[tor-commits] [tor/master] Add a convenience macro to get a fast one-in-n calculation

[dgoulet at torproject.org]

commit 97b9dfe3052f1fe3b14f47fc1326e235f96305b7
Author: Nick Mathewson <nickm at torproject.org>
Date:   Wed Feb 20 12:21:05 2019 -0500

    Add a convenience macro to get a fast one-in-n calculation
---
 src/lib/crypt_ops/crypto_rand.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/lib/crypt_ops/crypto_rand.h b/src/lib/crypt_ops/crypto_rand.h
index 6eef22ed4..bb424fd69 100644
--- a/src/lib/crypt_ops/crypto_rand.h
+++ b/src/lib/crypt_ops/crypto_rand.h
@@ -68,6 +68,9 @@ unsigned crypto_fast_rng_get_uint(crypto_fast_rng_t *rng, unsigned limit);
 uint64_t crypto_fast_rng_get_uint64(crypto_fast_rng_t *rng, uint64_t limit);
 double crypto_fast_rng_get_double(crypto_fast_rng_t *rng);
 
+#define crypto_fast_rng_one_in_n(rng, n)        \
+  (0 == (crypto_fast_rng_get_uint((rng), (n))))
+
 crypto_fast_rng_t *get_thread_fast_rng(void);
 
 #ifdef CRYPTO_PRIVATE