Make SimpleRandom faster by using Chacha20 as underlying primitive.
This does alter the output of the RNG, but that's a one-time cost, and one SHA-1 call per byte is highly suboptimal for anything but very short unit tests.
gfe-relnote: n/a (test-only change)
PiperOrigin-RevId: 245501012
Change-Id: I16d9f5b174ef65cfb4ece3ef0699bf1b29b81de5
diff --git a/quic/test_tools/quic_test_utils_test.cc b/quic/test_tools/quic_test_utils_test.cc
index aeccc70..8c30335 100644
--- a/quic/test_tools/quic_test_utils_test.cc
+++ b/quic/test_tools/quic_test_utils_test.cc
@@ -52,8 +52,27 @@
TEST_F(QuicTestUtilsTest, SimpleRandomStability) {
SimpleRandom rng;
rng.set_seed(UINT64_C(0x1234567800010001));
- EXPECT_EQ(UINT64_C(14865409841904857791), rng.RandUint64());
- EXPECT_EQ(UINT64_C(12139094019410129741), rng.RandUint64());
+ EXPECT_EQ(UINT64_C(12589383305231984671), rng.RandUint64());
+ EXPECT_EQ(UINT64_C(17775425089941798664), rng.RandUint64());
+}
+
+// Ensure that the output of SimpleRandom does not depend on the size of the
+// read calls.
+TEST_F(QuicTestUtilsTest, SimpleRandomChunks) {
+ SimpleRandom rng;
+ std::string reference(16 * 1024, '\0');
+ rng.RandBytes(&reference[0], reference.size());
+
+ for (size_t chunk_size : {3, 4, 7, 4096}) {
+ rng.set_seed(0);
+ size_t chunks = reference.size() / chunk_size;
+ std::string buffer(chunks * chunk_size, '\0');
+ for (size_t i = 0; i < chunks; i++) {
+ rng.RandBytes(&buffer[i * chunk_size], chunk_size);
+ }
+ EXPECT_EQ(reference.substr(0, buffer.size()), buffer)
+ << "Failed for chunk_size = " << chunk_size;
+ }
}
} // namespace test
