示例#1
0
 /**
  * A method to return a singleton database connection resource.
  *
  * Example usage:
  * $oDbh = OA_DB::singleton();
  *
  * Warning: In order to work correctly, the singleton method must
  * be instantiated statically and by reference, as in the above
  * example.
  *
  * @static
  * @param string $dsn Optional database DSN details - connects to the
  *                    database defined by the configuration file otherwise.
  *                    See {@link OA_DB::getDsn()} for format.
  *
  * @param array $aDriverOptions An optional array of driver options. Currently
  *                              supported options are:
  *                  - For MySQL:
  *                      ['ssl']      = false|true Perform connection over SSL?
  *                      ['ca']       = Name of CA file, if "ssl" true
  *                      ['capath']   = Path to CA file above, is "ssl" true
  *                      ['compress'] = false|true Use client compression?
  *
  * @return MDB2_Driver_Common An MDB2 connection resource, or PEAR_Error
  *                            on failure to connect.
  */
 static function singleton($dsn = null, $aDriverOptions = array())
 {
     $aConf = $GLOBALS['_MAX']['CONF'];
     // Get the driver options, if not set
     if (!is_array($aDriverOptions) || is_null($dsn) && empty($aDriverOptions)) {
         $aDriverOptions = OA_DB::getDsnOptions();
     }
     // Get the DSN, if not set
     $dsn = is_null($dsn) ? OA_DB::getDsn() : $dsn;
     // Check that the parameter is a string, not an array
     if (is_array($dsn)) {
         return Max::raiseError('Bad argument: DSN should be a string', MAX_ERROR_INVALIDARGS);
     }
     // A hack to allow for installation on pgsql
     // If the configuration hasn't been defined prevent
     // loading mysql MDB2 driver.
     if (strpos($dsn, '//:@') !== false) {
         // Return a silent error
         return new PEAR_Error('Bad argument: Empty DSN');
     }
     // Get the database type in use from the DNS, not from the
     // configuration file
     $aDSN = MDB2::parseDSN($dsn);
     $databaseType = $aDSN['phptype'];
     // Is this a MySQL database connection that should happen via SSL?
     if (strcasecmp($databaseType, 'mysql') === 0 && @$aDriverOptions['ssl']) {
         // Modify the DSN string to include the required CA and CAPATH options
         if (!empty($aDriverOptions['ca']) && !empty($aDriverOptions['capath'])) {
             $dsn .= "?ca={$aDriverOptions['ca']}&capth={$aDriverOptions['capath']}";
         }
     }
     // Create an MD5 checksum of the DSN
     $dsnMd5 = md5($dsn);
     // Does this database connection already exist?
     if (isset($GLOBALS['_OA']['CONNECTIONS'])) {
         $aConnections = array_keys($GLOBALS['_OA']['CONNECTIONS']);
     } else {
         $aConnections = array();
     }
     if (!(count($aConnections) > 0) || !in_array($dsnMd5, $aConnections)) {
         // Prepare options for a new database connection
         $aOptions = array();
         // Sequence column name
         $aOptions['seqcol_name'] = 'id';
         // Set the index name format
         $aOptions['idxname_format'] = '%s';
         // Use 4 decimal places in DECIMAL nativetypes
         $aOptions['decimal_places'] = 4;
         // Set the portability options
         $aOptions['portability'] = OA_DB_MDB2_DEFAULT_OPTIONS;
         // Set the default table type for MySQL, if appropriate
         if (strcasecmp($databaseType, 'mysql') === 0) {
             if (!empty($aConf['table']['type'])) {
                 $aOptions['default_table_type'] = $aConf['table']['type'];
                 // Enable transaction support when using InnoDB tables
                 if (strcasecmp($aOptions['default_table_type'], 'innodb') === 0) {
                     // Enable transaction support
                     $aOptions['use_transactions'] = true;
                 }
             }
         } elseif (strcasecmp($databaseType, 'pgsql') === 0) {
             $aOptions['quote_identifier'] = true;
         }
         // Add default charset - custom OpenX
         if (defined('OA_DB_MDB2_DEFAULT_CHARSET')) {
             $aOptions['default_charset'] = OA_DB_MDB2_DEFAULT_CHARSET;
         } else {
             $aOptions['default_charset'] = 'utf8';
         }
         // this will log select queries to a var/sql.log
         // currently used for analysis purposes
         if (isset($aConf['debug']['logSQL']) && $aConf['debug']['logSQL']) {
             $aOptions['log_statements'] = explode('|', $aConf['debug']['logSQL']);
             $aOptions['debug'] = true;
             $aOptions['debug_handler'] = 'logSQL';
         }
         $aOptions += OA_DB::getDatatypeMapOptions();
         // Is this a MySQL database connection?
         if (strcasecmp($databaseType, 'mysql') === 0) {
             // Should this connection happen over SSL?
             if (@$aDriverOptions['ssl']) {
                 $aOptions['ssl'] = true;
             }
         }
         // Create the new database connection
         OA::disableErrorHandling();
         $oDbh = MDB2::singleton($dsn, $aOptions);
         OA::enableErrorHandling();
         if (PEAR::isError($oDbh)) {
             return $oDbh;
         }
         // Is this a MySQL database connection?
         if (strcasecmp($databaseType, 'mysql') === 0) {
             $client_flags = 0;
             // Should this connection happen over SSL?
             if (@$aDriverOptions['ssl']) {
                 $client_flags = $client_flags | MYSQL_CLIENT_SSL;
             }
             // Should this connection use compression?
             if (@$aDriverOptions['compress']) {
                 $client_flags = $client_flags | MYSQL_CLIENT_COMPRESS;
             }
             // Are there any MySQL connection flags to set?
             if ($client_flags != 0) {
                 $oDbh->dsn['client_flags'] = $client_flags;
             }
         }
         OA::disableErrorHandling();
         $success = $oDbh->connect();
         OA::enableErrorHandling();
         if (PEAR::isError($success)) {
             return $success;
         }
         // Set charset if needed
         $success = OA_DB::setCharset($oDbh);
         if (PEAR::isError($success)) {
             return $success;
         }
         // Set schema if needed
         $success = OA_DB::setSchema($oDbh);
         if (PEAR::isError($success)) {
             return $success;
         }
         // Set the fetchmode to be use used
         $oDbh->setFetchMode(MDB2_FETCHMODE_ASSOC);
         // Load modules that are likely to be needed
         $oDbh->loadModule('Extended');
         $oDbh->loadModule('Datatype');
         $oDbh->loadModule('Manager');
         // Store the database connection
         $GLOBALS['_OA']['CONNECTIONS'][$dsnMd5] = $oDbh;
         // Set MySQL 4 compatibility if needed
         if (strcasecmp($databaseType, 'mysql') === 0 && !empty($aConf['database']['mysql4_compatibility'])) {
             $oDbh->exec("SET SESSION sql_mode='MYSQL40'");
         }
     }
     return $GLOBALS['_OA']['CONNECTIONS'][$dsnMd5];
 }