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-rw-r--r--util/random.lua43
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;
+};