Roll forward to cl/338482889

Signed-off-by: Alexey Polyudov <apolyudov@google.com> Change-Id: Ic2bdb234e89f3c5860d1b483dd4bce689f13d057
2026-09-16 15:36:12 -04:00 · 2020-10-22 11:30:33 -07:00
parent 13f8fddfde
commit ce4807935e
564 changed files with 13720 additions and 48704 deletions
@@ -0,0 +1,91 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "platform/base/prng.h"
+
+#include "gtest/gtest.h"
+
+namespace location {
+namespace nearby {
+
+enum class TestMode {
+  kUpperHalfOfInt64,
+  kLowerHalfOfInt64,
+  kInt32,
+  kUint32,
+};
+
+TEST(PrngTest, NextInt32) {
+  std::int32_t i = Prng().NextInt32();
+  EXPECT_LE(i, std::numeric_limits<std::int32_t>::max());
+  EXPECT_GE(i, std::numeric_limits<std::int32_t>::min());
+}
+
+TEST(PrngTest, NextUInt32) {
+  std::uint32_t i = Prng().NextUint32();
+  EXPECT_LE(i, std::numeric_limits<std::uint32_t>::max());
+  EXPECT_GE(i, std::numeric_limits<std::uint32_t>::min());
+}
+
+TEST(PrngTest, NextInt64) {
+  std::int64_t i = Prng().NextInt64();
+  EXPECT_LE(i, std::numeric_limits<std::int64_t>::max());
+  EXPECT_GE(i, std::numeric_limits<std::int64_t>::min());
+}
+
+void ValidateRandom(TestMode mode) {
+  int count_all_zeros = 0;
+  int count_all_ones = 0;
+  std::uint32_t i;
+  Prng prng;
+  for (int count = 0; count < 100; ++count) {
+    switch (mode) {
+      case TestMode::kUpperHalfOfInt64:
+        i = static_cast<std::uint32_t>(prng.NextInt64() >> 32);
+        break;
+      case TestMode::kLowerHalfOfInt64:
+        i = static_cast<std::uint32_t>(prng.NextInt64());
+        break;
+      case TestMode::kInt32:
+        i = static_cast<std::uint32_t>(prng.NextInt32());
+        break;
+      case TestMode::kUint32:
+        i = static_cast<std::uint32_t>(prng.NextUint32());
+        break;
+    }
+    if (!i) count_all_zeros++;
+    if (i == 0xFFFFFFFF) count_all_ones++;
+  }
+  EXPECT_LE(count_all_zeros, 1);
+  EXPECT_LE(count_all_ones, 1);
+}
+
+TEST(PrngTest, ValidateUpperHalfOfInt64) {
+  ValidateRandom(TestMode::kUpperHalfOfInt64);
+}
+
+TEST(PrngTest, ValidateLowerHalfOfInt64) {
+  ValidateRandom(TestMode::kLowerHalfOfInt64);
+}
+
+TEST(PrngTest, ValidateInt32) {
+  ValidateRandom(TestMode::kInt32);
+}
+
+TEST(PrngTest, ValidateUint32) {
+  ValidateRandom(TestMode::kUint32);
+}
+
+}  // namespace nearby
+}  // namespace location