System and methods for improved file management in a multi-user environment

A multi-client data processing system comprising:

• a server computer storing a plurality of files as a plurality of logical files stored in a single physical file, said physical file residing as a single disk file on a storage device of said server computer, each logical file being stored as a contiguous sequence of uniform storage blocks in the physical file, said physical file including a directory describing each logical file stored within the physical file;
• a client computer capable of generating a first request from a client for information from a particular logical file;
• means, responsive to said first request, for determining from said directory where said logical file is located in said physical file, said means storing at the client computer information comprising a pointer describing that location, so that a subsequent request for the logical lock file can be satisfied without the directory;
• means for receiving a second request from another client computer requesting storage of new information in the logical file, said new information causing overflow of the logical file;
• means, responsive to said second request, for storing the new information by:
• (i) appending to one end of the physical file a sufficient number of new uniform storage blocks for storing the new information,
• (ii) storing information for the logical lock file together with the new information being added in said new uniform storage blocks,
• (iii) marking storage block which previously comprised the logical file as invalid, and
• (iv) storing with the invalidated storage blocks a pointer which points to said storage blocks being appended to said physical file;
• and
• means for updating the pointer stored at the client computer to reference a location in the physical file where the new storage blocks have been appended, as each client requests access to information stored in the logical file.