gnu-social/lib/schema.php
Brion Vibber 2d0807bc1c Starting on adapting postgresql schema class to look stuff up in the new drupalish format...
Fetching basic column data and unique indexes. Still needs detail work, multi-value indexes, foreign keys, and distinguishing the primary key.
Since we don't get comments and such, for cleaner comparisons we should probably do a filtering on supported features.
2010-10-08 16:36:32 -07:00

635 lines
16 KiB
PHP

<?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>
* @author Brion Vibber <brion@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 $_static = null;
protected $conn = null;
/**
* Constructor. Only run once for singleton object.
*/
protected function __construct($conn = null)
{
if (is_null($conn)) {
// XXX: there should be an easier way to do this.
$user = new User();
$conn = $user->getDatabaseConnection();
$user->free();
unset($user);
}
$this->conn = $conn;
}
/**
* Main public entry point. Use this to get
* the schema object.
*
* @return Schema the Schema object for the connection
*/
static function get($conn = null)
{
if (is_null($conn)) {
$key = 'default';
} else {
$key = md5(serialize($conn->dsn));
}
$type = common_config('db', 'type');
if (empty(self::$_static[$key])) {
$schemaClass = ucfirst($type).'Schema';
self::$_static[$key] = new $schemaClass($conn);
}
return self::$_static[$key];
}
/**
* Gets a ColumnDef object for a single column.
*
* Throws an exception if the table is not found.
*
* @param string $table name of the table
* @param string $column name of the column
*
* @return ColumnDef definition of the column or null
* if not found.
*/
public function getColumnDef($table, $column)
{
$td = $this->getTableDef($table);
foreach ($td->columns as $cd) {
if ($cd->name == $column) {
return $cd;
}
}
return null;
}
/**
* 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);
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 .= "); ";
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Drops a table from the schema
*
* Throws an exception if the table is not found.
*
* @param string $name Name of the table to drop
*
* @return boolean success flag
*/
public function dropTable($name)
{
$res = $this->conn->query("DROP TABLE $name");
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Adds an index to a table.
*
* If no name is provided, a name will be made up based
* on the table name and column names.
*
* Throws an exception on database error, esp. if the table
* does not exist.
*
* @param string $table Name of the table
* @param array $columnNames Name of columns to index
* @param string $name (Optional) name of the index
*
* @return boolean success flag
*/
public function createIndex($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;
}
/**
* Drops a named index from a table.
*
* @param string $table name of the table the index is on.
* @param string $name name of the index
*
* @return boolean success flag
*/
public function dropIndex($table, $name)
{
$res = $this->conn->query("ALTER TABLE $table DROP INDEX $name");
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
return true;
}
/**
* Adds a column to a table
*
* @param string $table name of the table
* @param ColumnDef $columndef Definition of the new
* column.
*
* @return boolean success flag
*/
public function addColumn($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;
}
/**
* Modifies a column in the schema.
*
* The name must match an existing column and table.
*
* @param string $table name of the table
* @param ColumnDef $columndef new definition of the column.
*
* @return boolean success flag
*/
public function modifyColumn($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;
}
/**
* Drops a column from a table
*
* The name must match an existing column.
*
* @param string $table name of the table
* @param string $columnName name of the column to drop
*
* @return boolean success flag
*/
public function dropColumn($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;
}
/**
* 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 (Exception $e) {
if (preg_match('/no such table/', $e->getMessage())) {
return $this->createTable($tableName, $columns);
} 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;
}
/**
* Returns the array of names from an array of
* ColumnDef objects.
*
* @param array $cds array of ColumnDef objects
*
* @return array strings for name values
*/
protected function _names($cds)
{
$names = array();
foreach ($cds as $cd) {
$names[] = $cd->name;
}
return $names;
}
/**
* Get a ColumnDef from an array matching
* name.
*
* @param array $cds Array of ColumnDef objects
* @param string $name Name of the column
*
* @return ColumnDef matching item or null if no match.
*/
protected function _byName($cds, $name)
{
foreach ($cds as $cd) {
if ($cd->name == $name) {
return $cd;
}
}
return null;
}
/**
* 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[] = $this->typeAndSize();
if (isset($cd['default'])) {
$line[] = 'default';
$line[] = $this->quoted($cd['default']);
} else if (!empty($cd['not null'])) {
// Can't have both not null AND default!
$line[] = 'not null';
}
return implode(' ', $line);
}
/**
*
* @param string $column canonical type name in defs
* @return string native DB type name
*/
function mapType($column)
{
return $column;
}
function typeAndSize($column)
{
$type = $this->mapType($column);
$lengths = array();
if ($column['type'] == 'numeric') {
if (isset($column['precision'])) {
$lengths[] = $column['precision'];
if (isset($column['scale'])) {
$lengths[] = $column['scale'];
}
}
} else if (isset($column['length'])) {
$lengths[] = $column['length'];
}
if ($lengths) {
return $type . '(' . implode(',', $lengths) . ')';
} else {
return $type;
}
}
/**
* Map a native type back to an independent type + size
*
* @param string $type
* @return array ($type, $size) -- $size may be null
*/
protected function reverseMapType($type)
{
return array($type, null);
}
/**
* Convert an old-style set of ColumnDef objects into the current
* Drupal-style schema definition array, for backwards compatibility
* with plugins written for 0.9.x.
*
* @param string $tableName
* @param array $defs
* @return array
*/
function oldToNew($tableName, $defs)
{
$table = array();
$prefixes = array(
'tiny',
'small',
'medium',
'big',
);
foreach ($defs as $cd) {
$cd->addToTableDef($table);
$column = array();
$column['type'] = $cd->type;
foreach ($prefixes as $prefix) {
if (substr($cd->type, 0, strlen($prefix)) == $prefix) {
$column['type'] = substr($cd->type, strlen($prefix));
$column['size'] = $prefix;
break;
}
}
if ($cd->size) {
if ($cd->type == 'varchar' || $cd->type == 'char') {
$column['length'] = $cd->size;
}
}
if (!$cd->nullable) {
$column['not null'] = true;
}
if ($cd->autoincrement) {
$column['type'] = 'serial';
}
if ($cd->default) {
$column['default'] = $cd->default;
}
$table['fields'][$cd->name] = $column;
if ($cd->key == 'PRI') {
// If multiple columns are defined as primary key,
// we'll pile them on in sequence.
if (!isset($table['primary key'])) {
$table['primary key'] = array();
}
$table['primary key'][] = $cd->name;
} else if ($cd->key == 'MUL') {
// Individual multiple-value indexes are only per-column
// using the old ColumnDef syntax.
$idx = "{$tableName}_{$cd->name}_idx";
$table['indexes'][$idx] = array($cd->name);
} else if ($cd->key == 'UNI') {
// Individual unique-value indexes are only per-column
// using the old ColumnDef syntax.
$idx = "{$tableName}_{$cd->name}_idx";
$table['unique keys'][$idx] = array($cd->name);
}
}
return $table;
}
function isNumericType($type)
{
$type = strtolower($type);
$known = array('int', 'serial', 'numeric');
return in_array($type, $known);
}
/**
* Pull info from the query into a fun-fun array of dooooom
*
* @param string $sql
* @return array of arrays
*/
protected function fetchQueryData($sql)
{
$res = $this->conn->query($sql);
if (PEAR::isError($res)) {
throw new Exception($res->getMessage());
}
$out = array();
$row = array();
while ($res->fetchInto($row, DB_FETCHMODE_ASSOC)) {
$out[] = $row;
}
$res->free();
return $out;
}
}
class SchemaTableMissingException extends Exception
{
// no-op
}