Hypertext markup language cache system and method

• US 6,681,298 B1
• Filed: 07/12/2000
• Issued: 01/20/2004
• Est. Priority Date: 07/12/2000
• Status: Expired due to Term

• Current Assignee: Tech 5 SAS
• Original Assignee: Powertv Incorporated (Cisco Systems, Inc.)
• Inventors: Tso, Victor, Knittel, Brian
• Primary Examiner(s): Kim, Matthew
• Assistant Examiner(s): ELMORE, STEPHEN C
• Application Number:
  US09/614,239
• Time in Patent Office: 1,287 Days
• Field of Search: 711/133, 711/134, 711/136, 709/245, 725/46, 725/110
• US Class Current: 711/133
• CPC Class Codes: G06F 16/9574 of access to content, e.g. by caching

Abstract

The present invention is directed towards a cache management system for a set top box that improves the loading speed of hypertext markup language (HTML) documents that are provided by web servers. The cache management system includes a set top box with a processor and memory that includes cache, where a plurality of HTML documents is stored in the cache. A cache manager manages the cache and calculates a removal factor for each of the HTML documents. The cache manager removes at least one of the HTML documents based on its removal factor until sufficient room is available for an additional HTML document. Additionally, the cache manager keeps the maximum number of relevant web pages in cache to maximize loading speed.

Claims

1. A cache management system for a set top box that improves the loading speed of hypertext markup language (HTML) documents that are provided by web servers throughout a distributed communications system, comprising:

a set top box including a processor and memory, wherein said memory includes cache;

a plurality of HTML documents that are stored in said cache; and

a cache manager that manages said cache and that calculates a removal factor for each of said HTML documents, wherein said removal factor is at least partially based on whether said at least one of said HTML documents is compressed or decompressed,

wherein said cache manager removes at least one of said HTML documents based on its removal factor until sufficient room is available for an additional HTML document when a user requests access to said additional HTML document and insufficient cache is available to store said additional HTML document in said cache.

2. The cache management system of claim 1 wherein said removal factor is calculated using at least one of a logical and an arithmetic function.

3. The cache management system of claim 1 wherein said removal factor is at least partially based on a number of times that said at least one of said HTML documents was used while it was stored in cache.

4. The cache management system of claim 1 wherein said removal factor is at least partially based on how long since said at least one of said HTML documents was last used.

5.. The cache management system of claim 1 wherein said removal factor is at least partially based on a size of said at least one of said HTML documents.

5. The cache management system of claim 1 wherein said removal factor is at least partially based on a file type of said at least one of said HTML documents.

6. The cache management system of claim 1 wherein said removal factor is at least partially based on a content developer-designated priority for said at least one of said HTML documents.

7. The cache management system of claim 1 wherein said removal factor is calculated by multiplying a first factor by a first weight to generated a first product, a second factor by a second weight to generate a second product, and an n^th factor by an n^th weight to generate an n^th product.

11. The cache management system of claim 1 wherein said cache manager employs a lookup table when calculating said removal factors.

12. The cache management system of claim 1 further comprising:

a table that is accessible by said cache manager, that is stored in memory of said set top box and that arranges said HTML documents in an ordered list based on said removal factors.

13. The cache management system of claim 1, wherein said cache manager employs a threshold when removing said HTML documents from said cache to create room for said additional HTML document when said user requests access to said additional HTML document and insufficient cache is available to store said additional HTML document.

15. The cache management system of claim 1 wherein said cache manager continues to remove said HTML documents until available system memory is above a threshold.

8. The cache management system of claim 8 wherein said first, second and nth products are summed.

9. The cache management system of claim 9 wherein said first, second and n^th products are normalized prior to being summed.

10. The cache management system of claim 9 wherein said first factor is normalized prior to being multiplied by said first weight.

14. The cache management system of claim 14, wherein said cache manager continues to remove said HTML documents until a predetermined extra amount of said cache is available.

16. A method for managing a cache in a set top box to improve the loading speed of hypertext markup language (HTML) documents that are provided by web servers through a distributed communications system, comprising the steps of:

storing a plurality of HTML documents in said cache;

calculating a removal factor for each of said HTML documents, wherein said removal factor is at least partially based on whether said at least one of said HTML documents is compressed or decompressed; and

removing at least one of said HTML documents based on its removal factor until sufficient room is available for an additional HTML document when a user requests access to said additional HTML document and insufficient cache is available to store said additional HTML document.

17. The method of claim 17 wherein said removal factor is calculated using at least one of an arithmetic function and a logical function.

18. The method of claim 17 wherein said removal factor is at least partially based on a number of times that said at least one of said HTML documents was used.

19. The method of claim 17 wherein said removal factor is at least partially based on how long since said at least one of said HTML documents was last used.

20. The method of claim 17 wherein said removal factor is at least partially based on a size of said at least one of said HTML documents.

21. The method of claim 17 wherein said removal factor is at least partially based on a file type of said at least one of said HTML documents.

22. The method of claim 17 wherein said removal factor is at least partially based on a content developer-designated priority for said at least one of said HTML documents.

23. The method of claim 17 wherein said step of calculating said removal factors includes the steps of:

multiplying a first factor by a first weight to generated a first product;

multiplying a second factor by a second weight to generate a second product; and

multiplying an n^th factor by an n^th weight to generate an n^th product.

25. The method of claim 20 wherein said step of calculating said removal factors includes the step of:

normalizing said first, second and third products prior to said summing step.

27. The method of claim 17 wherein said step of calculating includes the step of:

using a lookup table.

28. The method of claim 17, further comprising the steps of:

employing a threshold when removing said HTML documents from said cache to create room for said additional HTML document when said user requests access to said additional HTML document and insufficient cache is available to store said additional HTML document.

30. The method of claim 17 further comprising the step of:

removing said HTML documents until available system memory is above a threshold.

31. The method of claim 17 further comprising the step of:

removing preloaded HTML documents that are related to said at least one of said HTML documents that is removed based on its removal factor.

24. The method of claim 24 wherein said step of calculating said removal factors includes the step of:

summing said first, second and n^th products.

26. The method of claim 24 wherein said first factor is normalized prior to being multiplied by said first weight.

29. The method of claim 29, further comprising the step of:

continuing to remove said HTML documents until a predetermined extra amount of said cache is available.