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| -rw-r--r-- | util/random.lua | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/util/random.lua b/util/random.lua new file mode 100644 index 00000000..ed5cdf4b --- /dev/null +++ b/util/random.lua @@ -0,0 +1,43 @@ +-- Prosody IM +-- Copyright (C) 2008-2014 Matthew Wild +-- Copyright (C) 2008-2014 Waqas Hussain +-- +-- This project is MIT/X11 licensed. Please see the +-- COPYING file in the source package for more information. +-- + +local tostring = tostring; +local os_time = os.time; +local os_clock = os.clock; +local ceil = math.ceil; +local sha1 = require "util.hashes".sha1; + +local last_uniq_time = 0; +local function uniq_time() + local new_uniq_time = os_time(); + if last_uniq_time >= new_uniq_time then new_uniq_time = last_uniq_time + 1; end + last_uniq_time = new_uniq_time; + return new_uniq_time; +end + +local function new_random(x) + return sha1(x..os_clock()..tostring({})); +end + +local buffer = new_random(uniq_time()); + +local function seed(x) + buffer = new_random(buffer..x); +end + +local function bytes(n) + if #buffer < n then seed(uniq_time()); end + local r = buffer:sub(0, n); + buffer = buffer:sub(n+1); + return r; +end + +return { + seed = seed; + bytes = bytes; +}; |