From 126ed2c6e94e1caee3365408d15d200332027374 Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Thu, 28 May 2015 15:38:28 +0100
Subject: [PATCH] Add routine to generate jittered timeout.

---
 src/libutil/util.c | 18 ++++++++++++++++++
 src/libutil/util.h |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/src/libutil/util.c b/src/libutil/util.c
index 5e3e9c4e1..23451412c 100644
--- a/src/libutil/util.c
+++ b/src/libutil/util.c
@@ -2609,3 +2609,21 @@ rspamd_hash_seed (void)
 
 	return seed;
 }
+
+gdouble
+rspamd_time_jitter (gdouble in, gdouble jitter)
+{
+	guint64 rnd_int;
+	double res;
+	const double transform_bias = 2.2204460492503130808472633361816e-16;
+
+	rnd_int = ottery_rand_uint64 () >> 12;
+	res = rnd_int;
+	res *= transform_bias;
+
+	if (jitter == 0) {
+		jitter = in;
+	}
+
+	return in + jitter * res;
+}
diff --git a/src/libutil/util.h b/src/libutil/util.h
index 80896083c..abc949dfc 100644
--- a/src/libutil/util.h
+++ b/src/libutil/util.h
@@ -480,4 +480,9 @@ void rspamd_init_libs (void);
  */
 guint64 rspamd_hash_seed (void);
 
+/**
+ * Return jittered time value
+ */
+gdouble rspamd_time_jitter (gdouble in, gdouble jitter);
+
 #endif
-- 
2.39.5