This makes debugging easier, you can pass an AUMHash to a printf and get
a string that is easy to debug.
Also rearrange how directories/files work in the FS store: use the first
two characters of the string representation as the prefix directory, and
use the entire AUMHash string as the file name. This is again to aid
debugging: you can `ls` a directory and line up what prints out easily
with what you get from a printf in debug code.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
FS implements Chonk, and given the expected load characteristics (frequent use
of AUM() + ChildAUMs(), and infrequent use of Heads() + CommitVerifiedAUMs()), the
implementation avoids scanning the filesystem to service AUM() and ChildAUMs().
Signed-off-by: Tom DNetto <tom@tailscale.com>
Chonks are responsible for efficient storage of AUMs and other TKA state.
For testing/prototyping I've implemented an in-memory version, but once we
start to use this from tailscaled we'll need a file-based version.
Signed-off-by: Tom DNetto <tom@tailscale.com>
