Dynamic network cache directories

• US 6,272,593 B1
• Filed: 04/10/1998
• Issued: 08/07/2001
• Est. Priority Date: 04/10/1998
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Dujari, Rajeev
• Primary Examiner(s): Yoo, Do Hyun
• Assistant Examiner(s): GOODARZI, NASSER MOAZZAMI
• Application Number:
  US09/058,982
• Time in Patent Office: 1,215 Days
• Field of Search: 711/118, 711/205, 711/158, 711/163, 713/200-201, 707/10
• US Class Current: 711/118
• CPC Class Codes: G06F 21/51 at application loading time, e.g. accepting, rejecting, starting or inhibiting executable software based on integrity or source reliability
• CPC Class Codes: Y10S 707/99937 Sorting
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system and method for virtually eliminating a potential security risk inherent with the caching of network content. Random subdirectory names are generated for cache directories, while continuing to generate user-friendly file names. Security is achieved since malicious sites cannot guess the cache location, which if guessed along with the filename, could cause a user connected to the site to inadvertently execute malicious content downloaded by the site to the cache. In addition to generating random subdirectory names, the system and method provide enhanced performance by balancing the number of files among the cache directories, and by limiting the number of files in any cache directory by creating additional cache directories as needed.

Claims

1. In a computer system, a method of storing content in a cache, the method comprising:

generating at least one subdirectory name that is random, wherein said at least one subdirectory name is highly unlikely to be guessed by a site remote to the system;

for each random subdirectory name, creating a randomly-named cache directory corresponding to a cache based on the random subdirectory name;

downloading content from a server;

determining a predictable filename for the downloaded content; and

storing the content as a file named with the predictable filename in at least one randomly-named cache directory.

2. The method of claim 1 wherein at least two random subdirectory names are generated, providing a plurality of randomly-named cache directories.

3. The method of claim 1 further comprising maintaining an indexed table including each random subdirectory name therein.

4. The method of claim 2 further comprising downloading content from a plurality of network servers, and balancing the storing of the content among each of the randomly-named cache directories corresponding to a cache.

5. The method of claim 4 wherein balancing the storing of the content includes determining which of the randomly-named cache directories has a least number of files therein.

6. The method of claim 5 wherein determining which of the randomly-named cache directories has the least number of files includes maintaining a file count in association with each cache directory, each file count corresponding to a number of files in the cache directory associated therewith.

7. The method of claim 6 wherein maintaining each file count includes storing information in the indexed table that includes each random subdirectory name.

8. The method of claim 5 further comprising comparing a number of files in the cache directory having the least number of files therein against a predetermined threshold value, and based on the comparison, generating at least one additional random subdirectory name, and for each additional random subdirectory name, creating an additional random cache directory based thereon.

9. The method of claim 1 wherein determining a predictable filename for the downloaded content includes converting a server content reference to the predictable filename.

10. The method of claim 9 further comprising

maintaining a table including server content references and filenames converted therefrom.

11. The method of claim 9 further comprising:

maintaining an indexed subdirectory table including each random subdirectory name therein; and

maintaining a table including server content references and corresponding file locations, and wherein the file location associated with each server content reference includes an index to the randomly-named cache directory under which the corresponding file is stored and the filename converted from that reference.

12. The method of claim 1 wherein downloading content from a server comprises accessing a network site.

13. The method of claim 2 wherein creating a randomly-named cache directory includes creating the cache directory as a nested subdirectory based on the at least two random subdirectory names.

24. The method of claim 9 wherein the filename includes a name closely matched to the server content reference.

25. A computer-readable medium having computer-executable instructions for performing the method of claim 1.

14. In a computer system, a system for caching downloaded content in a file of a file system, comprising a random generator, a name-generation mechanism connected to the random generator to generate a subdirectory name that is random, wherein said subdirectory name is highly unlikely to be guessed by a site remote to the system, the name-generation mechanism being connected via an interface to the file system to create a randomly-named cache directory based on the random subdirectory name, and a mechanism configured to determine a predictable filename for the downloaded content and to store the downloaded content as a file with the predictable filename in the randomly-named cache directory of the file system.

15. The system of claim 14 wherein the name-generation mechanism generates at least one other random subdirectory name corresponding to at least one other cache to provide a plurality of random subdirectory names, and wherein the name-generation mechanism creates a randomly-named cache directory for each other random subdirectory name generated thereby, to provide a plurality of randomly-named cache directories.

16. The system of claim 15 further comprising an indexed table including the random subdirectory names therein.

17. The system of claim 15 wherein content is downloaded from a plurality of network servers, and further comprising a balancing mechanism for distributing the content among each of the randomly-named cache directories.

18. The system of claim 17 further comprising an indexed table including the random subdirectory names therein and a count of a number of files in each cache directory, and wherein the balancing mechanism accesses the indexed table to determine which of the cache directories has a least number of files therein and writes at least one file of a server'"'"'s downloaded content into that cache directory.

19. The system of claim 17 wherein the balancing mechanism communicates with the name-generation mechanism to generate at least one additional random subdirectory name, and a cache directory for each additional random subdirectory name.

20. The system of claim 14 further comprising a table of server content references and corresponding file locations each including one of the predictable filenames.

21. The system of claim 14 wherein the name-generation mechanism generates at least two random subdirectory names and creates the randomly-named cache directory based on at least two of the random subdirectory names in a nested relationship.

26. The system of claim 20 wherein the filename includes a name closely matched to the server content reference.

22. In a computer system, a method of caching content downloaded from servers to a plurality of cache directories, the method comprising:

generating a plurality of subdirectory names, wherein each subdirectory name is random and wherein said each subdirectory name is highly unlikely to be guessed by a site remote to the system;

creating a randomly-named cache directory for said each random subdirectory name generated;

downloading content from a plurality of servers;

for each distinctly referenced portion of downloaded content, selecting one of the randomly-named cache directories as a selected cache directory, converting a reference for that content to a predictable filename and storing the content as a file having that filename under the selected cache directory.

23. The method of claim 22 wherein selecting one of the randomly named cache directories includes determining which of the randomly named cache directories has a least number of files therein and selecting that cache directory as the selected cache directory.

27. The method of claim 22 wherein the filename includes a name closely matched to the server content reference.

28. A computer-readable medium having computer-executable instructions for performing the method of claim 22.