File management system for use in an optical data storage system

A method for writing data to an optical disk of an optical data storage system in which files of information data are written to indexed locations of an information data region and directory data is written to indexed locations of a directory data region, including:

• associating each file of information data with a subdirectory;
• writing a group of one or more files of information data to an information region;
• writing a current subdirectory record including data representative of a location, within an information region, of each file of information data associated with the subdirectory to which the just written group of files are associated, after the group of files are written;
• writing a current root record including data representative of a location within a directory data region of each current subdirectory record;
• and
• repeating the above steps of each group of one or more files of information data to be written to the optical disk.

A method for writing files of information data and directory data to an optical disk of the type having a plurality of consecutive addressed sectors, including:

• associating each file of information data to be written to the disk with a subdirectory;
• reserving a first directory region on the disk having a predetermined number of consecutive sectors;
• writing a group of one or more files of information data to consecutive sectors of a first information region on the disk adjacent the first directory region;
• writing, to consecutive sectors of the first directory region, a current subdirectory record including data representative of a location within an information region of each file of information data associated with the subdirectory to which the just-written group of files are associated;
• writing, to consecutive sectors in the first directory region, a current root record including data representative of a location within a directory region of each current subdirectory record;
• repeating the steps of writing files to the first information region, writing a current subdirectory record to the first directory region, and writing a current root record to the first directory region, until the first directory region is filled with directory data;
• reserving a second directory region having a predetermined number of consecutive sectors adjacent the first information region;
• writing a group of one or more files of information data to consecutive sectors of a second information region adjacent the second directory region;
• writing, to consecutive sectors of the second directory region, a current subdirectory record including data representative of a location within an information region of each file of information data associated with the subdirectory to which the just-written group of files are associated;
• writing, to consecutive sectors of the second directory directory region, a current root record including data representative of a location within a directory region of each current subdirectory record;
• repeating the steps of writing files to the second information region, writing a current subdirectory record to the second directory region, and writing a current root record to the second directory region, until the second directory region is filled with directory data;
• and
• repeating the above steps in third and subsequent directory regions and information regions for additional groups of one or more files of information data to be written to the optical disk.

For use in conjunction with an optical data storage system of the type in which files of information data written to an optical disk are associated with a subdirectory and written to one of a plurality of information regions radially interleaved on the disk with a plurality of directory regions, the directory regions having, for each group of one or more just-written files, a subdirectory record including data representative of a location within an information region of each file of information data associated with the subdirectory to which the just-written group of files was associated, a current root record including data representative of a location within a directory region of each current subdirectory record, and ending with a trailer including data representative of a beginning location of a next directory region, a method of accessing and reading a desired file of information data, including:

• locating a most current directory region;
• locating a most recently written root record in the most current directory region;
• searching the root record and identifying data representative of the location of the subdirectory record of the subdirectory with which the desired file is associated;
• accessing the subdirectory record as a function of the data representative of its location identified while searching the root record;
• searching the subdirectory record and identifying data representative of the location of the desired file;
• accessing the file as a function of the data representative of its location identified while searching the subdirectory record;
• and
• reading the file of data.