util.id: Add a 'tiny' variant

Conversations uses this for its randomized resources. Presumably fine
and collision resistant enough when you have a few devices at most.

1 files changed, 3 insertions, 0 deletions

diff --git a/util/id.lua b/util/id.lua
index 64b56662..ff4e919d 100644
--- a/util/id.lua
+++ b/util/id.lua
@@ -19,6 +19,9 @@ end
 return {
 	-- sizes divisible by 3 fit nicely into base64 without padding==
 
+	-- for short lived things with low risk of collisions
+	tiny = function() return b64url_random(3); end;
+
 	-- close to 8 bytes, should be good enough for relatively short lived or uses
 	-- scoped by host or users, half the size of an uuid
 	short = function() return b64url_random(9); end;