Disk driver cluster management of time shift buffer
View Patent ↗A file allocation system for a hard disk drive includes a memory with driver logic and a processor configured with the driver logic to receive a request to allocate hard disk space of a defined size for a buffer file. In some embodiments, the processor is configured with the driver logic to allocate clusters for the buffer file from a plurality of clusters on the hard disk, wherein the clusters for the buffer file store media content instances. In some embodiments, the processor is configured with the driver logic to designate a portion of the clusters of the buffer file for at least one non-buffer file such that the non-buffer file is permitted to share the portion of the clusters of the buffer file with the buffer file.
1. A device driver on a recordable media comprising:
logic configured to allocate clusters for a buffer file for buffer space on a disk and cause media content instances to be written to the buffer space;
logic configured to limit the buffer file to a substantially constant buffer file size, such that when the buffer file approaches a full status, the cluster storing the oldest media content is first deallocated from the buffer file and a new cluster is correspondingly allocated to the buffer file; and
logic configured to maintain the buffer space as substantially constant in size by autonomously and automatically removing the buffer space clusters designated for a permanent recording and replacing the removed buffer space clusters with replacement clusters.
2. The device driver of claim 1 , wherein the buffer space clusters designated for the permanent recording are permitted to be simultaneously shared among the buffer file and a file for the permanent recording.
3. The device driver of claim 1 , wherein the logic is further configured to use a file allocation table.
4. The device driver of claim 3 , wherein the file allocation table includes a first data structure comprising a list of the clusters for each of the files, and a second data structure comprising a list of the clusters located on the disk and a file sharing counter of how many of the files share each of the clusters.
5. The device driver of claim 4 , wherein the logic is further configured to increment the file sharing counter when the number of the files that are shared are increased and decrement the file sharing counter when the number of the files that are shared are decreased.
6. The device driver of claim 1 , wherein the logic is further configured to generate normal play time for each one of the files to track locations in each of the files and to track locations of media content instances.
7. The device driver of claim 1 , wherein the logic is further configured to generate normal play time for write operations and the read operations to the disk.
8. The device driver of claim 1 , wherein the logic is further configured to maintain a file sharing count for the clusters of the buffer file, such that the clusters with the file sharing count greater than one are removed from the buffer file.
9. The device driver of claim 8 , wherein the logic is further configured to find the clusters on a disk that have the file sharing count equal to zero and increment the file sharing count of said clusters to one.
10. The device driver of claim 4 , wherein the file list entries further include the filename for each of the files and the starting and ending sector of each of the files.
11. The device driver of claim 1 , wherein the permanently recorded file can be deleted and the clusters of the deleted permanently recorded file are configured as writeable.