1 files changed, 213 insertions, 0 deletions
diff --git a/src/test/crimson/test_lru.cc b/src/test/crimson/test_lru.cc
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+++ b/src/test/crimson/test_lru.cc
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2013 Cloudwatt <libre.licensing@cloudwatt.com>
+ *
+ * Author: Loic Dachary <loic@dachary.org>
+ *         Cheng Cheng <ccheng.leo@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library Public License for more details.
+ *
+ */
+
+#include <stdio.h>
+#include "gtest/gtest.h"
+#include "crimson/common/shared_lru.h"
+
+class LRUTest : public SharedLRU<unsigned int, int> {
+public:
+  auto add(unsigned int key, int value, bool* existed = nullptr) {
+    auto pv = new int{value};
+    auto ptr = insert(key, std::unique_ptr<int>{pv});
+    if (existed) {
+      *existed = (ptr.get() != pv);
+    }
+    return ptr;
+  }
+};
+
+TEST(LRU, add) {
+  LRUTest cache;
+  unsigned int key = 1;
+  int value1 = 2;
+  bool existed = false;
+  {
+    auto ptr = cache.add(key, value1, &existed);
+    ASSERT_TRUE(ptr);
+    ASSERT_TRUE(ptr.get());
+    ASSERT_EQ(value1, *ptr);
+    ASSERT_FALSE(existed);
+  }
+  {
+    auto ptr = cache.add(key, 3, &existed);
+    ASSERT_EQ(value1, *ptr);
+    ASSERT_TRUE(existed);
+  }
+}
+
+TEST(LRU, empty) {
+  LRUTest cache;
+  unsigned int key = 1;
+  bool existed = false;
+
+  ASSERT_TRUE(cache.empty());
+  {
+    int value1 = 2;
+    auto ptr = cache.add(key, value1, &existed);
+    ASSERT_EQ(value1, *ptr);
+    ASSERT_FALSE(existed);
+  }
+  ASSERT_FALSE(cache.empty());
+
+  cache.clear();
+  ASSERT_TRUE(cache.empty());
+}
+
+TEST(LRU, lookup) {
+  LRUTest cache;
+  unsigned int key = 1;
+  {
+    int value = 2;
+    auto ptr = cache.add(key, value);
+    ASSERT_TRUE(ptr);
+    ASSERT_TRUE(ptr.get());
+    ASSERT_TRUE(cache.find(key).get());
+    ASSERT_EQ(value, *cache.find(key));
+  }
+  ASSERT_TRUE(cache.find(key).get());
+}
+
+TEST(LRU, lookup_or_create) {
+  LRUTest cache;
+  {
+    int value = 2;
+    unsigned int key = 1;
+    ASSERT_TRUE(cache.add(key, value).get());
+    ASSERT_TRUE(cache[key].get());
+    ASSERT_EQ(value, *cache.find(key));
+  }
+  {
+    unsigned int key = 2;
+    ASSERT_TRUE(cache[key].get());
+    ASSERT_EQ(0, *cache.find(key));
+  }
+  ASSERT_TRUE(cache.find(1).get());
+  ASSERT_TRUE(cache.find(2).get());
+}
+
+TEST(LRU, lower_bound) {
+  LRUTest cache;
+
+  {
+    unsigned int key = 1;
+    ASSERT_FALSE(cache.lower_bound(key));
+    int value = 2;
+
+    ASSERT_TRUE(cache.add(key, value).get());
+    ASSERT_TRUE(cache.lower_bound(key).get());
+    EXPECT_EQ(value, *cache.lower_bound(key));
+  }
+}
+
+TEST(LRU, get_next) {
+
+  {
+    LRUTest cache;
+    const unsigned int key = 0;
+    EXPECT_FALSE(cache.upper_bound(key));
+  }
+  {
+    LRUTest cache;
+    const unsigned int key1 = 111;
+    auto ptr1 = cache[key1];
+    const unsigned int key2 = 222;
+    auto ptr2 = cache[key2];
+
+    auto i = cache.upper_bound(0);
+    ASSERT_TRUE(i);
+    EXPECT_EQ(i->first, key1);
+    auto j = cache.upper_bound(i->first);
+    ASSERT_TRUE(j);
+    EXPECT_EQ(j->first, key2);
+  }
+}
+
+TEST(LRU, clear) {
+  LRUTest cache;
+  unsigned int key = 1;
+  int value = 2;
+  cache.add(key, value);
+  {
+    auto found = cache.find(key);
+    ASSERT_TRUE(found);
+    ASSERT_EQ(value, *found);
+  }
+  ASSERT_TRUE(cache.find(key).get());
+  cache.clear();
+  ASSERT_FALSE(cache.find(key));
+  ASSERT_TRUE(cache.empty());
+}
+
+TEST(LRU, eviction) {
+  LRUTest cache{5};
+  bool existed;
+  // add a bunch of elements, some of them will be evicted
+  for (size_t i = 0; i < 2 * cache.capacity(); ++i) {
+    cache.add(i, i, &existed);
+    ASSERT_FALSE(existed);
+  }
+  size_t i = 0;
+  for (; i < cache.capacity(); ++i) {
+    ASSERT_FALSE(cache.find(i));
+  }
+  for (; i < 2 * cache.capacity(); ++i) {
+    ASSERT_TRUE(cache.find(i));
+  }
+}
+
+TEST(LRU, track_weak) {
+  constexpr int SIZE = 5;
+  LRUTest cache{SIZE};
+
+  bool existed = false;
+  // strong reference to keep 0 alive
+  auto ptr = cache.add(0, 0, &existed);
+  ASSERT_FALSE(existed);
+
+  // add a bunch of elements to get 0 evicted
+  for (size_t i = 1; i < 2 * cache.capacity(); ++i) {
+    cache.add(i, i, &existed);
+    ASSERT_FALSE(existed);
+  }
+  // 0 is still reachable via the cache
+  ASSERT_TRUE(cache.find(0));
+  ASSERT_TRUE(cache.find(0).get());
+  ASSERT_EQ(0, *cache.find(0));
+
+  // [0..SIZE) are evicted when adding [SIZE..2*SIZE)
+  // [SIZE..SIZE * 2) were still in the cache before accessing 0,
+  // but SIZE got evicted when accessing 0
+  ASSERT_FALSE(cache.find(SIZE-1));
+  ASSERT_FALSE(cache.find(SIZE));
+  ASSERT_TRUE(cache.find(SIZE+1));
+  ASSERT_TRUE(cache.find(SIZE+1).get());
+  ASSERT_EQ((int)SIZE+1, *cache.find(SIZE+1));
+
+  ptr.reset();
+  // 0 is still reachable, as it is now put back into LRU cache
+  ASSERT_TRUE(cache.find(0));
+}
+
+// Local Variables:
+// compile-command: "cmake --build ../../../build -j 8 --target unittest_seastar_lru  && ctest -R unittest_seastar_lru # --gtest_filter=*.* --log-to-stderr=true"
+// End: