[sgentle]

Fun! This is similar to how git stores files internally. You can do some neat tricks like this:

  $ ls
  01.jpg      03.jpg      03_copy.jpg 04.jpg      05.jpg

  $ git init
  Initialized empty Git repository in /tmp/test/.git/

  $ git hash-object -w *
  82f7d50fc89d2fd47150aff539ea4acf45ec1589
  0080672bc4f248c400d569cce1a2a3d743eb1331
  0080672bc4f248c400d569cce1a2a3d743eb1331
  58db57b10c219b9b71f0223e58a6dc0d51cfe207
  05dcde743807bddaf55ad1231572c1365d4db4af

  $ find .git/objects -type f
  .git/objects/00/80672bc4f248c400d569cce1a2a3d743eb1331
  .git/objects/05/dcde743807bddaf55ad1231572c1365d4db4af
  .git/objects/58/db57b10c219b9b71f0223e58a6dc0d51cfe207
  .git/objects/82/f7d50fc89d2fd47150aff539ea4acf45ec1589

If you're curious, you can read more about how it works here: https://git-scm.com/book/en/v1/Git-Internals-Git-Objects

[cperciva]

This is also how FreeBSD Update and Portsnap store files. This technique has been around for a long time.

[patrickmn]

https://en.wikipedia.org/wiki/Content-addressable_storage

[cperciva]

Right. I'm not a fan of the terminology though; I prefer hash-addressed storage to avoid the potential confusion with associative memory.