Shared cache parsing and pre-fetch

• US 20010000083A1
• Filed: 11/29/2000
• Published: 03/29/2001
• Est. Priority Date: 10/28/1997
• Status: Active Grant

• Current Assignee: CA, Inc. (d/b/a CA Technologies) (Broadcom, Inc.)
• Original Assignee: Blue Coat Systems Incorporated (Gen Digital Inc.)
• Inventors: Crow, Doug, Jenks, Tim, Bonkowski, Bert, Czegledi, Harold
• Granted Patent: US 6,442,651 B2
• Time in Patent Office: Days
• US Class Current: 711/130
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

The invention provides a method and system for reducing latency in reviewing and presenting web documents to the user. A cache coupled to one or more web clients request web documents from web servers on behalf of those web clients and communicates those web documents to the web clients for display. The cache parses the web documents as they are received from the web server, identifies references to any embedded objects, and determines if those embedded objects are already maintained in the cache. If those embedded objects are not in the cache, the cache automatically pre-fetches those embedded objects from the web server without need for a command from the web client. The cache maintains a two-level memory including primary memory and secondary mass storage. At the time the web document is received, the cache determines if any embedded objects are maintained in the cache but are not in primary memory. If those embedded objects are not in primary memory, the cache automatically pre-fetches those embedded objects from secondary mass storage to primary memory without need for a request from the web client. Web documents maintained in the cache are periodically refreshed, so as to assure those web documents are not stale. The invention is applied both to original requests to communicate web documents and their embedded objects from the web server to the web client, and to refresh requests to communicate web documents and their embedded objects from the web server to the cache.

Claims

1. A method, including the steps of

receiving web documents at a shared cache from a web server or mass storage for communicating said web documents to a web client for display;

parsing said web documents for references to embedded objects;

determining if said embedded objects are already maintained in said shared cache; and

conditionally pre-fetching said embedded objects from said web server in response to said step of determining, without need for a command from said web client.

2. A method as in

claim 1

, including the steps of

maintaining at said shared cache a two-level memory including primary memory and secondary mass storage;

locating said embedded objects in said shared cache but not in said primary memory;

conditionally pre-loading said embedded objects from said secondary mass storage into said primary memory in response to said step of locating, without need for a request from said web client.

3. A method as in

claim 1

, wherein said web documents include refresh copies of said web documents requested by said shared cache from said web server.

4. A system, including

a shared cache coupled to at least one web server and coupled to a plurality of web clients, said shared cache being capable of receiving requests for web documents from said web clients, requesting said web documents from said web server or mass storage, receiving said web documents from said web server or mass storage, and communicating said web documents to said web clients;

said shared cache including

means for parsing said web documents for references to embedded objects;

means for determining if said embedded objects are already maintained in said shared cache; and

means for conditionally pre-fetching said embedded objects from said web server in response to said means for determining, without need for a command from said web client.

5. A system as in

claim 4

, including

a two-level memory at said shared cache, said two-level memory including primary memory and secondary mass storage;

means for locating said embedded objects in said shared cache but not in said primary memory; and

means for conditionally pre-loading said embedded objects from said secondary mass storage into said primary memory in response to said means for locating, without need for a request from said web client.

6. A system as in

claim 4

, wherein said web documents include refresh copies of said web documents requested by said shared cache from said web server.

7. A shared cache, including

means for parsing said web documents, said web documents being received from a web server or from mass storage, for references to embedded objects;

means for determining if said embedded objects are already maintained in said shared cache; and

means for conditionally pre-fetching said embedded objects from said web server in response to said means for determining, without need for a command from said web client.

8. A cache as in

claim 7

, including

a two-level memory at said shared cache, said two-level memory including primary memory and secondary mass storage;

means for locating said embedded objects in said shared cache but not in said primary memory; and

means for conditionally pre-loading said embedded objects from said secondary mass storage into said primary memory in response to said means for locating, without need for a request from said web client.

9. A cache as in

claim 7

, wherein said web documents include refresh copies of said web documents requested by said shared cache from said web server.