1 files changed, 306 insertions, 0 deletions
diff --git a/mfbt/tests/TestDoublyLinkedList.cpp b/mfbt/tests/TestDoublyLinkedList.cpp
new file mode 100644
index 0000000000..3065b15ddb
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+++ b/mfbt/tests/TestDoublyLinkedList.cpp
@@ -0,0 +1,306 @@
+/* -*- 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/DoublyLinkedList.h"
+
+using mozilla::DoublyLinkedList;
+using mozilla::DoublyLinkedListElement;
+
+struct SomeClass : public DoublyLinkedListElement<SomeClass> {
+  unsigned int mValue;
+  explicit SomeClass(int aValue) : mValue(aValue) {}
+  void incr() { ++mValue; }
+  bool operator==(const SomeClass& other) const {
+    return mValue == other.mValue;
+  }
+};
+
+template <typename ListType, size_t N>
+static void CheckListValues(ListType& list, unsigned int (&values)[N]) {
+  size_t count = 0;
+  for (auto& x : list) {
+    MOZ_RELEASE_ASSERT(x.mValue == values[count]);
+    ++count;
+  }
+  MOZ_RELEASE_ASSERT(count == N);
+}
+
+static void TestDoublyLinkedList() {
+  DoublyLinkedList<SomeClass> list;
+
+  SomeClass one(1), two(2), three(3);
+
+  MOZ_RELEASE_ASSERT(list.isEmpty());
+  MOZ_RELEASE_ASSERT(!list.begin());
+  MOZ_RELEASE_ASSERT(!list.end());
+
+  for (SomeClass& x : list) {
+    MOZ_RELEASE_ASSERT(x.mValue);
+    MOZ_RELEASE_ASSERT(false);
+  }
+
+  list.pushFront(&one);
+  {
+    unsigned int check[]{1};
+    CheckListValues(list, check);
+  }
+
+  MOZ_RELEASE_ASSERT(list.contains(one));
+  MOZ_RELEASE_ASSERT(!list.contains(two));
+  MOZ_RELEASE_ASSERT(!list.contains(three));
+
+  MOZ_RELEASE_ASSERT(!list.isEmpty());
+  MOZ_RELEASE_ASSERT(list.begin()->mValue == 1);
+  MOZ_RELEASE_ASSERT(!list.end());
+
+  list.pushFront(&two);
+  {
+    unsigned int check[]{2, 1};
+    CheckListValues(list, check);
+  }
+
+  MOZ_RELEASE_ASSERT(list.begin()->mValue == 2);
+  MOZ_RELEASE_ASSERT(!list.end());
+  MOZ_RELEASE_ASSERT(!list.contains(three));
+
+  list.pushBack(&three);
+  {
+    unsigned int check[]{2, 1, 3};
+    CheckListValues(list, check);
+  }
+
+  MOZ_RELEASE_ASSERT(list.begin()->mValue == 2);
+  MOZ_RELEASE_ASSERT(!list.end());
+
+  list.remove(&one);
+  {
+    unsigned int check[]{2, 3};
+    CheckListValues(list, check);
+  }
+
+  list.insertBefore(list.find(three), &one);
+  {
+    unsigned int check[]{2, 1, 3};
+    CheckListValues(list, check);
+  }
+
+  list.remove(&three);
+  {
+    unsigned int check[]{2, 1};
+    CheckListValues(list, check);
+  }
+
+  list.insertBefore(list.find(two), &three);
+  {
+    unsigned int check[]{3, 2, 1};
+    CheckListValues(list, check);
+  }
+
+  list.remove(&three);
+  {
+    unsigned int check[]{2, 1};
+    CheckListValues(list, check);
+  }
+
+  list.insertBefore(++list.find(two), &three);
+  {
+    unsigned int check[]{2, 3, 1};
+    CheckListValues(list, check);
+  }
+
+  list.remove(&one);
+  {
+    unsigned int check[]{2, 3};
+    CheckListValues(list, check);
+  }
+
+  list.remove(&two);
+  {
+    unsigned int check[]{3};
+    CheckListValues(list, check);
+  }
+
+  list.insertBefore(list.find(three), &two);
+  {
+    unsigned int check[]{2, 3};
+    CheckListValues(list, check);
+  }
+
+  list.remove(&three);
+  {
+    unsigned int check[]{2};
+    CheckListValues(list, check);
+  }
+
+  list.remove(&two);
+  MOZ_RELEASE_ASSERT(list.isEmpty());
+
+  list.pushBack(&three);
+  {
+    unsigned int check[]{3};
+    CheckListValues(list, check);
+  }
+
+  list.pushFront(&two);
+  {
+    unsigned int check[]{2, 3};
+    CheckListValues(list, check);
+  }
+
+  // This should modify the values of |two| and |three| as pointers to them are
+  // stored in the list, not copies.
+  for (SomeClass& x : list) {
+    x.incr();
+  }
+
+  MOZ_RELEASE_ASSERT(*list.begin() == two);
+  MOZ_RELEASE_ASSERT(*++list.begin() == three);
+
+  SomeClass four(4);
+  MOZ_RELEASE_ASSERT(++list.begin() == list.find(four));
+}
+
+struct InTwoLists {
+  explicit InTwoLists(unsigned int aValue) : mValue(aValue) {}
+  DoublyLinkedListElement<InTwoLists> mListOne;
+  DoublyLinkedListElement<InTwoLists> mListTwo;
+  unsigned int mValue;
+
+  struct GetListOneTrait {
+    static DoublyLinkedListElement<InTwoLists>& Get(InTwoLists* aThis) {
+      return aThis->mListOne;
+    }
+  };
+};
+
+namespace mozilla {
+
+template <>
+struct GetDoublyLinkedListElement<InTwoLists> {
+  static DoublyLinkedListElement<InTwoLists>& Get(InTwoLists* aThis) {
+    return aThis->mListTwo;
+  }
+};
+
+}  // namespace mozilla
+
+static void TestCustomAccessor() {
+  DoublyLinkedList<InTwoLists, InTwoLists::GetListOneTrait> listOne;
+  DoublyLinkedList<InTwoLists> listTwo;
+
+  InTwoLists one(1);
+  InTwoLists two(2);
+
+  listOne.pushBack(&one);
+  listOne.pushBack(&two);
+  {
+    unsigned int check[]{1, 2};
+    CheckListValues(listOne, check);
+  }
+
+  listTwo.pushBack(&one);
+  listTwo.pushBack(&two);
+  {
+    unsigned int check[]{1, 2};
+    CheckListValues(listOne, check);
+  }
+  {
+    unsigned int check[]{1, 2};
+    CheckListValues(listTwo, check);
+  }
+
+  (void)listTwo.popBack();
+  {
+    unsigned int check[]{1, 2};
+    CheckListValues(listOne, check);
+  }
+  {
+    unsigned int check[]{1};
+    CheckListValues(listTwo, check);
+  }
+
+  (void)listOne.popBack();
+  {
+    unsigned int check[]{1};
+    CheckListValues(listOne, check);
+  }
+  {
+    unsigned int check[]{1};
+    CheckListValues(listTwo, check);
+  }
+}
+
+static void TestSafeDoubleLinkedList() {
+  mozilla::SafeDoublyLinkedList<SomeClass> list;
+  auto* elt1 = new SomeClass(0);
+  auto* elt2 = new SomeClass(0);
+  auto* elt3 = new SomeClass(0);
+  auto* elt4 = new SomeClass(0);
+  list.pushBack(elt1);
+  list.pushBack(elt2);
+  list.pushBack(elt3);
+  auto iter = list.begin();
+
+  // basic tests for iterator validity
+  MOZ_RELEASE_ASSERT(
+      &*iter == elt1,
+      "iterator returned by begin() must point to the first element!");
+  MOZ_RELEASE_ASSERT(
+      &*(iter.next()) == elt2,
+      "iterator returned by begin() must have the second element as 'next'!");
+  list.remove(elt2);
+  MOZ_RELEASE_ASSERT(
+      &*(iter.next()) == elt3,
+      "After removal of the 2nd element 'next' must point to the 3rd element!");
+  ++iter;
+  MOZ_RELEASE_ASSERT(
+      &*iter == elt3,
+      "After advancing one step the current element must be the 3rd one!");
+  MOZ_RELEASE_ASSERT(!iter.next(), "This is the last element of the list!");
+  list.pushBack(elt4);
+  MOZ_RELEASE_ASSERT(&*(iter.next()) == elt4,
+                     "After adding an element at the end of the list the "
+                     "iterator must be updated!");
+
+  // advance to last element, then remove last element
+  ++iter;
+  list.popBack();
+  MOZ_RELEASE_ASSERT(bool(iter) == false,
+                     "After removing the last element, the iterator pointing "
+                     "to the last element must be empty!");
+
+  // iterate the whole remaining list, increment values
+  for (auto& el : list) {
+    el.incr();
+  }
+  MOZ_RELEASE_ASSERT(elt1->mValue == 1);
+  MOZ_RELEASE_ASSERT(elt2->mValue == 0);
+  MOZ_RELEASE_ASSERT(elt3->mValue == 1);
+  MOZ_RELEASE_ASSERT(elt4->mValue == 0);
+
+  // Removing the first element of the list while iterating must empty the
+  // iterator
+  for (auto it = list.begin(); it != list.end(); ++it) {
+    MOZ_RELEASE_ASSERT(bool(it) == true, "The iterator must contain a value!");
+    list.popFront();
+    MOZ_RELEASE_ASSERT(
+        bool(it) == false,
+        "After removing the first element, the iterator must be empty!");
+  }
+
+  delete elt1;
+  delete elt2;
+  delete elt3;
+  delete elt4;
+}
+
+int main() {
+  TestDoublyLinkedList();
+  TestCustomAccessor();
+  TestSafeDoubleLinkedList();
+  return 0;
+}