Apparatus for controlling subscriptions

• US 8,375,051 B2
• Filed: 01/21/2009
• Issued: 02/12/2013
• Est. Priority Date: 01/21/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Postlethwaite, David, Siddall, Peter, Rumsey, Jonathan Lee, Edwards, Ian Charles
• Primary Examiner(s): Perveen, Rehana
• Assistant Examiner(s): BUI, THUY T
• Application Number:
  US12/357,127
• Publication Number:
  US 20090187570A1
• Time in Patent Office: 1,483 Days
• Field of Search: 707/705, 707/706, 707/708, 707/797, 707/771, 707/778
• US Class Current: 707/778
• CPC Class Codes: G06F 16/90344 by using string matching techniques

Abstract

An apparatus for controlling subscriptions comprising: a detector operable to detect to a subscription associated with a wildcard topic string; and an analyzer, responsive to the detection of the subscription associated with a wildcard topic string and a topic string of a topic node matching the wildcard topic string, for analyzing a first attribute of the topic node; and means for determining whether a subscriber associated with the subscription should receive a message associated with the topic string of the topic node.

Claims

1. An apparatus for controlling subscriptions, the apparatus comprising:

a processor;

a non-transitory computer-readable storage having stored thereon a computer program configured for controlling the processor to perform the steps of;

assigning one of a PASSTHROUGH value and a BLOCK value to a first attribute of each topic node of a topic tree based on at least one assignment rule;

responsive to a wildcard topic string, determining a highest level topic node of the topic tree matching the wildcard topic string to define a root node;

traversing each topic node of the topic tree starting the root node, the traversing comprising;

analyzing the first attribute of the topic node to determine whether the first attribute specifies the PASSTHROUGH value or the BLOCK value,

if the first attribute specifies the PASSTHROUGH value, determining a subscriber associated with the subscription should receive a message associated with the topic string of the topic node, and

if the first attribute specifies the BLOCK value, determining that the subscriber should not receive a message associated with the topic string of the topic node or a message associated with other topic strings more specific than the topic string of the topic node when the wildcard topic string is less specific than the topic string of the topic node;

detecting a generation of a new topic node; and

performing the traversing for the new topic node.

2. The apparatus of claim 1, the traversing further comprising that when the first attribute specifies the BLOCK value and the wildcard topic string directly matches the topic string of the topic node, determining that the subscriber should receive a message associated with the topic string.

3. The apparatus of claim 1, wherein the computer program further configured for controlling the processor to perform the step of adding data associated with the subscriber to a linked list data structure associated with the topic node.

4. A method for controlling subscriptions, the method comprising:

assigning one of a PASSTHROUGH value and a BLOCK value to a first attribute of each topic node of a topic tree based on at least one assignment rule;

responsive to a wildcard topic string, determining a highest level topic node of the topic tree matching the wildcard topic string to define a root node;

traversing, via a processor, each topic node of the topic tree starting the root node, the traversing comprising;

analyzing the first attribute of the topic node to determine whether the first attribute specifies the PASSTHROUGH value or the BLOCK value,

if the first attribute specifies the PASSTHROUGH value, determining a subscriber associated with the subscription should receive a message associated with the topic string of the topic node, and

if the first attribute specifies the BLOCK value, determining that the subscriber should not receive a message associated with the topic string of the topic node and topic strings more specific than the topic string of the topic node when the wildcard topic string is less specific than the topic string of the topic node;

detecting a generation of a new topic node; and

performing the traversing for the new topic node.

5. The method of claim 4, the traversing further comprising that when the first attribute specifies the BLOCK value and the wildcard topic string directly matches the topic string of the topic node, determining that the subscriber should receive a message associated with the topic string.

6. The method of claim 4, further comprising adding data associated with the subscriber to a linked list data structure associated with the topic node.

7. A non-transitory computer-readable storage-medium containing a computer program comprising program code, which, when loaded in and executed by a computer causes the computer to perform the steps of:

assigning one of a PASSTHROUGH value and a BLOCK value to a first attribute of each topic node of a topic tree based on at least one assignment rule;

responsive to a wildcard topic string, determining a highest level topic node of the topic tree matching the wildcard topic string to define a root node; and

traversing, via a processor, each topic node of the topic tree starting the root node, the traversing comprising;

analyzing the first attribute of the topic node to determine whether the first attribute specifies the PASSTHROUGH value or the BLOCK value,

if the first attribute specifies the PASSTHROUGH value, determining a subscriber associated with the subscription should receive a message associated with the topic string of the topic node, and

if the first attribute specifies the BLOCK value, determining that the subscriber should not receive a message associated with the topic string of the topic node and topic strings more specific than the topic string of the topic node when the wildcard topic string is less specific than the topic string of the topic node;

detecting a generation of a new topic node; and

performing the traversing for the new topic node.