'];
$packed = $row['COLUMN_TYPE'];
if (preg_match('/^(\w+)\((\d+)\)$/', $packed, $match)) {
$cd->type = $match[1];
$cd->size = $match[2];
} else {
$cd->type = $packed;
}
$cd->nullable = ($row['IS_NULLABLE'] == 'YES') ? true : false;
$cd->key = $row['COLUMN_KEY'];
$cd->default = $row['COLUMN_DEFAULT'];
$cd->extra = $row['EXTRA'];
// Autoincrement is stuck into the extra column.
// Pull it out so we don't accidentally mod it every time...
$extra = preg_replace('/(^|\s)auto_increment(\s|$)/i', '$1$2', $cd->extra);
if ($extra != $cd->extra) {
$cd->extra = trim($extra);
$cd->auto_increment = true;
}
// mysql extensions -- not (yet) used by base class
$cd->charset = $row['CHARACTER_SET_NAME'];
$cd->collate = $row['COLLATION_NAME'];
$td->columns[] = $cd;
}
$res->free();
return $td;
}
/**
* Pull the given table properties from INFORMATION_SCHEMA.
* Most of the good stuff is MySQL extensions.
*
* @return array
* @throws Exception if table info can't be looked up
*/
function getTableProperties($table, $props)
{
$query = "SELECT %s FROM INFORMATION_SCHEMA.TABLES " .
"WHERE TABLE_SCHEMA='%s' AND TABLE_NAME='%s'";
$schema = $this->conn->dsn['database'];
$sql = sprintf($query, implode(',', $props), $schema, $table);
$res = $this->conn->query($sql);
$row = array();
$ok = $res->fetchInto($row, DB_FETCHMODE_ASSOC);
$res->free();
if ($ok) {
return $row;
} else {
throw new SchemaTableMissingException("No such table: $table");
}
}
/**
* Creates a table with the given names and columns.
*
* @param string $name Name of the table
* @param array $columns Array of ColumnDef objects
* for new table.
*
* @return boolean success flag
*/
public function createTable($name, $columns)
{
$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);
}
$idx = $this->_indexList($columns);
if ($idx['primary']) {
$sql .= ",\nconstraint primary key (" . implode(',', $idx['primary']) . ")";
}
foreach ($idx['uniques'] as $u) {
$key = $this->_uniqueKey($name, $u);
$sql .= ",\nunique index $key ($u)";
}
foreach ($idx['indices'] as $i) {
$key = $this->_key($name, $i);
$sql .= ",\nindex $key ($i)";
}
$sql .= ") ENGINE=InnoDB CHARACTER SET utf8 COLLATE utf8_bin; ";
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Look over a list of column definitions and list up which
* indices will be present
*/
private function _indexList(array $columns)
{
$list = array('uniques' => array(),
'primary' => array(),
'indices' => array());
foreach ($columns as $cd) {
switch ($cd->key) {
case 'UNI':
$list['uniques'][] = $cd->name;
break;
case 'PRI':
$list['primary'][] = $cd->name;
break;
case 'MUL':
$list['indices'][] = $cd->name;
break;
}
}
return $list;
}
/**
* Get the unique index key name for a given column on this table
*/
function _uniqueKey($tableName, $columnName)
{
return $this->_key($tableName, $columnName);
}
/**
* Get the index key name for a given column on this table
*/
function _key($tableName, $columnName)
{
return "{$tableName}_{$columnName}_idx";
}
/**
* Ensures that a table exists with the given
* name and the given column definitions.
*
* If the table does not yet exist, it will
* create the table. If it does exist, it will
* alter the table to match the column definitions.
*
* @param string $tableName name of the table
* @param array $columns array of ColumnDef
* objects for the table
*
* @return boolean success flag
*/
public function ensureTable($tableName, $columns)
{
// XXX: DB engine portability -> toilet
try {
$td = $this->getTableDef($tableName);
} catch (SchemaTableMissingException $e) {
return $this->createTable($tableName, $columns);
}
$cur = $this->_names($td->columns);
$new = $this->_names($columns);
$dropIndex = array();
$toadd = array_diff($new, $cur);
$todrop = array_diff($cur, $new);
$same = array_intersect($new, $cur);
$tomod = array();
$addIndex = array();
$tableProps = array();
foreach ($same as $m) {
$curCol = $this->_byName($td->columns, $m);
$newCol = $this->_byName($columns, $m);
if (!$newCol->equals($curCol)) {
$tomod[] = $newCol->name;
continue;
}
// Earlier versions may have accidentally left tables at default
// charsets which might be latin1 or other freakish things.
if ($this->_isString($curCol)) {
if ($curCol->charset != 'utf8') {
$tomod[] = $newCol->name;
continue;
}
}
}
// Find any indices we have to change...
$curIdx = $this->_indexList($td->columns);
$newIdx = $this->_indexList($columns);
if ($curIdx['primary'] != $newIdx['primary']) {
if ($curIdx['primary']) {
$dropIndex[] = 'drop primary key';
}
if ($newIdx['primary']) {
$keys = implode(',', $newIdx['primary']);
$addIndex[] = "add constraint primary key ($keys)";
}
}
$dropUnique = array_diff($curIdx['uniques'], $newIdx['uniques']);
$addUnique = array_diff($newIdx['uniques'], $curIdx['uniques']);
foreach ($dropUnique as $columnName) {
$dropIndex[] = 'drop key ' . $this->_uniqueKey($tableName, $columnName);
}
foreach ($addUnique as $columnName) {
$addIndex[] = 'add constraint unique key ' . $this->_uniqueKey($tableName, $columnName) . " ($columnName)";;
}
$dropMultiple = array_diff($curIdx['indices'], $newIdx['indices']);
$addMultiple = array_diff($newIdx['indices'], $curIdx['indices']);
foreach ($dropMultiple as $columnName) {
$dropIndex[] = 'drop key ' . $this->_key($tableName, $columnName);
}
foreach ($addMultiple as $columnName) {
$addIndex[] = 'add key ' . $this->_key($tableName, $columnName) . " ($columnName)";
}
// Check for table properties: make sure we're using a sane
// engine type and charset/collation.
// @fixme make the default engine configurable?
$oldProps = $this->getTableProperties($tableName, array('ENGINE', 'TABLE_COLLATION'));
if (strtolower($oldProps['ENGINE']) != 'innodb') {
$tableProps['ENGINE'] = 'InnoDB';
}
if (strtolower($oldProps['TABLE_COLLATION']) != 'utf8_bin') {
$tableProps['DEFAULT CHARSET'] = 'utf8';
$tableProps['COLLATE'] = 'utf8_bin';
}
if (count($dropIndex) + count($toadd) + count($todrop) + count($tomod) + count($addIndex) + count($tableProps) == 0) {
// nothing to do
return true;
}
// For efficiency, we want this all in one
// query, instead of using our methods.
$phrase = array();
foreach ($dropIndex as $indexSql) {
$phrase[] = $indexSql;
}
foreach ($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);
}
foreach ($addIndex as $indexSql) {
$phrase[] = $indexSql;
}
foreach ($tableProps as $key => $val) {
$phrase[] = "$key=$val";
}
$sql = 'ALTER TABLE ' . $tableName . ' ' . implode(', ', $phrase);
common_log(LOG_DEBUG, __METHOD__ . ': ' . $sql);
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Is this column a string type?
*/
private function _isString(array $cd)
{
$strings = array('char', 'varchar', 'text');
return in_array(strtolower($cd['type']), $strings);
}
/**
* Return the proper SQL for creating or
* altering a column.
*
* Appropriate for use in CREATE TABLE or
* ALTER TABLE statements.
*
* @param ColumnDef $cd column to create
*
* @return string correct SQL for that column
*/
function columnSql(array $cd)
{
$line = array();
$line[] = parent::_columnSql($cd);
if ($cd['type'] == 'serial') {
$line[] = 'auto_increment';
}
if (!empty($cd['extra'])) {
$line[] = $cd['extra']; // hisss boooo
}
if (!empty($cd['description'])) {
$line[] = 'comment';
$line[] = $this->quote($cd['description']);
}
return implode(' ', $line);
}
function mapType($column)
{
$map = array('serial' => 'int',
'integer' => 'int',
'numeric' => 'decimal');
$type = $column['type'];
if (isset($map[$type])) {
$type = $map[$type];
}
if (!empty($column['size'])) {
$size = $column['size'];
if ($type == 'int' &&
in_array($size, array('tiny', 'small', 'medium', 'big'))) {
$type = $size . $type;
} else if (in_array($type, array('blob', 'text')) &&
in_array($size, array('tiny', 'medium', 'long'))) {
$type = $size . $type;
}
}
return $type;
}
function typeAndSize($column)
{
if ($column['type'] == 'enum') {
$vals = array_map(array($this, 'quote'), $column['enum']);
return 'enum(' . implode(',', $vals) . ')';
} else if ($this->_isString($column)) {
return parent::typeAndSize($column) . ' CHARSET utf8';
} else {
return parent::typeAndSize($column);
}
}
}