SYSTEM AND METHODS FOR EFFICIENT MEDIA DELIVERY USING CACHE

• US 20130311596A1
• Filed: 07/25/2013
• Published: 11/21/2013
• Est. Priority Date: 12/01/2009
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Vantrix Corporation
• Inventors: COURTEMANCHE, Marc, MAYRAND, Jean
• Granted Patent: US 10,097,463 B2
• Time in Patent Office: Days
• US Class Current: 709/216
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/2895 Intermediate processing functionally located close to the data provider application, e.g. reverse proxies
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

To improve the efficiency of media delivery over the Internet, a system and a method are provided for caching remote media files and retrieving cached media files, comprising hardware and software modules as well as steps for storing a remote media file into the cache and retrieving the cached media file based on a signature created by hashing only discrete parts of the media file. The signature is a key for finding the cached media files in the cache upon subsequent requests for the same media file, even if it is received from a different internet location. Media files may be adapted to the characteristics of different media clients, and adapted media files may be equally cached.

Claims

1. A cache service module, determining a presence of a media file in a cache, the media file being a copy of a remote media file stored at a remote media source, the cache service module comprising:

a non-transitory computer readable storage medium having computer readable instructions stored thereon for execution by a processor, causing the processor to;

(a) obtain, from the remote media source;

(i) a content length of the remote media file;

(ii) M ranges of bytes, M>

=2, at respective offsets relative to the beginning of the remote media file, such that;

a number M of the ranges of bytes being variable for different remote media files, and being dynamically defined depending on the content length of the remote media file; and

a sum of all M ranges of bytes being less than the content length of the remote media file;

(b) generate a digital signature for the media file using bytes from the obtained M ranges of bytes; and

(c) determine the presence of the media file in the cache, including interrogating the cache with the digital signature for the media file.

2. The cache service module of claim 1, wherein the M ranges of bytes are not overlapping.

3. The cache service module of claim 1, wherein the M ranges of bytes are not adjacent to each other.

4. The cache service module of claim 1, wherein the sum of all M ranges of bytes is substantially less than the content length of the remote media file.

5. The cache service module of claim 4, wherein the sum of all M ranges is less than 1% of the content length of the remote media file.

6. The cache service module of claim 1, wherein a first range of bytes is obtained at an offset of zero relative to the beginning of the remote media file.

7. The cache service module of claim 1, wherein the offsets are specified as proportions of the content length of the remote media file.

8. The cache service module of claim 1, wherein a variable number of bytes is specified for at least some ranges of bytes in the M ranges of bytes.

9. The cache service module of claim 1, wherein a fixed number of bytes is specified for each byte range in the M ranges of bytes.

10. The cache service module of claim 1, wherein the computer readable instructions further cause the processor to concatenate all bytes in the M ranges of bytes into a string of bytes, and generate the digital signature using the string of bytes.

11. The cache service module of claim 1, wherein, provided the media file is absent in the cache, the computer readable instructions further cause the processor to obtain a complete media file from the remote media source and store the media file in the cache along with the digital signature.

12. The cache service module of claim 11, wherein the computer readable instructions further cause the processor to obtain and store the complete media file along with the digital signature only upon a number of media requests from media client devices for the media file exceeding a predetermined threshold, otherwise store only the digital signature.

13. A system for caching a media file, the system comprising:

a cache, comprising a non-transitory computer readable storage medium, for storing a media file, which is a copy of a remote media file stored at a remote media source; and

a cache server comprising a cache service module for determining a presence of the media file in the cache, the cache service module comprising;

a non-transitory computer readable storage medium having computer readable instructions stored thereon for execution by a processor, causing the processor to;

(a) obtain, from the remote media source;

(i) a content length of the remote media file;

(ii) M ranges of bytes, M>

=2, at respective offsets relative to the beginning of the remote media file, such that;

a number M of the ranges of bytes being variable for different remote media files, and being dynamically defined depending on the content length of the remote media file; and

a sum of all M ranges of bytes being less than the content length of the remote media file;

(b) generate a digital signature for the media file using bytes from the obtained M ranges of bytes; and

(c) determine the presence of the media file in the cache, including interrogating the cache with the digital signature for the media file.

14. The system of claim 13, wherein the M ranges of bytes are not overlapping and not adjacent.

15. The system of claim 13, wherein the offsets are specified as proportions of the content length of the remote media file.

16. The system of claim 13, wherein a variable number of bytes is specified for at least some ranges of bytes in the M ranges of bytes.

17. The system of claim 13, wherein, provided the media file is absent in the cache, the computer readable instructions further cause the processor to obtain a complete media file from the remote media source and store the media file in the cache along with the digital signature, upon a number of media requests from media client devices for the media file exceeding a predetermined threshold.

18. A method for caching a media file, which is a copy of a remote media file stored at a remote media source, the method comprising:

(a) obtaining, from the remote media source;

(i) a content length of the remote media file;

(ii) M ranges of bytes, M>

=2, at respective offsets relative to the beginning of the remote media file, such that;

a number M of the ranges of bytes being variable for different remote media files, and being dynamically defined depending on the content length of the remote media file; and

a sum of all M ranges of bytes being less than the content length of the remote media file;

(b) generating a digital signature for the media file using bytes from the obtained M ranges of bytes; and

(c) determining the presence of the media file in the cache, including interrogating the cache with the digital signature for the media file.

19. The method of claim 18, wherein the M ranges of bytes are not overlapping and not adjacent.

20. The method of claim 18, wherein the offsets are specified as proportions of the content length of the remote media file.

21. The method of claim 18, wherein a variable number of bytes is specified for at least some ranges of bytes in the M ranges of bytes.

22. The method of claim 18, further comprising, provided the media file is absent in the cache, obtaining a complete media file from the remote media source and storing the media file in the cache along with the digital signature, upon a number of media requests from media client devices for the media file exceeding a predetermined threshold.