69bb210d58
Summary: Add the funcion Cache.GetPinnedUsage() to return the memory size of entries that are in use by the system (that is, all the entries not in the LRU list). Test Plan: Run ./cache_test and examine PinnedUsageTest. Reviewers: tnovak, igor Reviewed By: igor Subscribers: dhruba Differential Revision: https://reviews.facebook.net/D40305
509 lines
14 KiB
C++
509 lines
14 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "rocksdb/cache.h"
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#include <vector>
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#include <string>
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#include <iostream>
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#include "util/coding.h"
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#include "util/string_util.h"
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#include "util/testharness.h"
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namespace rocksdb {
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// Conversions between numeric keys/values and the types expected by Cache.
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static std::string EncodeKey(int k) {
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std::string result;
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PutFixed32(&result, k);
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return result;
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}
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static int DecodeKey(const Slice& k) {
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assert(k.size() == 4);
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return DecodeFixed32(k.data());
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}
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static void* EncodeValue(uintptr_t v) { return reinterpret_cast<void*>(v); }
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static int DecodeValue(void* v) {
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return static_cast<int>(reinterpret_cast<uintptr_t>(v));
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}
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class CacheTest : public testing::Test {
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public:
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static CacheTest* current_;
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static void Deleter(const Slice& key, void* v) {
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current_->deleted_keys_.push_back(DecodeKey(key));
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current_->deleted_values_.push_back(DecodeValue(v));
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}
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static const int kCacheSize = 1000;
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static const int kNumShardBits = 4;
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static const int kCacheSize2 = 100;
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static const int kNumShardBits2 = 2;
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std::vector<int> deleted_keys_;
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std::vector<int> deleted_values_;
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shared_ptr<Cache> cache_;
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shared_ptr<Cache> cache2_;
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CacheTest() :
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cache_(NewLRUCache(kCacheSize, kNumShardBits)),
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cache2_(NewLRUCache(kCacheSize2, kNumShardBits2)) {
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current_ = this;
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}
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~CacheTest() {
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}
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int Lookup(shared_ptr<Cache> cache, int key) {
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Cache::Handle* handle = cache->Lookup(EncodeKey(key));
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const int r = (handle == nullptr) ? -1 : DecodeValue(cache->Value(handle));
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if (handle != nullptr) {
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cache->Release(handle);
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}
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return r;
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}
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void Insert(shared_ptr<Cache> cache, int key, int value, int charge = 1) {
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cache->Release(cache->Insert(EncodeKey(key), EncodeValue(value), charge,
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&CacheTest::Deleter));
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}
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void Erase(shared_ptr<Cache> cache, int key) {
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cache->Erase(EncodeKey(key));
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}
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int Lookup(int key) {
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return Lookup(cache_, key);
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}
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void Insert(int key, int value, int charge = 1) {
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Insert(cache_, key, value, charge);
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}
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void Erase(int key) {
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Erase(cache_, key);
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}
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int Lookup2(int key) {
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return Lookup(cache2_, key);
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}
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void Insert2(int key, int value, int charge = 1) {
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Insert(cache2_, key, value, charge);
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}
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void Erase2(int key) {
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Erase(cache2_, key);
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}
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};
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CacheTest* CacheTest::current_;
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namespace {
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void dumbDeleter(const Slice& key, void* value) { }
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} // namespace
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TEST_F(CacheTest, UsageTest) {
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// cache is shared_ptr and will be automatically cleaned up.
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const uint64_t kCapacity = 100000;
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auto cache = NewLRUCache(kCapacity, 8);
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size_t usage = 0;
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const char* value = "abcdef";
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// make sure everything will be cached
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for (int i = 1; i < 100; ++i) {
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std::string key(i, 'a');
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auto kv_size = key.size() + 5;
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cache->Release(
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cache->Insert(key, (void*)value, kv_size, dumbDeleter)
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);
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usage += kv_size;
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ASSERT_EQ(usage, cache->GetUsage());
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}
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// make sure the cache will be overloaded
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for (uint64_t i = 1; i < kCapacity; ++i) {
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auto key = ToString(i);
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cache->Release(
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cache->Insert(key, (void*)value, key.size() + 5, dumbDeleter)
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);
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}
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// the usage should be close to the capacity
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ASSERT_GT(kCapacity, cache->GetUsage());
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ASSERT_LT(kCapacity * 0.95, cache->GetUsage());
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}
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TEST_F(CacheTest, PinnedUsageTest) {
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// cache is shared_ptr and will be automatically cleaned up.
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const uint64_t kCapacity = 100000;
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auto cache = NewLRUCache(kCapacity, 8);
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size_t pinned_usage = 0;
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const char* value = "abcdef";
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// Add entries. Unpin some of them after insertion. Then, pin some of them
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// again. Check GetPinnedUsage().
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for (int i = 1; i < 100; ++i) {
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std::string key(i, 'a');
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auto kv_size = key.size() + 5;
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auto handle = cache->Insert(key, (void*)value, kv_size, dumbDeleter);
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pinned_usage += kv_size;
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ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
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if (i % 2 == 0) {
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cache->Release(handle);
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pinned_usage -= kv_size;
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ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
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}
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if (i % 3 == 0) {
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cache->Lookup(key);
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// If i % 2 == 0, then the entry was unpinned before Lookup, so pinned
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// usage increased
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if (i % 2 == 0) {
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pinned_usage += kv_size;
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}
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ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
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}
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}
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// check that overloading the cache does not change the pinned usage
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for (uint64_t i = 1; i < 2 * kCapacity; ++i) {
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auto key = ToString(i);
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cache->Release(
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cache->Insert(key, (void*)value, key.size() + 5, dumbDeleter));
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}
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ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
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}
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TEST_F(CacheTest, HitAndMiss) {
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ASSERT_EQ(-1, Lookup(100));
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Insert(100, 101);
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ASSERT_EQ(101, Lookup(100));
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ASSERT_EQ(-1, Lookup(200));
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ASSERT_EQ(-1, Lookup(300));
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Insert(200, 201);
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ASSERT_EQ(101, Lookup(100));
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ASSERT_EQ(201, Lookup(200));
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ASSERT_EQ(-1, Lookup(300));
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Insert(100, 102);
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ASSERT_EQ(102, Lookup(100));
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ASSERT_EQ(201, Lookup(200));
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ASSERT_EQ(-1, Lookup(300));
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ASSERT_EQ(1U, deleted_keys_.size());
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ASSERT_EQ(100, deleted_keys_[0]);
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ASSERT_EQ(101, deleted_values_[0]);
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}
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TEST_F(CacheTest, Erase) {
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Erase(200);
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ASSERT_EQ(0U, deleted_keys_.size());
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Insert(100, 101);
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Insert(200, 201);
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Erase(100);
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ASSERT_EQ(-1, Lookup(100));
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ASSERT_EQ(201, Lookup(200));
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ASSERT_EQ(1U, deleted_keys_.size());
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ASSERT_EQ(100, deleted_keys_[0]);
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ASSERT_EQ(101, deleted_values_[0]);
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Erase(100);
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ASSERT_EQ(-1, Lookup(100));
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ASSERT_EQ(201, Lookup(200));
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ASSERT_EQ(1U, deleted_keys_.size());
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}
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TEST_F(CacheTest, EntriesArePinned) {
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Insert(100, 101);
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Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
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ASSERT_EQ(101, DecodeValue(cache_->Value(h1)));
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ASSERT_EQ(1U, cache_->GetUsage());
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Insert(100, 102);
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Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
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ASSERT_EQ(102, DecodeValue(cache_->Value(h2)));
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ASSERT_EQ(0U, deleted_keys_.size());
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ASSERT_EQ(2U, cache_->GetUsage());
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cache_->Release(h1);
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ASSERT_EQ(1U, deleted_keys_.size());
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ASSERT_EQ(100, deleted_keys_[0]);
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ASSERT_EQ(101, deleted_values_[0]);
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ASSERT_EQ(1U, cache_->GetUsage());
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Erase(100);
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ASSERT_EQ(-1, Lookup(100));
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ASSERT_EQ(1U, deleted_keys_.size());
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ASSERT_EQ(1U, cache_->GetUsage());
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cache_->Release(h2);
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ASSERT_EQ(2U, deleted_keys_.size());
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ASSERT_EQ(100, deleted_keys_[1]);
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ASSERT_EQ(102, deleted_values_[1]);
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ASSERT_EQ(0U, cache_->GetUsage());
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}
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TEST_F(CacheTest, EvictionPolicy) {
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Insert(100, 101);
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Insert(200, 201);
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// Frequently used entry must be kept around
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for (int i = 0; i < kCacheSize + 100; i++) {
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Insert(1000+i, 2000+i);
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ASSERT_EQ(2000+i, Lookup(1000+i));
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ASSERT_EQ(101, Lookup(100));
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}
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ASSERT_EQ(101, Lookup(100));
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ASSERT_EQ(-1, Lookup(200));
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}
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TEST_F(CacheTest, EvictionPolicyRef) {
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Insert(100, 101);
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Insert(101, 102);
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Insert(102, 103);
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Insert(103, 104);
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Insert(200, 101);
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Insert(201, 102);
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Insert(202, 103);
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Insert(203, 104);
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Cache::Handle* h201 = cache_->Lookup(EncodeKey(200));
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Cache::Handle* h202 = cache_->Lookup(EncodeKey(201));
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Cache::Handle* h203 = cache_->Lookup(EncodeKey(202));
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Cache::Handle* h204 = cache_->Lookup(EncodeKey(203));
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Insert(300, 101);
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Insert(301, 102);
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Insert(302, 103);
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Insert(303, 104);
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// Insert entries much more than Cache capacity
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for (int i = 0; i < kCacheSize + 100; i++) {
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Insert(1000 + i, 2000 + i);
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}
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// Check whether the entries inserted in the beginning
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// are evicted. Ones without extra ref are evicted and
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// those with are not.
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ASSERT_EQ(-1, Lookup(100));
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ASSERT_EQ(-1, Lookup(101));
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ASSERT_EQ(-1, Lookup(102));
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ASSERT_EQ(-1, Lookup(103));
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ASSERT_EQ(-1, Lookup(300));
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ASSERT_EQ(-1, Lookup(301));
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ASSERT_EQ(-1, Lookup(302));
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ASSERT_EQ(-1, Lookup(303));
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ASSERT_EQ(101, Lookup(200));
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ASSERT_EQ(102, Lookup(201));
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ASSERT_EQ(103, Lookup(202));
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ASSERT_EQ(104, Lookup(203));
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// Cleaning up all the handles
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cache_->Release(h201);
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cache_->Release(h202);
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cache_->Release(h203);
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cache_->Release(h204);
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}
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TEST_F(CacheTest, ErasedHandleState) {
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// insert a key and get two handles
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Insert(100, 1000);
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Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
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Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
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ASSERT_EQ(h1, h2);
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ASSERT_EQ(DecodeValue(cache_->Value(h1)), 1000);
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ASSERT_EQ(DecodeValue(cache_->Value(h2)), 1000);
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// delete the key from the cache
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Erase(100);
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// can no longer find in the cache
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ASSERT_EQ(-1, Lookup(100));
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// release one handle
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cache_->Release(h1);
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// still can't find in cache
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ASSERT_EQ(-1, Lookup(100));
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cache_->Release(h2);
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}
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TEST_F(CacheTest, HeavyEntries) {
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// Add a bunch of light and heavy entries and then count the combined
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// size of items still in the cache, which must be approximately the
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// same as the total capacity.
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const int kLight = 1;
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const int kHeavy = 10;
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int added = 0;
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int index = 0;
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while (added < 2*kCacheSize) {
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const int weight = (index & 1) ? kLight : kHeavy;
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Insert(index, 1000+index, weight);
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added += weight;
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index++;
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}
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int cached_weight = 0;
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for (int i = 0; i < index; i++) {
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const int weight = (i & 1 ? kLight : kHeavy);
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int r = Lookup(i);
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if (r >= 0) {
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cached_weight += weight;
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ASSERT_EQ(1000+i, r);
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}
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}
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ASSERT_LE(cached_weight, kCacheSize + kCacheSize/10);
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}
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TEST_F(CacheTest, NewId) {
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uint64_t a = cache_->NewId();
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uint64_t b = cache_->NewId();
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ASSERT_NE(a, b);
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}
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class Value {
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private:
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size_t v_;
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public:
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explicit Value(size_t v) : v_(v) { }
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~Value() { std::cout << v_ << " is destructed\n"; }
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};
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namespace {
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void deleter(const Slice& key, void* value) {
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delete static_cast<Value *>(value);
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}
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} // namespace
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TEST_F(CacheTest, SetCapacity) {
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// test1: increase capacity
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// lets create a cache with capacity 5,
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// then, insert 5 elements, then increase capacity
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// to 10, returned capacity should be 10, usage=5
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std::shared_ptr<Cache> cache = NewLRUCache(5, 0);
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std::vector<Cache::Handle*> handles(10);
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// Insert 5 entries, but not releasing.
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for (size_t i = 0; i < 5; i++) {
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std::string key = ToString(i+1);
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handles[i] = cache->Insert(key, new Value(i+1), 1, &deleter);
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}
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ASSERT_EQ(5U, cache->GetCapacity());
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ASSERT_EQ(5U, cache->GetUsage());
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cache->SetCapacity(10);
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ASSERT_EQ(10U, cache->GetCapacity());
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ASSERT_EQ(5U, cache->GetUsage());
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// test2: decrease capacity
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// insert 5 more elements to cache, then release 5,
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// then decrease capacity to 7, final capacity should be 7
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// and usage should be 7
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for (size_t i = 5; i < 10; i++) {
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std::string key = ToString(i+1);
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handles[i] = cache->Insert(key, new Value(i+1), 1, &deleter);
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}
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ASSERT_EQ(10U, cache->GetCapacity());
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ASSERT_EQ(10U, cache->GetUsage());
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for (size_t i = 0; i < 5; i++) {
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cache->Release(handles[i]);
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}
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ASSERT_EQ(10U, cache->GetCapacity());
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ASSERT_EQ(10U, cache->GetUsage());
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cache->SetCapacity(7);
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ASSERT_EQ(7, cache->GetCapacity());
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ASSERT_EQ(7, cache->GetUsage());
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// release remaining 5 to keep valgrind happy
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for (size_t i = 5; i < 10; i++) {
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cache->Release(handles[i]);
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}
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}
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TEST_F(CacheTest, OverCapacity) {
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size_t n = 10;
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// a LRUCache with n entries and one shard only
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std::shared_ptr<Cache> cache = NewLRUCache(n, 0);
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std::vector<Cache::Handle*> handles(n+1);
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// Insert n+1 entries, but not releasing.
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for (size_t i = 0; i < n + 1; i++) {
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std::string key = ToString(i+1);
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handles[i] = cache->Insert(key, new Value(i+1), 1, &deleter);
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}
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// Guess what's in the cache now?
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for (size_t i = 0; i < n + 1; i++) {
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std::string key = ToString(i+1);
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auto h = cache->Lookup(key);
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std::cout << key << (h?" found\n":" not found\n");
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ASSERT_TRUE(h != nullptr);
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if (h) cache->Release(h);
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}
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// the cache is over capacity since nothing could be evicted
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ASSERT_EQ(n + 1U, cache->GetUsage());
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for (size_t i = 0; i < n + 1; i++) {
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cache->Release(handles[i]);
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}
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// cache is under capacity now since elements were released
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ASSERT_EQ(n, cache->GetUsage());
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// element 0 is evicted and the rest is there
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// This is consistent with the LRU policy since the element 0
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// was released first
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for (size_t i = 0; i < n + 1; i++) {
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std::string key = ToString(i+1);
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auto h = cache->Lookup(key);
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if (h) {
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ASSERT_NE(i, 0U);
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cache->Release(h);
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} else {
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ASSERT_EQ(i, 0U);
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}
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}
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}
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namespace {
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std::vector<std::pair<int, int>> callback_state;
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void callback(void* entry, size_t charge) {
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callback_state.push_back({DecodeValue(entry), static_cast<int>(charge)});
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}
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};
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TEST_F(CacheTest, ApplyToAllCacheEntiresTest) {
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std::vector<std::pair<int, int>> inserted;
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callback_state.clear();
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for (int i = 0; i < 10; ++i) {
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Insert(i, i * 2, i + 1);
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inserted.push_back({i * 2, i + 1});
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}
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cache_->ApplyToAllCacheEntries(callback, true);
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sort(inserted.begin(), inserted.end());
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sort(callback_state.begin(), callback_state.end());
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ASSERT_TRUE(inserted == callback_state);
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}
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} // namespace rocksdb
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int main(int argc, char** argv) {
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::testing::InitGoogleTest(&argc, argv);
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return RUN_ALL_TESTS();
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}
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