LDAP: Virtual List View

The Simple Paged Results Request Control provides LDAP clients with a means to view sequential data at a rate controlled by the client, but it’s limited by the fact that clients can only scroll through pages in order. The Virtual List View Request Control, currently in draft form at the IETF, provides a way for LDAP clients to scroll through results from an arbitrary point in in the result set. Use of the Virtual List View Request Control requires the Server Side Sort Request Control with at least one sort key. The UnboundID Directory Server supports the virtual list view request control.

As always when working with request controls, features, and extensions, programmers must check that the object identifier is listed in the root DSE, and server administrators must allow the controls to be used by the authorization id.

Object identifiers:

• Simple Paged Results Request Control: 1.2.840.113556.1.4.319
• Virtual List View Request Control: 2.16.840.1.113730.3.4.9
• Server Side Sort Request Control: 1.2.840.113556.1.4.473

Check the root DSE using the command line tool:

/usr/bin/ldapsearch -xLLLH ldap://localhost:1389 \
  -b '' -s base '(&)' supportedControl | \
  perl -lane 'print if /1.2.840.113556.1.4.319/ or
  /2.16.840.1.113730.3.4.9/ or
  /1.2.840.113556.1.4.473/'
supportedControl: 1.2.840.113556.1.4.319
supportedControl: 1.2.840.113556.1.4.473
supportedControl: 2.16.840.1.113730.3.4.9

VirtualListViewDemo.java is a demonstration of the use of the Virtual List View Request Control and Response Control in Java using the UnboundID LDAP SDK.