Read-write access in a read-only environment

摘要

In one example, a method for processing data includes receiving a request to perform an operation concerning stored data that is ‘read only’ data. The request includes one or more data blocks, and has an offset and an end. Next, a data structure is created that is a representation of the stored ‘read only’ data with which the request is concerned, and the data structure includes data blocks. Finally, the requested operation is performed with respect to the data blocks of the data structure, but without modification of the stored ‘read only’ data to which those data blocks correspond.

主权项

1. A method for processing data, the method comprising:
receiving a request concerning stored data that is ‘read only’ data, the request including one or more data blocks, and the request having an offset and an end, wherein the request comprises a request to perform an operation relating to the stored ‘read only’ data; creating a data structure that is a representation of the stored ‘read only’ data with which the request is concerned, wherein the data structure includes data blocks; and; performing the requested operation with respect to the data blocks of the data structure, wherein the requested operation is performed without modifying the stored ‘read only’ data, wherein the requested operation is one of a view operation, a read operation, a write operation, a testing operation, or a delete operation, and when the requested operation is a write operation, the write operation comprises: examining the data structure and identifying an offset of a leading data block residing in the data structure; and calculating a last position of the leading data block, and either; storing the one or more data blocks of the write request in the data structure, if the last position of the leading data block is less than the offset of the write request; or merging the one or more data blocks of the write request with the leading data block to produce a defragmented merged data block and then storing the defragmented merged data block in the data structure, id the last position of the leading data block is equal to or greater than the offset of the write request.