nameserv::auto(3tcl) 0.1 nns "Name service facility"

NAME

nameserv::auto - Name service facility, Client Extension

    TABLE OF CONTENTS
    SYNOPSIS
    DESCRIPTION
    API
    OPTIONS
    BUGS, IDEAS, FEEDBACK
    SEE ALSO
    KEYWORDS
    COPYRIGHT

SYNOPSIS

package require Tcl 8.4
package require nameserv::auto ?0.1?
package require nameserv

::nameserv::auto::bind name data

::nameserv::auto::cget -option

::nameserv::auto::configure

::nameserv::auto::configure -option

::nameserv::auto::configure -option value...

This package sits on top of the regular name service client (nameserv) and provides automatic restoration of a lost connection, and automatic rebinding of name/data pairs. The latter is however restricted to names which registered through this package instead of the regular client.

It does this by watching for the lost-connection events generated by nameserv and then trying to reconnect every N milliseconds (configurable, default is 1000, i.e. 1 second).

An important case to detect and handle is where a registered name was bound by a different client in the interval between loss and restoration of the connection. When that happens an automatic rebinding is not possible anymore for the specific name/data pair. This package will generate a lost-name event (tag nameserv) for all such names. The detail information of these events will be a Tcl dictionary containing two keys, name, and data, whose values hold the information of the lost pair.

API

The package exports three commands, as specified below:

::nameserv::auto::bind name data: This command is identical to ::nameserv::bind of package nameserv, except that it remembers the name/data information and rebinds them automatically when a lost connection is restored.
::nameserv::auto::cget -option: This command returns the currently configured value for the specified -option. The list of supported options and their meaning can be found in section OPTIONS.
::nameserv::auto::configure: In this form the command returns a dictionary of all supported options, and their current values. The list of supported options and their meaning can be found in section OPTIONS.
::nameserv::auto::configure -option: In this form the command is an alias for "::nameserv::auto::cget -option]". The list of supported options and their meaning can be found in section OPTIONS.
::nameserv::auto::configure -option value...: In this form the command is used to configure one or more of the supported options. At least one option has to be specified, and each option is followed by its new value. The list of supported options and their meaning can be found in section OPTIONS.

OPTIONS

The one option supported by the auto-client specifies the time interval between attempts to restore a lost connection. It is:

-delay milliseconds: This option specifies the interval to wait between attempts to restore a lost connection, in milliseconds. The default value is 1000, i.e. one second.

BUGS, IDEAS, FEEDBACK

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category nameserv of the Tcllib SF Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

KEYWORDS

automatic, client, name service, reconnect, restore