System and methods for efficient media delivery using cache
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.
1. A 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:
(i) a content length of a remote media file;
(ii) a predetermined number of M ranges of bytes, M>=2, at respective predetermined offsets relative to the beginning of the remote media file, each range of bytes having a predetermined byte length, such that a sum of all M ranges of bytes is smaller than the content length of the remote media file;
(b) generate a digital signature for the remote media file using bytes from the obtained M ranges of bytes; and
(c) determine a presence of a copy of the remote media file in a cache memory, including interrogating the cache memory with the digital signature, thereby providing efficient caching and retrieving of media files.
2. The cache service module of claim 1 , wherein the M ranges of bytes are not overlapping and are not adjacent.
3. 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.
4. The cache service module of claim 1 , wherein the offsets are specified as proportions of the content length of the remote media file.
5. The cache service module of claim 1 , wherein a different number of bytes is specified for at least some ranges of bytes in the M ranges of bytes.
6. The cache service module of claim 1 , wherein the same number of bytes is specified for each byte range in the M ranges of bytes.
7. 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.
8. The cache service module of claim 1 , wherein the computer readable instructions further cause the processor to obtain and store the copy of the remote media file along with the digital signature in the cache memory upon a number of requests from media client devices for the remote media file exceeding a predetermined threshold.
9. The cache service module of claim 1 , wherein the computer readable instructions further cause the processor to store only the digital signature in the cache memory, provided a number of requests from media client devices for the remote media file is below a predetermined threshold.
10. A system for caching media files, comprising:
at least one processor;
a non-transitory computer readable storage medium having computer readable instructions stored thereon for execution by the at least one processor, causing the at least one processor to:
(a) obtain:
(i) a content length of a remote media file;
(ii) a predetermined number of M ranges of bytes, M>=2, at respective predetermined offsets relative to the beginning of the remote media file, each range of bytes having a predetermined byte length, such that a sum of all M ranges of bytes is smaller than the content length of the remote media file;
(b) generate a digital signature for the remote media file using bytes from the obtained M ranges of bytes; and
(c) determine a presence of a copy of the remote media file in a cache memory, including interrogating the cache memory with the digital signature, thereby providing efficient caching and retrieving of media files.
11. The system of claim 10 , further comprising the cache memory for storing the copy of the remote media file.
12. The system of claim 10 , wherein the M ranges of bytes are not overlapping and not adjacent.
13. The system of claim 10 , wherein the offsets are specified as proportions of the content length of the remote media file.
14. The system of claim 10 , wherein a different number of bytes is specified for at least some ranges of bytes in the M ranges of bytes.
15. A method for caching media files, comprising:
employing at least one processor for:
(a) obtaining:
(i) a content length of a remote media file;
(ii) a predetermined number of M ranges of bytes, M>=2, at respective predetermined offsets relative to the beginning of the remote media file, each range of bytes having a predetermined byte length, such that a sum of all M ranges of bytes is smaller than the content length of the remote media file;
(b) generating a digital signature for the remote media file using bytes from the obtained M ranges of bytes; and
(c) determining a presence of a copy of the remote media file in a cache memory, including interrogating the cache memory with the digital signature, thereby providing efficient caching and retrieving of media files.
16. The method of claim 15 , wherein the M ranges of bytes are not overlapping and not adjacent.
17. The method of claim 15 , wherein the offsets are specified as proportions of the content length of the remote media file.
18. The method of claim 15 , wherein a different number of bytes is specified for at least some ranges of bytes in the M ranges of bytes.
19. The method of claim 15 , further comprising, obtaining and storing the copy of the remote media file in the cache memory, upon a number of requests for the remote media file exceeding a predetermined threshold.
20. The method of claim 15 , further comprising storing only the digital signature in the cache memory, provided a number of requests from media client devices for the remote media file is below a predetermined threshold.