Removable storage data hash

Patent metadata

Field	Value
Publication number	US-2016292173-A1
Application number	US-201315035443-A
Country	US
Kind code	A1
Filing date	Nov 20, 2013
Priority date	Nov 20, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

A media server in accordance with an example may include a reader, a hash checker, a database manager, and a server. The reader may read data from a removable storage. The hash checker may calculated a calculated hash value and determine if it is equal to a saved hash value. If the calculated hash value is equal to or does not equal the saved hash value, the database manager may retrieve a saved database or generate a generated database. The server may serve the saved database or the generated database.

First claim

1 . A media server, comprising:
a reader to read data from a removable storage; a hash checker to calculate a calculated hash value using the data and to determine if the calculated hash value equals a saved hash value; and a database manager to:
retrieve a saved database if the calculated hash value equals the saved hash value; and
generate a generated database if the calculated hash value does not equal the saved hash value; and
a server to serve the saved database or the generated database.

2 . The media server of claim 1 , wherein:
the reader is to read an identification from the removable storage; and the hash checker is to use the identification to identify the saved hash value.

3 . The media server of claim 1 , wherein:
the hash checker is to save the calculated hash value as the saved hash value if the calculated hash value is not equal to the saved hash value.

4 . The media server of claim 1 , wherein:
the database manager is to save the generated database associated with the calculated hash value.

5 . A method, comprising:
a media server obtaining data from a removable storage; the media server using the data as an argument in a hash function to obtain a calculated hash value; the media server comparing the calculated hash value to a saved hash value; if the calculated hash value equals the saved hash value, the media server providing a saved database to serve media files stored on the removable storage; and if the calculated hash value does not equal the saved hash value, the media server generating a generated database and providing the generating database.

6 . The method of claim 5 , wherein the data comprises a file system structure.

7 . The method of claim 5 , wherein the data comprises a plurality of file systems structures.

8 . The method of claim 5 , further comprising:
obtaining the saved hash value using an identifier stored on the removable storage.

9 . The method of claim 5 , further comprising:
the media server obtaining a file system structure; the media server apportioning the file system structure into a plurality of file system portions, the data being one of the file system portions; the media server determining a calculated portion hash value for each file system portion, the calculated hash value being one of the calculated portion hash values; for calculated portion hash values equal to corresponding saved portion hash values, the media server providing saved databases; and for calculated portion hash values not equal to corresponding saved portion hash values, the media server generating generated databases and providing the generated databases.

10 . The method of claim 5 , wherein the data comprises a portion of a file system structure, and the method further comprising:
if the calculated hash value does not equal the saved hash value, the media server determining files corresponding to the portion of the file structure and generating the generated database for the files.

11 . A non-transitory computer readable medium storing instructions executable by a processor to:
retrieve a file system structure from a removable storage; hash the file system structure to calculate a calculated hash value; determine whether the calculated hash value equals a saved hash value; if the calculated hash value equals the saved hash value, provide a saved database corresponding to the saved hash value; and if the calculated hash value differs from the saved hash value,
generate a generated database from contents of the removable storage, and
provide the generated database.

12 . The non-transitory computer readable medium of claim 11 storing further instructions executable by the processor to:
if the calculated hash value differs from the saved hash value, store the calculated hash value as the saved hash value and store the generated database as the saved database.

13 . The non-transitory computer readable medium of claim 11 storing further instructions executable by the processor to:
retrieve an identification from the removable storage; and
obtain the saved hash value using the identification.

14 . The non-transitory computer readable medium of claim 11 storing further instructions executable by the processor to:
hash the file system structure by partitioning the file system structure into a plurality of file system partitions and hashing each of the file system partitions to calculate a plurality of calculated hash values, the calculated hash value being one of the plurality.

15 . The non-transitory computer readable medium of claim 14 storing further instructions executable by the processor to:
for each respective calculated hash value of the plurality equal to a corresponding saved hash value, provide a saved database corresponding to the respective calculated hash value; and
for each respective calculated hash value of the plurality not equal to any corresponding saved hash value, generate a corresponding generated database and provide the corresponding generated database.

Assignees

• Hewlett Packard Development Co

Inventors

• Hanes David H

Classifications

• G06F16/152

  using file content signatures, e.g. hash values · CPC title

• G06F16/172

  Caching, prefetching or hoarding of files · CPC title

• G06F16/2255

  Hash tables · CPC title

• G06F16/137 Primary

  Hash-based (content-based indexing of textual data G06F16/31) · CPC title

• G06F17/30109

  Physics · mapped topic