rocksdb/cache/cache_test.cc

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// 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) {
auto type = GetParam();
if (type == kLRU) {
return NewLRUCache(capacity, num_shard_bits, strict_capacity_limit);
}
if (type == kClock) {
return NewClockCache(capacity, num_shard_bits, strict_capacity_limit);
}
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_;
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);
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);
usage += kv_size;
ASSERT_EQ(usage, 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);
}
// the usage should be close to the capacity
ASSERT_GT(kCapacity, cache->GetUsage());
ASSERT_LT(kCapacity * 0.95, cache->GetUsage());
}
TEST_P(CacheTest, PinnedUsageTest) {
// cache is std::shared_ptr and will be automatically cleaned up.
const uint64_t kCapacity = 100000;
auto cache = NewCache(kCapacity, 8, false);
size_t pinned_usage = 0;
char value[10] = "abcdef";
std::forward_list<Cache::Handle*> unreleased_handles;
// 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->Insert(key, reinterpret_cast<void*>(value), kv_size, dumbDeleter,
&handle);
pinned_usage += kv_size;
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
if (i % 2 == 0) {
cache->Release(handle);
pinned_usage -= kv_size;
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
} else {
unreleased_handles.push_front(handle);
}
if (i % 3 == 0) {
unreleased_handles.push_front(cache->Lookup(key));
// 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());
}
}
// 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);
}
ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
// release handles for pinned entries to prevent memory leaks
for (auto handle : unreleased_handles) {
cache->Release(handle);
}
}
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
Consolidate hash function used for non-persistent data in a new function (#5155) Summary: Create new function NPHash64() and GetSliceNPHash64(), which are currently implemented using murmurhash. Replace the current direct call of murmurhash() to use the new functions if the hash results are not used in on-disk format. This will make it easier to try out or switch to alternative functions in the uses where data format compatibility doesn't need to be considered. This part shouldn't have any performance impact. Also, the sharded cache hash function is changed to the new format, because it falls into this categoery. It doesn't show visible performance impact in db_bench results. CPU showed by perf is increased from about 0.2% to 0.4% in an extreme benchmark setting (4KB blocks, no-compression, everything cached in block cache). We've known that the current hash function used, our own Hash() has serious hash quality problem. It can generate a lots of conflicts with similar input. In this use case, it means extra lock contention for reads from the same file. This slight CPU regression is worthy to me to counter the potential bad performance with hot keys. And hopefully this will get further improved in the future with a better hash function. cache_test's condition is relaxed a little bit to. The new hash is slightly more skewed in this use case, but I manually checked the data and see the hash results are still in a reasonable range. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5155 Differential Revision: D14834821 Pulled By: siying fbshipit-source-id: ec9a2c0a2f8ae4b54d08b13a5c2e9cc97aa80cb5
2019-04-08 22:24:29 +02:00
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
Consolidate hash function used for non-persistent data in a new function (#5155) Summary: Create new function NPHash64() and GetSliceNPHash64(), which are currently implemented using murmurhash. Replace the current direct call of murmurhash() to use the new functions if the hash results are not used in on-disk format. This will make it easier to try out or switch to alternative functions in the uses where data format compatibility doesn't need to be considered. This part shouldn't have any performance impact. Also, the sharded cache hash function is changed to the new format, because it falls into this categoery. It doesn't show visible performance impact in db_bench results. CPU showed by perf is increased from about 0.2% to 0.4% in an extreme benchmark setting (4KB blocks, no-compression, everything cached in block cache). We've known that the current hash function used, our own Hash() has serious hash quality problem. It can generate a lots of conflicts with similar input. In this use case, it means extra lock contention for reads from the same file. This slight CPU regression is worthy to me to counter the potential bad performance with hot keys. And hopefully this will get further improved in the future with a better hash function. cache_test's condition is relaxed a little bit to. The new hash is slightly more skewed in this use case, but I manually checked the data and see the hash results are still in a reasonable range. Pull Request resolved: https://github.com/facebook/rocksdb/pull/5155 Differential Revision: D14834821 Pulled By: siying fbshipit-source-id: ec9a2c0a2f8ae4b54d08b13a5c2e9cc97aa80cb5
2019-04-08 22:24:29 +02:00
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) {
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
// 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);
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
// delete the key from the cache
Erase(100);
// can no longer find in the cache
ASSERT_EQ(-1, Lookup(100));
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
// release one handle
cache_->Release(h1);
// still can't find in cache
ASSERT_EQ(-1, Lookup(100));
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
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(CacheTest, SetStrictCapacityLimit) {
// test1: set the flag to false. Insert more keys than capacity. See if they
// all go through.
std::shared_ptr<Cache> cache = NewLRUCache(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]);
}
// 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);
for (size_t i = 0; i < 10; i++) {
cache->Release(handles[i]);
}
// test3: init with flag being true.
std::shared_ptr<Cache> cache2 = NewLRUCache(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, cache->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);
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
ASSERT_TRUE(h != nullptr);
if (h) cache->Release(h);
}
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
// 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);
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
// 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++) {
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
std::string key = ToString(i+1);
auto h = cache->Lookup(key);
if (h) {
ASSERT_NE(i, 0U);
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
cache->Release(h);
} else {
ASSERT_EQ(i, 0U);
Modifed the LRU cache eviction code so that it doesn't evict blocks which have exteranl references Summary: Currently, blocks which have more than one reference (ie referenced by something other than cache itself) are evicted from cache. This doesn't make much sense: - blocks are still in RAM, so the RAM usage reported by the cache is incorrect - if the same block is needed by another iterator, it will be loaded and decompressed again This diff changes the reference counting scheme a bit. Previously, if the cache contained the block, this was accounted for in its refcount. After this change, the refcount is only used to track external references. There is a boolean flag which indicates whether or not the block is contained in the cache. This diff also changes how LRU list is used. Previously, both hashtable and the LRU list contained all blocks. After this change, the LRU list contains blocks with the refcount==0, ie those which can be evicted from the cache. Note that this change still allows for cache to grow beyond its capacity. This happens when all blocks are pinned (ie refcount>0). This is consistent with the current behavior. The cache's insert function never fails. I spent lots of time trying to make table_reader and other places work with the insert which might failed. It turned out to be pretty hard. It might really destabilize some customers, so finally, I decided against doing this. table_cache_remove_scan_count_limit option will be unneeded after this change, but I will remove it in the following diff, if this one gets approved Test Plan: Ran tests, made sure they pass Reviewers: sdong, ljin Differential Revision: https://reviews.facebook.net/D25503
2014-10-21 20:49:13 +02:00
}
}
}
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) = 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
} // namespace rocksdb
int main(int argc, char** argv) {
rocksdb: switch to gtest Summary: Our existing test notation is very similar to what is used in gtest. It makes it easy to adopt what is different. In this diff I modify existing [[ https://code.google.com/p/googletest/wiki/Primer#Test_Fixtures:_Using_the_Same_Data_Configuration_for_Multiple_Te | test fixture ]] classes to inherit from `testing::Test`. Also for unit tests that use fixture class, `TEST` is replaced with `TEST_F` as required in gtest. There are several custom `main` functions in our existing tests. To make this transition easier, I modify all `main` functions to fallow gtest notation. But eventually we can remove them and use implementation of `main` that gtest provides. ```lang=bash % cat ~/transform #!/bin/sh files=$(git ls-files '*test\.cc') for file in $files do if grep -q "rocksdb::test::RunAllTests()" $file then if grep -Eq '^class \w+Test {' $file then perl -pi -e 's/^(class \w+Test) {/${1}: public testing::Test {/g' $file perl -pi -e 's/^(TEST)/${1}_F/g' $file fi perl -pi -e 's/(int main.*\{)/${1}::testing::InitGoogleTest(&argc, argv);/g' $file perl -pi -e 's/rocksdb::test::RunAllTests/RUN_ALL_TESTS/g' $file fi done % sh ~/transform % make format ``` Second iteration of this diff contains only scripted changes. Third iteration contains manual changes to fix last errors and make it compilable. Test Plan: Build and notice no errors. ```lang=bash % USE_CLANG=1 make check -j55 ``` Tests are still testing. Reviewers: meyering, sdong, rven, igor Reviewed By: igor Subscribers: dhruba, leveldb Differential Revision: https://reviews.facebook.net/D35157
2015-03-17 22:08:00 +01:00
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}