gnu-social/lib/database/pgsqlschema.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

469 lines
15 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 PostgreSQL
*
* @category Database
* @package GNUsocial
* @author Evan Prodromou <evan@status.net>
* @author Brenda Wallace <shiny@cpan.org>
* @author Brion Vibber <brion@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 PostgreSQL
*
* 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 PgsqlSchema 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, $_ = 'pgsql')
{
if (empty(self::$_single)) {
self::$_single = new Schema($conn, 'pgsql');
}
return self::$_single;
}
/**
* Returns a table definition array for the table
* in the schema with the given name.
*
* Throws an exception if the table is not found.
*
* @param string $table Name of the table to get
*
* @return array tabledef for that table.
* @throws SchemaTableMissingException
*/
public function getTableDef($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");
}
// Get information on the emulated "enum" type
$enum_info = $this->fetchEnumInfo($table);
foreach ($columns as $row) {
$name = $row['column_name'];
$field = [];
$field['type'] = $type = $row['udt_name'];
if (in_array($type, ['char', 'bpchar', 'varchar'])) {
if ($row['character_maximum_length'] !== null) {
$field['length'] = intval($row['character_maximum_length']);
}
}
if ($type == 'numeric') {
// Other int types may report these values, but they're irrelevant.
// Just ignore them!
if ($row['numeric_precision'] !== null) {
$field['precision'] = intval($row['numeric_precision']);
}
if ($row['numeric_scale'] !== null) {
$field['scale'] = intval($row['numeric_scale']);
}
}
if ($row['is_nullable'] == 'NO') {
$field['not null'] = true;
}
$col_default = $row['column_default'];
if (!is_null($col_default)) {
if ($this->isNumericType($field)) {
$field['default'] = (int) $col_default;
} elseif ($type === 'bool') {
$field['default'] = ($col_default === 'true') ? true : false;
} else {
$match = "/^'(.*)'(::.+)*$/";
if (preg_match($match, $col_default)) {
$field['default'] = preg_replace(
$match,
'\1',
$col_default
);
} else {
$field['default'] = $col_default;
}
}
}
if (
$row['is_identity'] === 'YES'
&& $row['identity_generation'] = 'BY DEFAULT'
) {
$field['auto_increment'] = true;
} elseif (array_key_exists($name, $enum_info)) {
$field['type'] = $type = 'enum';
$field['enum'] = $enum_info[$name];
}
$def['fields'][$name] = $field;
}
$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;
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 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)
{
$catalog = $this->conn->dsn['database'];
return $this->fetchQueryData(sprintf(
<<<'END'
SELECT * FROM information_schema.%1$s
WHERE table_catalog = '%2$s' AND table_name = '%3$s'%4$s;
END,
$this->quoteIdentifier($infoTable),
$catalog,
$table,
($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
{
$data = $this->fetchQueryData(sprintf(
<<<'EOT'
SELECT "rel"."relname" AS "key_name",
CASE
WHEN "idx"."indisprimary" IS TRUE THEN 'primary'
WHEN "idx"."indisunique" IS TRUE THEN 'unique'
ELSE "am"."amname"
END AS "key_type",
"cols"."attname" AS "col"
FROM pg_index AS "idx"
CROSS JOIN LATERAL unnest("idx"."indkey")
WITH ORDINALITY AS "col_nums" ("num", "pos")
INNER JOIN pg_class AS "rel"
ON "idx"."indexrelid" = "rel".oid
LEFT JOIN pg_attribute AS "cols"
ON "idx"."indrelid" = "cols"."attrelid"
AND "col_nums"."num" = "cols"."attnum"
LEFT JOIN pg_am AS "am"
ON "rel"."relam" = "am".oid
WHERE "idx"."indrelid" = CAST('%s' AS REGCLASS)
ORDER BY "key_type", "key_name", "col_nums"."pos";
EOT,
$table
));
$rows = [];
foreach ($data as $row) {
$name = $row['key_name'];
if (!array_key_exists($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
{
$data = $this->fetchQueryData(sprintf(
<<<'END'
SELECT "con"."conname" AS "key_name",
"cols"."attname" AS "col",
"ref_rel"."relname" AS "ref_table",
"ref_cols"."attname" AS "ref_col"
FROM pg_constraint AS "con"
CROSS JOIN LATERAL unnest("con"."conkey", "con"."confkey")
WITH ORDINALITY AS "col_nums" ("num", "ref_num", "pos")
LEFT JOIN pg_attribute AS "cols"
ON "con"."conrelid" = "cols"."attrelid"
AND "col_nums"."num" = "cols"."attnum"
LEFT JOIN pg_class AS "ref_rel"
ON "con"."confrelid" = "ref_rel".oid
LEFT JOIN pg_attribute AS "ref_cols"
ON "con"."confrelid" = "ref_cols"."attrelid"
AND "col_nums"."ref_num" = "ref_cols"."attnum"
WHERE "con"."contype" = 'f'
AND "con"."conrelid" = CAST('%s' AS REGCLASS)
ORDER BY "key_name", "col_nums"."pos";
END,
$table
));
$rows = [];
foreach ($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);
}
/**
* Pull information about the emulated enum columns
*
* @param string $table
* @return array of arrays
* @throws PEAR_Exception
*/
private function fetchEnumInfo($table)
{
$data = $this->fetchQueryData(
<<<END
SELECT "cols"."attname" AS "col", "con"."consrc" AS "check"
FROM pg_constraint AS "con"
INNER JOIN pg_attribute AS "cols"
ON "con"."conrelid" = "cols"."attrelid"
AND "con"."conkey"[1] = "cols"."attnum"
WHERE "cols".atttypid = CAST('text' AS REGTYPE)
AND "con"."contype" = 'c'
AND cardinality("con"."conkey") = 1
AND "con"."conrelid" = CAST('{$table}' AS REGCLASS);
END
);
$rows = [];
foreach ($data as $row) {
// PostgreSQL can show either
$name_regex = '(' . preg_quote($this->quoteIdentifier($row['col']))
. '|' . preg_quote($row['col']) . ')';
$enum = explode("'::text, '", preg_replace(
"/^\({$name_regex} = ANY \(ARRAY\['(.+)'::text]\)\)$/D",
'\2',
$row['check']
));
$rows[$row['col']] = $enum;
}
return $rows;
}
private function isNumericType(array $cd): bool
{
$ints = ['int', 'numeric', 'serial'];
return in_array(strtolower($cd['type']), $ints);
}
/**
* 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'])) {
$line[] = 'GENERATED BY DEFAULT AS IDENTITY';
} elseif (!empty($cd['enum'])) {
foreach ($cd['enum'] as &$val) {
$vals[] = "'" . $val . "'";
}
$line[] = 'CHECK (' . $name . ' IN (' . implode(',', $vals) . '))';
}
return implode(' ', $line);
}
public function appendAlterDropPrimary(array &$phrase, string $tableName)
{
// name hack -- is this reliable?
$phrase[] = 'DROP CONSTRAINT ' . $this->quoteIdentifier($tableName . '_pkey');
}
public function mapType($column)
{
$map = [
'integer' => 'int',
'char' => 'bpchar',
'datetime' => 'timestamp',
'blob' => 'bytea'
];
$type = $column['type'];
if (isset($map[$type])) {
$type = $map[$type];
}
$size = $column['size'] ?? null;
if ($type === 'int') {
if (in_array($size, ['tiny', 'small'])) {
$type = 'int2';
} elseif ($size === 'big') {
$type = 'int8';
} else {
$type = 'int4';
}
} elseif ($type === 'float') {
$type = ($size !== 'big') ? 'float4' : 'float8';
}
return $type;
}
/**
* 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, $tableDef);
foreach ($tableDef['fields'] as $name => &$col) {
// No convenient support for field descriptions
unset($col['description']);
// @fixme Nor for MariaDB-specific collations
unset($col['collate']);
if ($col['type'] === 'serial') {
$col['type'] = 'int';
$col['auto_increment'] = true;
}
$col['type'] = $this->mapType($col);
unset($col['size']);
}
if (!empty($tableDef['primary key'])) {
$tableDef['primary key'] = $this->filterKeyDef($tableDef['primary key']);
}
if (!empty($tableDef['unique keys'])) {
foreach ($tableDef['unique keys'] as $i => $def) {
$tableDef['unique keys'][$i] = $this->filterKeyDef($def);
}
}
return $tableDef;
}
/**
* Filter the given key/index definition to match features available
* in this database.
*
* @param array $def
* @return array
*/
public function filterKeyDef(array $def)
{
// PostgreSQL doesn't like prefix lengths specified on keys...?
foreach ($def as $i => $item) {
if (is_array($item)) {
$def[$i] = $item[0];
}
}
return $def;
}
}