SYSTEMS AND METHODS FOR IDENTIFYING LONG MATCHES OF DATA IN A COMPRESSION HISTORY

• US 20120300993A1
• Filed: 08/06/2012
• Published: 11/29/2012
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: PLAMONDON, ROBERT
• Granted Patent: US 8,832,300 B2
• Time in Patent Office: Days
• US Class Current: 382/124
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC

Abstract

Systems and methods of storing previously transmitted data and using it to reduce bandwidth usage and accelerate future communications are described. By using algorithms to identify long compression history matches, a network device may improve compression efficiently and speed. A network device may also use application specific parsing to improve the length and number of compression history matches. Further, by sharing compression histories, compression history indexes and caches across multiple devices, devices can utilize data previously transmitted to other devices to compress network traffic. Any combination of the systems and methods may be used to efficiently find long matches to stored data, synchronize the storage of previously sent data, and share previously sent data among one or more other devices.

Claims

1. A method for matching fingerprints of data from network traffic to an index of fingerprints identifying locations of stored data in a compression history, the method comprising:

(a) storing, by a device intermediary to a plurality of clients and a plurality of servers, data from network traffic communicated between the plurality of clients and the plurality of servers in a plurality of storage locations of a compression history, the device establishing a compression index comprising indexes of fingerprints of data stored in the plurality of storage locations of the compression history;

(b) identifying, by the device, that a fingerprint of data received via network traffic between a client and a server matches a plurality of indexes in the compression index, each index of the plurality of indexes identifying one or more storage location identifiers corresponding to a storage location of the plurality of storage locations of the compression history; and

(c) selecting, by the device from the plurality of matching entries, a matching entry having a number of storage location identifiers less than one or more other matching entries from the plurality of matching entries; and

(d) compressing, by the device, the received data using data stored at a storage location identified by the selected matching entry.

2. The method of claim 1, wherein step (a) further comprises storing, by the device, with each index in the compression index a count of a number of storage location identifiers having matching fingerprints.

3. The method of claim 1, wherein step (a) further comprises establishing, by the device, a portion of the compression index based on fingerprints taken from a plurality of overlapping shingles.

4. The method of claim 1, wherein step (b) further comprises identifying, by the device, that a plurality of fingerprints corresponding to a successive overlapping shingle of data match the plurality of indexes.

5. The method of claim 1, wherein step (c) further comprises selecting, by the device, the matching entry having a single storage location identifier.

6. The method of claim 1, wherein step (c) further comprises selecting, by the device, the matching entry from the plurality of matching entries having the least number of storage location identifiers.

7. The method of claim 1, wherein step (d) further comprises using, by the device for compression, data stored at a storage location identified by a storage location identifier of the one or more storage location identifiers corresponding to the selected matching entry.

8. The method of claim 1, further comprising compressing, by the device, the received data using data stored in a second storage location subsequent to the storage location identified by a storage location identifier of the selected matching entry.

9. The method of claim 1, further comprising determining, by the device, a total length of a match of the received data to the compression history by performing an expansion of the match across one or more storage locations subsequent to the storage location identified by a storage location identifier of the selected matching entry.

10. The method of claim 1, further comprising transmitting, by the device, the compressed received data to a second device intermediary to the device and one of the client or the server.

11. A system for matching fingerprints of data from network traffic to an index of fingerprints identifying locations of stored data in a compression history, the system comprising:

a compression history comprising a plurality of storage locations;

a compression index comprising indexes of fingerprints of data stored in the plurality of storage locations of the compression history, each index of the plurality of indexes identifying one or more storage location identifiers corresponding to a storage location of the plurality of storage locations of the compression history;

a device intermediary to a plurality of clients and a plurality of servers storing data received from network traffic between the plurality of clients and the plurality of servers to the compression history;

a compression engine identifying that a fingerprint of data received via network traffic between a client and a server matches a plurality of indexes in the compression index and selecting from the plurality of matching entries, a matching entry having a number of storage location identifiers less than one or more other matching entries from the plurality of matching entries; and

wherein the compression engine compresses the received data using data stored at a storage location identified by the selected matching entry.

12. The system of claim 11, wherein each index in the compression index stores a count of a number of storage location identifiers having matching fingerprints.

13. The system of claim 11, wherein a portion of the compression index is based on fingerprints taken from a plurality of overlapping shingles.

14. The system of claim 11, wherein the compression engine identifies that a plurality of fingerprints corresponding to a successive overlapping shingle of data match the plurality of indexes.

15. The system of claim 11, wherein the compression engine selects the matching entry having a single storage location identifier.

16. The system of claim 11, wherein the compression engine selects the matching entry from the plurality of matching entries having the least number of storage location identifiers.

17. The system of claim 11, the compression engine compresses the received data using data stored at storage location identified by a storage location identifier of a plurality of storage location identifiers corresponding to the selected matching entry.

18. The system of claim 11, wherein the compression engine compresses the received data using data stored in a second storage location subsequent to the storage location identified by a storage location identifier of the selected matching entry.

19. The system of claim 11, wherein the compression engine determines a total length of a match of the received data to the compression history by performing an expansion of the match across one or more storage locations subsequent to the storage location identified by a storage location identifier of the selected matching entry.

20. The system of claim 11, further the device transmits the compressed received data to a second device intermediary to the device and one of the client or the server.