Postgres.php

<?php
/*
Copyright (C) 2014, Siemens AG
Authors: Steffen Weber, Andreas Würl

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
version 2 as published by the Free Software Foundation.

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.
*/

namespace Fossology\Lib\Db\Driver;

use Fossology\Lib\Db\Driver;

class Postgres implements Driver
{

  private $dbConnection;

  public function __construct($dbConnection)
  {
    $this->dbConnection = $dbConnection;
  }

  private function identifierHash($stmt)
  {
    $namedatalen = 63;
    if ($namedatalen >= strlen($stmt)) {
      return $stmt;
    }
    $hash = substr($stmt, 0, $namedatalen);
    for ($i = $namedatalen; $i < strlen($stmt); $i ++) {
      $hash[$i%$namedatalen] = chr((ord($hash[$i%$namedatalen])+ord($stmt[$i])-32)%96+32);
    }
    return $hash;
  }

  public function prepare($statementName, $sqlStatement)
  {
    return pg_prepare($this->dbConnection, $this->identifierHash($statementName), $sqlStatement);
  }

  public function execute($statementName, $parameters)
  {
    return pg_execute($this->dbConnection, $this->identifierHash($statementName), $parameters);
  }

  public function query($sqlStatement)
  {
    return pg_query($this->dbConnection, $sqlStatement);
  }

  public function isConnected()
  {
    return pg_connection_status($this->dbConnection) === PGSQL_CONNECTION_OK;
  }

  public function getLastError()
  {
    return pg_last_error($this->dbConnection);
  }

  public function freeResult($res)
  {
    return pg_free_result($res);
  }

  public function fetchArray($res)
  {
    return pg_fetch_array($res, null, PGSQL_ASSOC);
  }

  public function fetchAll($res)
  {
    if (pg_num_rows($res) == 0) {
      return array();
    }
    return pg_fetch_all($res);
  }

  public function begin()
  {
    pg_query($this->dbConnection, "BEGIN");
    return;
  }

  public function commit()
  {
    pg_query($this->dbConnection, "COMMIT");
    return;
  }

  public function rollback()
  {
    pg_query($this->dbConnection, "ROLLBACK");
    return;
  }

  public function booleanFromDb($booleanValue)
  {
    return $booleanValue === 't';
  }

  public function booleanToDb($booleanValue)
  {
    return $booleanValue ? 't' : 'f';
  }

  public function escapeString($string)
  {
    return pg_escape_string($string);
  }

  public function existsTable($tableName)
  {
    $dbName = pg_dbname($this->dbConnection);
    $sql = "SELECT count(*) cnt
              FROM information_schema.tables
             WHERE table_catalog='$dbName'
               AND table_name='". strtolower($tableName) . "'";
    $res = pg_query($this->dbConnection, $sql);
    if (!$res && pg_connection_status($this->dbConnection) === PGSQL_CONNECTION_OK) {
      throw new \Exception(pg_last_error($this->dbConnection));
    } else if (! $res) {
      throw new \Exception('DB connection lost');
    }
    $row = pg_fetch_assoc($res);
    pg_free_result($res);
    return($row['cnt']>0);
  }

  public function existsColumn($tableName, $columnName)
  {
    $dbName = pg_dbname($this->dbConnection);
    $sql = "SELECT count(*) cnt
              FROM information_schema.columns
             WHERE table_catalog='$dbName'
               AND table_name='". strtolower($tableName) . "'
               AND column_name='". strtolower($columnName) . "'";
    $res = pg_query($this->dbConnection, $sql);
    if (!$res && pg_connection_status($this->dbConnection) === PGSQL_CONNECTION_OK) {
      throw new \Exception(pg_last_error($this->dbConnection));
    } else if (! $res) {
      throw new \Exception('DB connection lost');
    }
    $row = pg_fetch_assoc($res);
    pg_free_result($res);
    return($row['cnt']>0);
  }

  public function insertPreparedAndReturn($stmt, $sql, $params, $colName)
  {
    $sql .= " RETURNING $colName";
    $stmt .= ".returning:$colName";
    $this->prepare($stmt,$sql);
    $res = $this->execute($stmt,$params);
    $return = $this->fetchArray($res);
    $this->freeResult($res);
    return $return[$colName];
  }
}