Defrag Simulator

Your daily dose of negentropy.

This simulation attempts to be somewhat authentic to vintage FAT-style filesystems. The drive is an array of integers where each element is either -9999 (unused), -1 (EOF), or the address of the next block in the chain of blocks for a given file.

Defragging sorts files largest to smallest, then creates a single dictionary where the keys are the current address of a block and the values are the desired destination address for that block. Movement is stack based and recursive—if the desired destination is occupied, that block is moved first, which can trigger further recursive moves.