Method for caching information between work sessions

• US 6,598,125 B2
• Filed: 05/25/2001
• Issued: 07/22/2003
• Est. Priority Date: 05/25/2000
• Status: Expired due to Fees

• Current Assignee: Exent Technologies Incorporated
• Original Assignee: Exent Technologies Incorporated
• Inventors: Romm, Amnon
• Primary Examiner(s): Yoo, Do Hyun
• Assistant Examiner(s): MOAZZAMI, NASSER G
• Application Number:
  US09/866,509
• Publication Number:
  US 20020091901A1
• Time in Patent Office: 788 Days
• Field of Search: 711/129-136, 711/147-159, 711/170-173, 345/557, 709/203, 709/213-226
• US Class Current: 711/133
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 12/121 using replacement algorithms
• CPC Class Codes: G06F 12/122 of the least frequently used [LFU] type, e.g. with individual count value

Abstract

A method of caching information between work sessions for future use is described. The method efficiently determines those blocks of information least likely to be required for future use and preferentially discards such blocks from the cache when additional cache storage space is needed. The method also provides for the dynamic allocation of cache space between work sessions of different content.

Claims

1. A method for caching blocks of information for content utilized by a client computer in an active work session and one or more previous work sessions, the method comprising:

a) caching blocks of information in allocated storage space on a hard drive of the client computer;

b) storing, for each block of information, a first parameter corresponding to when the block of information was accessed by the active work session, and a second parameter corresponding to the number of times the block of information was accessed by the client computer in the one or more previous work sessions;

c) determining a discard priority value for each block of information using the first parameter and the second parameter; and

d) discarding stored blocks of information from the storage space based upon their discard priority value to create additional room for new blocks of information in the storage space.

2. The method of claim 1 wherein step a) further comprises dynamically allocating storage space or the hard drive of the client computer.

3. The method of claim 1 wherein step a) further comprises dynamically allocating storage space on the hard drive of the client computer by reassigning storage space from a cache of an inactive work session to a cache of the active work session.

4. The method of claim 1 wherein step a) further comprises dynamically allocating storage space on the hard drive of the client computer by reassigning storage space from a cache of the active work session to a cache of another active work session.

5. The method of claim 1 further comprising e) changing the size of the allocated storage space for a cache of any of the work sessions.

6. The method of claim 1 further comprising e) reducing the size of the allocated storage space for a cache of any of the work sessions by discarding blocks of information based upon their discard priority values.

7. The method of claim 1 further comprising:

e) retaining cached blocks of information at the end of a work session for use in a subsequent work session.

8. The method of claim 1 wherein step b) further comprises determining the second parameter for each block of information based on at least one of the number of times the block has been accessed during the active work session, the number of times the block was accessed in a prior work session, or the number of times the block was accessed in a plurality of prior work sessions.

9. The method of claim 1 wherein step b) further comprises determining the second parameter for each block of information based on at least one of the number of times the block has been accessed during the active work session, the number of times the block was accessed in a prior work session, or the number of times the block was accessed in a plurality of prior work sessions, and step c) further comprises determining the discard priority value for each block of information based on at least one of the second parameter or a number of access cycles of the cache since which the block of information has been used.

10. A method for caching blocks of information on the hard drive of a client computer, the method comprising:

a) allocating storage space on a hard drive of the client computer for each active work session;

b) caching the blocks of information for each active work session in the allocated storage space;

c) storing, for each block of information, a first parameter corresponding to the number of times the block of information has been accessed by the client computer;

d) determining a discard priority value for each block of information using the first parameter;

e) discarding stored blocks of information from the storage space of each work session based upon their discard priority value, to provide additional storage space for new blocks of information for each such active work session on the hard drive of the client computer.

11. The method of claim 10 wherein step e) further comprises discarding stored blocks of information from the storage space of an inactive work session.

12. The method of claim 10 wherein step e) further comprises discarding stored blocks of information from the storage space of another active work session.

13. The method of claim 10 further comprising:

f) retaining cached blocks of information at the end of a work session for use in a subsequent work session.

14. The method of claim 10 further comprising f) changing the size of the allocated storage space for one of the active work sessions.

15. The method of claim 10 further comprising f) reducing the size of the allocated storage space for one of the active work sessions by discarding blocks of information based upon their discard priority values.

16. The method of claim 10 wherein step c) further comprises determining the first parameter for each block of information based on at least one of the number of times the block has been accessed during the current work session, the number of times the block was accessed in a prior work session, or the number of times the block was accessed in a plurality of prior work sessions.

17. The method of claim 10 wherein step c) further comprises determining the first parameter for each block of information based on at least one of the number of times the block has been accessed during the current work session, the number of times the block was accessed in a prior work session, or the number of times the block was accessed in a plurality of prior work sessions, and step d) further comprises determining the discard priority value for each block of information based on at least one of the first parameter or a number of access cycles of the cache since which the block of information has been used.

18. A method for caching blocks of information for content utilized by a client computer in an active work session and one or more previous work sessions, the method comprising:

a) caching blocks of information in allocated storage space on the client computer;

b) storing, for each block of information, a first parameter corresponding to when the block of information was accessed by the active work session, and a second parameter corresponding to the number of times the block of information was accessed by the client computer in the one or more previous work sessions;

c) determining a discard priority value for each block of information using the second parameter; and

d) discarding stored blocks of information from the storage space based upon their discard priority value to create additional room for new blocks of information in the storage space.

19. The method of claim 18 wherein step a) further comprises dynamically allocating the storage space, and step b) further comprises determining the second parameter for each block of information based on at least one of the number of times the block has been accessed during the active work session, the number of times the block was accessed in a prior work session, or the number of times the block was accessed in a plurality of prior work sessions.

20. The method of claim 18 wherein step a) further comprises dynamically allocating the storage space, step b) further comprises determining the second parameter for each block of information based on at least one of the number of times the block has been accessed during the active work session, the number of times the block was accessed in a prior work session, or the number of times the block was accessed in a plurality of prior work sessions, and step c) further comprises determining the discard priority value for each block of information based on at least one of the first parameter or a number of access cycles of the cache since which the block of information has been used.