1 files changed, 158 insertions, 0 deletions
diff --git a/mfbt/tests/TestBinarySearch.cpp b/mfbt/tests/TestBinarySearch.cpp
new file mode 100644
index 0000000000..3cd28b309f
--- /dev/null
+++ b/mfbt/tests/TestBinarySearch.cpp
@@ -0,0 +1,158 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Assertions.h"
+#include "mozilla/BinarySearch.h"
+#include "mozilla/Vector.h"
+
+#include <cstdlib>
+
+using mozilla::ArrayLength;
+using mozilla::BinarySearch;
+using mozilla::BinarySearchIf;
+using mozilla::Vector;
+
+#define A(a) MOZ_RELEASE_ASSERT(a)
+
+struct Person {
+  int mAge;
+  int mId;
+  Person(int aAge, int aId) : mAge(aAge), mId(aId) {}
+};
+
+struct GetAge {
+  Vector<Person>& mV;
+  explicit GetAge(Vector<Person>& aV) : mV(aV) {}
+  int operator[](size_t index) const { return mV[index].mAge; }
+};
+
+struct RangeFinder {
+  const int mLower, mUpper;
+  RangeFinder(int lower, int upper) : mLower(lower), mUpper(upper) {}
+  int operator()(int val) const {
+    if (val >= mUpper) return -1;
+    if (val < mLower) return 1;
+    return 0;
+  }
+};
+
+static void TestBinarySearch() {
+  size_t m;
+
+  Vector<int> v1;
+  MOZ_RELEASE_ASSERT(v1.append(2));
+  MOZ_RELEASE_ASSERT(v1.append(4));
+  MOZ_RELEASE_ASSERT(v1.append(6));
+  MOZ_RELEASE_ASSERT(v1.append(8));
+
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, v1.length(), 1, &m) && m == 0);
+  MOZ_RELEASE_ASSERT(BinarySearch(v1, 0, v1.length(), 2, &m) && m == 0);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, v1.length(), 3, &m) && m == 1);
+  MOZ_RELEASE_ASSERT(BinarySearch(v1, 0, v1.length(), 4, &m) && m == 1);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, v1.length(), 5, &m) && m == 2);
+  MOZ_RELEASE_ASSERT(BinarySearch(v1, 0, v1.length(), 6, &m) && m == 2);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, v1.length(), 7, &m) && m == 3);
+  MOZ_RELEASE_ASSERT(BinarySearch(v1, 0, v1.length(), 8, &m) && m == 3);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, v1.length(), 9, &m) && m == 4);
+
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 1, &m) && m == 1);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 2, &m) && m == 1);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 3, &m) && m == 1);
+  MOZ_RELEASE_ASSERT(BinarySearch(v1, 1, 3, 4, &m) && m == 1);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 5, &m) && m == 2);
+  MOZ_RELEASE_ASSERT(BinarySearch(v1, 1, 3, 6, &m) && m == 2);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 7, &m) && m == 3);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 8, &m) && m == 3);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 1, 3, 9, &m) && m == 3);
+
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, 0, 0, &m) && m == 0);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v1, 0, 0, 9, &m) && m == 0);
+
+  Vector<int> v2;
+  MOZ_RELEASE_ASSERT(!BinarySearch(v2, 0, 0, 0, &m) && m == 0);
+  MOZ_RELEASE_ASSERT(!BinarySearch(v2, 0, 0, 9, &m) && m == 0);
+
+  Vector<Person> v3;
+  MOZ_RELEASE_ASSERT(v3.append(Person(2, 42)));
+  MOZ_RELEASE_ASSERT(v3.append(Person(4, 13)));
+  MOZ_RELEASE_ASSERT(v3.append(Person(6, 360)));
+
+  A(!BinarySearch(GetAge(v3), 0, v3.length(), 1, &m) && m == 0);
+  A(BinarySearch(GetAge(v3), 0, v3.length(), 2, &m) && m == 0);
+  A(!BinarySearch(GetAge(v3), 0, v3.length(), 3, &m) && m == 1);
+  A(BinarySearch(GetAge(v3), 0, v3.length(), 4, &m) && m == 1);
+  A(!BinarySearch(GetAge(v3), 0, v3.length(), 5, &m) && m == 2);
+  A(BinarySearch(GetAge(v3), 0, v3.length(), 6, &m) && m == 2);
+  A(!BinarySearch(GetAge(v3), 0, v3.length(), 7, &m) && m == 3);
+}
+
+static void TestBinarySearchIf() {
+  const int v1[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  const size_t len = ArrayLength(v1);
+  size_t m;
+
+  A(BinarySearchIf(v1, 0, len, RangeFinder(2, 3), &m) && m == 2);
+  A(!BinarySearchIf(v1, 0, len, RangeFinder(-5, -2), &m) && m == 0);
+  A(BinarySearchIf(v1, 0, len, RangeFinder(3, 5), &m) && m >= 3 && m < 5);
+  A(!BinarySearchIf(v1, 0, len, RangeFinder(10, 12), &m) && m == 10);
+}
+
+static void TestEqualRange() {
+  struct CompareN {
+    int mVal;
+    explicit CompareN(int n) : mVal(n) {}
+    int operator()(int aVal) const { return mVal - aVal; }
+  };
+
+  constexpr int kMaxNumber = 100;
+  constexpr int kMaxRepeat = 2;
+
+  Vector<int> sortedArray;
+  MOZ_RELEASE_ASSERT(sortedArray.reserve(kMaxNumber * kMaxRepeat));
+
+  // Make a sorted array by appending the loop counter [0, kMaxRepeat] times
+  // in each iteration.  The array will be something like:
+  //   [0, 0, 1, 1, 2, 2, 8, 9, ..., kMaxNumber]
+  for (int i = 0; i <= kMaxNumber; ++i) {
+    int repeat = rand() % (kMaxRepeat + 1);
+    for (int j = 0; j < repeat; ++j) {
+      MOZ_RELEASE_ASSERT(sortedArray.emplaceBack(i));
+    }
+  }
+
+  for (int i = -1; i < kMaxNumber + 1; ++i) {
+    auto bounds = EqualRange(sortedArray, 0, sortedArray.length(), CompareN(i));
+
+    MOZ_RELEASE_ASSERT(bounds.first <= sortedArray.length());
+    MOZ_RELEASE_ASSERT(bounds.second <= sortedArray.length());
+    MOZ_RELEASE_ASSERT(bounds.first <= bounds.second);
+
+    if (bounds.first == 0) {
+      MOZ_RELEASE_ASSERT(sortedArray[0] >= i);
+    } else if (bounds.first == sortedArray.length()) {
+      MOZ_RELEASE_ASSERT(sortedArray[sortedArray.length() - 1] < i);
+    } else {
+      MOZ_RELEASE_ASSERT(sortedArray[bounds.first - 1] < i);
+      MOZ_RELEASE_ASSERT(sortedArray[bounds.first] >= i);
+    }
+
+    if (bounds.second == 0) {
+      MOZ_RELEASE_ASSERT(sortedArray[0] > i);
+    } else if (bounds.second == sortedArray.length()) {
+      MOZ_RELEASE_ASSERT(sortedArray[sortedArray.length() - 1] <= i);
+    } else {
+      MOZ_RELEASE_ASSERT(sortedArray[bounds.second - 1] <= i);
+      MOZ_RELEASE_ASSERT(sortedArray[bounds.second] > i);
+    }
+  }
+}
+
+int main() {
+  TestBinarySearch();
+  TestBinarySearchIf();
+  TestEqualRange();
+  return 0;
+}