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// 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 "leveldb/cache.h"
#include <vector>
#include "util/coding.h"
#include "util/testharness.h"
namespace leveldb {
// 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 reinterpret_cast<uintptr_t>(v); }
class CacheTest {
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;
std::vector<int> deleted_keys_;
std::vector<int> deleted_values_;
Cache* cache_;
CacheTest() : cache_(NewLRUCache(kCacheSize)) {
current_ = this;
}
~CacheTest() {
delete cache_;
}
int Lookup(int key) {
Cache::Handle* handle = cache_->Lookup(EncodeKey(key));
const int r = (handle == NULL) ? -1 : DecodeValue(cache_->Value(handle));
if (handle != NULL) {
cache_->Release(handle);
}
return r;
}
void Insert(int key, int value, int charge = 1) {
cache_->Release(cache_->Insert(EncodeKey(key), EncodeValue(value), charge,
&CacheTest::Deleter));
}
Cache::Handle* InsertAndReturnHandle(int key, int value, int charge = 1) {
return cache_->Insert(EncodeKey(key), EncodeValue(value), charge,
&CacheTest::Deleter);
}
void Erase(int key) {
cache_->Erase(EncodeKey(key));
}
};
CacheTest* CacheTest::current_;
TEST(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(1, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[0]);
ASSERT_EQ(101, deleted_values_[0]);
}
TEST(CacheTest, Erase) {
Erase(200);
ASSERT_EQ(0, deleted_keys_.size());
Insert(100, 101);
Insert(200, 201);
Erase(100);
ASSERT_EQ(-1, Lookup(100));
ASSERT_EQ(201, Lookup(200));
ASSERT_EQ(1, 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(1, deleted_keys_.size());
}
TEST(CacheTest, EntriesArePinned) {
Insert(100, 101);
Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
ASSERT_EQ(101, DecodeValue(cache_->Value(h1)));
Insert(100, 102);
Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
ASSERT_EQ(102, DecodeValue(cache_->Value(h2)));
ASSERT_EQ(0, deleted_keys_.size());
cache_->Release(h1);
ASSERT_EQ(1, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[0]);
ASSERT_EQ(101, deleted_values_[0]);
Erase(100);
ASSERT_EQ(-1, Lookup(100));
ASSERT_EQ(1, deleted_keys_.size());
cache_->Release(h2);
ASSERT_EQ(2, deleted_keys_.size());
ASSERT_EQ(100, deleted_keys_[1]);
ASSERT_EQ(102, deleted_values_[1]);
}
TEST(CacheTest, EvictionPolicy) {
Insert(100, 101);
Insert(200, 201);
Insert(300, 301);
Cache::Handle* h = cache_->Lookup(EncodeKey(300));
// Frequently used entry must be kept around,
// as must things that are still in use.
for (int i = 0; i < kCacheSize + 100; i++) {
Insert(1000+i, 2000+i);
ASSERT_EQ(2000+i, Lookup(1000+i));
ASSERT_EQ(101, Lookup(100));
}
ASSERT_EQ(101, Lookup(100));
ASSERT_EQ(-1, Lookup(200));
ASSERT_EQ(301, Lookup(300));
cache_->Release(h);
}
TEST(CacheTest, UseExceedsCacheSize) {
// Overfill the cache, keeping handles on all inserted entries.
std::vector<Cache::Handle*> h;
for (int i = 0; i < kCacheSize + 100; i++) {
h.push_back(InsertAndReturnHandle(1000+i, 2000+i));
}
// Check that all the entries can be found in the cache.
for (int i = 0; i < h.size(); i++) {
ASSERT_EQ(2000+i, Lookup(1000+i));
}
for (int i = 0; i < h.size(); i++) {
cache_->Release(h[i]);
}
}
TEST(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(CacheTest, NewId) {
uint64_t a = cache_->NewId();
uint64_t b = cache_->NewId();
ASSERT_NE(a, b);
}
TEST(CacheTest, Prune) {
Insert(1, 100);
Insert(2, 200);
Cache::Handle* handle = cache_->Lookup(EncodeKey(1));
ASSERT_TRUE(handle);
cache_->Prune();
cache_->Release(handle);
ASSERT_EQ(100, Lookup(1));
ASSERT_EQ(-1, Lookup(2));
}
} // namespace leveldb
int main(int argc, char** argv) {
return leveldb::test::RunAllTests();
}
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