Considered 2 arrays A and B as 2 disks of size 200 and 300 blocks each. But the user gets a view of single disk of size 500 blocks.
- CreateDisk(Id, num_blocks)
to create a smaller disk of size num_blocks with a unique Id within a larger available disk of 500 blocks.
- DeleteDisk(Id)
to delete a disk of given id. This would create a hole in larger disk, leading to fragmentation. Fragmentation has been handled using merging and splitting of blocks.
- readFromDisk(Id, block_no)
read from a disk Id and its block block_no.
- writeToDisk(Id, block_no, block_info)
write to disk Id on block block_no and content is block_info.
- createCheckpoint(Id)
to save the current state of disk Id and return a state number. This disk can be later rolled back to the current state using the returned state number.
- RollBack(Id, state)
to roll back Id to state.
- write_with_replicate(Id, block_no, block_info)
to write on the disk Id and also create a copy in the backup disk.
- read_with_replicate(Id, block_no)
to read from main disk but if block is corrupted, read from backup and create one more copy in backup