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Diffstat (limited to 'www/wiki/includes/libs/rdbms/database/DatabasePostgres.php')
| -rw-r--r-- | www/wiki/includes/libs/rdbms/database/DatabasePostgres.php | 1459 |
1 files changed, 1459 insertions, 0 deletions
diff --git a/www/wiki/includes/libs/rdbms/database/DatabasePostgres.php b/www/wiki/includes/libs/rdbms/database/DatabasePostgres.php new file mode 100644 index 00000000..94509a3c --- /dev/null +++ b/www/wiki/includes/libs/rdbms/database/DatabasePostgres.php @@ -0,0 +1,1459 @@ +<?php +/** + * This is the Postgres database abstraction layer. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + * @ingroup Database + */ +namespace Wikimedia\Rdbms; + +use Wikimedia\Timestamp\ConvertibleTimestamp; +use Wikimedia\WaitConditionLoop; +use Wikimedia; +use Exception; + +/** + * @ingroup Database + */ +class DatabasePostgres extends Database { + /** @var int|bool */ + protected $port; + + /** @var resource */ + protected $lastResultHandle = null; + + /** @var float|string */ + private $numericVersion = null; + /** @var string Connect string to open a PostgreSQL connection */ + private $connectString; + /** @var string */ + private $coreSchema; + /** @var string */ + private $tempSchema; + /** @var string[] Map of (reserved table name => alternate table name) */ + private $keywordTableMap = []; + + /** + * @see Database::__construct() + * @param array $params Additional parameters include: + * - keywordTableMap : Map of reserved table names to alternative table names to use + */ + public function __construct( array $params ) { + $this->port = isset( $params['port'] ) ? $params['port'] : false; + $this->keywordTableMap = isset( $params['keywordTableMap'] ) + ? $params['keywordTableMap'] + : []; + + parent::__construct( $params ); + } + + public function getType() { + return 'postgres'; + } + + public function implicitGroupby() { + return false; + } + + public function implicitOrderby() { + return false; + } + + public function hasConstraint( $name ) { + foreach ( $this->getCoreSchemas() as $schema ) { + $sql = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n " . + "WHERE c.connamespace = n.oid AND conname = " . + $this->addQuotes( $name ) . " AND n.nspname = " . + $this->addQuotes( $schema ); + $res = $this->doQuery( $sql ); + if ( $res && $this->numRows( $res ) ) { + return true; + } + } + return false; + } + + public function open( $server, $user, $password, $dbName ) { + # Test for Postgres support, to avoid suppressed fatal error + if ( !function_exists( 'pg_connect' ) ) { + throw new DBConnectionError( + $this, + "Postgres functions missing, have you compiled PHP with the --with-pgsql\n" . + "option? (Note: if you recently installed PHP, you may need to restart your\n" . + "webserver and database)\n" + ); + } + + $this->server = $server; + $this->user = $user; + $this->password = $password; + $this->dbName = $dbName; + + $connectVars = [ + // pg_connect() user $user as the default database. Since a database is *required*, + // at least pick a "don't care" database that is more likely to exist. This case + // arrises when LoadBalancer::getConnection( $i, [], '' ) is used. + 'dbname' => strlen( $dbName ) ? $dbName : 'postgres', + 'user' => $user, + 'password' => $password + ]; + if ( $server != false && $server != '' ) { + $connectVars['host'] = $server; + } + if ( (int)$this->port > 0 ) { + $connectVars['port'] = (int)$this->port; + } + if ( $this->flags & self::DBO_SSL ) { + $connectVars['sslmode'] = 1; + } + + $this->connectString = $this->makeConnectionString( $connectVars ); + $this->close(); + $this->installErrorHandler(); + + try { + // Use new connections to let LoadBalancer/LBFactory handle reuse + $this->conn = pg_connect( $this->connectString, PGSQL_CONNECT_FORCE_NEW ); + } catch ( Exception $ex ) { + $this->restoreErrorHandler(); + throw $ex; + } + + $phpError = $this->restoreErrorHandler(); + + if ( !$this->conn ) { + $this->queryLogger->debug( + "DB connection error\n" . + "Server: $server, Database: $dbName, User: $user, Password: " . + substr( $password, 0, 3 ) . "...\n" + ); + $this->queryLogger->debug( $this->lastError() . "\n" ); + throw new DBConnectionError( $this, str_replace( "\n", ' ', $phpError ) ); + } + + $this->opened = true; + + # If called from the command-line (e.g. importDump), only show errors + if ( $this->cliMode ) { + $this->doQuery( "SET client_min_messages = 'ERROR'" ); + } + + $this->query( "SET client_encoding='UTF8'", __METHOD__ ); + $this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ ); + $this->query( "SET timezone = 'GMT'", __METHOD__ ); + $this->query( "SET standard_conforming_strings = on", __METHOD__ ); + $this->query( "SET bytea_output = 'escape'", __METHOD__ ); // PHP bug 53127 + + $this->determineCoreSchema( $this->schema ); + // The schema to be used is now in the search path; no need for explicit qualification + $this->schema = ''; + + return $this->conn; + } + + public function databasesAreIndependent() { + return true; + } + + /** + * Postgres doesn't support selectDB in the same way MySQL does. So if the + * DB name doesn't match the open connection, open a new one + * @param string $db + * @return bool + * @throws DBUnexpectedError + */ + public function selectDB( $db ) { + if ( $this->dbName !== $db ) { + return (bool)$this->open( $this->server, $this->user, $this->password, $db ); + } else { + return true; + } + } + + /** + * @param string[] $vars + * @return string + */ + private function makeConnectionString( $vars ) { + $s = ''; + foreach ( $vars as $name => $value ) { + $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' "; + } + + return $s; + } + + protected function closeConnection() { + return $this->conn ? pg_close( $this->conn ) : true; + } + + protected function isTransactableQuery( $sql ) { + return parent::isTransactableQuery( $sql ) && + !preg_match( '/^SELECT\s+pg_(try_|)advisory_\w+\(/', $sql ); + } + + public function doQuery( $sql ) { + $conn = $this->getBindingHandle(); + + $sql = mb_convert_encoding( $sql, 'UTF-8' ); + // Clear previously left over PQresult + while ( $res = pg_get_result( $conn ) ) { + pg_free_result( $res ); + } + if ( pg_send_query( $conn, $sql ) === false ) { + throw new DBUnexpectedError( $this, "Unable to post new query to PostgreSQL\n" ); + } + $this->lastResultHandle = pg_get_result( $conn ); + if ( pg_result_error( $this->lastResultHandle ) ) { + return false; + } + + return $this->lastResultHandle; + } + + protected function dumpError() { + $diags = [ + PGSQL_DIAG_SEVERITY, + PGSQL_DIAG_SQLSTATE, + PGSQL_DIAG_MESSAGE_PRIMARY, + PGSQL_DIAG_MESSAGE_DETAIL, + PGSQL_DIAG_MESSAGE_HINT, + PGSQL_DIAG_STATEMENT_POSITION, + PGSQL_DIAG_INTERNAL_POSITION, + PGSQL_DIAG_INTERNAL_QUERY, + PGSQL_DIAG_CONTEXT, + PGSQL_DIAG_SOURCE_FILE, + PGSQL_DIAG_SOURCE_LINE, + PGSQL_DIAG_SOURCE_FUNCTION + ]; + foreach ( $diags as $d ) { + $this->queryLogger->debug( sprintf( "PgSQL ERROR(%d): %s\n", + $d, pg_result_error_field( $this->lastResultHandle, $d ) ) ); + } + } + + public function freeResult( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + Wikimedia\suppressWarnings(); + $ok = pg_free_result( $res ); + Wikimedia\restoreWarnings(); + if ( !$ok ) { + throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" ); + } + } + + public function fetchObject( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + Wikimedia\suppressWarnings(); + $row = pg_fetch_object( $res ); + Wikimedia\restoreWarnings(); + # @todo FIXME: HACK HACK HACK HACK debug + + # @todo hashar: not sure if the following test really trigger if the object + # fetching failed. + $conn = $this->getBindingHandle(); + if ( pg_last_error( $conn ) ) { + throw new DBUnexpectedError( + $this, + 'SQL error: ' . htmlspecialchars( pg_last_error( $conn ) ) + ); + } + + return $row; + } + + public function fetchRow( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + Wikimedia\suppressWarnings(); + $row = pg_fetch_array( $res ); + Wikimedia\restoreWarnings(); + + $conn = $this->getBindingHandle(); + if ( pg_last_error( $conn ) ) { + throw new DBUnexpectedError( + $this, + 'SQL error: ' . htmlspecialchars( pg_last_error( $conn ) ) + ); + } + + return $row; + } + + public function numRows( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + Wikimedia\suppressWarnings(); + $n = pg_num_rows( $res ); + Wikimedia\restoreWarnings(); + + $conn = $this->getBindingHandle(); + if ( pg_last_error( $conn ) ) { + throw new DBUnexpectedError( + $this, + 'SQL error: ' . htmlspecialchars( pg_last_error( $conn ) ) + ); + } + + return $n; + } + + public function numFields( $res ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + return pg_num_fields( $res ); + } + + public function fieldName( $res, $n ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + return pg_field_name( $res, $n ); + } + + public function insertId() { + $res = $this->query( "SELECT lastval()" ); + $row = $this->fetchRow( $res ); + return is_null( $row[0] ) ? null : (int)$row[0]; + } + + public function dataSeek( $res, $row ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + return pg_result_seek( $res, $row ); + } + + public function lastError() { + if ( $this->conn ) { + if ( $this->lastResultHandle ) { + return pg_result_error( $this->lastResultHandle ); + } else { + return pg_last_error(); + } + } + + return $this->getLastPHPError() ?: 'No database connection'; + } + + public function lastErrno() { + if ( $this->lastResultHandle ) { + return pg_result_error_field( $this->lastResultHandle, PGSQL_DIAG_SQLSTATE ); + } else { + return false; + } + } + + protected function fetchAffectedRowCount() { + if ( !$this->lastResultHandle ) { + return 0; + } + + return pg_affected_rows( $this->lastResultHandle ); + } + + /** + * Estimate rows in dataset + * Returns estimated count, based on EXPLAIN output + * This is not necessarily an accurate estimate, so use sparingly + * Returns -1 if count cannot be found + * Takes same arguments as Database::select() + * + * @param string $table + * @param string $var + * @param string $conds + * @param string $fname + * @param array $options + * @param array $join_conds + * @return int + */ + public function estimateRowCount( $table, $var = '*', $conds = '', + $fname = __METHOD__, $options = [], $join_conds = [] + ) { + $conds = $this->normalizeConditions( $conds, $fname ); + $column = $this->extractSingleFieldFromList( $var ); + if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) { + $conds[] = "$column IS NOT NULL"; + } + + $options['EXPLAIN'] = true; + $res = $this->select( $table, $var, $conds, $fname, $options, $join_conds ); + $rows = -1; + if ( $res ) { + $row = $this->fetchRow( $res ); + $count = []; + if ( preg_match( '/rows=(\d+)/', $row[0], $count ) ) { + $rows = (int)$count[1]; + } + } + + return $rows; + } + + public function indexInfo( $table, $index, $fname = __METHOD__ ) { + $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'"; + $res = $this->query( $sql, $fname ); + if ( !$res ) { + return null; + } + foreach ( $res as $row ) { + if ( $row->indexname == $this->indexName( $index ) ) { + return $row; + } + } + + return false; + } + + public function indexAttributes( $index, $schema = false ) { + if ( $schema === false ) { + $schemas = $this->getCoreSchemas(); + } else { + $schemas = [ $schema ]; + } + + $eindex = $this->addQuotes( $index ); + + foreach ( $schemas as $schema ) { + $eschema = $this->addQuotes( $schema ); + /* + * A subquery would be not needed if we didn't care about the order + * of attributes, but we do + */ + $sql = <<<__INDEXATTR__ + + SELECT opcname, + attname, + i.indoption[s.g] as option, + pg_am.amname + FROM + (SELECT generate_series(array_lower(isub.indkey,1), array_upper(isub.indkey,1)) AS g + FROM + pg_index isub + JOIN pg_class cis + ON cis.oid=isub.indexrelid + JOIN pg_namespace ns + ON cis.relnamespace = ns.oid + WHERE cis.relname=$eindex AND ns.nspname=$eschema) AS s, + pg_attribute, + pg_opclass opcls, + pg_am, + pg_class ci + JOIN pg_index i + ON ci.oid=i.indexrelid + JOIN pg_class ct + ON ct.oid = i.indrelid + JOIN pg_namespace n + ON ci.relnamespace = n.oid + WHERE + ci.relname=$eindex AND n.nspname=$eschema + AND attrelid = ct.oid + AND i.indkey[s.g] = attnum + AND i.indclass[s.g] = opcls.oid + AND pg_am.oid = opcls.opcmethod +__INDEXATTR__; + $res = $this->query( $sql, __METHOD__ ); + $a = []; + if ( $res ) { + foreach ( $res as $row ) { + $a[] = [ + $row->attname, + $row->opcname, + $row->amname, + $row->option ]; + } + return $a; + } + } + return null; + } + + public function indexUnique( $table, $index, $fname = __METHOD__ ) { + $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'" . + " AND indexdef LIKE 'CREATE UNIQUE%(" . + $this->strencode( $this->indexName( $index ) ) . + ")'"; + $res = $this->query( $sql, $fname ); + if ( !$res ) { + return null; + } + + return $res->numRows() > 0; + } + + public function selectSQLText( + $table, $vars, $conds = '', $fname = __METHOD__, $options = [], $join_conds = [] + ) { + if ( is_string( $options ) ) { + $options = [ $options ]; + } + + // Change the FOR UPDATE option as necessary based on the join conditions. Then pass + // to the parent function to get the actual SQL text. + // In Postgres when using FOR UPDATE, only the main table and tables that are inner joined + // can be locked. That means tables in an outer join cannot be FOR UPDATE locked. Trying to + // do so causes a DB error. This wrapper checks which tables can be locked and adjusts it + // accordingly. + // MySQL uses "ORDER BY NULL" as an optimization hint, but that is illegal in PostgreSQL. + if ( is_array( $options ) ) { + $forUpdateKey = array_search( 'FOR UPDATE', $options, true ); + if ( $forUpdateKey !== false && $join_conds ) { + unset( $options[$forUpdateKey] ); + $options['FOR UPDATE'] = []; + + $toCheck = $table; + reset( $toCheck ); + while ( $toCheck ) { + $alias = key( $toCheck ); + $name = $toCheck[$alias]; + unset( $toCheck[$alias] ); + + $hasAlias = !is_numeric( $alias ); + if ( !$hasAlias && is_string( $name ) ) { + $alias = $name; + } + + if ( !isset( $join_conds[$alias] ) || + !preg_match( '/^(?:LEFT|RIGHT|FULL)(?: OUTER)? JOIN$/i', $join_conds[$alias][0] ) + ) { + if ( is_array( $name ) ) { + // It's a parenthesized group, process all the tables inside the group. + $toCheck = array_merge( $toCheck, $name ); + } else { + // Quote alias names so $this->tableName() won't mangle them + $options['FOR UPDATE'][] = $hasAlias ? $this->addIdentifierQuotes( $alias ) : $alias; + } + } + } + } + + if ( isset( $options['ORDER BY'] ) && $options['ORDER BY'] == 'NULL' ) { + unset( $options['ORDER BY'] ); + } + } + + return parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds ); + } + + /** @inheritDoc */ + public function insert( $table, $args, $fname = __METHOD__, $options = [] ) { + if ( !count( $args ) ) { + return true; + } + + $table = $this->tableName( $table ); + if ( !isset( $this->numericVersion ) ) { + $this->getServerVersion(); + } + + if ( !is_array( $options ) ) { + $options = [ $options ]; + } + + if ( isset( $args[0] ) && is_array( $args[0] ) ) { + $rows = $args; + $keys = array_keys( $args[0] ); + } else { + $rows = [ $args ]; + $keys = array_keys( $args ); + } + + $ignore = in_array( 'IGNORE', $options ); + + $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES '; + + if ( $this->numericVersion >= 9.5 || !$ignore ) { + // No IGNORE or our PG has "ON CONFLICT DO NOTHING" + $first = true; + foreach ( $rows as $row ) { + if ( $first ) { + $first = false; + } else { + $sql .= ','; + } + $sql .= '(' . $this->makeList( $row ) . ')'; + } + if ( $ignore ) { + $sql .= ' ON CONFLICT DO NOTHING'; + } + $this->query( $sql, $fname ); + } else { + // Emulate IGNORE by doing each row individually, with savepoints + // to roll back as necessary. + $numrowsinserted = 0; + + $tok = $this->startAtomic( "$fname (outer)", self::ATOMIC_CANCELABLE ); + try { + foreach ( $rows as $row ) { + $tempsql = $sql; + $tempsql .= '(' . $this->makeList( $row ) . ')'; + + $this->startAtomic( "$fname (inner)", self::ATOMIC_CANCELABLE ); + try { + $this->query( $tempsql, $fname ); + $this->endAtomic( "$fname (inner)" ); + $numrowsinserted++; + } catch ( DBQueryError $e ) { + $this->cancelAtomic( "$fname (inner)" ); + // Our IGNORE is supposed to ignore duplicate key errors, but not others. + // (even though MySQL's version apparently ignores all errors) + if ( $e->errno !== '23505' ) { + throw $e; + } + } + } + } catch ( Exception $e ) { + $this->cancelAtomic( "$fname (outer)", $tok ); + throw $e; + } + $this->endAtomic( "$fname (outer)" ); + + // Set the affected row count for the whole operation + $this->affectedRowCount = $numrowsinserted; + } + + return true; + } + + protected function makeUpdateOptionsArray( $options ) { + if ( !is_array( $options ) ) { + $options = [ $options ]; + } + + // PostgreSQL doesn't support anything like "ignore" for + // UPDATE. + $options = array_diff( $options, [ 'IGNORE' ] ); + + return parent::makeUpdateOptionsArray( $options ); + } + + /** + * INSERT SELECT wrapper + * $varMap must be an associative array of the form [ 'dest1' => 'source1', ... ] + * Source items may be literals rather then field names, but strings should + * be quoted with Database::addQuotes() + * $conds may be "*" to copy the whole table + * srcTable may be an array of tables. + * @todo FIXME: Implement this a little better (seperate select/insert)? + * + * @param string $destTable + * @param array|string $srcTable + * @param array $varMap + * @param array $conds + * @param string $fname + * @param array $insertOptions + * @param array $selectOptions + * @param array $selectJoinConds + * @return bool + */ + public function nativeInsertSelect( + $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__, + $insertOptions = [], $selectOptions = [], $selectJoinConds = [] + ) { + if ( !is_array( $insertOptions ) ) { + $insertOptions = [ $insertOptions ]; + } + + if ( in_array( 'IGNORE', $insertOptions ) ) { + if ( $this->getServerVersion() >= 9.5 ) { + // Use ON CONFLICT DO NOTHING if we have it for IGNORE + $destTable = $this->tableName( $destTable ); + + $selectSql = $this->selectSQLText( + $srcTable, + array_values( $varMap ), + $conds, + $fname, + $selectOptions, + $selectJoinConds + ); + + $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' . + $selectSql . ' ON CONFLICT DO NOTHING'; + + return $this->query( $sql, $fname ); + } else { + // IGNORE and we don't have ON CONFLICT DO NOTHING, so just use the non-native version + return $this->nonNativeInsertSelect( + $destTable, $srcTable, $varMap, $conds, $fname, + $insertOptions, $selectOptions, $selectJoinConds + ); + } + } + + return parent::nativeInsertSelect( $destTable, $srcTable, $varMap, $conds, $fname, + $insertOptions, $selectOptions, $selectJoinConds ); + } + + public function tableName( $name, $format = 'quoted' ) { + // Replace reserved words with better ones + $name = $this->remappedTableName( $name ); + + return parent::tableName( $name, $format ); + } + + /** + * @param string $name + * @return string Value of $name or remapped name if $name is a reserved keyword + */ + public function remappedTableName( $name ) { + return isset( $this->keywordTableMap[$name] ) ? $this->keywordTableMap[$name] : $name; + } + + /** + * @param string $name + * @param string $format + * @return string Qualified and encoded (if requested) table name + */ + public function realTableName( $name, $format = 'quoted' ) { + return parent::tableName( $name, $format ); + } + + public function nextSequenceValue( $seqName ) { + return new NextSequenceValue; + } + + /** + * Return the current value of a sequence. Assumes it has been nextval'ed in this session. + * + * @param string $seqName + * @return int + */ + public function currentSequenceValue( $seqName ) { + $safeseq = str_replace( "'", "''", $seqName ); + $res = $this->query( "SELECT currval('$safeseq')" ); + $row = $this->fetchRow( $res ); + $currval = $row[0]; + + return $currval; + } + + public function textFieldSize( $table, $field ) { + $table = $this->tableName( $table ); + $sql = "SELECT t.typname as ftype,a.atttypmod as size + FROM pg_class c, pg_attribute a, pg_type t + WHERE relname='$table' AND a.attrelid=c.oid AND + a.atttypid=t.oid and a.attname='$field'"; + $res = $this->query( $sql ); + $row = $this->fetchObject( $res ); + if ( $row->ftype == 'varchar' ) { + $size = $row->size - 4; + } else { + $size = $row->size; + } + + return $size; + } + + public function limitResult( $sql, $limit, $offset = false ) { + return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' ); + } + + public function wasDeadlock() { + // https://www.postgresql.org/docs/9.2/static/errcodes-appendix.html + return $this->lastErrno() === '40P01'; + } + + public function wasLockTimeout() { + // https://www.postgresql.org/docs/9.2/static/errcodes-appendix.html + return $this->lastErrno() === '55P03'; + } + + public function wasConnectionError( $errno ) { + // https://www.postgresql.org/docs/9.2/static/errcodes-appendix.html + static $codes = [ '08000', '08003', '08006', '08001', '08004', '57P01', '57P03', '53300' ]; + + return in_array( $errno, $codes, true ); + } + + protected function wasKnownStatementRollbackError() { + return false; // transaction has to be rolled-back from error state + } + + public function duplicateTableStructure( + $oldName, $newName, $temporary = false, $fname = __METHOD__ + ) { + $newNameE = $this->addIdentifierQuotes( $newName ); + $oldNameE = $this->addIdentifierQuotes( $oldName ); + + $temporary = $temporary ? 'TEMPORARY' : ''; + + $ret = $this->query( "CREATE $temporary TABLE $newNameE " . + "(LIKE $oldNameE INCLUDING DEFAULTS INCLUDING INDEXES)", $fname ); + if ( !$ret ) { + return $ret; + } + + $res = $this->query( 'SELECT attname FROM pg_class c' + . ' JOIN pg_namespace n ON (n.oid = c.relnamespace)' + . ' JOIN pg_attribute a ON (a.attrelid = c.oid)' + . ' JOIN pg_attrdef d ON (c.oid=d.adrelid and a.attnum=d.adnum)' + . ' WHERE relkind = \'r\'' + . ' AND nspname = ' . $this->addQuotes( $this->getCoreSchema() ) + . ' AND relname = ' . $this->addQuotes( $oldName ) + . ' AND adsrc LIKE \'nextval(%\'', + $fname + ); + $row = $this->fetchObject( $res ); + if ( $row ) { + $field = $row->attname; + $newSeq = "{$newName}_{$field}_seq"; + $fieldE = $this->addIdentifierQuotes( $field ); + $newSeqE = $this->addIdentifierQuotes( $newSeq ); + $newSeqQ = $this->addQuotes( $newSeq ); + $this->query( "CREATE $temporary SEQUENCE $newSeqE OWNED BY $newNameE.$fieldE", $fname ); + $this->query( + "ALTER TABLE $newNameE ALTER COLUMN $fieldE SET DEFAULT nextval({$newSeqQ}::regclass)", + $fname + ); + } + + return $ret; + } + + public function resetSequenceForTable( $table, $fname = __METHOD__ ) { + $table = $this->tableName( $table, 'raw' ); + foreach ( $this->getCoreSchemas() as $schema ) { + $res = $this->query( + 'SELECT c.oid FROM pg_class c JOIN pg_namespace n ON (n.oid = c.relnamespace)' + . ' WHERE relkind = \'r\'' + . ' AND nspname = ' . $this->addQuotes( $schema ) + . ' AND relname = ' . $this->addQuotes( $table ), + $fname + ); + if ( !$res || !$this->numRows( $res ) ) { + continue; + } + + $oid = $this->fetchObject( $res )->oid; + $res = $this->query( 'SELECT adsrc FROM pg_attribute a' + . ' JOIN pg_attrdef d ON (a.attrelid=d.adrelid and a.attnum=d.adnum)' + . " WHERE a.attrelid = $oid" + . ' AND adsrc LIKE \'nextval(%\'', + $fname + ); + $row = $this->fetchObject( $res ); + if ( $row ) { + $this->query( + 'SELECT ' . preg_replace( '/^nextval\((.+)\)$/', 'setval($1,1,false)', $row->adsrc ), + $fname + ); + return true; + } + return false; + } + + return false; + } + + public function listTables( $prefix = null, $fname = __METHOD__ ) { + $eschemas = implode( ',', array_map( [ $this, 'addQuotes' ], $this->getCoreSchemas() ) ); + $result = $this->query( + "SELECT DISTINCT tablename FROM pg_tables WHERE schemaname IN ($eschemas)", $fname ); + $endArray = []; + + foreach ( $result as $table ) { + $vars = get_object_vars( $table ); + $table = array_pop( $vars ); + if ( !$prefix || strpos( $table, $prefix ) === 0 ) { + $endArray[] = $table; + } + } + + return $endArray; + } + + public function timestamp( $ts = 0 ) { + $ct = new ConvertibleTimestamp( $ts ); + + return $ct->getTimestamp( TS_POSTGRES ); + } + + /** + * Posted by cc[plus]php[at]c2se[dot]com on 25-Mar-2009 09:12 + * to https://secure.php.net/manual/en/ref.pgsql.php + * + * Parsing a postgres array can be a tricky problem, he's my + * take on this, it handles multi-dimensional arrays plus + * escaping using a nasty regexp to determine the limits of each + * data-item. + * + * This should really be handled by PHP PostgreSQL module + * + * @since 1.19 + * @param string $text Postgreql array returned in a text form like {a,b} + * @param string[] $output + * @param int|bool $limit + * @param int $offset + * @return string[] + */ + private function pg_array_parse( $text, &$output, $limit = false, $offset = 1 ) { + if ( false === $limit ) { + $limit = strlen( $text ) - 1; + $output = []; + } + if ( '{}' == $text ) { + return $output; + } + do { + if ( '{' != $text[$offset] ) { + preg_match( "/(\\{?\"([^\"\\\\]|\\\\.)*\"|[^,{}]+)+([,}]+)/", + $text, $match, 0, $offset ); + $offset += strlen( $match[0] ); + $output[] = ( '"' != $match[1][0] + ? $match[1] + : stripcslashes( substr( $match[1], 1, -1 ) ) ); + if ( '},' == $match[3] ) { + return $output; + } + } else { + $offset = $this->pg_array_parse( $text, $output, $limit, $offset + 1 ); + } + } while ( $limit > $offset ); + + return $output; + } + + public function aggregateValue( $valuedata, $valuename = 'value' ) { + return $valuedata; + } + + public function getSoftwareLink() { + return '[{{int:version-db-postgres-url}} PostgreSQL]'; + } + + /** + * Return current schema (executes SELECT current_schema()) + * Needs transaction + * + * @since 1.19 + * @return string Default schema for the current session + */ + public function getCurrentSchema() { + $res = $this->query( "SELECT current_schema()", __METHOD__ ); + $row = $this->fetchRow( $res ); + + return $row[0]; + } + + /** + * Return list of schemas which are accessible without schema name + * This is list does not contain magic keywords like "$user" + * Needs transaction + * + * @see getSearchPath() + * @see setSearchPath() + * @since 1.19 + * @return array List of actual schemas for the current sesson + */ + public function getSchemas() { + $res = $this->query( "SELECT current_schemas(false)", __METHOD__ ); + $row = $this->fetchRow( $res ); + $schemas = []; + + /* PHP pgsql support does not support array type, "{a,b}" string is returned */ + + return $this->pg_array_parse( $row[0], $schemas ); + } + + /** + * Return search patch for schemas + * This is different from getSchemas() since it contain magic keywords + * (like "$user"). + * Needs transaction + * + * @since 1.19 + * @return array How to search for table names schemas for the current user + */ + public function getSearchPath() { + $res = $this->query( "SHOW search_path", __METHOD__ ); + $row = $this->fetchRow( $res ); + + /* PostgreSQL returns SHOW values as strings */ + + return explode( ",", $row[0] ); + } + + /** + * Update search_path, values should already be sanitized + * Values may contain magic keywords like "$user" + * @since 1.19 + * + * @param array $search_path List of schemas to be searched by default + */ + private function setSearchPath( $search_path ) { + $this->query( "SET search_path = " . implode( ", ", $search_path ) ); + } + + /** + * Determine default schema for the current application + * Adjust this session schema search path if desired schema exists + * and is not alread there. + * + * We need to have name of the core schema stored to be able + * to query database metadata. + * + * This will be also called by the installer after the schema is created + * + * @since 1.19 + * + * @param string $desiredSchema + */ + public function determineCoreSchema( $desiredSchema ) { + $this->begin( __METHOD__, self::TRANSACTION_INTERNAL ); + if ( $this->schemaExists( $desiredSchema ) ) { + if ( in_array( $desiredSchema, $this->getSchemas() ) ) { + $this->coreSchema = $desiredSchema; + $this->queryLogger->debug( + "Schema \"" . $desiredSchema . "\" already in the search path\n" ); + } else { + /** + * Prepend our schema (e.g. 'mediawiki') in front + * of the search path + * Fixes T17816 + */ + $search_path = $this->getSearchPath(); + array_unshift( $search_path, + $this->addIdentifierQuotes( $desiredSchema ) ); + $this->setSearchPath( $search_path ); + $this->coreSchema = $desiredSchema; + $this->queryLogger->debug( + "Schema \"" . $desiredSchema . "\" added to the search path\n" ); + } + } else { + $this->coreSchema = $this->getCurrentSchema(); + $this->queryLogger->debug( + "Schema \"" . $desiredSchema . "\" not found, using current \"" . + $this->coreSchema . "\"\n" ); + } + /* Commit SET otherwise it will be rollbacked on error or IGNORE SELECT */ + $this->commit( __METHOD__, self::FLUSHING_INTERNAL ); + } + + /** + * Return schema name for core application tables + * + * @since 1.19 + * @return string Core schema name + */ + public function getCoreSchema() { + return $this->coreSchema; + } + + /** + * Return schema names for temporary tables and core application tables + * + * @since 1.31 + * @return string[] schema names + */ + public function getCoreSchemas() { + if ( $this->tempSchema ) { + return [ $this->tempSchema, $this->getCoreSchema() ]; + } + + $res = $this->query( + "SELECT nspname FROM pg_catalog.pg_namespace n WHERE n.oid = pg_my_temp_schema()", __METHOD__ + ); + $row = $this->fetchObject( $res ); + if ( $row ) { + $this->tempSchema = $row->nspname; + return [ $this->tempSchema, $this->getCoreSchema() ]; + } + + return [ $this->getCoreSchema() ]; + } + + public function getServerVersion() { + if ( !isset( $this->numericVersion ) ) { + $conn = $this->getBindingHandle(); + $versionInfo = pg_version( $conn ); + if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) { + // Old client, abort install + $this->numericVersion = '7.3 or earlier'; + } elseif ( isset( $versionInfo['server'] ) ) { + // Normal client + $this->numericVersion = $versionInfo['server']; + } else { + // T18937: broken pgsql extension from PHP<5.3 + $this->numericVersion = pg_parameter_status( $conn, 'server_version' ); + } + } + + return $this->numericVersion; + } + + /** + * Query whether a given relation exists (in the given schema, or the + * default mw one if not given) + * @param string $table + * @param array|string $types + * @param bool|string $schema + * @return bool + */ + private function relationExists( $table, $types, $schema = false ) { + if ( !is_array( $types ) ) { + $types = [ $types ]; + } + if ( $schema === false ) { + $schemas = $this->getCoreSchemas(); + } else { + $schemas = [ $schema ]; + } + $table = $this->realTableName( $table, 'raw' ); + $etable = $this->addQuotes( $table ); + foreach ( $schemas as $schema ) { + $eschema = $this->addQuotes( $schema ); + $sql = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n " + . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema " + . "AND c.relkind IN ('" . implode( "','", $types ) . "')"; + $res = $this->query( $sql ); + if ( $res && $res->numRows() ) { + return true; + } + } + + return false; + } + + /** + * For backward compatibility, this function checks both tables and views. + * @param string $table + * @param string $fname + * @param bool|string $schema + * @return bool + */ + public function tableExists( $table, $fname = __METHOD__, $schema = false ) { + return $this->relationExists( $table, [ 'r', 'v' ], $schema ); + } + + public function sequenceExists( $sequence, $schema = false ) { + return $this->relationExists( $sequence, 'S', $schema ); + } + + public function triggerExists( $table, $trigger ) { + $q = <<<SQL + SELECT 1 FROM pg_class, pg_namespace, pg_trigger + WHERE relnamespace=pg_namespace.oid AND relkind='r' + AND tgrelid=pg_class.oid + AND nspname=%s AND relname=%s AND tgname=%s +SQL; + foreach ( $this->getCoreSchemas() as $schema ) { + $res = $this->query( + sprintf( + $q, + $this->addQuotes( $schema ), + $this->addQuotes( $table ), + $this->addQuotes( $trigger ) + ) + ); + if ( $res && $res->numRows() ) { + return true; + } + } + + return false; + } + + public function ruleExists( $table, $rule ) { + $exists = $this->selectField( 'pg_rules', 'rulename', + [ + 'rulename' => $rule, + 'tablename' => $table, + 'schemaname' => $this->getCoreSchemas() + ] + ); + + return $exists === $rule; + } + + public function constraintExists( $table, $constraint ) { + foreach ( $this->getCoreSchemas() as $schema ) { + $sql = sprintf( "SELECT 1 FROM information_schema.table_constraints " . + "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s", + $this->addQuotes( $schema ), + $this->addQuotes( $table ), + $this->addQuotes( $constraint ) + ); + $res = $this->query( $sql ); + if ( $res && $res->numRows() ) { + return true; + } + } + return false; + } + + /** + * Query whether a given schema exists. Returns true if it does, false if it doesn't. + * @param string $schema + * @return bool + */ + public function schemaExists( $schema ) { + if ( !strlen( $schema ) ) { + return false; // short-circuit + } + + $exists = $this->selectField( + '"pg_catalog"."pg_namespace"', 1, [ 'nspname' => $schema ], __METHOD__ ); + + return (bool)$exists; + } + + /** + * Returns true if a given role (i.e. user) exists, false otherwise. + * @param string $roleName + * @return bool + */ + public function roleExists( $roleName ) { + $exists = $this->selectField( '"pg_catalog"."pg_roles"', 1, + [ 'rolname' => $roleName ], __METHOD__ ); + + return (bool)$exists; + } + + /** + * @param string $table + * @param string $field + * @return PostgresField|null + */ + public function fieldInfo( $table, $field ) { + return PostgresField::fromText( $this, $table, $field ); + } + + /** + * pg_field_type() wrapper + * @param ResultWrapper|resource $res ResultWrapper or PostgreSQL query result resource + * @param int $index Field number, starting from 0 + * @return string + */ + public function fieldType( $res, $index ) { + if ( $res instanceof ResultWrapper ) { + $res = $res->result; + } + + return pg_field_type( $res, $index ); + } + + public function encodeBlob( $b ) { + return new PostgresBlob( pg_escape_bytea( $b ) ); + } + + public function decodeBlob( $b ) { + if ( $b instanceof PostgresBlob ) { + $b = $b->fetch(); + } elseif ( $b instanceof Blob ) { + return $b->fetch(); + } + + return pg_unescape_bytea( $b ); + } + + public function strencode( $s ) { + // Should not be called by us + return pg_escape_string( $this->getBindingHandle(), (string)$s ); + } + + public function addQuotes( $s ) { + $conn = $this->getBindingHandle(); + + if ( is_null( $s ) ) { + return 'NULL'; + } elseif ( is_bool( $s ) ) { + return intval( $s ); + } elseif ( $s instanceof Blob ) { + if ( $s instanceof PostgresBlob ) { + $s = $s->fetch(); + } else { + $s = pg_escape_bytea( $conn, $s->fetch() ); + } + return "'$s'"; + } elseif ( $s instanceof NextSequenceValue ) { + return 'DEFAULT'; + } + + return "'" . pg_escape_string( $conn, (string)$s ) . "'"; + } + + public function makeSelectOptions( $options ) { + $preLimitTail = $postLimitTail = ''; + $startOpts = $useIndex = $ignoreIndex = ''; + + $noKeyOptions = []; + foreach ( $options as $key => $option ) { + if ( is_numeric( $key ) ) { + $noKeyOptions[$option] = true; + } + } + + $preLimitTail .= $this->makeGroupByWithHaving( $options ); + + $preLimitTail .= $this->makeOrderBy( $options ); + + if ( isset( $options['FOR UPDATE'] ) ) { + $postLimitTail .= ' FOR UPDATE OF ' . + implode( ', ', array_map( [ $this, 'tableName' ], $options['FOR UPDATE'] ) ); + } elseif ( isset( $noKeyOptions['FOR UPDATE'] ) ) { + $postLimitTail .= ' FOR UPDATE'; + } + + if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) { + $startOpts .= 'DISTINCT'; + } + + return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ]; + } + + public function getDBname() { + return $this->dbName; + } + + public function getServer() { + return $this->server; + } + + public function buildConcat( $stringList ) { + return implode( ' || ', $stringList ); + } + + public function buildGroupConcatField( + $delimiter, $table, $field, $conds = '', $options = [], $join_conds = [] + ) { + $fld = "array_to_string(array_agg($field)," . $this->addQuotes( $delimiter ) . ')'; + + return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')'; + } + + public function buildStringCast( $field ) { + return $field . '::text'; + } + + public function streamStatementEnd( &$sql, &$newLine ) { + # Allow dollar quoting for function declarations + if ( substr( $newLine, 0, 4 ) == '$mw$' ) { + if ( $this->delimiter ) { + $this->delimiter = false; + } else { + $this->delimiter = ';'; + } + } + + return parent::streamStatementEnd( $sql, $newLine ); + } + + public function doLockTables( array $read, array $write, $method ) { + $tablesWrite = []; + foreach ( $write as $table ) { + $tablesWrite[] = $this->tableName( $table ); + } + $tablesRead = []; + foreach ( $read as $table ) { + $tablesRead[] = $this->tableName( $table ); + } + + // Acquire locks for the duration of the current transaction... + if ( $tablesWrite ) { + $this->query( + 'LOCK TABLE ONLY ' . implode( ',', $tablesWrite ) . ' IN EXCLUSIVE MODE', + $method + ); + } + if ( $tablesRead ) { + $this->query( + 'LOCK TABLE ONLY ' . implode( ',', $tablesRead ) . ' IN SHARE MODE', + $method + ); + } + + return true; + } + + public function lockIsFree( $lockName, $method ) { + if ( !parent::lockIsFree( $lockName, $method ) ) { + return false; // already held + } + // http://www.postgresql.org/docs/9.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS + $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) ); + $result = $this->query( "SELECT (CASE(pg_try_advisory_lock($key)) + WHEN 'f' THEN 'f' ELSE pg_advisory_unlock($key) END) AS lockstatus", $method ); + $row = $this->fetchObject( $result ); + + return ( $row->lockstatus === 't' ); + } + + public function lock( $lockName, $method, $timeout = 5 ) { + // http://www.postgresql.org/docs/9.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS + $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) ); + $loop = new WaitConditionLoop( + function () use ( $lockName, $key, $timeout, $method ) { + $res = $this->query( "SELECT pg_try_advisory_lock($key) AS lockstatus", $method ); + $row = $this->fetchObject( $res ); + if ( $row->lockstatus === 't' ) { + parent::lock( $lockName, $method, $timeout ); // record + return true; + } + + return WaitConditionLoop::CONDITION_CONTINUE; + }, + $timeout + ); + + return ( $loop->invoke() === $loop::CONDITION_REACHED ); + } + + public function unlock( $lockName, $method ) { + // http://www.postgresql.org/docs/9.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS + $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) ); + $result = $this->query( "SELECT pg_advisory_unlock($key) as lockstatus", $method ); + $row = $this->fetchObject( $result ); + + if ( $row->lockstatus === 't' ) { + parent::unlock( $lockName, $method ); // record + return true; + } + + $this->queryLogger->debug( __METHOD__ . " failed to release lock\n" ); + + return false; + } + + public function serverIsReadOnly() { + $res = $this->query( "SHOW default_transaction_read_only", __METHOD__ ); + $row = $this->fetchObject( $res ); + + return $row ? ( strtolower( $row->default_transaction_read_only ) === 'on' ) : false; + } + + /** + * @param string $lockName + * @return string Integer + */ + private function bigintFromLockName( $lockName ) { + return \Wikimedia\base_convert( substr( sha1( $lockName ), 0, 15 ), 16, 10 ); + } +} + +class_alias( DatabasePostgres::class, 'DatabasePostgres' ); |