rocksdb/cache/cache_reservation_manager_test.cc
Peter Dillinger 86a1e3e0e7 Derive cache keys from SST unique IDs (#10394)
Summary:
... so that cache keys can be derived from DB manifest data
before reading the file from storage--so that every part of the file
can potentially go in a persistent cache.

See updated comments in cache_key.cc for technical details. Importantly,
the new cache key encoding uses some fancy but efficient math to pack
data into the cache key without depending on the sizes of the various
pieces. This simplifies some existing code creating cache keys, like
cache warming before the file size is known.

This should provide us an essentially permanent mapping between SST
unique IDs and base cache keys, with the ability to "upgrade" SST
unique IDs (and thus cache keys) with new SST format_versions.

These cache keys are of similar, perhaps indistinguishable quality to
the previous generation. Before this change (see "corrected" days
between collision):

```
./cache_bench -stress_cache_key -sck_keep_bits=43
18 collisions after 2 x 90 days, est 10 days between (1.15292e+19 corrected)
```

After this change (keep 43 bits, up through 50, to validate "trajectory"
is ok on "corrected" days between collision):
```
19 collisions after 3 x 90 days, est 14.2105 days between (1.63836e+19 corrected)
16 collisions after 5 x 90 days, est 28.125 days between (1.6213e+19 corrected)
15 collisions after 7 x 90 days, est 42 days between (1.21057e+19 corrected)
15 collisions after 17 x 90 days, est 102 days between (1.46997e+19 corrected)
15 collisions after 49 x 90 days, est 294 days between (2.11849e+19 corrected)
15 collisions after 62 x 90 days, est 372 days between (1.34027e+19 corrected)
15 collisions after 53 x 90 days, est 318 days between (5.72858e+18 corrected)
15 collisions after 309 x 90 days, est 1854 days between (1.66994e+19 corrected)
```

However, the change does modify (probably weaken) the "guaranteed unique" promise from this

> SST files generated in a single process are guaranteed to have unique cache keys, unless/until number session ids * max file number = 2**86

to this (see https://github.com/facebook/rocksdb/issues/10388)

> With the DB id limitation, we only have nice guaranteed unique cache keys for files generated in a single process until biggest session_id_counter and offset_in_file reach combined 64 bits

I don't think this is a practical concern, though.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10394

Test Plan: unit tests updated, see simulation results above

Reviewed By: jay-zhuang

Differential Revision: D38667529

Pulled By: pdillinger

fbshipit-source-id: 49af3fe7f47e5b61162809a78b76c769fd519fba
2022-08-12 13:49:49 -07:00

469 lines
22 KiB
C++

// 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).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "cache/cache_reservation_manager.h"
#include <cstddef>
#include <cstring>
#include <memory>
#include "cache/cache_entry_roles.h"
#include "rocksdb/cache.h"
#include "rocksdb/slice.h"
#include "test_util/testharness.h"
#include "util/coding.h"
namespace ROCKSDB_NAMESPACE {
class CacheReservationManagerTest : public ::testing::Test {
protected:
static constexpr std::size_t kSizeDummyEntry =
CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
static constexpr std::size_t kCacheCapacity = 4096 * kSizeDummyEntry;
static constexpr int kNumShardBits = 0; // 2^0 shard
static constexpr std::size_t kMetaDataChargeOverhead = 10000;
std::shared_ptr<Cache> cache = NewLRUCache(kCacheCapacity, kNumShardBits);
std::shared_ptr<CacheReservationManager> test_cache_rev_mng;
CacheReservationManagerTest() {
test_cache_rev_mng =
std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
cache);
}
};
TEST_F(CacheReservationManagerTest, GenerateCacheKey) {
std::size_t new_mem_used = 1 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
ASSERT_EQ(s, Status::OK());
ASSERT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry);
ASSERT_LT(cache->GetPinnedUsage(),
1 * kSizeDummyEntry + kMetaDataChargeOverhead);
// Next unique Cache key
CacheKey ckey = CacheKey::CreateUniqueForCacheLifetime(cache.get());
// Get to the underlying values
uint64_t* ckey_data = reinterpret_cast<uint64_t*>(&ckey);
// Back it up to the one used by CRM (using CacheKey implementation details)
ckey_data[1]--;
// Specific key (subject to implementation details)
EXPECT_EQ(ckey_data[0], 0);
EXPECT_EQ(ckey_data[1], 2);
Cache::Handle* handle = cache->Lookup(ckey.AsSlice());
EXPECT_NE(handle, nullptr)
<< "Failed to generate the cache key for the dummy entry correctly";
// Clean up the returned handle from Lookup() to prevent memory leak
cache->Release(handle);
}
TEST_F(CacheReservationManagerTest, KeepCacheReservationTheSame) {
std::size_t new_mem_used = 1 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
ASSERT_EQ(s, Status::OK());
ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
1 * kSizeDummyEntry);
ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
std::size_t initial_pinned_usage = cache->GetPinnedUsage();
ASSERT_GE(initial_pinned_usage, 1 * kSizeDummyEntry);
ASSERT_LT(initial_pinned_usage,
1 * kSizeDummyEntry + kMetaDataChargeOverhead);
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to keep cache reservation the same when new_mem_used equals "
"to current cache reservation";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
1 * kSizeDummyEntry)
<< "Failed to bookkeep correctly when new_mem_used equals to current "
"cache reservation";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly when new_mem_used "
"equals to current cache reservation";
EXPECT_EQ(cache->GetPinnedUsage(), initial_pinned_usage)
<< "Failed to keep underlying dummy entries the same when new_mem_used "
"equals to current cache reservation";
}
TEST_F(CacheReservationManagerTest,
IncreaseCacheReservationByMultiplesOfDummyEntrySize) {
std::size_t new_mem_used = 2 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to increase cache reservation correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
2 * kSizeDummyEntry)
<< "Failed to bookkeep cache reservation increase correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry)
<< "Failed to increase underlying dummy entries in cache correctly";
EXPECT_LT(cache->GetPinnedUsage(),
2 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to increase underlying dummy entries in cache correctly";
}
TEST_F(CacheReservationManagerTest,
IncreaseCacheReservationNotByMultiplesOfDummyEntrySize) {
std::size_t new_mem_used = 2 * kSizeDummyEntry + kSizeDummyEntry / 2;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to increase cache reservation correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
3 * kSizeDummyEntry)
<< "Failed to bookkeep cache reservation increase correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 3 * kSizeDummyEntry)
<< "Failed to increase underlying dummy entries in cache correctly";
EXPECT_LT(cache->GetPinnedUsage(),
3 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to increase underlying dummy entries in cache correctly";
}
TEST(CacheReservationManagerIncreaseReservcationOnFullCacheTest,
IncreaseCacheReservationOnFullCache) {
;
constexpr std::size_t kSizeDummyEntry =
CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
constexpr std::size_t kSmallCacheCapacity = 4 * kSizeDummyEntry;
constexpr std::size_t kBigCacheCapacity = 4096 * kSizeDummyEntry;
constexpr std::size_t kMetaDataChargeOverhead = 10000;
LRUCacheOptions lo;
lo.capacity = kSmallCacheCapacity;
lo.num_shard_bits = 0; // 2^0 shard
lo.strict_capacity_limit = true;
std::shared_ptr<Cache> cache = NewLRUCache(lo);
std::shared_ptr<CacheReservationManager> test_cache_rev_mng =
std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
cache);
std::size_t new_mem_used = kSmallCacheCapacity + 1;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::MemoryLimit())
<< "Failed to return status to indicate failure of dummy entry insertion "
"during cache reservation on full cache";
EXPECT_GE(test_cache_rev_mng->GetTotalReservedCacheSize(),
1 * kSizeDummyEntry)
<< "Failed to bookkeep correctly before cache resevation failure happens "
"due to full cache";
EXPECT_LE(test_cache_rev_mng->GetTotalReservedCacheSize(),
kSmallCacheCapacity)
<< "Failed to bookkeep correctly (i.e, bookkeep only successful dummy "
"entry insertions) when encountering cache resevation failure due to "
"full cache";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
<< "Failed to insert underlying dummy entries correctly when "
"encountering cache resevation failure due to full cache";
EXPECT_LE(cache->GetPinnedUsage(), kSmallCacheCapacity)
<< "Failed to insert underlying dummy entries correctly when "
"encountering cache resevation failure due to full cache";
new_mem_used = kSmallCacheCapacity / 2; // 2 dummy entries
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to decrease cache reservation after encountering cache "
"reservation failure due to full cache";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
2 * kSizeDummyEntry)
<< "Failed to bookkeep cache reservation decrease correctly after "
"encountering cache reservation due to full cache";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry)
<< "Failed to release underlying dummy entries correctly on cache "
"reservation decrease after encountering cache resevation failure due "
"to full cache";
EXPECT_LT(cache->GetPinnedUsage(),
2 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to release underlying dummy entries correctly on cache "
"reservation decrease after encountering cache resevation failure due "
"to full cache";
// Create cache full again for subsequent tests
new_mem_used = kSmallCacheCapacity + 1;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::MemoryLimit())
<< "Failed to return status to indicate failure of dummy entry insertion "
"during cache reservation on full cache";
EXPECT_GE(test_cache_rev_mng->GetTotalReservedCacheSize(),
1 * kSizeDummyEntry)
<< "Failed to bookkeep correctly before cache resevation failure happens "
"due to full cache";
EXPECT_LE(test_cache_rev_mng->GetTotalReservedCacheSize(),
kSmallCacheCapacity)
<< "Failed to bookkeep correctly (i.e, bookkeep only successful dummy "
"entry insertions) when encountering cache resevation failure due to "
"full cache";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
<< "Failed to insert underlying dummy entries correctly when "
"encountering cache resevation failure due to full cache";
EXPECT_LE(cache->GetPinnedUsage(), kSmallCacheCapacity)
<< "Failed to insert underlying dummy entries correctly when "
"encountering cache resevation failure due to full cache";
// Increase cache capacity so the previously failed insertion can fully
// succeed
cache->SetCapacity(kBigCacheCapacity);
new_mem_used = kSmallCacheCapacity + 1;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to increase cache reservation after increasing cache capacity "
"and mitigating cache full error";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
5 * kSizeDummyEntry)
<< "Failed to bookkeep cache reservation increase correctly after "
"increasing cache capacity and mitigating cache full error";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 5 * kSizeDummyEntry)
<< "Failed to insert underlying dummy entries correctly after increasing "
"cache capacity and mitigating cache full error";
EXPECT_LT(cache->GetPinnedUsage(),
5 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to insert underlying dummy entries correctly after increasing "
"cache capacity and mitigating cache full error";
}
TEST_F(CacheReservationManagerTest,
DecreaseCacheReservationByMultiplesOfDummyEntrySize) {
std::size_t new_mem_used = 2 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
ASSERT_EQ(s, Status::OK());
ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
2 * kSizeDummyEntry);
ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
ASSERT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry);
ASSERT_LT(cache->GetPinnedUsage(),
2 * kSizeDummyEntry + kMetaDataChargeOverhead);
new_mem_used = 1 * kSizeDummyEntry;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to decrease cache reservation correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
1 * kSizeDummyEntry)
<< "Failed to bookkeep cache reservation decrease correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
<< "Failed to decrease underlying dummy entries in cache correctly";
EXPECT_LT(cache->GetPinnedUsage(),
1 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to decrease underlying dummy entries in cache correctly";
}
TEST_F(CacheReservationManagerTest,
DecreaseCacheReservationNotByMultiplesOfDummyEntrySize) {
std::size_t new_mem_used = 2 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
ASSERT_EQ(s, Status::OK());
ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
2 * kSizeDummyEntry);
ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
ASSERT_GE(cache->GetPinnedUsage(), 2 * kSizeDummyEntry);
ASSERT_LT(cache->GetPinnedUsage(),
2 * kSizeDummyEntry + kMetaDataChargeOverhead);
new_mem_used = kSizeDummyEntry / 2;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to decrease cache reservation correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
1 * kSizeDummyEntry)
<< "Failed to bookkeep cache reservation decrease correctly";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry)
<< "Failed to decrease underlying dummy entries in cache correctly";
EXPECT_LT(cache->GetPinnedUsage(),
1 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to decrease underlying dummy entries in cache correctly";
}
TEST(CacheReservationManagerWithDelayedDecreaseTest,
DecreaseCacheReservationWithDelayedDecrease) {
constexpr std::size_t kSizeDummyEntry =
CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
constexpr std::size_t kCacheCapacity = 4096 * kSizeDummyEntry;
constexpr std::size_t kMetaDataChargeOverhead = 10000;
LRUCacheOptions lo;
lo.capacity = kCacheCapacity;
lo.num_shard_bits = 0;
std::shared_ptr<Cache> cache = NewLRUCache(lo);
std::shared_ptr<CacheReservationManager> test_cache_rev_mng =
std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
cache, true /* delayed_decrease */);
std::size_t new_mem_used = 8 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
ASSERT_EQ(s, Status::OK());
ASSERT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
8 * kSizeDummyEntry);
ASSERT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used);
std::size_t initial_pinned_usage = cache->GetPinnedUsage();
ASSERT_GE(initial_pinned_usage, 8 * kSizeDummyEntry);
ASSERT_LT(initial_pinned_usage,
8 * kSizeDummyEntry + kMetaDataChargeOverhead);
new_mem_used = 6 * kSizeDummyEntry;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK()) << "Failed to delay decreasing cache reservation";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
8 * kSizeDummyEntry)
<< "Failed to bookkeep correctly when delaying cache reservation "
"decrease";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_EQ(cache->GetPinnedUsage(), initial_pinned_usage)
<< "Failed to delay decreasing underlying dummy entries in cache";
new_mem_used = 7 * kSizeDummyEntry;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK()) << "Failed to delay decreasing cache reservation";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
8 * kSizeDummyEntry)
<< "Failed to bookkeep correctly when delaying cache reservation "
"decrease";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_EQ(cache->GetPinnedUsage(), initial_pinned_usage)
<< "Failed to delay decreasing underlying dummy entries in cache";
new_mem_used = 6 * kSizeDummyEntry - 1;
s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
EXPECT_EQ(s, Status::OK())
<< "Failed to decrease cache reservation correctly when new_mem_used < "
"GetTotalReservedCacheSize() * 3 / 4 on delayed decrease mode";
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(),
6 * kSizeDummyEntry)
<< "Failed to bookkeep correctly when new_mem_used < "
"GetTotalReservedCacheSize() * 3 / 4 on delayed decrease mode";
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), new_mem_used)
<< "Failed to bookkeep the used memory correctly";
EXPECT_GE(cache->GetPinnedUsage(), 6 * kSizeDummyEntry)
<< "Failed to decrease underlying dummy entries in cache when "
"new_mem_used < GetTotalReservedCacheSize() * 3 / 4 on delayed "
"decrease mode";
EXPECT_LT(cache->GetPinnedUsage(),
6 * kSizeDummyEntry + kMetaDataChargeOverhead)
<< "Failed to decrease underlying dummy entries in cache when "
"new_mem_used < GetTotalReservedCacheSize() * 3 / 4 on delayed "
"decrease mode";
}
TEST(CacheReservationManagerDestructorTest,
ReleaseRemainingDummyEntriesOnDestruction) {
constexpr std::size_t kSizeDummyEntry =
CacheReservationManagerImpl<CacheEntryRole::kMisc>::GetDummyEntrySize();
constexpr std::size_t kCacheCapacity = 4096 * kSizeDummyEntry;
constexpr std::size_t kMetaDataChargeOverhead = 10000;
LRUCacheOptions lo;
lo.capacity = kCacheCapacity;
lo.num_shard_bits = 0;
std::shared_ptr<Cache> cache = NewLRUCache(lo);
{
std::shared_ptr<CacheReservationManager> test_cache_rev_mng =
std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
cache);
std::size_t new_mem_used = 1 * kSizeDummyEntry;
Status s = test_cache_rev_mng->UpdateCacheReservation(new_mem_used);
ASSERT_EQ(s, Status::OK());
ASSERT_GE(cache->GetPinnedUsage(), 1 * kSizeDummyEntry);
ASSERT_LT(cache->GetPinnedUsage(),
1 * kSizeDummyEntry + kMetaDataChargeOverhead);
}
EXPECT_EQ(cache->GetPinnedUsage(), 0 * kSizeDummyEntry)
<< "Failed to release remaining underlying dummy entries in cache in "
"CacheReservationManager's destructor";
}
TEST(CacheReservationHandleTest, HandleTest) {
constexpr std::size_t kOneGigabyte = 1024 * 1024 * 1024;
constexpr std::size_t kSizeDummyEntry = 256 * 1024;
constexpr std::size_t kMetaDataChargeOverhead = 10000;
LRUCacheOptions lo;
lo.capacity = kOneGigabyte;
lo.num_shard_bits = 0;
std::shared_ptr<Cache> cache = NewLRUCache(lo);
std::shared_ptr<CacheReservationManager> test_cache_rev_mng(
std::make_shared<CacheReservationManagerImpl<CacheEntryRole::kMisc>>(
cache));
std::size_t mem_used = 0;
const std::size_t incremental_mem_used_handle_1 = 1 * kSizeDummyEntry;
const std::size_t incremental_mem_used_handle_2 = 2 * kSizeDummyEntry;
std::unique_ptr<CacheReservationManager::CacheReservationHandle> handle_1,
handle_2;
// To test consecutive CacheReservationManager::MakeCacheReservation works
// correctly in terms of returning the handle as well as updating cache
// reservation and the latest total memory used
Status s = test_cache_rev_mng->MakeCacheReservation(
incremental_mem_used_handle_1, &handle_1);
mem_used = mem_used + incremental_mem_used_handle_1;
ASSERT_EQ(s, Status::OK());
EXPECT_TRUE(handle_1 != nullptr);
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(), mem_used);
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), mem_used);
EXPECT_GE(cache->GetPinnedUsage(), mem_used);
EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
s = test_cache_rev_mng->MakeCacheReservation(incremental_mem_used_handle_2,
&handle_2);
mem_used = mem_used + incremental_mem_used_handle_2;
ASSERT_EQ(s, Status::OK());
EXPECT_TRUE(handle_2 != nullptr);
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(), mem_used);
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), mem_used);
EXPECT_GE(cache->GetPinnedUsage(), mem_used);
EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
// To test
// CacheReservationManager::CacheReservationHandle::~CacheReservationHandle()
// works correctly in releasing the cache reserved for the handle
handle_1.reset();
EXPECT_TRUE(handle_1 == nullptr);
mem_used = mem_used - incremental_mem_used_handle_1;
EXPECT_EQ(test_cache_rev_mng->GetTotalReservedCacheSize(), mem_used);
EXPECT_EQ(test_cache_rev_mng->GetTotalMemoryUsed(), mem_used);
EXPECT_GE(cache->GetPinnedUsage(), mem_used);
EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
// To test the actual CacheReservationManager object won't be deallocated
// as long as there remain handles pointing to it.
// We strongly recommend deallocating CacheReservationManager object only
// after all its handles are deallocated to keep things easy to reasonate
test_cache_rev_mng.reset();
EXPECT_GE(cache->GetPinnedUsage(), mem_used);
EXPECT_LT(cache->GetPinnedUsage(), mem_used + kMetaDataChargeOverhead);
handle_2.reset();
// The CacheReservationManager object is now deallocated since all the handles
// and its original pointer is gone
mem_used = mem_used - incremental_mem_used_handle_2;
EXPECT_EQ(mem_used, 0);
EXPECT_EQ(cache->GetPinnedUsage(), mem_used);
}
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}