Decayfmt – a file format that corrupts itself a little every time you open it

decayfmt Featured in This Week in Rust #660 . A file format that corrupts itself a little every time you open it. Every open permanently damages the file on disk, by an amount baked into the filename, before it is ever shown to you. There is no recovery from the file alone. The file is the only copy that matters, and every read destroys a little more of it. Two file types: .idcy<x> for images (example: photo.idcy3 ) .tdcy<x> for text (example: note.tdcy7 ) x is a positive integer in the filename, the instability parameter. Higher x means more corruption per open. Watch it decay The grid above is one image encoded at x=1 , x=3 , x=8 , and x=15 , each opened the same number of times. Same picture, four rates of decay. To follow a single instability value across individual opens instead, each open corrupting the file further on disk before it is ever shown, with no way back: The clean original: Instability After 1 open After 3 opens x=3 (gentle) x=10 (severe) At x=3 the image degrades gracefully over many opens. At x=10 it is nearly gone after one open and pure noise after three. x is the dial between a slow fade and near-instant destruction. Text decays the same way. A sentence encoded at x=1 (a slow burn), printed after a few opens: original : This sentence is dying, and every time you read it you kill it a little more. open 1 : This sgntence is d+ingd !nd every time you re&p it P~u kiKl it a little more} open 3 : This sgfxFn0e is d+ingd 3D6 every tibe you re&a…