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-rw-r--r--src/leveldb/util/cache_test.cc186
1 files changed, 186 insertions, 0 deletions
diff --git a/src/leveldb/util/cache_test.cc b/src/leveldb/util/cache_test.cc
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+++ b/src/leveldb/util/cache_test.cc
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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));
+ }
+
+ 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);
+
+ // Frequently used entry must be kept around
+ 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));
+}
+
+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);
+}
+
+} // namespace leveldb
+
+int main(int argc, char** argv) {
+ return leveldb::test::RunAllTests();
+}