Method and apparatus for serving files from a mainframe to one or more clients
AssigneeSerena Software, Inc.
InventorsBruce Engle, Kevin Parker
Life of this patent
Estimating the term…
Abstract
A method and apparatus provides random access to mainframe files that are accessed using an operating system that does not provide random access. This allows a computer system such as a mainframe on which random access is not supported to act as a file server for a computer system on which random access is supported without requiring the entire file to be downloaded to the client computer system.
Claims23
A method of providing access to a file stored on a mainframe, the method comprising:
- receiving from a client computer system a request to provide access to a file stored on the mainframe computer system, the request comprising an offset, the offset capable of identifying a position in the file other than a block boundary;
- retrieving at least a first portion of the file using an operating system that allows access to the file solely starting on block boundaries;
- and
- providing access to at least a second portion of the file at the position.
A computer program product comprising a computer useable medium having computer readable program code embodied therein for providing access to a file stored on a mainframe, the computer program product comprising:
- computer readable program code devices configured to cause a computer to receive from a client computer system a request to provide access to a file stored on the mainframe computer system, the request comprising an offset, the offset capable of identifying a position in the file other than a block boundary;
- computer readable program code devices configured to cause a computer to retrieve at least a first portion of the file using an operating system that allows access to the file solely starting on block boundaries;
- and
- computer readable program code devices configured to cause a computer to provide access to at least a second portion of the file at the position.
An apparatus for providing random access to a file stored in a mainframe computer system, the apparatus comprising
- a mainframe accessor having a first input/output operatively coupled for receiving a file access request for a mainframe file stored using an operating system that allows access to the file only on block boundaries, the request comprising an offset capable of identifying a position in the file other than a block boundary, the mainframe accessor for providing an identifier of the mainframe file at a mainframe accessor second input/output responsive to the request received at the mainframe accessor first input/output, for retrieving at a third input/output at least a portion of the mainframe file responsive to the request received at the first input/output, and for providing at the first input/output the portion of the mainframe file received at the mainframe accessor third input/output;
- a formatter having a first input/output coupled to the mainframe accessor second input/output for receiving the identifier of the mainframe file and the set of conversion information, the formatter for requesting and receiving at a second input/output at least a first portion of the mainframe file, and for providing to an output a second portion of the mainframe file corresponding to the at least a portion of the mainframe file received at the formatter second input/output;
- and
- a cache having an input/output coupled to the formatter output for receiving the at least the second portion of the mainframe file and coupled to the mainframe accessor third input/output for receiving the request and providing a third portion of the mainframe file responsive to the request.
Dependencies are inferred from the claim text.