lb_$lookup_interface Library Routine (NCS)

Purpose

Looks up information about an interface in the Global Location Broker (GLB) database.

Syntax

void lb_$lookup_interface ( object_interface, lookup_handle) void lb_$lookup_interface ( max_results, num_results, results, status) uuid_$t *object_interface; lb_$lookup_handle_t *lookup_handle; unsigned long max_results; unsigned long *num_results; lb_$entry_t results [ ]; status_$t *status;

Description

The lb_$lookup_interface routine returns GLB database entries whose fields in the object_interface parameters match the specified interface. It returns information about all replicas of all objects that can be accessed through that interface.

The lb_$lookup_interface routine cannot return more than the number of matching entries specified by the max_results parameter at one time. The lookup_handle parameter directs this routine to do sequential lookup calls to find all matching entries.

Note:

The Location Broker does not prevent modification of the database between lookup calls, which can cause the locations of entries relative to a lookup_handle value to change. If multiple calls are made to find all matching results in the database, the returned information may skip or duplicate entries from the database.
It is also possible for the results of a single lookup call to skip or duplicate entries. This can occur if the size of the results exceeds the size of a remote procedure call (RPC) packet (64KB).

Parameters

Input

Item	Description
object_interface	Points to the Universal Unique Identifier (UUID) of the interface being looked up.
max_results	Specifies the maximum number of matching entries that can be returned by a single call. This should be the number of elements in the results parameter array.

Input/Output

Item	Description
lookup_handle	Specifies a location in the database. On input, the lookup_handle value indicates the location in the database where the search begins. An input value of lb_$default_lookup_handle specifies that the search starts at the beginning of the database.
	On return, the lookup_handle parameter indicates the next unsearched part of the database (that is, the point at which the next search should begin). A return value of lb_$default_lookup_handle indicates that the search reached the end of the database. Any other value indicates that the search found the number of matching entries specified by the max_results parameter before it reached the end of the database.

Item

Description

lookup_handle

Specifies a location in the database. On input, the lookup_handle value indicates the location in the database where the search begins. An input value of lb_$default_lookup_handle specifies that the search starts at the beginning of the database.

On return, the lookup_handle parameter indicates the next unsearched part of the database (that is, the point at which the next search should begin). A return value of lb_$default_lookup_handle indicates that the search reached the end of the database. Any other value indicates that the search found the number of matching entries specified by the max_results parameter before it reached the end of the database.

Output

Item	Description
num_results	Points to the number of entries that are returned in the results parameter array.
results	Specifies the array that contains the matching GLB database entries, up to the number specified in the max_results parameter. If the array contains any entries for servers on the local network, those entries appear first.
status	Points to the completion status.

Examples

To look up information in the GLB database about a matrix multiplication interface, enter:

lb_$lookup_interface (&matrix_if_id, &lookup_handle,
   results_array_size, &num_results,
   &matrix_if_results_array, &status);