rocksdb/cache/cache_test.cc
Maysam Yabandeh 638d239507 Charge block cache for cache internal usage (#5797)
Summary:
For our default block cache, each additional entry has extra memory overhead. It include LRUHandle (72 bytes currently) and the cache key (two varint64, file id and offset). The usage is not negligible. For example for block_size=4k, the overhead accounts for an extra 2% memory usage for the cache. The patch charging the cache for the extra usage, reducing untracked memory usage outside block cache. The feature is enabled by default and can be disabled by passing kDontChargeCacheMetadata to the cache constructor.
This PR builds up on https://github.com/facebook/rocksdb/issues/4258
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5797

Test Plan:
- Existing tests are updated to either disable the feature when the test has too much dependency on the old way of accounting the usage or increasing the cache capacity to account for the additional charge of metadata.
- The Usage tests in cache_test.cc are augmented to test the cache usage under kFullChargeCacheMetadata.

Differential Revision: D17396833

Pulled By: maysamyabandeh

fbshipit-source-id: 7684ccb9f8a40ca595e4f5efcdb03623afea0c6f
2019-09-16 15:26:21 -07:00

774 lines
23 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 "rocksdb/cache.h"
#include <forward_list>
#include <functional>
#include <iostream>
#include <string>
#include <vector>
#include "cache/clock_cache.h"
#include "cache/lru_cache.h"
#include "test_util/testharness.h"
#include "util/coding.h"
#include "util/string_util.h"
namespace rocksdb {
// Conversions between numeric keys/values and the types expected by Cache.
static std::string EncodeKey(int k) {
std::string result;
PutFixed32(&result, k);
return result;
}
static int DecodeKey(const Slice& k) {
assert(k.size() == 4);
return DecodeFixed32(k.data());
}
static void* EncodeValue(uintptr_t v) { return reinterpret_cast<void*>(v); }
static int DecodeValue(void* v) {
return static_cast<int>(reinterpret_cast<uintptr_t>(v));
}
const std::string kLRU = "lru";
const std::string kClock = "clock";
void dumbDeleter(const Slice& /*key*/, void* /*value*/) {}
void eraseDeleter(const Slice& /*key*/, void* value) {
Cache* cache = reinterpret_cast<Cache*>(value);
cache->Erase("foo");
}
class CacheTest : public testing::TestWithParam<std::string> {
public:
static CacheTest* current_;
static void Deleter(const Slice& key, void* v) {
current_->deleted_keys_.push_back(DecodeKey(key));
current_->deleted_values_.push_back(DecodeValue(v));
}
static const int kCacheSize = 1000;
static const int kNumShardBits = 4;
static const int kCacheSize2 = 100;
static const int kNumShardBits2 = 2;
std::vector<int> deleted_keys_;
std::vector<int> deleted_values_;
std::shared_ptr<Cache> cache_;
std::shared_ptr<Cache> cache2_;
CacheTest()
: cache_(NewCache(kCacheSize, kNumShardBits, false)),
cache2_(NewCache(kCacheSize2, kNumShardBits2, false)) {
current_ = this;
}
~CacheTest() override {}
std::shared_ptr<Cache> NewCache(size_t capacity) {
auto type = GetParam();
if (type == kLRU) {
return NewLRUCache(capacity);
}
if (type == kClock) {
return NewClockCache(capacity);
}
return nullptr;
}
std::shared_ptr<Cache> NewCache(
size_t capacity, int num_shard_bits, bool strict_capacity_limit,
CacheMetadataChargePolicy charge_policy = kDontChargeCacheMetadata) {
auto type = GetParam();
if (type == kLRU) {
LRUCacheOptions co;
co.capacity = capacity;
co.num_shard_bits = num_shard_bits;
co.strict_capacity_limit = strict_capacity_limit;
co.high_pri_pool_ratio = 0;
co.metadata_charge_policy = charge_policy;
return NewLRUCache(co);
}
if (type == kClock) {
return NewClockCache(capacity, num_shard_bits, strict_capacity_limit,
charge_policy);
}
return nullptr;
}
int Lookup(std::shared_ptr<Cache> cache, int key) {
Cache::Handle* handle = cache->Lookup(EncodeKey(key));
const int r = (handle == nullptr) ? -1 : DecodeValue(cache->Value(handle));
if (handle != nullptr) {
cache->Release(handle);
}
return r;
}
void Insert(std::shared_ptr<Cache> cache, int key, int value,
int charge = 1) {
cache->Insert(EncodeKey(key), EncodeValue(value), charge,
&CacheTest::Deleter);
}
void Erase(std::shared_ptr<Cache> cache, int key) {
cache->Erase(EncodeKey(key));
}
int Lookup(int key) {
return Lookup(cache_, key);
}
void Insert(int key, int value, int charge = 1) {
Insert(cache_, key, value, charge);
}
void Erase(int key) {
Erase(cache_, key);
}
int Lookup2(int key) {
return Lookup(cache2_, key);
}
void Insert2(int key, int value, int charge = 1) {
Insert(cache2_, key, value, charge);
}
void Erase2(int key) {
Erase(cache2_, key);
}
};
CacheTest* CacheTest::current_;
class LRUCacheTest : public CacheTest {};
TEST_P(CacheTest, UsageTest) {
// cache is std::shared_ptr and will be automatically cleaned up.
const uint64_t kCapacity = 100000;
auto cache = NewCache(kCapacity, 8, false, kDontChargeCacheMetadata);
auto precise_cache = NewCache(kCapacity, 0, false, kFullChargeCacheMetadata);
ASSERT_EQ(0, cache->GetUsage());
ASSERT_EQ(0, precise_cache->GetUsage());
size_t usage = 0;
char value[10] = "abcdef";
// make sure everything will be cached
for (int i = 1; i < 100; ++i) {
std::string key(i, 'a');
auto kv_size = key.size() + 5;
cache->Insert(key, reinterpret_cast<void*>(value), kv_size, dumbDeleter);
precise_cache->Insert(key, reinterpret_cast<void*>(value), kv_size,
dumbDeleter);
usage += kv_size;
ASSERT_EQ(usage, cache->GetUsage());
ASSERT_LT(usage, precise_cache->GetUsage());
}
cache->EraseUnRefEntries();
precise_cache->EraseUnRefEntries();
ASSERT_EQ(0, cache->GetUsage());
ASSERT_EQ(0, precise_cache->GetUsage());
// make sure the cache will be overloaded
for (uint64_t i = 1; i < kCapacity; ++i) {
auto key = ToString(i);
cache->Insert(key, reinterpret_cast<void*>(value), key.size() + 5,
dumbDeleter);
precise_cache->Insert(key, reinterpret_cast<void*>(value), key.size() + 5,
dumbDeleter);
}
// the usage should be close to the capacity
ASSERT_GT(kCapacity, cache->GetUsage());
ASSERT_GT(kCapacity, precise_cache->GetUsage());
ASSERT_LT(kCapacity * 0.95, cache->GetUsage());
ASSERT_LT(kCapacity * 0.95, precise_cache->GetUsage());
}
TEST_P(CacheTest, PinnedUsageTest) {
// cache is std::shared_ptr and will be automatically cleaned up.
const uint64_t kCapacity = 200000;
auto cache = NewCache(kCapacity, 8, false, kDontChargeCacheMetadata);
auto precise_cache = NewCache(kCapacity, 8, false, kFullChargeCacheMetadata);
size_t pinned_usage = 0;
char value[10] = "abcdef";
std::forward_list<Cache::Handle*> unreleased_handles;
std::forward_list<Cache::Handle*> unreleased_handles_in_precise_cache;
// Add entries. Unpin some of them after insertion. Then, pin some of them
// again. Check GetPinnedUsage().
for (int i = 1; i < 100; ++i) {
std::string key(i, 'a');
auto kv_size = key.size() + 5;
Cache::Handle* handle;
Cache::Handle* handle_in_precise_cache;
cache->Insert(key, reinterpret_cast<void*>(value), kv_size, dumbDeleter,
&handle);
assert(handle);
precise_cache->Insert(key, reinterpret_cast<void*>(value), kv_size,
dumbDeleter, &handle_in_precise_cache);
assert(handle_in_precise_cache);
pinned_usage += kv_size;
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
ASSERT_LT(pinned_usage, precise_cache->GetPinnedUsage());
if (i % 2 == 0) {
cache->Release(handle);
precise_cache->Release(handle_in_precise_cache);
pinned_usage -= kv_size;
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
ASSERT_LT(pinned_usage, precise_cache->GetPinnedUsage());
} else {
unreleased_handles.push_front(handle);
unreleased_handles_in_precise_cache.push_front(handle_in_precise_cache);
}
if (i % 3 == 0) {
unreleased_handles.push_front(cache->Lookup(key));
auto x = precise_cache->Lookup(key);
assert(x);
unreleased_handles_in_precise_cache.push_front(x);
// If i % 2 == 0, then the entry was unpinned before Lookup, so pinned
// usage increased
if (i % 2 == 0) {
pinned_usage += kv_size;
}
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
ASSERT_LT(pinned_usage, precise_cache->GetPinnedUsage());
}
}
auto precise_cache_pinned_usage = precise_cache->GetPinnedUsage();
ASSERT_LT(pinned_usage, precise_cache_pinned_usage);
// check that overloading the cache does not change the pinned usage
for (uint64_t i = 1; i < 2 * kCapacity; ++i) {
auto key = ToString(i);
cache->Insert(key, reinterpret_cast<void*>(value), key.size() + 5,
dumbDeleter);
precise_cache->Insert(key, reinterpret_cast<void*>(value), key.size() + 5,
dumbDeleter);
}
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
ASSERT_EQ(precise_cache_pinned_usage, precise_cache->GetPinnedUsage());
cache->EraseUnRefEntries();
precise_cache->EraseUnRefEntries();
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
ASSERT_EQ(precise_cache_pinned_usage, precise_cache->GetPinnedUsage());
// release handles for pinned entries to prevent memory leaks
for (auto handle : unreleased_handles) {
cache->Release(handle);
}
for (auto handle : unreleased_handles_in_precise_cache) {
precise_cache->Release(handle);
}
ASSERT_EQ(0, cache->GetPinnedUsage());
ASSERT_EQ(0, precise_cache->GetPinnedUsage());
cache->EraseUnRefEntries();
precise_cache->EraseUnRefEntries();
ASSERT_EQ(0, cache->GetUsage());
ASSERT_EQ(0, precise_cache->GetUsage());
}
TEST_P(CacheTest, HitAndMiss) {
ASSERT_EQ(-1, Lookup(100));
Insert(100, 101);
ASSERT_EQ(101, Lookup(100));
ASSERT_EQ(-1, Lookup(200));
ASSERT_EQ(-1, Lookup(300));
Insert(200, 201);
ASSERT_EQ(101, Lookup(100));
ASSERT_EQ(201, Lookup(200));
ASSERT_EQ(-1, Lookup(300));
Insert(100, 102);
ASSERT_EQ(102, Lookup(100));
ASSERT_EQ(201, Lookup(200));
ASSERT_EQ(-1, Lookup(300));
ASSERT_EQ(1U, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[0]);
ASSERT_EQ(101, deleted_values_[0]);
}
TEST_P(CacheTest, InsertSameKey) {
Insert(1, 1);
Insert(1, 2);
ASSERT_EQ(2, Lookup(1));
}
TEST_P(CacheTest, Erase) {
Erase(200);
ASSERT_EQ(0U, deleted_keys_.size());
Insert(100, 101);
Insert(200, 201);
Erase(100);
ASSERT_EQ(-1, Lookup(100));
ASSERT_EQ(201, Lookup(200));
ASSERT_EQ(1U, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[0]);
ASSERT_EQ(101, deleted_values_[0]);
Erase(100);
ASSERT_EQ(-1, Lookup(100));
ASSERT_EQ(201, Lookup(200));
ASSERT_EQ(1U, deleted_keys_.size());
}
TEST_P(CacheTest, EntriesArePinned) {
Insert(100, 101);
Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
ASSERT_EQ(101, DecodeValue(cache_->Value(h1)));
ASSERT_EQ(1U, cache_->GetUsage());
Insert(100, 102);
Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
ASSERT_EQ(102, DecodeValue(cache_->Value(h2)));
ASSERT_EQ(0U, deleted_keys_.size());
ASSERT_EQ(2U, cache_->GetUsage());
cache_->Release(h1);
ASSERT_EQ(1U, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[0]);
ASSERT_EQ(101, deleted_values_[0]);
ASSERT_EQ(1U, cache_->GetUsage());
Erase(100);
ASSERT_EQ(-1, Lookup(100));
ASSERT_EQ(1U, deleted_keys_.size());
ASSERT_EQ(1U, cache_->GetUsage());
cache_->Release(h2);
ASSERT_EQ(2U, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[1]);
ASSERT_EQ(102, deleted_values_[1]);
ASSERT_EQ(0U, cache_->GetUsage());
}
TEST_P(CacheTest, EvictionPolicy) {
Insert(100, 101);
Insert(200, 201);
// Frequently used entry must be kept around
for (int i = 0; i < kCacheSize + 200; i++) {
Insert(1000+i, 2000+i);
ASSERT_EQ(101, Lookup(100));
}
ASSERT_EQ(101, Lookup(100));
ASSERT_EQ(-1, Lookup(200));
}
TEST_P(CacheTest, ExternalRefPinsEntries) {
Insert(100, 101);
Cache::Handle* h = cache_->Lookup(EncodeKey(100));
ASSERT_TRUE(cache_->Ref(h));
ASSERT_EQ(101, DecodeValue(cache_->Value(h)));
ASSERT_EQ(1U, cache_->GetUsage());
for (int i = 0; i < 3; ++i) {
if (i > 0) {
// First release (i == 1) corresponds to Ref(), second release (i == 2)
// corresponds to Lookup(). Then, since all external refs are released,
// the below insertions should push out the cache entry.
cache_->Release(h);
}
// double cache size because the usage bit in block cache prevents 100 from
// being evicted in the first kCacheSize iterations
for (int j = 0; j < 2 * kCacheSize + 100; j++) {
Insert(1000 + j, 2000 + j);
}
if (i < 2) {
ASSERT_EQ(101, Lookup(100));
}
}
ASSERT_EQ(-1, Lookup(100));
}
TEST_P(CacheTest, EvictionPolicyRef) {
Insert(100, 101);
Insert(101, 102);
Insert(102, 103);
Insert(103, 104);
Insert(200, 101);
Insert(201, 102);
Insert(202, 103);
Insert(203, 104);
Cache::Handle* h201 = cache_->Lookup(EncodeKey(200));
Cache::Handle* h202 = cache_->Lookup(EncodeKey(201));
Cache::Handle* h203 = cache_->Lookup(EncodeKey(202));
Cache::Handle* h204 = cache_->Lookup(EncodeKey(203));
Insert(300, 101);
Insert(301, 102);
Insert(302, 103);
Insert(303, 104);
// Insert entries much more than Cache capacity
for (int i = 0; i < kCacheSize + 200; i++) {
Insert(1000 + i, 2000 + i);
}
// Check whether the entries inserted in the beginning
// are evicted. Ones without extra ref are evicted and
// those with are not.
ASSERT_EQ(-1, Lookup(100));
ASSERT_EQ(-1, Lookup(101));
ASSERT_EQ(-1, Lookup(102));
ASSERT_EQ(-1, Lookup(103));
ASSERT_EQ(-1, Lookup(300));
ASSERT_EQ(-1, Lookup(301));
ASSERT_EQ(-1, Lookup(302));
ASSERT_EQ(-1, Lookup(303));
ASSERT_EQ(101, Lookup(200));
ASSERT_EQ(102, Lookup(201));
ASSERT_EQ(103, Lookup(202));
ASSERT_EQ(104, Lookup(203));
// Cleaning up all the handles
cache_->Release(h201);
cache_->Release(h202);
cache_->Release(h203);
cache_->Release(h204);
}
TEST_P(CacheTest, EvictEmptyCache) {
// Insert item large than capacity to trigger eviction on empty cache.
auto cache = NewCache(1, 0, false);
ASSERT_OK(cache->Insert("foo", nullptr, 10, dumbDeleter));
}
TEST_P(CacheTest, EraseFromDeleter) {
// Have deleter which will erase item from cache, which will re-enter
// the cache at that point.
std::shared_ptr<Cache> cache = NewCache(10, 0, false);
ASSERT_OK(cache->Insert("foo", nullptr, 1, dumbDeleter));
ASSERT_OK(cache->Insert("bar", cache.get(), 1, eraseDeleter));
cache->Erase("bar");
ASSERT_EQ(nullptr, cache->Lookup("foo"));
ASSERT_EQ(nullptr, cache->Lookup("bar"));
}
TEST_P(CacheTest, ErasedHandleState) {
// insert a key and get two handles
Insert(100, 1000);
Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
ASSERT_EQ(h1, h2);
ASSERT_EQ(DecodeValue(cache_->Value(h1)), 1000);
ASSERT_EQ(DecodeValue(cache_->Value(h2)), 1000);
// delete the key from the cache
Erase(100);
// can no longer find in the cache
ASSERT_EQ(-1, Lookup(100));
// release one handle
cache_->Release(h1);
// still can't find in cache
ASSERT_EQ(-1, Lookup(100));
cache_->Release(h2);
}
TEST_P(CacheTest, HeavyEntries) {
// Add a bunch of light and heavy entries and then count the combined
// size of items still in the cache, which must be approximately the
// same as the total capacity.
const int kLight = 1;
const int kHeavy = 10;
int added = 0;
int index = 0;
while (added < 2*kCacheSize) {
const int weight = (index & 1) ? kLight : kHeavy;
Insert(index, 1000+index, weight);
added += weight;
index++;
}
int cached_weight = 0;
for (int i = 0; i < index; i++) {
const int weight = (i & 1 ? kLight : kHeavy);
int r = Lookup(i);
if (r >= 0) {
cached_weight += weight;
ASSERT_EQ(1000+i, r);
}
}
ASSERT_LE(cached_weight, kCacheSize + kCacheSize/10);
}
TEST_P(CacheTest, NewId) {
uint64_t a = cache_->NewId();
uint64_t b = cache_->NewId();
ASSERT_NE(a, b);
}
class Value {
public:
explicit Value(size_t v) : v_(v) { }
size_t v_;
};
namespace {
void deleter(const Slice& /*key*/, void* value) {
delete static_cast<Value *>(value);
}
} // namespace
TEST_P(CacheTest, ReleaseAndErase) {
std::shared_ptr<Cache> cache = NewCache(5, 0, false);
Cache::Handle* handle;
Status s = cache->Insert(EncodeKey(100), EncodeValue(100), 1,
&CacheTest::Deleter, &handle);
ASSERT_TRUE(s.ok());
ASSERT_EQ(5U, cache->GetCapacity());
ASSERT_EQ(1U, cache->GetUsage());
ASSERT_EQ(0U, deleted_keys_.size());
auto erased = cache->Release(handle, true);
ASSERT_TRUE(erased);
// This tests that deleter has been called
ASSERT_EQ(1U, deleted_keys_.size());
}
TEST_P(CacheTest, ReleaseWithoutErase) {
std::shared_ptr<Cache> cache = NewCache(5, 0, false);
Cache::Handle* handle;
Status s = cache->Insert(EncodeKey(100), EncodeValue(100), 1,
&CacheTest::Deleter, &handle);
ASSERT_TRUE(s.ok());
ASSERT_EQ(5U, cache->GetCapacity());
ASSERT_EQ(1U, cache->GetUsage());
ASSERT_EQ(0U, deleted_keys_.size());
auto erased = cache->Release(handle);
ASSERT_FALSE(erased);
// This tests that deleter is not called. When cache has free capacity it is
// not expected to immediately erase the released items.
ASSERT_EQ(0U, deleted_keys_.size());
}
TEST_P(CacheTest, SetCapacity) {
// test1: increase capacity
// lets create a cache with capacity 5,
// then, insert 5 elements, then increase capacity
// to 10, returned capacity should be 10, usage=5
std::shared_ptr<Cache> cache = NewCache(5, 0, false);
std::vector<Cache::Handle*> handles(10);
// Insert 5 entries, but not releasing.
for (size_t i = 0; i < 5; i++) {
std::string key = ToString(i+1);
Status s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
ASSERT_TRUE(s.ok());
}
ASSERT_EQ(5U, cache->GetCapacity());
ASSERT_EQ(5U, cache->GetUsage());
cache->SetCapacity(10);
ASSERT_EQ(10U, cache->GetCapacity());
ASSERT_EQ(5U, cache->GetUsage());
// test2: decrease capacity
// insert 5 more elements to cache, then release 5,
// then decrease capacity to 7, final capacity should be 7
// and usage should be 7
for (size_t i = 5; i < 10; i++) {
std::string key = ToString(i+1);
Status s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
ASSERT_TRUE(s.ok());
}
ASSERT_EQ(10U, cache->GetCapacity());
ASSERT_EQ(10U, cache->GetUsage());
for (size_t i = 0; i < 5; i++) {
cache->Release(handles[i]);
}
ASSERT_EQ(10U, cache->GetCapacity());
ASSERT_EQ(10U, cache->GetUsage());
cache->SetCapacity(7);
ASSERT_EQ(7, cache->GetCapacity());
ASSERT_EQ(7, cache->GetUsage());
// release remaining 5 to keep valgrind happy
for (size_t i = 5; i < 10; i++) {
cache->Release(handles[i]);
}
}
TEST_P(LRUCacheTest, SetStrictCapacityLimit) {
// test1: set the flag to false. Insert more keys than capacity. See if they
// all go through.
std::shared_ptr<Cache> cache = NewCache(5, 0, false);
std::vector<Cache::Handle*> handles(10);
Status s;
for (size_t i = 0; i < 10; i++) {
std::string key = ToString(i + 1);
s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
ASSERT_OK(s);
ASSERT_NE(nullptr, handles[i]);
}
ASSERT_EQ(10, cache->GetUsage());
// test2: set the flag to true. Insert and check if it fails.
std::string extra_key = "extra";
Value* extra_value = new Value(0);
cache->SetStrictCapacityLimit(true);
Cache::Handle* handle;
s = cache->Insert(extra_key, extra_value, 1, &deleter, &handle);
ASSERT_TRUE(s.IsIncomplete());
ASSERT_EQ(nullptr, handle);
ASSERT_EQ(10, cache->GetUsage());
for (size_t i = 0; i < 10; i++) {
cache->Release(handles[i]);
}
// test3: init with flag being true.
std::shared_ptr<Cache> cache2 = NewCache(5, 0, true);
for (size_t i = 0; i < 5; i++) {
std::string key = ToString(i + 1);
s = cache2->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
ASSERT_OK(s);
ASSERT_NE(nullptr, handles[i]);
}
s = cache2->Insert(extra_key, extra_value, 1, &deleter, &handle);
ASSERT_TRUE(s.IsIncomplete());
ASSERT_EQ(nullptr, handle);
// test insert without handle
s = cache2->Insert(extra_key, extra_value, 1, &deleter);
// AS if the key have been inserted into cache but get evicted immediately.
ASSERT_OK(s);
ASSERT_EQ(5, cache2->GetUsage());
ASSERT_EQ(nullptr, cache2->Lookup(extra_key));
for (size_t i = 0; i < 5; i++) {
cache2->Release(handles[i]);
}
}
TEST_P(CacheTest, OverCapacity) {
size_t n = 10;
// a LRUCache with n entries and one shard only
std::shared_ptr<Cache> cache = NewCache(n, 0, false);
std::vector<Cache::Handle*> handles(n+1);
// Insert n+1 entries, but not releasing.
for (size_t i = 0; i < n + 1; i++) {
std::string key = ToString(i+1);
Status s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
ASSERT_TRUE(s.ok());
}
// Guess what's in the cache now?
for (size_t i = 0; i < n + 1; i++) {
std::string key = ToString(i+1);
auto h = cache->Lookup(key);
ASSERT_TRUE(h != nullptr);
if (h) cache->Release(h);
}
// the cache is over capacity since nothing could be evicted
ASSERT_EQ(n + 1U, cache->GetUsage());
for (size_t i = 0; i < n + 1; i++) {
cache->Release(handles[i]);
}
// Make sure eviction is triggered.
cache->SetCapacity(n);
// cache is under capacity now since elements were released
ASSERT_EQ(n, cache->GetUsage());
// element 0 is evicted and the rest is there
// This is consistent with the LRU policy since the element 0
// was released first
for (size_t i = 0; i < n + 1; i++) {
std::string key = ToString(i+1);
auto h = cache->Lookup(key);
if (h) {
ASSERT_NE(i, 0U);
cache->Release(h);
} else {
ASSERT_EQ(i, 0U);
}
}
}
namespace {
std::vector<std::pair<int, int>> callback_state;
void callback(void* entry, size_t charge) {
callback_state.push_back({DecodeValue(entry), static_cast<int>(charge)});
}
};
TEST_P(CacheTest, ApplyToAllCacheEntiresTest) {
std::vector<std::pair<int, int>> inserted;
callback_state.clear();
for (int i = 0; i < 10; ++i) {
Insert(i, i * 2, i + 1);
inserted.push_back({i * 2, i + 1});
}
cache_->ApplyToAllCacheEntries(callback, true);
std::sort(inserted.begin(), inserted.end());
std::sort(callback_state.begin(), callback_state.end());
ASSERT_TRUE(inserted == callback_state);
}
TEST_P(CacheTest, DefaultShardBits) {
// test1: set the flag to false. Insert more keys than capacity. See if they
// all go through.
std::shared_ptr<Cache> cache = NewCache(16 * 1024L * 1024L);
ShardedCache* sc = dynamic_cast<ShardedCache*>(cache.get());
ASSERT_EQ(5, sc->GetNumShardBits());
cache = NewLRUCache(511 * 1024L, -1, true);
sc = dynamic_cast<ShardedCache*>(cache.get());
ASSERT_EQ(0, sc->GetNumShardBits());
cache = NewLRUCache(1024L * 1024L * 1024L, -1, true);
sc = dynamic_cast<ShardedCache*>(cache.get());
ASSERT_EQ(6, sc->GetNumShardBits());
}
TEST_P(CacheTest, GetCharge) {
Insert(1, 2);
Cache::Handle* h1 = cache_->Lookup(EncodeKey(1));
ASSERT_EQ(2, DecodeValue(cache_->Value(h1)));
ASSERT_EQ(1, cache_->GetCharge(h1));
cache_->Release(h1);
}
#ifdef SUPPORT_CLOCK_CACHE
std::shared_ptr<Cache> (*new_clock_cache_func)(
size_t, int, bool, CacheMetadataChargePolicy) = NewClockCache;
INSTANTIATE_TEST_CASE_P(CacheTestInstance, CacheTest,
testing::Values(kLRU, kClock));
#else
INSTANTIATE_TEST_CASE_P(CacheTestInstance, CacheTest, testing::Values(kLRU));
#endif // SUPPORT_CLOCK_CACHE
INSTANTIATE_TEST_CASE_P(CacheTestInstance, LRUCacheTest, testing::Values(kLRU));
} // namespace rocksdb
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}