rocksdb/cache/compressed_secondary_cache_test.cc

//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).

#include "cache/compressed_secondary_cache.h"

#include <iterator>
#include <memory>
#include <tuple>

#include "memory/jemalloc_nodump_allocator.h"
#include "rocksdb/convenience.h"
#include "test_util/testharness.h"
#include "test_util/testutil.h"

namespace ROCKSDB_NAMESPACE {

class CompressedSecondaryCacheTest : public testing::Test,
                                     public Cache::CreateContext {
 public:
  CompressedSecondaryCacheTest() : fail_create_(false) {}
  ~CompressedSecondaryCacheTest() override = default;

 protected:
  class TestItem {
   public:
    TestItem(const char* buf, size_t size) : buf_(new char[size]), size_(size) {
      memcpy(buf_.get(), buf, size);
    }
    ~TestItem() = default;

    char* Buf() { return buf_.get(); }
    [[nodiscard]] size_t Size() const { return size_; }

   private:
    std::unique_ptr<char[]> buf_;
    size_t size_;
  };

  static size_t SizeCallback(Cache::ObjectPtr obj) {
    return static_cast<TestItem*>(obj)->Size();
  }

  static Status SaveToCallback(Cache::ObjectPtr from_obj, size_t from_offset,
                               size_t length, char* out) {
    auto item = static_cast<TestItem*>(from_obj);
    const char* buf = item->Buf();
    EXPECT_EQ(length, item->Size());
    EXPECT_EQ(from_offset, 0);
    memcpy(out, buf, length);
    return Status::OK();
  }

  static void DeletionCallback(Cache::ObjectPtr obj,
                               MemoryAllocator* /*alloc*/) {
    delete static_cast<TestItem*>(obj);
    obj = nullptr;
  }

  static Status SaveToCallbackFail(Cache::ObjectPtr /*obj*/, size_t /*offset*/,
                                   size_t /*size*/, char* /*out*/) {
    return Status::NotSupported();
  }

  static Status CreateCallback(const Slice& data, Cache::CreateContext* context,
                               MemoryAllocator* /*allocator*/,
                               Cache::ObjectPtr* out_obj, size_t* out_charge) {
    auto t = static_cast<CompressedSecondaryCacheTest*>(context);
    if (t->fail_create_) {
      return Status::NotSupported();
    }
    *out_obj = new TestItem(data.data(), data.size());
    *out_charge = data.size();
    return Status::OK();
  }

  static constexpr Cache::CacheItemHelper kHelper{
      CacheEntryRole::kMisc, &DeletionCallback, &SizeCallback, &SaveToCallback,
      &CreateCallback};

  static constexpr Cache::CacheItemHelper kHelperFail{
      CacheEntryRole::kMisc, &DeletionCallback, &SizeCallback,
      &SaveToCallbackFail, &CreateCallback};

  void SetFailCreate(bool fail) { fail_create_ = fail; }

  void BasicTestHelper(std::shared_ptr<SecondaryCache> sec_cache,
                       bool sec_cache_is_compressed) {
    get_perf_context()->Reset();
    bool is_in_sec_cache{true};
    // Lookup an non-existent key.
    std::unique_ptr<SecondaryCacheResultHandle> handle0 = sec_cache->Lookup(
        "k0", &kHelper, this, true, /*advise_erase=*/true, is_in_sec_cache);
    ASSERT_EQ(handle0, nullptr);

    Random rnd(301);
    // Insert and Lookup the item k1 for the first time.
    std::string str1(rnd.RandomString(1000));
    TestItem item1(str1.data(), str1.length());
    // A dummy handle is inserted if the item is inserted for the first time.
    ASSERT_OK(sec_cache->Insert("k1", &item1, &kHelper));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 1);
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);

    std::unique_ptr<SecondaryCacheResultHandle> handle1_1 = sec_cache->Lookup(
        "k1", &kHelper, this, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_EQ(handle1_1, nullptr);

    // Insert and Lookup the item k1 for the second time and advise erasing it.
    ASSERT_OK(sec_cache->Insert("k1", &item1, &kHelper));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 1);

    std::unique_ptr<SecondaryCacheResultHandle> handle1_2 = sec_cache->Lookup(
        "k1", &kHelper, this, true, /*advise_erase=*/true, is_in_sec_cache);
    ASSERT_NE(handle1_2, nullptr);
    ASSERT_FALSE(is_in_sec_cache);
    if (sec_cache_is_compressed) {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
                1000);
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
                1007);
    } else {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
    }

    std::unique_ptr<TestItem> val1 =
        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle1_2->Value()));
    ASSERT_NE(val1, nullptr);
    ASSERT_EQ(memcmp(val1->Buf(), item1.Buf(), item1.Size()), 0);

    // Lookup the item k1 again.
    std::unique_ptr<SecondaryCacheResultHandle> handle1_3 = sec_cache->Lookup(
        "k1", &kHelper, this, true, /*advise_erase=*/true, is_in_sec_cache);
    ASSERT_EQ(handle1_3, nullptr);

    // Insert and Lookup the item k2.
    std::string str2(rnd.RandomString(1000));
    TestItem item2(str2.data(), str2.length());
    ASSERT_OK(sec_cache->Insert("k2", &item2, &kHelper));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 2);
    std::unique_ptr<SecondaryCacheResultHandle> handle2_1 = sec_cache->Lookup(
        "k2", &kHelper, this, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_EQ(handle2_1, nullptr);

    ASSERT_OK(sec_cache->Insert("k2", &item2, &kHelper));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 2);
    if (sec_cache_is_compressed) {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
                2000);
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
                2014);
    } else {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
    }
    std::unique_ptr<SecondaryCacheResultHandle> handle2_2 = sec_cache->Lookup(
        "k2", &kHelper, this, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_NE(handle2_2, nullptr);
    std::unique_ptr<TestItem> val2 =
        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle2_2->Value()));
    ASSERT_NE(val2, nullptr);
    ASSERT_EQ(memcmp(val2->Buf(), item2.Buf(), item2.Size()), 0);

    std::vector<SecondaryCacheResultHandle*> handles = {handle1_2.get(),
                                                        handle2_2.get()};
    sec_cache->WaitAll(handles);

    sec_cache.reset();
  }

  void BasicTest(bool sec_cache_is_compressed, bool use_jemalloc) {
    CompressedSecondaryCacheOptions opts;
    opts.capacity = 2048;
    opts.num_shard_bits = 0;

    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        opts.compression_type = CompressionType::kNoCompression;
        sec_cache_is_compressed = false;
      }
    } else {
      opts.compression_type = CompressionType::kNoCompression;
    }

    if (use_jemalloc) {
      JemallocAllocatorOptions jopts;
      std::shared_ptr<MemoryAllocator> allocator;
      std::string msg;
      if (JemallocNodumpAllocator::IsSupported(&msg)) {
        Status s = NewJemallocNodumpAllocator(jopts, &allocator);
        if (s.ok()) {
          opts.memory_allocator = allocator;
        }
      } else {
        ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
      }
    }
    std::shared_ptr<SecondaryCache> sec_cache =
        NewCompressedSecondaryCache(opts);

    BasicTestHelper(sec_cache, sec_cache_is_compressed);
  }

  void FailsTest(bool sec_cache_is_compressed) {
    CompressedSecondaryCacheOptions secondary_cache_opts;
    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
      }
    } else {
      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
    }

    secondary_cache_opts.capacity = 1100;
    secondary_cache_opts.num_shard_bits = 0;
    std::shared_ptr<SecondaryCache> sec_cache =
        NewCompressedSecondaryCache(secondary_cache_opts);

    // Insert and Lookup the first item.
    Random rnd(301);
    std::string str1(rnd.RandomString(1000));
    TestItem item1(str1.data(), str1.length());
    // Insert a dummy handle.
    ASSERT_OK(sec_cache->Insert("k1", &item1, &kHelper));
    // Insert k1.
    ASSERT_OK(sec_cache->Insert("k1", &item1, &kHelper));

    // Insert and Lookup the second item.
    std::string str2(rnd.RandomString(200));
    TestItem item2(str2.data(), str2.length());
    // Insert a dummy handle, k1 is not evicted.
    ASSERT_OK(sec_cache->Insert("k2", &item2, &kHelper));
    bool is_in_sec_cache{false};
    std::unique_ptr<SecondaryCacheResultHandle> handle1 = sec_cache->Lookup(
        "k1", &kHelper, this, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_EQ(handle1, nullptr);

    // Insert k2 and k1 is evicted.
    ASSERT_OK(sec_cache->Insert("k2", &item2, &kHelper));
    std::unique_ptr<SecondaryCacheResultHandle> handle2 = sec_cache->Lookup(
        "k2", &kHelper, this, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_NE(handle2, nullptr);
    std::unique_ptr<TestItem> val2 =
        std::unique_ptr<TestItem>(static_cast<TestItem*>(handle2->Value()));
    ASSERT_NE(val2, nullptr);
    ASSERT_EQ(memcmp(val2->Buf(), item2.Buf(), item2.Size()), 0);

    // Insert k1 again and a dummy handle is inserted.
    ASSERT_OK(sec_cache->Insert("k1", &item1, &kHelper));

    std::unique_ptr<SecondaryCacheResultHandle> handle1_1 = sec_cache->Lookup(
        "k1", &kHelper, this, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_EQ(handle1_1, nullptr);

    // Create Fails.
    SetFailCreate(true);
    std::unique_ptr<SecondaryCacheResultHandle> handle2_1 = sec_cache->Lookup(
        "k2", &kHelper, this, true, /*advise_erase=*/true, is_in_sec_cache);
    ASSERT_EQ(handle2_1, nullptr);

    // Save Fails.
    std::string str3 = rnd.RandomString(10);
    TestItem item3(str3.data(), str3.length());
    // The Status is OK because a dummy handle is inserted.
    ASSERT_OK(sec_cache->Insert("k3", &item3, &kHelperFail));
    ASSERT_NOK(sec_cache->Insert("k3", &item3, &kHelperFail));

    sec_cache.reset();
  }

  void BasicIntegrationTest(bool sec_cache_is_compressed,
                            bool enable_custom_split_merge) {
    CompressedSecondaryCacheOptions secondary_cache_opts;

    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
        sec_cache_is_compressed = false;
      }
    } else {
      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
    }

    secondary_cache_opts.capacity = 6000;
    secondary_cache_opts.num_shard_bits = 0;
    secondary_cache_opts.enable_custom_split_merge = enable_custom_split_merge;
    std::shared_ptr<SecondaryCache> secondary_cache =
        NewCompressedSecondaryCache(secondary_cache_opts);
    LRUCacheOptions lru_cache_opts(
        /*_capacity =*/1300, /*_num_shard_bits =*/0,
        /*_strict_capacity_limit =*/false, /*_high_pri_pool_ratio =*/0.5,
        /*_memory_allocator =*/nullptr, kDefaultToAdaptiveMutex,
        kDefaultCacheMetadataChargePolicy, /*_low_pri_pool_ratio =*/0.0);
    lru_cache_opts.secondary_cache = secondary_cache;
    std::shared_ptr<Cache> cache = NewLRUCache(lru_cache_opts);
    std::shared_ptr<Statistics> stats = CreateDBStatistics();

    get_perf_context()->Reset();
    Random rnd(301);
    std::string str1 = rnd.RandomString(1001);
    auto item1_1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1_1, &kHelper, str1.length()));

    std::string str2 = rnd.RandomString(1012);
    auto item2_1 = new TestItem(str2.data(), str2.length());
    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's dummy item.
    ASSERT_OK(cache->Insert("k2", item2_1, &kHelper, str2.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 1);
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);

    std::string str3 = rnd.RandomString(1024);
    auto item3_1 = new TestItem(str3.data(), str3.length());
    // After this Insert, primary cache contains k3 and secondary cache contains
    // k1's dummy item and k2's dummy item.
    ASSERT_OK(cache->Insert("k3", item3_1, &kHelper, str3.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 2);

    // After this Insert, primary cache contains k1 and secondary cache contains
    // k1's dummy item, k2's dummy item, and k3's dummy item.
    auto item1_2 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1_2, &kHelper, str1.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 3);

    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's item, k2's dummy item, and k3's dummy item.
    auto item2_2 = new TestItem(str2.data(), str2.length());
    ASSERT_OK(cache->Insert("k2", item2_2, &kHelper, str2.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 1);
    if (sec_cache_is_compressed) {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
                str1.length());
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
                1008);
    } else {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
    }

    // After this Insert, primary cache contains k3 and secondary cache contains
    // k1's item and k2's item.
    auto item3_2 = new TestItem(str3.data(), str3.length());
    ASSERT_OK(cache->Insert("k3", item3_2, &kHelper, str3.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 2);
    if (sec_cache_is_compressed) {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes,
                str1.length() + str2.length());
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes,
                2027);
    } else {
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_uncompressed_bytes, 0);
      ASSERT_EQ(get_perf_context()->compressed_sec_cache_compressed_bytes, 0);
    }

    Cache::Handle* handle;
    handle = cache->Lookup("k3", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    auto val3 = static_cast<TestItem*>(cache->Value(handle));
    ASSERT_NE(val3, nullptr);
    ASSERT_EQ(memcmp(val3->Buf(), item3_2->Buf(), item3_2->Size()), 0);
    cache->Release(handle);

    // Lookup an non-existent key.
    handle = cache->Lookup("k0", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_EQ(handle, nullptr);

    // This Lookup should just insert a dummy handle in the primary cache
    // and the k1 is still in the secondary cache.
    handle = cache->Lookup("k1", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 1);
    auto val1_1 = static_cast<TestItem*>(cache->Value(handle));
    ASSERT_NE(val1_1, nullptr);
    ASSERT_EQ(memcmp(val1_1->Buf(), str1.data(), str1.size()), 0);
    cache->Release(handle);

    // This Lookup should erase k1 from the secondary cache and insert
    // it into primary cache; then k3 is demoted.
    // k2 and k3 are in secondary cache.
    handle = cache->Lookup("k1", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 1);
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 3);
    cache->Release(handle);

    // k2 is still in secondary cache.
    handle = cache->Lookup("k2", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 2);
    cache->Release(handle);

    // Testing SetCapacity().
    ASSERT_OK(secondary_cache->SetCapacity(0));
    handle = cache->Lookup("k3", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_EQ(handle, nullptr);

    ASSERT_OK(secondary_cache->SetCapacity(7000));
    size_t capacity;
    ASSERT_OK(secondary_cache->GetCapacity(capacity));
    ASSERT_EQ(capacity, 7000);
    auto item1_3 = new TestItem(str1.data(), str1.length());
    // After this Insert, primary cache contains k1.
    ASSERT_OK(cache->Insert("k1", item1_3, &kHelper, str2.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 3);
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 4);

    auto item2_3 = new TestItem(str2.data(), str2.length());
    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's dummy item.
    ASSERT_OK(cache->Insert("k2", item2_3, &kHelper, str1.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 4);

    auto item1_4 = new TestItem(str1.data(), str1.length());
    // After this Insert, primary cache contains k1 and secondary cache contains
    // k1's dummy item and k2's dummy item.
    ASSERT_OK(cache->Insert("k1", item1_4, &kHelper, str2.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_dummy_count, 5);

    auto item2_4 = new TestItem(str2.data(), str2.length());
    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's real item and k2's dummy item.
    ASSERT_OK(cache->Insert("k2", item2_4, &kHelper, str2.length()));
    ASSERT_EQ(get_perf_context()->compressed_sec_cache_insert_real_count, 5);
    // This Lookup should just insert a dummy handle in the primary cache
    // and the k1 is still in the secondary cache.
    handle = cache->Lookup("k1", &kHelper, this, Cache::Priority::LOW, true,
                           stats.get());

    ASSERT_NE(handle, nullptr);
    cache->Release(handle);
    ASSERT_EQ(get_perf_context()->block_cache_standalone_handle_count, 3);

    cache.reset();
    secondary_cache.reset();
  }

  void BasicIntegrationFailTest(bool sec_cache_is_compressed) {
    CompressedSecondaryCacheOptions secondary_cache_opts;

    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
      }
    } else {
      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
    }

    secondary_cache_opts.capacity = 6000;
    secondary_cache_opts.num_shard_bits = 0;
    std::shared_ptr<SecondaryCache> secondary_cache =
        NewCompressedSecondaryCache(secondary_cache_opts);

    LRUCacheOptions opts(
        /*_capacity=*/1300, /*_num_shard_bits=*/0,
        /*_strict_capacity_limit=*/false, /*_high_pri_pool_ratio=*/0.5,
        /*_memory_allocator=*/nullptr, kDefaultToAdaptiveMutex,
        kDefaultCacheMetadataChargePolicy, /*_low_pri_pool_ratio=*/0.0);
    opts.secondary_cache = secondary_cache;
    std::shared_ptr<Cache> cache = NewLRUCache(opts);

    Random rnd(301);
    std::string str1 = rnd.RandomString(1001);
    auto item1 = std::make_unique<TestItem>(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1.get(), &kHelper, str1.length()));
    item1.release();  // Appease clang-analyze "potential memory leak"

    Cache::Handle* handle;
    handle = cache->Lookup("k2", nullptr, this, Cache::Priority::LOW, true);
    ASSERT_EQ(handle, nullptr);
    handle = cache->Lookup("k2", &kHelper, this, Cache::Priority::LOW, false);
    ASSERT_EQ(handle, nullptr);

    cache.reset();
    secondary_cache.reset();
  }

  void IntegrationSaveFailTest(bool sec_cache_is_compressed) {
    CompressedSecondaryCacheOptions secondary_cache_opts;

    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
      }
    } else {
      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
    }

    secondary_cache_opts.capacity = 6000;
    secondary_cache_opts.num_shard_bits = 0;

    std::shared_ptr<SecondaryCache> secondary_cache =
        NewCompressedSecondaryCache(secondary_cache_opts);

    LRUCacheOptions opts(
        /*_capacity=*/1300, /*_num_shard_bits=*/0,
        /*_strict_capacity_limit=*/false, /*_high_pri_pool_ratio=*/0.5,
        /*_memory_allocator=*/nullptr, kDefaultToAdaptiveMutex,
        kDefaultCacheMetadataChargePolicy, /*_low_pri_pool_ratio=*/0.0);
    opts.secondary_cache = secondary_cache;
    std::shared_ptr<Cache> cache = NewLRUCache(opts);

    Random rnd(301);
    std::string str1 = rnd.RandomString(1001);
    auto item1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1, &kHelperFail, str1.length()));

    std::string str2 = rnd.RandomString(1002);
    auto item2 = new TestItem(str2.data(), str2.length());
    // k1 should be demoted to the secondary cache.
    ASSERT_OK(cache->Insert("k2", item2, &kHelperFail, str2.length()));

    Cache::Handle* handle;
    handle =
        cache->Lookup("k2", &kHelperFail, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle, nullptr);
    cache->Release(handle);
    // This lookup should fail, since k1 demotion would have failed.
    handle =
        cache->Lookup("k1", &kHelperFail, this, Cache::Priority::LOW, true);
    ASSERT_EQ(handle, nullptr);
    // Since k1 was not promoted, k2 should still be in cache.
    handle =
        cache->Lookup("k2", &kHelperFail, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle, nullptr);
    cache->Release(handle);

    cache.reset();
    secondary_cache.reset();
  }

  void IntegrationCreateFailTest(bool sec_cache_is_compressed) {
    CompressedSecondaryCacheOptions secondary_cache_opts;

    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
      }
    } else {
      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
    }

    secondary_cache_opts.capacity = 6000;
    secondary_cache_opts.num_shard_bits = 0;

    std::shared_ptr<SecondaryCache> secondary_cache =
        NewCompressedSecondaryCache(secondary_cache_opts);

    LRUCacheOptions opts(
        /*_capacity=*/1300, /*_num_shard_bits=*/0,
        /*_strict_capacity_limit=*/false, /*_high_pri_pool_ratio=*/0.5,
        /*_memory_allocator=*/nullptr, kDefaultToAdaptiveMutex,
        kDefaultCacheMetadataChargePolicy, /*_low_pri_pool_ratio=*/0.0);
    opts.secondary_cache = secondary_cache;
    std::shared_ptr<Cache> cache = NewLRUCache(opts);

    Random rnd(301);
    std::string str1 = rnd.RandomString(1001);
    auto item1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1, &kHelper, str1.length()));

    std::string str2 = rnd.RandomString(1002);
    auto item2 = new TestItem(str2.data(), str2.length());
    // k1 should be demoted to the secondary cache.
    ASSERT_OK(cache->Insert("k2", item2, &kHelper, str2.length()));

    Cache::Handle* handle;
    SetFailCreate(true);
    handle = cache->Lookup("k2", &kHelper, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle, nullptr);
    cache->Release(handle);
    // This lookup should fail, since k1 creation would have failed
    handle = cache->Lookup("k1", &kHelper, this, Cache::Priority::LOW, true);
    ASSERT_EQ(handle, nullptr);
    // Since k1 didn't get promoted, k2 should still be in cache
    handle = cache->Lookup("k2", &kHelper, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle, nullptr);
    cache->Release(handle);

    cache.reset();
    secondary_cache.reset();
  }

  void IntegrationFullCapacityTest(bool sec_cache_is_compressed) {
    CompressedSecondaryCacheOptions secondary_cache_opts;

    if (sec_cache_is_compressed) {
      if (!LZ4_Supported()) {
        ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
        secondary_cache_opts.compression_type = CompressionType::kNoCompression;
      }
    } else {
      secondary_cache_opts.compression_type = CompressionType::kNoCompression;
    }

    secondary_cache_opts.capacity = 6000;
    secondary_cache_opts.num_shard_bits = 0;

    std::shared_ptr<SecondaryCache> secondary_cache =
        NewCompressedSecondaryCache(secondary_cache_opts);

    LRUCacheOptions opts(
        /*_capacity=*/1300, /*_num_shard_bits=*/0,
        /*_strict_capacity_limit=*/false, /*_high_pri_pool_ratio=*/0.5,
        /*_memory_allocator=*/nullptr, kDefaultToAdaptiveMutex,
        kDefaultCacheMetadataChargePolicy, /*_low_pri_pool_ratio=*/0.0);
    opts.secondary_cache = secondary_cache;
    std::shared_ptr<Cache> cache = NewLRUCache(opts);

    Random rnd(301);
    std::string str1 = rnd.RandomString(1001);
    auto item1_1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1_1, &kHelper, str1.length()));

    std::string str2 = rnd.RandomString(1002);
    std::string str2_clone{str2};
    auto item2 = new TestItem(str2.data(), str2.length());
    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's dummy item.
    ASSERT_OK(cache->Insert("k2", item2, &kHelper, str2.length()));

    // After this Insert, primary cache contains k1 and secondary cache contains
    // k1's dummy item and k2's dummy item.
    auto item1_2 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1_2, &kHelper, str1.length()));

    auto item2_2 = new TestItem(str2.data(), str2.length());
    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's item and k2's dummy item.
    ASSERT_OK(cache->Insert("k2", item2_2, &kHelper, str2.length()));

    Cache::Handle* handle2;
    handle2 = cache->Lookup("k2", &kHelper, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle2, nullptr);
    cache->Release(handle2);

    // k1 promotion should fail because cache is at capacity and
    // strict_capacity_limit is true, but the lookup should still succeed.
    // A k1's dummy item is inserted into primary cache.
    Cache::Handle* handle1;
    handle1 = cache->Lookup("k1", &kHelper, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle1, nullptr);
    cache->Release(handle1);

    // Since k1 didn't get inserted, k2 should still be in cache
    handle2 = cache->Lookup("k2", &kHelper, this, Cache::Priority::LOW, true);
    ASSERT_NE(handle2, nullptr);
    cache->Release(handle2);

    cache.reset();
    secondary_cache.reset();
  }

  void SplitValueIntoChunksTest() {
    JemallocAllocatorOptions jopts;
    std::shared_ptr<MemoryAllocator> allocator;
    std::string msg;
    if (JemallocNodumpAllocator::IsSupported(&msg)) {
      Status s = NewJemallocNodumpAllocator(jopts, &allocator);
      if (!s.ok()) {
        ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
      }
    } else {
      ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
    }

    using CacheValueChunk = CompressedSecondaryCache::CacheValueChunk;
    std::unique_ptr<CompressedSecondaryCache> sec_cache =
        std::make_unique<CompressedSecondaryCache>(1000, 0, true, 0.5, 0.0,
                                                   allocator);
    Random rnd(301);
    // 8500 = 8169 + 233 + 98, so there should be 3 chunks after split.
    size_t str_size{8500};
    std::string str = rnd.RandomString(static_cast<int>(str_size));
    size_t charge{0};
    CacheValueChunk* chunks_head =
        sec_cache->SplitValueIntoChunks(str, kLZ4Compression, charge);
    ASSERT_EQ(charge, str_size + 3 * (sizeof(CacheValueChunk) - 1));

    CacheValueChunk* current_chunk = chunks_head;
    ASSERT_EQ(current_chunk->size, 8192 - sizeof(CacheValueChunk) + 1);
    current_chunk = current_chunk->next;
    ASSERT_EQ(current_chunk->size, 256 - sizeof(CacheValueChunk) + 1);
    current_chunk = current_chunk->next;
    ASSERT_EQ(current_chunk->size, 98);

    sec_cache->GetHelper(true)->del_cb(chunks_head, /*alloc*/ nullptr);
  }

  void MergeChunksIntoValueTest() {
    using CacheValueChunk = CompressedSecondaryCache::CacheValueChunk;
    Random rnd(301);
    size_t size1{2048};
    std::string str1 = rnd.RandomString(static_cast<int>(size1));
    CacheValueChunk* current_chunk = reinterpret_cast<CacheValueChunk*>(
        new char[sizeof(CacheValueChunk) - 1 + size1]);
    CacheValueChunk* chunks_head = current_chunk;
    memcpy(current_chunk->data, str1.data(), size1);
    current_chunk->size = size1;

    size_t size2{256};
    std::string str2 = rnd.RandomString(static_cast<int>(size2));
    current_chunk->next = reinterpret_cast<CacheValueChunk*>(
        new char[sizeof(CacheValueChunk) - 1 + size2]);
    current_chunk = current_chunk->next;
    memcpy(current_chunk->data, str2.data(), size2);
    current_chunk->size = size2;

    size_t size3{31};
    std::string str3 = rnd.RandomString(static_cast<int>(size3));
    current_chunk->next = reinterpret_cast<CacheValueChunk*>(
        new char[sizeof(CacheValueChunk) - 1 + size3]);
    current_chunk = current_chunk->next;
    memcpy(current_chunk->data, str3.data(), size3);
    current_chunk->size = size3;
    current_chunk->next = nullptr;

    std::string str = str1 + str2 + str3;

    std::unique_ptr<CompressedSecondaryCache> sec_cache =
        std::make_unique<CompressedSecondaryCache>(1000, 0, true, 0.5, 0.0);
    size_t charge{0};
    CacheAllocationPtr value =
        sec_cache->MergeChunksIntoValue(chunks_head, charge);
    ASSERT_EQ(charge, size1 + size2 + size3);
    std::string value_str{value.get(), charge};
    ASSERT_EQ(strcmp(value_str.data(), str.data()), 0);

    while (chunks_head != nullptr) {
      CacheValueChunk* tmp_chunk = chunks_head;
      chunks_head = chunks_head->next;
      tmp_chunk->Free();
    }
  }

  void SplictValueAndMergeChunksTest() {
    JemallocAllocatorOptions jopts;
    std::shared_ptr<MemoryAllocator> allocator;
    std::string msg;
    if (JemallocNodumpAllocator::IsSupported(&msg)) {
      Status s = NewJemallocNodumpAllocator(jopts, &allocator);
      if (!s.ok()) {
        ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
      }
    } else {
      ROCKSDB_GTEST_BYPASS("JEMALLOC not supported");
    }

    using CacheValueChunk = CompressedSecondaryCache::CacheValueChunk;
    std::unique_ptr<CompressedSecondaryCache> sec_cache =
        std::make_unique<CompressedSecondaryCache>(1000, 0, true, 0.5, 0.0,
                                                   allocator);
    Random rnd(301);
    // 8500 = 8169 + 233 + 98, so there should be 3 chunks after split.
    size_t str_size{8500};
    std::string str = rnd.RandomString(static_cast<int>(str_size));
    size_t charge{0};
    CacheValueChunk* chunks_head =
        sec_cache->SplitValueIntoChunks(str, kLZ4Compression, charge);
    ASSERT_EQ(charge, str_size + 3 * (sizeof(CacheValueChunk) - 1));

    CacheAllocationPtr value =
        sec_cache->MergeChunksIntoValue(chunks_head, charge);
    ASSERT_EQ(charge, str_size);
    std::string value_str{value.get(), charge};
    ASSERT_EQ(strcmp(value_str.data(), str.data()), 0);

    sec_cache->GetHelper(true)->del_cb(chunks_head, /*alloc*/ nullptr);
  }

 private:
  bool fail_create_;
};

class CompressedSecCacheTestWithCompressAndAllocatorParam
    : public CompressedSecondaryCacheTest,
      public ::testing::WithParamInterface<std::tuple<bool, bool>> {
 public:
  CompressedSecCacheTestWithCompressAndAllocatorParam() {
    sec_cache_is_compressed_ = std::get<0>(GetParam());
    use_jemalloc_ = std::get<1>(GetParam());
  }
  bool sec_cache_is_compressed_;
  bool use_jemalloc_;
};

TEST_P(CompressedSecCacheTestWithCompressAndAllocatorParam, BasicTes) {
  BasicTest(sec_cache_is_compressed_, use_jemalloc_);
}

INSTANTIATE_TEST_CASE_P(CompressedSecCacheTests,
                        CompressedSecCacheTestWithCompressAndAllocatorParam,
                        ::testing::Combine(testing::Bool(), testing::Bool()));

class CompressedSecondaryCacheTestWithCompressionParam
    : public CompressedSecondaryCacheTest,
      public ::testing::WithParamInterface<bool> {
 public:
  CompressedSecondaryCacheTestWithCompressionParam() {
    sec_cache_is_compressed_ = GetParam();
  }
  bool sec_cache_is_compressed_;
};

#ifndef ROCKSDB_LITE

TEST_P(CompressedSecondaryCacheTestWithCompressionParam, BasicTestFromString) {
  std::shared_ptr<SecondaryCache> sec_cache{nullptr};
  std::string sec_cache_uri;
  if (sec_cache_is_compressed_) {
    if (LZ4_Supported()) {
      sec_cache_uri =
          "compressed_secondary_cache://"
          "capacity=2048;num_shard_bits=0;compression_type=kLZ4Compression;"
          "compress_format_version=2";
    } else {
      ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
      sec_cache_uri =
          "compressed_secondary_cache://"
          "capacity=2048;num_shard_bits=0;compression_type=kNoCompression";
      sec_cache_is_compressed_ = false;
    }
    Status s = SecondaryCache::CreateFromString(ConfigOptions(), sec_cache_uri,
                                                &sec_cache);
    EXPECT_OK(s);
  } else {
    sec_cache_uri =
        "compressed_secondary_cache://"
        "capacity=2048;num_shard_bits=0;compression_type=kNoCompression";
    Status s = SecondaryCache::CreateFromString(ConfigOptions(), sec_cache_uri,
                                                &sec_cache);
    EXPECT_OK(s);
  }
  BasicTestHelper(sec_cache, sec_cache_is_compressed_);
}

TEST_P(CompressedSecondaryCacheTestWithCompressionParam,
       BasicTestFromStringWithSplit) {
  std::shared_ptr<SecondaryCache> sec_cache{nullptr};
  std::string sec_cache_uri;
  if (sec_cache_is_compressed_) {
    if (LZ4_Supported()) {
      sec_cache_uri =
          "compressed_secondary_cache://"
          "capacity=2048;num_shard_bits=0;compression_type=kLZ4Compression;"
          "compress_format_version=2;enable_custom_split_merge=true";
    } else {
      ROCKSDB_GTEST_SKIP("This test requires LZ4 support.");
      sec_cache_uri =
          "compressed_secondary_cache://"
          "capacity=2048;num_shard_bits=0;compression_type=kNoCompression;"
          "enable_custom_split_merge=true";
      sec_cache_is_compressed_ = false;
    }
    Status s = SecondaryCache::CreateFromString(ConfigOptions(), sec_cache_uri,
                                                &sec_cache);
    EXPECT_OK(s);
  } else {
    sec_cache_uri =
        "compressed_secondary_cache://"
        "capacity=2048;num_shard_bits=0;compression_type=kNoCompression;"
        "enable_custom_split_merge=true";
    Status s = SecondaryCache::CreateFromString(ConfigOptions(), sec_cache_uri,
                                                &sec_cache);
    EXPECT_OK(s);
  }
  BasicTestHelper(sec_cache, sec_cache_is_compressed_);
}

#endif  // ROCKSDB_LITE

TEST_P(CompressedSecondaryCacheTestWithCompressionParam, FailsTest) {
  FailsTest(sec_cache_is_compressed_);
}

TEST_P(CompressedSecondaryCacheTestWithCompressionParam,
       BasicIntegrationFailTest) {
  BasicIntegrationFailTest(sec_cache_is_compressed_);
}

TEST_P(CompressedSecondaryCacheTestWithCompressionParam,
       IntegrationSaveFailTest) {
  IntegrationSaveFailTest(sec_cache_is_compressed_);
}

TEST_P(CompressedSecondaryCacheTestWithCompressionParam,
       IntegrationCreateFailTest) {
  IntegrationCreateFailTest(sec_cache_is_compressed_);
}

TEST_P(CompressedSecondaryCacheTestWithCompressionParam,
       IntegrationFullCapacityTest) {
  IntegrationFullCapacityTest(sec_cache_is_compressed_);
}

INSTANTIATE_TEST_CASE_P(CompressedSecCacheTests,
                        CompressedSecondaryCacheTestWithCompressionParam,
                        testing::Bool());

class CompressedSecCacheTestWithCompressAndSplitParam
    : public CompressedSecondaryCacheTest,
      public ::testing::WithParamInterface<std::tuple<bool, bool>> {
 public:
  CompressedSecCacheTestWithCompressAndSplitParam() {
    sec_cache_is_compressed_ = std::get<0>(GetParam());
    enable_custom_split_merge_ = std::get<1>(GetParam());
  }
  bool sec_cache_is_compressed_;
  bool enable_custom_split_merge_;
};

TEST_P(CompressedSecCacheTestWithCompressAndSplitParam, BasicIntegrationTest) {
  BasicIntegrationTest(sec_cache_is_compressed_, enable_custom_split_merge_);
}

INSTANTIATE_TEST_CASE_P(CompressedSecCacheTests,
                        CompressedSecCacheTestWithCompressAndSplitParam,
                        ::testing::Combine(testing::Bool(), testing::Bool()));

TEST_F(CompressedSecondaryCacheTest, SplitValueIntoChunksTest) {
  SplitValueIntoChunksTest();
}

TEST_F(CompressedSecondaryCacheTest, MergeChunksIntoValueTest) {
  MergeChunksIntoValueTest();
}

TEST_F(CompressedSecondaryCacheTest, SplictValueAndMergeChunksTest) {
  SplictValueAndMergeChunksTest();
}

}  // namespace ROCKSDB_NAMESPACE

int main(int argc, char** argv) {
  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}