gnu-social/lib/database/pgsqlschema.php
Alexei Sorokin 9a515b9234 [SCHEMA] Improve timestamp storage
Avoid the use of deprecated MariaDB "zero dates" globally. If they're present
as attribute defaults somewhere, they will be replaced with NULL implicitly.
The existing "zero dates" in MariaDB storage will be left intact and this
should not present any issues.

The "timestamp" type in table definitions now corresponds to DATETIME in
MariaDB with "DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP", which
should be close enough to the original behaviour for compatibility purposes.
It is now the recommended type for "modified" attributes, because of the
update trigger on MariaDB. But there is no such trigger implemented on
PostgreSQL as of this moment.
2020-06-29 01:41:46 +03:00

454 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");
}
// We'll need to match up fields by ordinal reference
$orderedFields = [];
foreach ($columns as $row) {
$name = $row['column_name'];
$orderedFields[$row['ordinal_position']] = $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') {
$field['not null'] = true;
}
if ($row['column_default'] !== null) {
$field['default'] = $row['column_default'];
if ($this->isNumericType($field)) {
$field['default'] = (int) $field['default'];
}
}
$def['fields'][$name] = $field;
}
// Pulling index info from pg_class & pg_index
// This can give us primary & unique key info, but not foreign key constraints
// so we exclude them and pick them up later.
$indexInfo = $this->fetchIndexInfo($table);
foreach ($indexInfo as $row) {
$keyName = $row['key_name'];
// Dig the column references out!
//
// These are inconvenient arrays with partial references to the
// pg_att table, but since we've already fetched up the column
// info on the current table, we can look those up locally.
$cols = [];
$colPositions = explode(' ', $row['indkey']);
foreach ($colPositions as $ord) {
if ($ord == 0) {
$cols[] = 'FUNCTION'; // @fixme
} else {
$cols[] = $orderedFields[$ord];
}
}
$def['indexes'][$keyName] = $cols;
}
// Pull constraint data from INFORMATION_SCHEMA:
// Primary key, unique keys, foreign keys
$keyColumns = $this->fetchMetaInfo($table, 'key_column_usage', 'constraint_name,ordinal_position');
$keys = [];
foreach ($keyColumns as $row) {
$keyName = $row['constraint_name'];
$keyCol = $row['column_name'];
if (!isset($keys[$keyName])) {
$keys[$keyName] = [];
}
$keys[$keyName][] = $keyCol;
}
foreach ($keys as $keyName => $cols) {
// name hack -- is this reliable?
if ($keyName == "{$table}_pkey") {
$def['primary key'] = $cols;
} elseif (preg_match("/^{$table}_(.*)_fkey$/", $keyName, $matches)) {
$fkey = $this->fetchForeignKeyInfo($table, $keyName);
$colMap = array_combine($cols, $fkey['col_names']);
$def['foreign keys'][$keyName] = [$fkey['table_name'], $colMap];
} else {
$def['unique keys'][$keyName] = $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)
{
$query = "SELECT * FROM information_schema.%s " .
"WHERE table_name='%s'";
$sql = sprintf($query, $infoTable, $table);
if ($orderBy) {
$sql .= ' ORDER BY ' . $orderBy;
}
return $this->fetchQueryData($sql);
}
/**
* Pull some PG-specific index info
* @param string $table
* @return array of arrays
* @throws PEAR_Exception
*/
public function fetchIndexInfo(string $table): array
{
$query = 'SELECT indexname AS key_name, indexdef AS key_def, pg_index.* ' .
'FROM pg_index INNER JOIN pg_indexes ON pg_index.indexrelid = CAST(pg_indexes.indexname AS regclass) ' .
'WHERE tablename = \'%s\' AND indisprimary = FALSE AND indisunique = FALSE ' .
'ORDER BY indrelid, indexrelid';
$sql = sprintf($query, $table);
return $this->fetchQueryData($sql);
}
/**
* @param string $table
* @param string $constraint_name
* @return array array of rows with keys: table_name, col_names (array of strings)
* @throws PEAR_Exception
*/
public function fetchForeignKeyInfo(string $table, string $constraint_name): array
{
// In a sane world, it'd be easier to query the column names directly.
// But it's pretty hard to work with arrays such as col_indexes in direct SQL here.
$query = 'SELECT ' .
'(SELECT relname FROM pg_class WHERE oid = confrelid) AS table_name, ' .
'confrelid AS table_id, ' .
'(SELECT indkey FROM pg_index WHERE indexrelid = conindid) AS col_indices ' .
'FROM pg_constraint ' .
'WHERE conrelid = CAST(\'%s\' AS regclass) AND conname = \'%s\' AND contype = \'f\'';
$sql = sprintf($query, $table, $constraint_name);
$data = $this->fetchQueryData($sql);
if (count($data) < 1) {
throw new Exception('Could not find foreign key ' . $constraint_name . ' on table ' . $table);
}
$row = $data[0];
return [
'table_name' => $row['table_name'],
'col_names' => $this->getTableColumnNames($row['table_id'], $row['col_indices'])
];
}
/**
*
* @param int $table_id
* @param array $col_indexes
* @return array of strings
* @throws PEAR_Exception
*/
public function getTableColumnNames($table_id, $col_indexes)
{
$indexes = array_map('intval', explode(' ', $col_indexes));
$query = 'SELECT attnum AS col_index, attname AS col_name ' .
'FROM pg_attribute where attrelid=%d ' .
'AND attnum IN (%s)';
$sql = sprintf($query, $table_id, implode(',', $indexes));
$data = $this->fetchQueryData($sql);
$byId = [];
foreach ($data as $row) {
$byId[$row['col_index']] = $row['col_name'];
}
$out = [];
foreach ($indexes as $id) {
$out[] = $byId[$id];
}
return $out;
}
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, $cd);
/*
if ($table['foreign keys'][$name]) {
foreach ($table['foreign keys'][$name] as $foreignTable => $foreignColumn) {
$line[] = 'references';
$line[] = $this->quoteIdentifier($foreignTable);
$line[] = '(' . $this->quoteIdentifier($foreignColumn) . ')';
}
}
*/
// 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);
}
/**
* 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, $columnName, array $old, array $cd)
{
$prefix = 'ALTER COLUMN ' . $this->quoteIdentifier($columnName) . ' ';
$oldType = $this->typeAndSize($columnName, $old);
$newType = $this->typeAndSize($columnName, $cd);
if ($oldType != $newType) {
$phrase[] = $prefix . 'TYPE ' . $newType;
}
if (!empty($old['not null']) && empty($cd['not null'])) {
$phrase[] = $prefix . 'DROP NOT NULL';
} elseif (empty($old['not null']) && !empty($cd['not null'])) {
$phrase[] = $prefix . 'SET NOT NULL';
}
if (isset($old['default']) && !isset($cd['default'])) {
$phrase[] = $prefix . 'DROP DEFAULT';
} elseif (!isset($old['default']) && isset($cd['default'])) {
$phrase[] = $prefix . 'SET DEFAULT ' . $this->quoteDefaultValue($cd);
}
}
public function appendAlterDropPrimary(array &$phrase, string $tableName)
{
// name hack -- is this reliable?
$phrase[] = 'DROP CONSTRAINT ' . $this->quoteIdentifier($tableName . '_pkey');
}
/**
* Append an SQL statement to drop an index from a table.
* Note that in PostgreSQL, index names are DB-unique.
*
* @param array $statements
* @param string $table
* @param string $name
*/
public function appendDropIndex(array &$statements, $table, $name)
{
$statements[] = "DROP INDEX $name";
}
public function mapType($column)
{
$map = [
'integer' => 'int',
'char' => 'bpchar',
'datetime' => 'timestamp',
'blob' => 'bytea',
'enum' => 'text',
];
$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($col['description']);
if ($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;
}
}