db.php

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            @include_once "DB/${type}.php";
        }

        $classname = "DB_${type}";
        if (!class_exists($classname)) {
            $tmp = PEAR::raiseError(null, DB_ERROR_NOT_FOUND, null, null,
                                    "Unable to include the DB/{$type}.php file for `$dsn'",
                                    'DB_Error', true);
            return $tmp;
        }

        @$obj =& new $classname;

        foreach ($options as $option => $value) {
            $test = $obj->setOption($option, $value);
            if (DB::isError($test)) {
                return $test;
            }
        }

        $err = $obj->connect($dsninfo, $obj->getOption('persistent'));
        if (DB::isError($err)) {
            $err->addUserInfo($dsn);
            return $err;
        }

        return $obj;
    }

    // }}}
    // {{{ apiVersion()

    /**
     * Return the DB API version
     *
     * @return int the DB API version number
     *
     * @access public
     */
    function apiVersion()
    {
        return 2;
    }

    // }}}
    // {{{ isError()

    /**
     * Tell whether a result code from a DB method is an error
     *
     * @param int $value result code
     *
     * @return bool whether $value is an error
     *
     * @access public
     */
    function isError($value)
    {
        return is_a($value, 'DB_Error');
    }

    // }}}
    // {{{ isConnection()

    /**
     * Tell whether a value is a DB connection
     *
     * @param mixed $value value to test
     *
     * @return bool whether $value is a DB connection
     *
     * @access public
     */
    function isConnection($value)
    {
        return (is_object($value) &&
                is_subclass_of($value, 'db_common') &&
                method_exists($value, 'simpleQuery'));
    }

    // }}}
    // {{{ isManip()

    /**
     * Tell whether a query is a data manipulation query (insert,
     * update or delete) or a data definition query (create, drop,
     * alter, grant, revoke).
     *
     * @access public
     *
     * @param string $query the query
     *
     * @return boolean whether $query is a data manipulation query
     */
    function isManip($query)
    {
        $manips = 'INSERT|UPDATE|DELETE|LOAD DATA|'.'REPLACE|CREATE|DROP|'.
                  'ALTER|GRANT|REVOKE|'.'LOCK|UNLOCK';
        if (preg_match('/^\s*"?('.$manips.')\s+/i', $query)) {
            return true;
        }
        return false;
    }

    // }}}
    // {{{ errorMessage()

    /**
     * Return a textual error message for a DB error code
     *
     * @param integer $value error code
     *
     * @return string error message, or false if the error code was
     * not recognized
     */
    function errorMessage($value)
    {
        static $errorMessages;
        if (!isset($errorMessages)) {
            $errorMessages = array(
                DB_ERROR                    => 'unknown error',
                DB_ERROR_ALREADY_EXISTS     => 'already exists',
                DB_ERROR_CANNOT_CREATE      => 'can not create',
                DB_ERROR_CANNOT_DELETE      => 'can not delete',
                DB_ERROR_CANNOT_DROP        => 'can not drop',
                DB_ERROR_CONSTRAINT         => 'constraint violation',
                DB_ERROR_CONSTRAINT_NOT_NULL=> 'null value violates not-null constraint',
                DB_ERROR_DIVZERO            => 'division by zero',
                DB_ERROR_INVALID            => 'invalid',
                DB_ERROR_INVALID_DATE       => 'invalid date or time',
                DB_ERROR_INVALID_NUMBER     => 'invalid number',
                DB_ERROR_MISMATCH           => 'mismatch',
                DB_ERROR_NODBSELECTED       => 'no database selected',
                DB_ERROR_NOSUCHFIELD        => 'no such field',
                DB_ERROR_NOSUCHTABLE        => 'no such table',
                DB_ERROR_NOT_CAPABLE        => 'DB backend not capable',
                DB_ERROR_NOT_FOUND          => 'not found',
                DB_ERROR_NOT_LOCKED         => 'not locked',
                DB_ERROR_SYNTAX             => 'syntax error',
                DB_ERROR_UNSUPPORTED        => 'not supported',
                DB_ERROR_VALUE_COUNT_ON_ROW => 'value count on row',
                DB_ERROR_INVALID_DSN        => 'invalid DSN',
                DB_ERROR_CONNECT_FAILED     => 'connect failed',
                DB_OK                       => 'no error',
                DB_ERROR_NEED_MORE_DATA     => 'insufficient data supplied',
                DB_ERROR_EXTENSION_NOT_FOUND=> 'extension not found',
                DB_ERROR_NOSUCHDB           => 'no such database',
                DB_ERROR_ACCESS_VIOLATION   => 'insufficient permissions',
                DB_ERROR_TRUNCATED          => 'truncated'
            );
        }

        if (DB::isError($value)) {
            $value = $value->getCode();
        }

        return isset($errorMessages[$value]) ? $errorMessages[$value] : $errorMessages[DB_ERROR];
    }

    // }}}
    // {{{ parseDSN()

    /**
     * Parse a data source name.
     *
     * Additional keys can be added by appending a URI query string to the
     * end of the DSN.
     *
     * The format of the supplied DSN is in its fullest form:
     * <code>
     *  phptype(dbsyntax)://username:password@protocol+hostspec/database?option=8&another=true
     * </code>
     *
     * Most variations are allowed:
     * <code>
     *  phptype://username:password@protocol+hostspec:110//usr/db_file.db?mode=0644
     *  phptype://username:password@hostspec/database_name
     *  phptype://username:password@hostspec
     *  phptype://username@hostspec
     *  phptype://hostspec/database
     *  phptype://hostspec
     *  phptype(dbsyntax)
     *  phptype
     * </code>
     *
     * @param string $dsn Data Source Name to be parsed
     *
     * @return array an associative array with the following keys:
     *  + phptype:  Database backend used in PHP (mysql, odbc etc.)
     *  + dbsyntax: Database used with regards to SQL syntax etc.
     *  + protocol: Communication protocol to use (tcp, unix etc.)
     *  + hostspec: Host specification (hostname[:port])
     *  + database: Database to use on the DBMS server
     *  + username: User name for login
     *  + password: Password for login
     *
     * @author Tomas V.V.Cox <[e-mail]>
     */
    function parseDSN($dsn)
    {
        $parsed = array(
            'phptype'  => false,
            'dbsyntax' => false,
            'username' => false,
            'password' => false,
            'protocol' => false,
            'hostspec' => false,
            'port'     => false,
            'socket'   => false,
            'database' => false,
        );

        if (is_array($dsn)) {
            $dsn = array_merge($parsed, $dsn);
            if (!$dsn['dbsyntax']) {
                $dsn['dbsyntax'] = $dsn['phptype'];
            }
            return $dsn;
        }

        // Find phptype and dbsyntax
        if (($pos = strpos($dsn, '://')) !== false) {
            $str = substr($dsn, 0, $pos);
            $dsn = substr($dsn, $pos + 3);
        } else {
            $str = $dsn;
            $dsn = null;
        }

        // Get phptype and dbsyntax
        // $str => phptype(dbsyntax)
        if (preg_match('|^(.+?)\((.*?)\)$|', $str, $arr)) {
            $parsed['phptype']  = $arr[1];
            $parsed['dbsyntax'] = !$arr[2] ? $arr[1] : $arr[2];
        } else {
            $parsed['phptype']  = $str;
            $parsed['dbsyntax'] = $str;
        }

        if (!count($dsn)) {
            return $parsed;
        }

        // Get (if found): username and password
        // $dsn => username:password@protocol+hostspec/database
        if (($at = strrpos($dsn,'@')) !== false) {
            $str = substr($dsn, 0, $at);
            $dsn = substr($dsn, $at + 1);
            if (($pos = strpos($str, ':')) !== false) {
                $parsed['username'] = rawurldecode(substr($str, 0, $pos));
                $parsed['password'] = rawurldecode(substr($str, $pos + 1));
            } else {
                $parsed['username'] = rawurldecode($str);
            }
        }

        // Find protocol and hostspec

        // $dsn => proto(proto_opts)/database
        if (preg_match('|^([^(]+)\((.*?)\)/?(.*?)$|', $dsn, $match)) {
            $proto       = $match[1];
            $proto_opts  = $match[2] ? $match[2] : false;
            $dsn         = $match[3];

        // $dsn => protocol+hostspec/database (old format)
        } else {
            if (strpos($dsn, '+') !== false) {
                list($proto, $dsn) = explode('+', $dsn, 2);
            }
            if (strpos($dsn, '/') !== false) {
                list($proto_opts, $dsn) = explode('/', $dsn, 2);
            } else {
                $proto_opts = $dsn;
                $dsn = null;
            }
        }

        // process the different protocol options
        $parsed['protocol'] = (!empty($proto)) ? $proto : 'tcp';
        $proto_opts = rawurldecode($proto_opts);
        if ($parsed['protocol'] == 'tcp') {
            if (strpos($proto_opts, ':') !== false) {
                list($parsed['hostspec'], $parsed['port']) = explode(':', $proto_opts);
            } else {
                $parsed['hostspec'] = $proto_opts;
            }
        } elseif ($parsed['protocol'] == 'unix') {
            $parsed['socket'] = $proto_opts;
        }

        // Get dabase if any
        // $dsn => database
        if ($dsn) {
            // /database
            if (($pos = strpos($dsn, '?')) === false) {
                $parsed['database'] = rawurldecode($dsn);
            // /database?param1=value1&param2=value2
            } else {
                $parsed['database'] = rawurldecode(substr($dsn, 0, $pos));
                $dsn = substr($dsn, $pos + 1);
                if (strpos($dsn, '&') !== false) {
                    $opts = explode('&', $dsn);
                } else { // database?param1=value1
                    $opts = array($dsn);
                }
                foreach ($opts as $opt) {
                    list($key, $value) = explode('=', $opt);
                    if (!isset($parsed[$key])) {
                        // don't allow params overwrite
                        $parsed[$key] = rawurldecode($value);
                    }
                }
            }
        }

        return $parsed;
    }

    // }}}
    // {{{ assertExtension()

    /**
     * Load a PHP database extension if it is not loaded already.
     *
     * @access public
     *
     * @param string $name the base name of the extension (without the .so or
     *                     .dll suffix)
     *
     * @return boolean true if the extension was already or successfully
     *                 loaded, false if it could not be loaded
     */
    function assertExtension($name)
    {
        if (!extension_loaded($name)) {
            $dlext = OS_WINDOWS ? '.dll' : '.so';
            $dlprefix = OS_WINDOWS ? 'php_' : '';
            @dl($dlprefix . $name . $dlext);
            return extension_loaded($name);
        }
        return true;
    }
    // }}}
}

// }}}
// {{{ class DB_Error

/**
 * DB_Error implements a class for reporting portable database error
 * messages.
 *
 * @package  DB
 * @author Stig Bakken <[e-mail]>
 */
class DB_Error extends PEAR_Error
{
    // {{{ constructor

    /**
     * DB_Error constructor.
     *
     * @param mixed   $code   DB error code, or string with error message.
     * @param integer $mode   what "error mode" to operate in
     * @param integer $level  what error level to use for $mode & PEAR_ERROR_TRIGGER
     * @param mixed   $debuginfo  additional debug info, such as the last query
     *
     * @access public
     *
     * @see PEAR_Error
     */
    function DB_Error($code = DB_ERROR, $mode = PEAR_ERROR_RETURN,