System and method for controlling the upload of data already accessible to a server

A system for controlling an upload of a block of data associated with an upload command, the system comprising:

• one or more processors;
• and
• a machine-readable medium comprising instructions stored therein, which when executed by the one or more processors, cause the one or more processors to perform operations comprising:
• beginning reception of the block of data associated with the upload;
• obtaining a first hash value for the block of data associated with the upload command;
• comparing the first hash value for the block of data associated with the upload command to a plurality of hash values for blocks of data previously uploaded to the server, wherein each hash value in the plurality of hash values is associated with a reference to a block of data previously uploaded to the server, and wherein the comparing is performed after the beginning of the reception of the block of data associated with the upload and prior to completing the reception of the block of data associated with the upload command;
• and
• allowing the reception of the block of data associated with the upload command to complete if the first hash value for the block of data associated with the upload command does not match any of the plurality of hash values for blocks of data previously uploaded to the server.

A non-transitory machine-readable medium comprising instructions stored therein, which when executed by a machine, cause the machine to perform operations comprising:

• beginning reception of the block of data associated with the upload;
• obtaining a first hash value for a file associated with an upload command;
• comparing, using a processor, the first hash value for the file associated with the upload command to a listing of hash values in an index storing hash values identifying files previously uploaded to a server and references to locations of the files previously uploaded to the server, wherein the comparing is performed after the beginning of the reception of the block of data associated with the upload and prior to completing the reception of the file associated with the upload command;
• and
• completing the reception of the file associated with the upload command if the first hash value for the file associated with the upload command does not match any hash value in the index.