Proxy cache preloader

• US 6,925,485 B1
• Filed: 05/24/2002
• Issued: 08/02/2005
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Wang, Feng, Tracey, David C., French, Ronan, Brandenburg, Jay
• Primary Examiner(s): Robertson, David L.
• Application Number:
  US10/155,694
• Time in Patent Office: 1,166 Days
• Field of Search: 709/202, 709/213, 709/217, 709/219, 711/156
• US Class Current: 709/202
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/5681 Pre-fetching or pre-delivering data based on network characteristics
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

The present invention is directed to a proxy cache preloader. According to an embodiment of the present invention, a Hyper Text Transfer Protocol (HTTP) client intermediary having a proxy cache is used to provide multiple client computing devices with access to Internet data in the cache. When a device needs access to Internet data (i.e., a web page), a preloader/refresh mechanism is employed which uses a preloader algorithm. In one embodiment, the preloader algorithm checks to see if the current request is for an HTTP Uniform Resource Locator (URL). If not, the data is re-loaded into the proxy cache. If the current request is a request for HTTP, the preloader mechanism determines if optimization is enabled for the URL. If not, the data is re-loaded into the proxy cache. Otherwise, an information retrieval method (e.g., an HTTP GET) optimization algorithm is employed.

Claims

1. A proxy cache preloader comprising:

a proxy cache connected to a network;

at least one computing device connected to said proxy cache wherein said computing device can request said proxy cache to retrieve an object from said network;

a preload/refresh mechanism configured to determine whether an optimization is enabled for said object; and

an optimization algorithm configured to determine whether or not to retrieve said object.

2. The preloader of claim 1 wherein said proxy cache is contained in a Hyper Text Transfer Protocol (HTTP) client intermediary.

3. The preloader of claim 2 wherein said preload/refresh mechanism is contained within said HTTP client intermediary.

4. The preloader of claim 2 further comprising a HTTP processor located physically away from said HTTP client intermediary and wherein said preload/refresh mechanism is contained within said HTTP processor.

5. The preloader of claim 1 wherein said preload/refresh mechanism is configured to determine whether said object is an HTTP Uniform Resource Locator (URL) and retrieve said object if said object is not an HTTP URL.

6. The preloader of claim 5 wherein said preload/refresh mechanism is configured to determine whether said object has an enabled optimization when said object is said HTTP URL.

7. The preloader of claim 6 wherein said preload/refresh mechanism is configured to invoke said optimization algorithm when said enabled optimization is found for said HTTP URL.

8. The preloader of claim 7 wherein said optimization algorithm is configured to parse a time and date indication field of a response header.

9. The preloader of claim 8 wherein said optimization algorithm is further configured to get said object if said time and date indication field is invalid or non-existent.

10. The preloader of claim 9 wherein said optimization algorithm is further configured to set said time and date indication field equal to a conditional field and to send an information retrieval method request when said time and date indication field is valid.

11. The preloader of claim 10 wherein said optimization algorithm is further configured to determine if a server sends a not modified response and to retrieve said object only if said server does not send said not modified response.

12. The preloader of claim 11 wherein said time and date indication field is an HTTP Last-Modified field and wherein said conditional field is an HTTP If-Modified-Since field.

13. The preloader of claim 12 wherein said informational retrieval method is an TTP GET method.

14. The preloader of claim 1 further comprising a plurality of computing devices connected to said proxy cache, wherein each of said computing devices can request said proxy cache to retrieve said object from said network.

15. The preloader of claim 14 wherein said network comprises a local network and an external network, wherein said plurality of computing devices are connected with said proxy cache via said local network and wherein said object is retrieved by said proxy cache from said external network.

16. The preloader of claim 15 wherein said plurality of computing devices comprise a first computing device and a second computing device and wherein after said first and second devices request said proxy cache for said object, said proxy cache can present a cached object, corresponding to said requested object, to said first computing device and to said second computing device via said local network.

17. A method for preloading a proxy cache comprising:

making a request to said proxy cache from at least one computing device connected to said proxy cache for retrieval of an object connected to said proxy cache;

initiating a preload/refresh mechanism to determine whether an optimization is enabled for said object; and

initiating an optimization algorithm to determine whether or not to retrieve said object.

18. The method of claim 17 wherein said initiating an optimization algorithm further comprises:

parsing a Last-Modified field of a response header.

19. The method of claim 18 wherein said initiating an optimization algorithm further comprises:

getting said object if said Last-Modified field is invalid or non-existent.

20. The method of claim 19 wherein said initiating an optimization algorithm further comprises:

setting said Last-Modified field equal to an If-Modified-Since field; and

sending a GET request, when said Last-Modified field is valid.

21. The method of claim 17 wherein said computing device is connected to said proxy cache via a local network and wherein said object is retrieved by said proxy cache through an external network.

22. A computer program product comprising:

a computer usable medium having computer readable program code embodied therein configured to preload a proxy cache comprising;

computer readable code configured to cause at least one computing device connected to said proxy cache to request said proxy cache to retrieve an object from a computer connected to said proxy cache;

computer readable code configured to cause a computer to initiate a preload/refresh mechanism to determine whether an optimization is enabled for said object; and

computer readable code configured to cause a computer to initiate an optimization algorithm to determine whether or not to retrieve said object.

23. The computer program product of claim 22 wherein said proxy cache is contained in a Hyper Text Transfer Protocol (HTTP) client intermediary and wherein said preload/refresh mechanism is also contained within said HTTP client intermediary.

24. The computer program product of claim 22 wherein said proxy cache is contained in Hyper Text Transfer Protocol (HTTP) client intermediary, wherein said preload/refresh mechanism is contained within an HTTP processor and wherein said HTTP process is physically located away from said HTTP client intermediary.

25. The computer program product of claim 22 wherein said object from said computer is connected to said proxy cache via an external network and wherein said computing device is connected to said proxy cache via a local network.

26. The computer program product of claim 25 wherein said computer usable medium further comprises:

computer readable code configured in certain circumstances to cause said proxy cache to present a cashed object corresponding to said requested object to said computer device and another computing device connected to said proxy cache via said local network.