Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 368 insertions, 0 deletions

diff --git a/xpcom/tests/gtest/TestSmallArrayLRUCache.cpp b/xpcom/tests/gtest/TestSmallArrayLRUCache.cpp
new file mode 100644
index 0000000000..10e2b71a69
--- /dev/null
+++ b/xpcom/tests/gtest/TestSmallArrayLRUCache.cpp
@@ -0,0 +1,368 @@
+/* -*- 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 "gtest/gtest.h"
+
+#include "mozilla/SmallArrayLRUCache.h"
+
+#include <algorithm>
+#include <cstring>
+#include <utility>
+
+using Key = unsigned;
+
+struct Value {
+  Value() : m(unsigned(-1)) {}
+  explicit Value(unsigned a) : m(a) {}
+
+  bool operator==(const Value& aOther) const { return m == aOther.m; }
+  bool operator!=(const Value& aOther) const { return m != aOther.m; }
+
+  unsigned m;
+};
+
+constexpr static unsigned CacheSize = 8;
+
+using TestCache = mozilla::SmallArrayLRUCache<Key, Value, CacheSize>;
+
+// This struct embeds a given object type between two "guard" objects, to check
+// if anything is written out of bounds.
+template <typename T>
+struct Boxed {
+  constexpr static size_t GuardSize = std::max(sizeof(T), size_t(256));
+
+  // A Guard is a character array with a pre-set content that can be checked for
+  // unwanted changes.
+  struct Guard {
+    char mGuard[GuardSize];
+    explicit Guard(char aValue) { memset(&mGuard, aValue, GuardSize); }
+    void Check(char aValue) {
+      for (const char& c : mGuard) {
+        ASSERT_EQ(c, aValue);
+      }
+    }
+  };
+
+  Guard mGuardBefore;
+  T mObject;
+  Guard mGuardAfter;
+
+  template <typename... Ts>
+  explicit Boxed(Ts&&... aTs)
+      : mGuardBefore(0x5a),
+        mObject(std::forward<Ts>(aTs)...),
+        mGuardAfter(0xa5) {
+    Check();
+  }
+
+  ~Boxed() { Check(); }
+
+  T& Object() { return mObject; }
+  const T& Object() const { return mObject; }
+
+  void Check() {
+    mGuardBefore.Check(0x5a);
+    mGuardAfter.Check(0xa5);
+  }
+};
+
+TEST(SmallArrayLRUCache, FetchOrAdd_KeysFitInCache)
+{
+  // We're going to add-or-fetch between 1 and CacheSize keys, so they all fit
+  // in the cache.
+  for (Key keys = 1; keys <= CacheSize; ++keys) {
+    Boxed<TestCache> boxedCache;
+    TestCache& cache = boxedCache.Object();
+    for (Key i = 0; i < keys; ++i) {
+      bool valueFunctionCalled = false;
+      Value v = cache.FetchOrAdd(i, [&]() {
+        valueFunctionCalled = true;
+        return Value{i};
+      });
+      ASSERT_EQ(v, Value{i});
+      ASSERT_TRUE(valueFunctionCalled);
+      boxedCache.Check();
+    }
+
+    // Fetching any key should never call the value function.
+    for (Key i = 0; i < CacheSize * 3; ++i) {
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_FALSE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+      // Fetching the same key again will never call the function value.
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_FALSE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+    }
+  }
+}
+
+TEST(SmallArrayLRUCache, Add_FetchOrAdd_KeysFitInCache)
+{
+  // We're going to add between 1 and CacheSize keys, so they all fit in the
+  // cache.
+  for (Key keys = 1; keys <= CacheSize; ++keys) {
+    Boxed<TestCache> boxedCache;
+    TestCache& cache = boxedCache.Object();
+    for (Key i = 0; i < keys; ++i) {
+      cache.Add(i, Value{i});
+      boxedCache.Check();
+    }
+
+    // Fetching any key should never call the value function.
+    for (Key i = 0; i < CacheSize * 3; ++i) {
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_FALSE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+      // Fetching the same key again will never call the function value.
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_FALSE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+    }
+  }
+}
+
+TEST(SmallArrayLRUCache, FetchOrAdd_KeysDoNotFitInCache)
+{
+  // We're going to add-or-fetch strictly more than CacheSize keys, so they
+  // cannot fit in the cache, only the last `CacheSize` ones are kept.
+  for (Key keys = CacheSize + 1; keys <= CacheSize * 2; ++keys) {
+    Boxed<TestCache> boxedCache;
+    TestCache& cache = boxedCache.Object();
+    for (Key i = 0; i < keys; ++i) {
+      bool valueFunctionCalled = false;
+      Value v = cache.FetchOrAdd(i, [&]() {
+        valueFunctionCalled = true;
+        return Value{i};
+      });
+      ASSERT_EQ(v, Value{i});
+      ASSERT_TRUE(valueFunctionCalled);
+      boxedCache.Check();
+    }
+
+    // Fetching keys from 0 should always call the function value:
+    // - 0 is the oldest key, it must have been pushed out when `CacheSize`
+    //   was added.
+    // - Once we've fetched 0, it's pushed out the old (smallest) key.
+    // Etc.
+    for (Key i = 0; i < CacheSize * 3; ++i) {
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_TRUE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+      // Fetching the same key again will never call the function value.
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_FALSE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+    }
+  }
+}
+
+TEST(SmallArrayLRUCache, Add_FetchOrAdd_KeysDoNotFitInCache)
+{
+  // We're going to add strictly more than CacheSize keys, so they cannot fit in
+  // the cache, only the last `CacheSize` ones are kept.
+  for (Key keys = CacheSize + 1; keys <= CacheSize * 2; ++keys) {
+    Boxed<TestCache> boxedCache;
+    TestCache& cache = boxedCache.Object();
+    for (Key i = 0; i < keys; ++i) {
+      cache.Add(i, Value{i});
+      boxedCache.Check();
+    }
+
+    // Fetching keys from 0 should always call the function value:
+    // - 0 is the oldest key, it must have been pushed out when `CacheSize`
+    //   was added.
+    // - Once we've fetched 0, it's pushed out the old (smallest) key.
+    // Etc.
+    for (Key i = 0; i < CacheSize * 3; ++i) {
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_TRUE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+      // Fetching the same key again will never call the function value.
+      {
+        bool valueFunctionCalled = false;
+        Value v = cache.FetchOrAdd(i % keys, [&]() {
+          valueFunctionCalled = true;
+          return Value{i % keys};
+        });
+        ASSERT_EQ(v, Value{i % keys});
+        ASSERT_FALSE(valueFunctionCalled);
+        boxedCache.Check();
+      }
+    }
+  }
+}
+
+TEST(SmallArrayLRUCache, Clear)
+{
+  Boxed<TestCache> boxedCache;
+  TestCache& cache = boxedCache.Object();
+
+  // First fetch will always call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_TRUE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+
+  // Second fetch will never call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_FALSE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+
+  cache.Clear();
+
+  // After Clear(), first fetch will always call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_TRUE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+
+  // Next fetch will never call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_FALSE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+}
+
+TEST(SmallArrayLRUCache, Shutdown)
+{
+  Boxed<TestCache> boxedCache;
+  TestCache& cache = boxedCache.Object();
+
+  // First fetch will always call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_TRUE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+
+  // Second fetch will never call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_FALSE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+
+  cache.Shutdown();
+
+  // After Shutdown(), any fetch will always call the function value.
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_TRUE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_TRUE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+  cache.Add(42, Value{4242});
+  boxedCache.Check();
+  {
+    bool valueFunctionCalled = false;
+    Value v = cache.FetchOrAdd(42, [&]() {
+      valueFunctionCalled = true;
+      return Value{4242};
+    });
+    ASSERT_EQ(v, Value{4242});
+    ASSERT_TRUE(valueFunctionCalled);
+    boxedCache.Check();
+  }
+}