NAME

IO::Lambda::DBI - asynchronous DBI

DESCRIPTION

The module implements asynchronous DBI proxy object, that remotes DBI calls using any given file handle, such as stream sockets, pipes, etc. All calls to DBI methods are implemented as method calls to the object, which return lambdas, that shall be subsequently called and awaited for completion.

SYNOPSIS

    use IO::Lambda qw(:all);
    use IO::Lambda::DBI;
    use IO::Lambda::Thread qw(new_thread);

    # use threads as a transport
    my ($thread, $socket) = new_thread( sub {
        my $socket = shift;
        IO::Lambda::Message::DBI-> new( $socket, $socket )-> run;
    }, 1);
	
    my $dbi = IO::Lambda::DBI-> new($socket, $socket);

    # execute a query
    print lambda {
        context $dbi-> connect('DBI:mysql:database=mysql', '', '');
    tail {
        return "connect error:$_[0]" unless shift;
        context $dbi-> selectrow_array('SELECT 5 + ?', {}, 2);
    tail {
        my ($ok,$result) = @_;
        return "dbi error:$result" unless $ok;
        context $dbi-> disconnect;
    tail {
        return "select=$result";
    }}}}-> wait, "\n";

    # finalize
    $thread-> join;

IO::Lambda::DBI

All remoted methods return lambdas of type

dbi_result :: () -> ( 1, @result | 0, $error )

where depending on the first returned item in the array, the other items are either DBI method results, or an error.

The class handles AUTOLOAD methods as proxy methods, so calls such as $dbh-> selectrow_array are perfectly legal.

new $class, $r, $w, %options

See "new" in IO::Lambda::Message.

connect($dsn, $user, $auth, %attr) :: dbi_result

Proxies DBI::connect. In case of failure, depending on RaiseError flag, returns either (0,$error) or (1,$error).

disconnect :: dbi_result

Proxies DBI::disconnect.

call($method, @parameters) :: dbi_result

Proxies DBI::$method(@parameters).

set_attr(%attr)

Sets attributes on a DBI handle.

get_attr(@keys)

Retrieves values for attribute keys from a DBI handle.

IO::Lambda::Message::DBI

Descendant of IO::Lambda::Message::Simple. Implements blocking, server side that does the actual calls to the DBI.

BUGS

DBI::prepare is unimplemented.

SEE ALSO

DBI, eg/dbi.pl.

AUTHOR

Dmitry Karasik, <dmitry@karasik.eu.org>.