gnu-social/lib/database/mysqlschema.php
Alexei Sorokin caac2cea44 [SCHEMA] Better DBMS information fetching
On PostgreSQL:
  - Parse defaults for strings and booleans properly.
  - Parse the "serial" definition type properly.
  - Get information on the "enum" definition type.
  - Re-work getting information about keys/indices.

On MariaDB:
  - Get information about lengths in indices.
  - Get foreign key information separately from the rest as they can have
    colliding names.
2021-07-16 19:44:38 +01:00

618 lines
20 KiB
PHP

<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social 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.
//
// GNU social 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 GNU social. If not, see <http://www.gnu.org/licenses/>.
/**
* Database schema for MariaDB
*
* @category Database
* @package GNUsocial
* @author Evan Prodromou <evan@status.net>
* @copyright 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
defined('GNUSOCIAL') || die();
/**
* Class representing the database schema for MariaDB
*
* A class representing the database schema. Can be used to
* manipulate the schema -- especially for plugins and upgrade
* utilities.
*
* @copyright 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class MysqlSchema extends Schema
{
public static $_single = null;
/**
* Main public entry point. Use this to get
* the singleton object.
*
* @param object|null $conn
* @param string|null dummy param
* @return Schema the (single) Schema object
*/
public static function get($conn = null, $_ = 'mysql')
{
if (empty(self::$_single)) {
self::$_single = new Schema($conn, 'mysql');
}
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 $table Name of the table to get
*
* @return array of tabledef for that table.
* @throws PEAR_Exception
* @throws SchemaTableMissingException
*/
public function getTableDef($table)
{
$def = [];
$hasKeys = false;
// Pull column data from INFORMATION_SCHEMA
$columns = $this->fetchMetaInfo($table, 'COLUMNS', 'ORDINAL_POSITION');
if (count($columns) == 0) {
throw new SchemaTableMissingException("No such table: $table");
}
foreach ($columns as $row) {
$name = $row['COLUMN_NAME'];
$field = [];
$type = $field['type'] = $row['DATA_TYPE'];
switch ($type) {
case 'char':
case 'varchar':
if (!is_null($row['CHARACTER_MAXIMUM_LENGTH'])) {
$field['length'] = (int) $row['CHARACTER_MAXIMUM_LENGTH'];
}
break;
case 'decimal':
// Other int types may report these values, but they're irrelevant.
// Just ignore them!
if (!is_null($row['NUMERIC_PRECISION'])) {
$field['precision'] = (int) $row['NUMERIC_PRECISION'];
}
if (!is_null($row['NUMERIC_SCALE'])) {
$field['scale'] = (int) $row['NUMERIC_SCALE'];
}
break;
case 'enum':
$enum = preg_replace("/^enum\('(.+)'\)$/", '\1', $row['COLUMN_TYPE']);
$field['enum'] = explode("','", $enum);
break;
}
if ($row['IS_NULLABLE'] == 'NO') {
$field['not null'] = true;
}
$col_default = $row['COLUMN_DEFAULT'];
if (!is_null($col_default) && $col_default !== 'NULL') {
if ($this->isNumericType($field)) {
$field['default'] = (int) $col_default;
} elseif ($col_default === 'CURRENT_TIMESTAMP'
|| $col_default === 'current_timestamp()') {
// A hack for "datetime" fields
// Skip "timestamp" as they get a CURRENT_TIMESTAMP default implicitly
if ($type !== 'timestamp') {
$field['default'] = 'CURRENT_TIMESTAMP';
}
} else {
$match = "/^'(.*)'$/";
if (preg_match($match, $col_default)) {
$field['default'] = preg_replace($match, '\1', $col_default);
} else {
$field['default'] = $col_default;
}
}
}
if ($row['COLUMN_KEY'] !== null) {
// We'll need to look up key info...
$hasKeys = true;
}
if ($row['COLUMN_COMMENT'] !== null && $row['COLUMN_COMMENT'] != '') {
$field['description'] = $row['COLUMN_COMMENT'];
}
$extra = $row['EXTRA'];
if ($extra) {
if (preg_match('/(^|\s)auto_increment(\s|$)/i', $extra)) {
$field['auto_increment'] = true;
}
}
$table_props = $this->getTableProperties($table, ['TABLE_COLLATION']);
$collate = $row['COLLATION_NAME'];
if (!empty($collate) && $collate !== $table_props['TABLE_COLLATION']) {
$field['collate'] = $collate;
}
$def['fields'][$name] = $field;
}
if ($hasKeys) {
$key_info = $this->fetchKeyInfo($table);
foreach ($key_info as $row) {
$key_name = $row['key_name'];
$cols = $row['cols'];
switch ($row['key_type']) {
case 'PRIMARY':
$def['primary key'] = $cols;
break;
case 'UNIQUE':
$def['unique keys'][$key_name] = $cols;
break;
case 'FULLTEXT':
$def['fulltext indexes'][$key_name] = $cols;
break;
default:
$def['indexes'][$key_name] = $cols;
}
}
}
$foreign_key_info = $this->fetchForeignKeyInfo($table);
foreach ($foreign_key_info as $row) {
$key_name = $row['key_name'];
$cols = $row['cols'];
$ref_table = $row['ref_table'];
$def['foreign keys'][$key_name] = [$ref_table, $cols];
}
return $def;
}
/**
* Pull the given table properties from INFORMATION_SCHEMA.
* Most of the good stuff is MySQL extensions.
*
* @param $table
* @param $props
* @return array
* @throws PEAR_Exception
* @throws SchemaTableMissingException
*/
public function getTableProperties($table, $props)
{
$data = $this->fetchMetaInfo($table, 'TABLES');
if ($data) {
return $data[0];
} else {
throw new SchemaTableMissingException("No such table: $table");
}
}
/**
* Pull some INFORMATION.SCHEMA data for the given table.
*
* @param string $table
* @param $infoTable
* @param null $orderBy
* @return array of arrays
* @throws PEAR_Exception
*/
public function fetchMetaInfo($table, $infoTable, $orderBy = null)
{
$schema = $this->conn->dsn['database'];
return $this->fetchQueryData(sprintf(
<<<'END'
SELECT * FROM INFORMATION_SCHEMA.%1$s
WHERE TABLE_SCHEMA = '%2$s' AND TABLE_NAME = '%3$s'%4$s;
END,
$this->quoteIdentifier($infoTable),
$schema,
$table,
($orderBy ? " ORDER BY {$orderBy}" : '')
));
}
/**
* Pull index and keys information for the given table.
*
* @param string $table
* @return array of arrays
* @throws PEAR_Exception
*/
private function fetchKeyInfo(string $table): array
{
$schema = $this->conn->dsn['database'];
$data = $this->fetchQueryData(
<<<EOT
SELECT INDEX_NAME AS `key_name`,
CASE
WHEN INDEX_NAME = 'PRIMARY' THEN 'PRIMARY'
WHEN NON_UNIQUE IS NOT TRUE THEN 'UNIQUE'
ELSE INDEX_TYPE
END AS `key_type`,
COLUMN_NAME AS `col`,
SUB_PART AS `col_length`
FROM INFORMATION_SCHEMA.STATISTICS
WHERE TABLE_SCHEMA = '{$schema}' AND TABLE_NAME = '{$table}'
ORDER BY `key_name`, `key_type`, SEQ_IN_INDEX;
EOT
);
$rows = [];
foreach ($data as $row) {
$name = $row['key_name'];
if (!is_null($row['col_length'])) {
$row['col'] = [$row['col'], (int) $row['col_length']];
}
unset($row['col_length']);
if (!array_key_exists($name, $rows)) {
$row['cols'] = [$row['col']];
unset($row['col']);
$rows[$name] = $row;
} else {
$rows[$name]['cols'][] = $row['col'];
}
}
return array_values($rows);
}
/**
* Pull foreign key information for the given table.
*
* @param string $table
* @return array array of arrays
* @throws PEAR_Exception
*/
private function fetchForeignKeyInfo(string $table): array
{
$schema = $this->conn->dsn['database'];
$data = $this->fetchQueryData(
<<<END
SELECT CONSTRAINT_NAME AS `key_name`,
COLUMN_NAME AS `col`,
REFERENCED_TABLE_NAME AS `ref_table`,
REFERENCED_COLUMN_NAME AS `ref_col`
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA = '{$schema}'
AND TABLE_NAME = '{$table}'
AND REFERENCED_TABLE_SCHEMA = '{$schema}'
ORDER BY `key_name`, ORDINAL_POSITION;
END
);
$rows = [];
foreach ($data as $row) {
$name = $row['key_name'];
if (!array_key_exists($name, $rows)) {
$row['cols'] = [$row['col'] => $row['ref_col']];
unset($row['col']);
unset($row['ref_col']);
$rows[$name] = $row;
} else {
$rows[$name]['cols'][$row['col']] = $row['ref_col'];
}
}
return array_values($rows);
}
/**
* Append an SQL statement with an index definition for a full-text search
* index over one or more columns on a table.
*
* @param array $statements
* @param string $table
* @param string $name
* @param array $def
*/
public function appendCreateFulltextIndex(array &$statements, $table, $name, array $def)
{
$statements[] = "CREATE FULLTEXT INDEX $name ON $table " . $this->buildIndexList($def);
}
/**
* Append an SQL statement with an index definition for an advisory
* index over one or more columns on a table.
*
* @param array $statements
* @param string $table
* @param string $name
* @param array $def
*/
public function appendCreateIndex(array &$statements, $table, $name, array $def)
{
$statements[] = "ALTER TABLE {$this->quoteIdentifier($table)} "
. "ADD INDEX {$name} {$this->buildIndexList($def)}";
}
/**
* Close out a 'create table' SQL statement.
*
* @param string $name
* @param array $def
* @return string;
*
*/
public function endCreateTable($name, array $def)
{
$engine = $this->preferredEngine($def);
return ") ENGINE=$engine CHARACTER SET utf8mb4 COLLATE utf8mb4_bin";
}
public function preferredEngine($def)
{
/* MyISAM is no longer required for fulltext indexes, fortunately
if (!empty($def['fulltext indexes'])) {
return 'MyISAM';
}
*/
return 'InnoDB';
}
/**
* Append phrase(s) to an array of partial ALTER TABLE chunks in order
* to alter the given column from its old state to a new one.
*
* @param array $phrase
* @param string $columnName
* @param array $old previous column definition as found in DB
* @param array $cd current column definition
*/
public function appendAlterModifyColumn(
array &$phrase,
string $columnName,
array $old,
array $cd
): void {
$phrase[] = 'MODIFY COLUMN ' . $this->quoteIdentifier($columnName)
. ' ' . $this->columnSql($columnName, $cd);
}
/**
* MySQL doesn't take 'DROP CONSTRAINT', need to treat primary keys as
* if they were indexes here, but can use 'PRIMARY KEY' special name.
*
* @param array $phrase
*/
public function appendAlterDropPrimary(array &$phrase, string $tableName)
{
$phrase[] = 'DROP PRIMARY KEY';
}
/**
* MySQL doesn't take 'DROP CONSTRAINT', need to treat unique keys as
* if they were indexes here.
*
* @param array $phrase
* @param string $keyName MySQL
*/
public function appendAlterDropUnique(array &$phrase, $keyName)
{
$phrase[] = 'DROP INDEX ' . $keyName;
}
public function appendAlterDropForeign(array &$phrase, $keyName)
{
$phrase[] = 'DROP FOREIGN KEY ' . $keyName;
}
/**
* Throw some table metadata onto the ALTER TABLE if we have a mismatch
* in expected type, collation.
* @param array $phrase
* @param $tableName
* @param array $def
* @throws Exception
*/
public function appendAlterExtras(array &$phrase, $tableName, array $def)
{
// Check for table properties: make sure we're using a sane
// engine type and collation.
// @fixme make the default engine configurable?
$oldProps = $this->getTableProperties($tableName, ['ENGINE', 'TABLE_COLLATION']);
$engine = $this->preferredEngine($def);
if (strtolower($oldProps['ENGINE']) != strtolower($engine)) {
$phrase[] = "ENGINE=$engine";
}
if (strtolower($oldProps['TABLE_COLLATION']) != 'utf8mb4_bin') {
$phrase[] = 'CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_bin';
$phrase[] = 'DEFAULT CHARACTER SET = utf8mb4';
$phrase[] = 'DEFAULT COLLATE = utf8mb4_bin';
}
}
/**
* Append an SQL statement to drop an index from a table.
* Note that in MariaDB index names are relation-specific.
*
* @param array $statements
* @param string $table
* @param string $name
*/
public function appendDropIndex(array &$statements, $table, $name)
{
$statements[] = "ALTER TABLE {$this->quoteIdentifier($table)} "
. "DROP INDEX {$name}";
}
private function isNumericType(array $cd): bool
{
$ints = array_map(
function ($s) {
return $s . 'int';
},
['tiny', 'small', 'medium', 'big']
);
$ints = array_merge($ints, ['int', 'numeric', 'serial']);
return in_array(strtolower($cd['type']), $ints);
}
/**
* Is this column a string type?
* @param array $cd
* @return bool
*/
private function isStringType(array $cd): bool
{
$strings = ['char', 'varchar', 'text'];
return in_array(strtolower($cd['type']), $strings);
}
/**
* Return the proper SQL for creating or
* altering a column.
*
* Appropriate for use in CREATE TABLE or
* ALTER TABLE statements.
*
* @param string $name column name to create
* @param array $cd column to create
*
* @return string correct SQL for that column
*/
public function columnSql(string $name, array $cd)
{
$line = [];
$line[] = parent::columnSql($name, $cd);
// This'll have been added from our transform of "serial" type
if (!empty($cd['auto_increment'])) {
$line[] = 'AUTO_INCREMENT';
}
if (!empty($cd['description'])) {
$line[] = 'COMMENT';
$line[] = $this->quoteValue($cd['description']);
}
return implode(' ', $line);
}
public function mapType($column)
{
$map = [
'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, ['tiny', 'small', 'medium', 'big'])) {
$type = $size . $type;
} elseif ($type == 'float' && $size == 'big') {
$type = 'double';
} elseif (in_array($type, ['blob', 'text']) &&
in_array($size, ['tiny', 'medium', 'long'])) {
$type = $size . $type;
}
}
return $type;
}
public function typeAndSize(string $name, array $column)
{
if ($column['type'] === 'enum') {
$vals = [];
foreach ($column['enum'] as &$val) {
$vals[] = "'{$val}'";
}
return 'enum(' . implode(',', $vals) . ')';
} elseif ($this->isStringType($column)) {
$col = parent::typeAndSize($name, $column);
if (!empty($column['collate'])) {
$col .= ' COLLATE ' . $column['collate'];
}
return $col;
} else {
return parent::typeAndSize($name, $column);
}
}
/**
* Filter the given table definition array to match features available
* in this database.
*
* This lets us strip out unsupported things like comments, foreign keys,
* or type variants that we wouldn't get back from getTableDef().
*
* @param string $tableName
* @param array $tableDef
* @return array
*/
public function filterDef(string $tableName, array $tableDef)
{
$tableDef = parent::filterDef($tableName, $tableDef);
// Get existing table collation if the table exists.
// To know if collation that's been set is unique for the table.
try {
$table_props = $this->getTableProperties($tableName, ['TABLE_COLLATION']);
$table_collate = $table_props['TABLE_COLLATION'];
} catch (SchemaTableMissingException $e) {
$table_collate = null;
}
foreach ($tableDef['fields'] as $name => &$col) {
switch ($col['type']) {
case 'serial':
$col['type'] = 'int';
$col['auto_increment'] = true;
break;
case 'bool':
$col['type'] = 'int';
$col['size'] = 'tiny';
$col['default'] = (int) $col['default'];
break;
}
if (!empty($col['collate'])
&& $col['collate'] === $table_collate) {
unset($col['collate']);
}
$col['type'] = $this->mapType($col);
unset($col['size']);
}
if (!common_config('db', 'mysql_foreign_keys')) {
unset($tableDef['foreign keys']);
}
return $tableDef;
}
}