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 <algorithm>
#include <cstdint>
#include <iterator>

#include "cache/lru_cache.h"
#include "memory/jemalloc_nodump_allocator.h"
#include "memory/memory_allocator.h"
#include "rocksdb/compression_type.h"
#include "rocksdb/convenience.h"
#include "rocksdb/secondary_cache.h"
#include "test_util/testharness.h"
#include "test_util/testutil.h"
#include "util/compression.h"
#include "util/random.h"

namespace ROCKSDB_NAMESPACE {

class CompressedSecondaryCacheTest : public testing::Test {
 public:
  CompressedSecondaryCacheTest() : fail_create_(false) {}
  ~CompressedSecondaryCacheTest() {}

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

    char* Buf() { return buf_.get(); }
    size_t Size() { return size_; }

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

  static size_t SizeCallback(void* obj) {
    return reinterpret_cast<TestItem*>(obj)->Size();
  }

  static Status SaveToCallback(void* from_obj, size_t from_offset,
                               size_t length, void* out) {
    TestItem* item = reinterpret_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(const Slice& /*key*/, void* obj) {
    delete reinterpret_cast<TestItem*>(obj);
    obj = nullptr;
  }

  static Cache::CacheItemHelper helper_;

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

  static Cache::CacheItemHelper helper_fail_;

  Cache::CreateCallback test_item_creator = [&](const void* buf, size_t size,
                                                void** out_obj,
                                                size_t* charge) -> Status {
    if (fail_create_) {
      return Status::NotSupported();
    }
    *out_obj = reinterpret_cast<void*>(new TestItem((char*)buf, size));
    *charge = size;
    return Status::OK();
  };

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

  void BasicTestHelper(std::shared_ptr<SecondaryCache> sec_cache) {
    bool is_in_sec_cache{true};
    // Lookup an non-existent key.
    std::unique_ptr<SecondaryCacheResultHandle> handle0 = sec_cache->Lookup(
        "k0", test_item_creator, 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,
                                &CompressedSecondaryCacheTest::helper_));

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

    // Insert and Lookup the item k1 for the second time.
    ASSERT_OK(sec_cache->Insert("k1", &item1,
                                &CompressedSecondaryCacheTest::helper_));
    std::unique_ptr<SecondaryCacheResultHandle> handle1_2 = sec_cache->Lookup(
        "k1", test_item_creator, true, /*advise_erase=*/true, is_in_sec_cache);
    ASSERT_NE(handle1_2, nullptr);
    ASSERT_FALSE(is_in_sec_cache);

    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", test_item_creator, 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,
                                &CompressedSecondaryCacheTest::helper_));
    std::unique_ptr<SecondaryCacheResultHandle> handle2_1 = sec_cache->Lookup(
        "k2", test_item_creator, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_EQ(handle2_1, nullptr);

    ASSERT_OK(sec_cache->Insert("k2", &item2,
                                &CompressedSecondaryCacheTest::helper_));
    std::unique_ptr<SecondaryCacheResultHandle> handle2_2 = sec_cache->Lookup(
        "k2", test_item_creator, true, /*advise_erase=*/false, is_in_sec_cache);
    ASSERT_EQ(handle2_1, 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;
      }
    } 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);
  }

  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,
                                &CompressedSecondaryCacheTest::helper_));
    // Insert k1.
    ASSERT_OK(sec_cache->Insert("k1", &item1,
                                &CompressedSecondaryCacheTest::helper_));

    // 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,
                                &CompressedSecondaryCacheTest::helper_));
    bool is_in_sec_cache{false};
    std::unique_ptr<SecondaryCacheResultHandle> handle1 = sec_cache->Lookup(
        "k1", test_item_creator, 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,
                                &CompressedSecondaryCacheTest::helper_));
    std::unique_ptr<SecondaryCacheResultHandle> handle2 = sec_cache->Lookup(
        "k2", test_item_creator, 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,
                                &CompressedSecondaryCacheTest::helper_));

    std::unique_ptr<SecondaryCacheResultHandle> handle1_1 = sec_cache->Lookup(
        "k1", test_item_creator, 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", test_item_creator, 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,
                                &CompressedSecondaryCacheTest::helper_fail_));
    ASSERT_NOK(sec_cache->Insert("k3", &item3,
                                 &CompressedSecondaryCacheTest::helper_fail_));

    sec_cache.reset();
  }

  void BasicIntegrationTest(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 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();

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

    std::string str2 = rnd.RandomString(1012);
    TestItem* 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, &CompressedSecondaryCacheTest::helper_, str2.length()));

    std::string str3 = rnd.RandomString(1024);
    TestItem* 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, &CompressedSecondaryCacheTest::helper_, str3.length()));

    // After this Insert, primary cache contains k1 and secondary cache contains
    // k1's dummy item, k2's dummy item, and k3's dummy item.
    TestItem* item1_2 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert(
        "k1", item1_2, &CompressedSecondaryCacheTest::helper_, str1.length()));

    // After this Insert, primary cache contains k2 and secondary cache contains
    // k1's item, k2's dummy item, and k3's dummy item.
    TestItem* item2_2 = new TestItem(str2.data(), str2.length());
    ASSERT_OK(cache->Insert(
        "k2", item2_2, &CompressedSecondaryCacheTest::helper_, str2.length()));

    // After this Insert, primary cache contains k3 and secondary cache contains
    // k1's item and k2's item.
    TestItem* item3_2 = new TestItem(str3.data(), str3.length());
    ASSERT_OK(cache->Insert(
        "k3", item3_2, &CompressedSecondaryCacheTest::helper_, str3.length()));

    Cache::Handle* handle;
    handle = cache->Lookup("k3", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    TestItem* 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", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, 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", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    TestItem* 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.
    handle = cache->Lookup("k1", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    cache->Release(handle);

    // k2 is still in secondary cache.
    handle = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, Cache::Priority::LOW, true,
                           stats.get());
    ASSERT_NE(handle, nullptr);
    cache->Release(handle);

    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::unique_ptr<TestItem>(new TestItem(str1.data(), str1.length()));
    ASSERT_NOK(cache->Insert("k1", item1.get(), nullptr, str1.length()));
    ASSERT_OK(cache->Insert("k1", item1.get(),
                            &CompressedSecondaryCacheTest::helper_,
                            str1.length()));
    item1.release();  // Appease clang-analyze "potential memory leak"

    Cache::Handle* handle;
    handle = cache->Lookup("k2", nullptr, test_item_creator,
                           Cache::Priority::LOW, true);
    ASSERT_EQ(handle, nullptr);
    handle = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, 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);
    TestItem* item1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1,
                            &CompressedSecondaryCacheTest::helper_fail_,
                            str1.length()));

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

    Cache::Handle* handle;
    handle = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_fail_,
                           test_item_creator, 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", &CompressedSecondaryCacheTest::helper_fail_,
                           test_item_creator, Cache::Priority::LOW, true);
    ASSERT_EQ(handle, nullptr);
    // Since k1 was not promoted, k2 should still be in cache.
    handle = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_fail_,
                           test_item_creator, 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);
    TestItem* item1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert("k1", item1, &CompressedSecondaryCacheTest::helper_,
                            str1.length()));

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

    Cache::Handle* handle;
    SetFailCreate(true);
    handle = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, 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", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, Cache::Priority::LOW, true);
    ASSERT_EQ(handle, nullptr);
    // Since k1 didn't get promoted, k2 should still be in cache
    handle = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_,
                           test_item_creator, 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);
    TestItem* item1_1 = new TestItem(str1.data(), str1.length());
    ASSERT_OK(cache->Insert(
        "k1", item1_1, &CompressedSecondaryCacheTest::helper_, str1.length()));

    std::string str2 = rnd.RandomString(1002);
    std::string str2_clone{str2};
    TestItem* 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, &CompressedSecondaryCacheTest::helper_,
                            str2.length()));

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

    TestItem* 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, &CompressedSecondaryCacheTest::helper_, str2.length()));

    Cache::Handle* handle2;
    handle2 = cache->Lookup("k2", &CompressedSecondaryCacheTest::helper_,
                            test_item_creator, 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", &CompressedSecondaryCacheTest::helper_,
                            test_item_creator, 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", &CompressedSecondaryCacheTest::helper_,
                            test_item_creator, 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 + 354, so there should be 2 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 + 2 * (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, 354 - sizeof(CacheValueChunk) + 1);

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

  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 + 354, so there should be 2 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 + 2 * (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);

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

 private:
  bool fail_create_;
};

Cache::CacheItemHelper CompressedSecondaryCacheTest::helper_(
    CompressedSecondaryCacheTest::SizeCallback,
    CompressedSecondaryCacheTest::SaveToCallback,
    CompressedSecondaryCacheTest::DeletionCallback);

Cache::CacheItemHelper CompressedSecondaryCacheTest::helper_fail_(
    CompressedSecondaryCacheTest::SizeCallback,
    CompressedSecondaryCacheTest::SaveToCallbackFail,
    CompressedSecondaryCacheTest::DeletionCallback);

TEST_F(CompressedSecondaryCacheTest, BasicTestWithNoCompression) {
  BasicTest(false, false);
}

TEST_F(CompressedSecondaryCacheTest,
       BasicTestWithMemoryAllocatorAndNoCompression) {
  BasicTest(false, true);
}

TEST_F(CompressedSecondaryCacheTest, BasicTestWithCompression) {
  BasicTest(true, false);
}

TEST_F(CompressedSecondaryCacheTest,
       BasicTestWithMemoryAllocatorAndCompression) {
  BasicTest(true, true);
}

#ifndef ROCKSDB_LITE

TEST_F(CompressedSecondaryCacheTest, BasicTestFromStringWithNoCompression) {
  std::string sec_cache_uri =
      "compressed_secondary_cache://"
      "capacity=2048;num_shard_bits=0;compression_type=kNoCompression";
  std::shared_ptr<SecondaryCache> sec_cache;
  Status s = SecondaryCache::CreateFromString(ConfigOptions(), sec_cache_uri,
                                              &sec_cache);
  EXPECT_OK(s);
  BasicTestHelper(sec_cache);
}

TEST_F(CompressedSecondaryCacheTest, BasicTestFromStringWithCompression) {
  std::string sec_cache_uri;
  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";
  }

  std::shared_ptr<SecondaryCache> sec_cache;
  Status s = SecondaryCache::CreateFromString(ConfigOptions(), sec_cache_uri,
                                              &sec_cache);
  EXPECT_OK(s);
  BasicTestHelper(sec_cache);
}

#endif  // ROCKSDB_LITE

TEST_F(CompressedSecondaryCacheTest, FailsTestWithNoCompression) {
  FailsTest(false);
}

TEST_F(CompressedSecondaryCacheTest, FailsTestWithCompression) {
  FailsTest(true);
}

TEST_F(CompressedSecondaryCacheTest, BasicIntegrationTestWithNoCompression) {
  BasicIntegrationTest(false);
}

TEST_F(CompressedSecondaryCacheTest, BasicIntegrationTestWithCompression) {
  BasicIntegrationTest(true);
}

TEST_F(CompressedSecondaryCacheTest,
       BasicIntegrationFailTestWithNoCompression) {
  BasicIntegrationFailTest(false);
}

TEST_F(CompressedSecondaryCacheTest, BasicIntegrationFailTestWithCompression) {
  BasicIntegrationFailTest(true);
}

TEST_F(CompressedSecondaryCacheTest, IntegrationSaveFailTestWithNoCompression) {
  IntegrationSaveFailTest(false);
}

TEST_F(CompressedSecondaryCacheTest, IntegrationSaveFailTestWithCompression) {
  IntegrationSaveFailTest(true);
}

TEST_F(CompressedSecondaryCacheTest,
       IntegrationCreateFailTestWithNoCompression) {
  IntegrationCreateFailTest(false);
}

TEST_F(CompressedSecondaryCacheTest, IntegrationCreateFailTestWithCompression) {
  IntegrationCreateFailTest(true);
}

TEST_F(CompressedSecondaryCacheTest,
       IntegrationFullCapacityTestWithNoCompression) {
  IntegrationFullCapacityTest(false);
}

TEST_F(CompressedSecondaryCacheTest,
       IntegrationFullCapacityTestWithCompression) {
  IntegrationFullCapacityTest(true);
}

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

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

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

}  // namespace ROCKSDB_NAMESPACE

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