ceph/src/rocksdb/cache/cache_test.cc

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 //
   6 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   7 // Use of this source code is governed by a BSD-style license that can be
   8 // found in the LICENSE file. See the AUTHORS file for names of contributors.
   9
  10 #include "rocksdb/cache.h"
  11
  12 #include <forward_list>
  13 #include <functional>
  14 #include <iostream>
  15 #include <string>
  16 #include <vector>
  17 #include "cache/clock_cache.h"
  18 #include "cache/lru_cache.h"
  19 #include "util/coding.h"
  20 #include "util/string_util.h"
  21 #include "util/testharness.h"
  22
  23 namespace rocksdb {
  24
  25 // Conversions between numeric keys/values and the types expected by Cache.
  26 static std::string EncodeKey(int k) {
  27   std::string result;
  28   PutFixed32(&result, k);
  29   return result;
  30 }
  31 static int DecodeKey(const Slice& k) {
  32   assert(k.size() == 4);
  33   return DecodeFixed32(k.data());
  34 }
  35 static void* EncodeValue(uintptr_t v) { return reinterpret_cast<void*>(v); }
  36 static int DecodeValue(void* v) {
  37   return static_cast<int>(reinterpret_cast<uintptr_t>(v));
  38 }
  39
  40 const std::string kLRU = "lru";
  41 const std::string kClock = "clock";
  42
  43 void dumbDeleter(const Slice& /*key*/, void* /*value*/) {}
  44
  45 void eraseDeleter(const Slice& /*key*/, void* value) {
  46   Cache* cache = reinterpret_cast<Cache*>(value);
  47   cache->Erase("foo");
  48 }
  49
  50 class CacheTest : public testing::TestWithParam<std::string> {
  51  public:
  52   static CacheTest* current_;
  53
  54   static void Deleter(const Slice& key, void* v) {
  55     current_->deleted_keys_.push_back(DecodeKey(key));
  56     current_->deleted_values_.push_back(DecodeValue(v));
  57   }
  58
  59   static const int kCacheSize = 1000;
  60   static const int kNumShardBits = 4;
  61
  62   static const int kCacheSize2 = 100;
  63   static const int kNumShardBits2 = 2;
  64
  65   std::vector<int> deleted_keys_;
  66   std::vector<int> deleted_values_;
  67   shared_ptr<Cache> cache_;
  68   shared_ptr<Cache> cache2_;
  69
  70   CacheTest()
  71       : cache_(NewCache(kCacheSize, kNumShardBits, false)),
  72         cache2_(NewCache(kCacheSize2, kNumShardBits2, false)) {
  73     current_ = this;
  74   }
  75
  76   ~CacheTest() {
  77   }
  78
  79   std::shared_ptr<Cache> NewCache(size_t capacity) {
  80     auto type = GetParam();
  81     if (type == kLRU) {
  82       return NewLRUCache(capacity);
  83     }
  84     if (type == kClock) {
  85       return NewClockCache(capacity);
  86     }
  87     return nullptr;
  88   }
  89
  90   std::shared_ptr<Cache> NewCache(size_t capacity, int num_shard_bits,
  91                                   bool strict_capacity_limit) {
  92     auto type = GetParam();
  93     if (type == kLRU) {
  94       return NewLRUCache(capacity, num_shard_bits, strict_capacity_limit);
  95     }
  96     if (type == kClock) {
  97       return NewClockCache(capacity, num_shard_bits, strict_capacity_limit);
  98     }
  99     return nullptr;
 100   }
 101
 102   int Lookup(shared_ptr<Cache> cache, int key) {
 103     Cache::Handle* handle = cache->Lookup(EncodeKey(key));
 104     const int r = (handle == nullptr) ? -1 : DecodeValue(cache->Value(handle));
 105     if (handle != nullptr) {
 106       cache->Release(handle);
 107     }
 108     return r;
 109   }
 110
 111   void Insert(shared_ptr<Cache> cache, int key, int value, int charge = 1) {
 112     cache->Insert(EncodeKey(key), EncodeValue(value), charge,
 113                   &CacheTest::Deleter);
 114   }
 115
 116   void Erase(shared_ptr<Cache> cache, int key) {
 117     cache->Erase(EncodeKey(key));
 118   }
 119
 120
 121   int Lookup(int key) {
 122     return Lookup(cache_, key);
 123   }
 124
 125   void Insert(int key, int value, int charge = 1) {
 126     Insert(cache_, key, value, charge);
 127   }
 128
 129   void Erase(int key) {
 130     Erase(cache_, key);
 131   }
 132
 133   int Lookup2(int key) {
 134     return Lookup(cache2_, key);
 135   }
 136
 137   void Insert2(int key, int value, int charge = 1) {
 138     Insert(cache2_, key, value, charge);
 139   }
 140
 141   void Erase2(int key) {
 142     Erase(cache2_, key);
 143   }
 144 };
 145 CacheTest* CacheTest::current_;
 146
 147 TEST_P(CacheTest, UsageTest) {
 148   // cache is shared_ptr and will be automatically cleaned up.
 149   const uint64_t kCapacity = 100000;
 150   auto cache = NewCache(kCapacity, 8, false);
 151
 152   size_t usage = 0;
 153   char value[10] = "abcdef";
 154   // make sure everything will be cached
 155   for (int i = 1; i < 100; ++i) {
 156     std::string key(i, 'a');
 157     auto kv_size = key.size() + 5;
 158     cache->Insert(key, reinterpret_cast<void*>(value), kv_size, dumbDeleter);
 159     usage += kv_size;
 160     ASSERT_EQ(usage, cache->GetUsage());
 161   }
 162
 163   // make sure the cache will be overloaded
 164   for (uint64_t i = 1; i < kCapacity; ++i) {
 165     auto key = ToString(i);
 166     cache->Insert(key, reinterpret_cast<void*>(value), key.size() + 5,
 167                   dumbDeleter);
 168   }
 169
 170   // the usage should be close to the capacity
 171   ASSERT_GT(kCapacity, cache->GetUsage());
 172   ASSERT_LT(kCapacity * 0.95, cache->GetUsage());
 173 }
 174
 175 TEST_P(CacheTest, PinnedUsageTest) {
 176   // cache is shared_ptr and will be automatically cleaned up.
 177   const uint64_t kCapacity = 100000;
 178   auto cache = NewCache(kCapacity, 8, false);
 179
 180   size_t pinned_usage = 0;
 181   char value[10] = "abcdef";
 182
 183   std::forward_list<Cache::Handle*> unreleased_handles;
 184
 185   // Add entries. Unpin some of them after insertion. Then, pin some of them
 186   // again. Check GetPinnedUsage().
 187   for (int i = 1; i < 100; ++i) {
 188     std::string key(i, 'a');
 189     auto kv_size = key.size() + 5;
 190     Cache::Handle* handle;
 191     cache->Insert(key, reinterpret_cast<void*>(value), kv_size, dumbDeleter,
 192                   &handle);
 193     pinned_usage += kv_size;
 194     ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
 195     if (i % 2 == 0) {
 196       cache->Release(handle);
 197       pinned_usage -= kv_size;
 198       ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
 199     } else {
 200       unreleased_handles.push_front(handle);
 201     }
 202     if (i % 3 == 0) {
 203       unreleased_handles.push_front(cache->Lookup(key));
 204       // If i % 2 == 0, then the entry was unpinned before Lookup, so pinned
 205       // usage increased
 206       if (i % 2 == 0) {
 207         pinned_usage += kv_size;
 208       }
 209       ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
 210     }
 211   }
 212
 213   // check that overloading the cache does not change the pinned usage
 214   for (uint64_t i = 1; i < 2 * kCapacity; ++i) {
 215     auto key = ToString(i);
 216     cache->Insert(key, reinterpret_cast<void*>(value), key.size() + 5,
 217                   dumbDeleter);
 218   }
 219   ASSERT_EQ(pinned_usage, cache->GetPinnedUsage());
 220
 221   // release handles for pinned entries to prevent memory leaks
 222   for (auto handle : unreleased_handles) {
 223     cache->Release(handle);
 224   }
 225 }
 226
 227 TEST_P(CacheTest, HitAndMiss) {
 228   ASSERT_EQ(-1, Lookup(100));
 229
 230   Insert(100, 101);
 231   ASSERT_EQ(101, Lookup(100));
 232   ASSERT_EQ(-1,  Lookup(200));
 233   ASSERT_EQ(-1,  Lookup(300));
 234
 235   Insert(200, 201);
 236   ASSERT_EQ(101, Lookup(100));
 237   ASSERT_EQ(201, Lookup(200));
 238   ASSERT_EQ(-1,  Lookup(300));
 239
 240   Insert(100, 102);
 241   ASSERT_EQ(102, Lookup(100));
 242   ASSERT_EQ(201, Lookup(200));
 243   ASSERT_EQ(-1,  Lookup(300));
 244
 245   ASSERT_EQ(1U, deleted_keys_.size());
 246   ASSERT_EQ(100, deleted_keys_[0]);
 247   ASSERT_EQ(101, deleted_values_[0]);
 248 }
 249
 250 TEST_P(CacheTest, InsertSameKey) {
 251   Insert(1, 1);
 252   Insert(1, 2);
 253   ASSERT_EQ(2, Lookup(1));
 254 }
 255
 256 TEST_P(CacheTest, Erase) {
 257   Erase(200);
 258   ASSERT_EQ(0U, deleted_keys_.size());
 259
 260   Insert(100, 101);
 261   Insert(200, 201);
 262   Erase(100);
 263   ASSERT_EQ(-1,  Lookup(100));
 264   ASSERT_EQ(201, Lookup(200));
 265   ASSERT_EQ(1U, deleted_keys_.size());
 266   ASSERT_EQ(100, deleted_keys_[0]);
 267   ASSERT_EQ(101, deleted_values_[0]);
 268
 269   Erase(100);
 270   ASSERT_EQ(-1,  Lookup(100));
 271   ASSERT_EQ(201, Lookup(200));
 272   ASSERT_EQ(1U, deleted_keys_.size());
 273 }
 274
 275 TEST_P(CacheTest, EntriesArePinned) {
 276   Insert(100, 101);
 277   Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
 278   ASSERT_EQ(101, DecodeValue(cache_->Value(h1)));
 279   ASSERT_EQ(1U, cache_->GetUsage());
 280
 281   Insert(100, 102);
 282   Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
 283   ASSERT_EQ(102, DecodeValue(cache_->Value(h2)));
 284   ASSERT_EQ(0U, deleted_keys_.size());
 285   ASSERT_EQ(2U, cache_->GetUsage());
 286
 287   cache_->Release(h1);
 288   ASSERT_EQ(1U, deleted_keys_.size());
 289   ASSERT_EQ(100, deleted_keys_[0]);
 290   ASSERT_EQ(101, deleted_values_[0]);
 291   ASSERT_EQ(1U, cache_->GetUsage());
 292
 293   Erase(100);
 294   ASSERT_EQ(-1, Lookup(100));
 295   ASSERT_EQ(1U, deleted_keys_.size());
 296   ASSERT_EQ(1U, cache_->GetUsage());
 297
 298   cache_->Release(h2);
 299   ASSERT_EQ(2U, deleted_keys_.size());
 300   ASSERT_EQ(100, deleted_keys_[1]);
 301   ASSERT_EQ(102, deleted_values_[1]);
 302   ASSERT_EQ(0U, cache_->GetUsage());
 303 }
 304
 305 TEST_P(CacheTest, EvictionPolicy) {
 306   Insert(100, 101);
 307   Insert(200, 201);
 308
 309   // Frequently used entry must be kept around
 310   for (int i = 0; i < kCacheSize + 100; i++) {
 311     Insert(1000+i, 2000+i);
 312     ASSERT_EQ(101, Lookup(100));
 313   }
 314   ASSERT_EQ(101, Lookup(100));
 315   ASSERT_EQ(-1, Lookup(200));
 316 }
 317
 318 TEST_P(CacheTest, ExternalRefPinsEntries) {
 319   Insert(100, 101);
 320   Cache::Handle* h = cache_->Lookup(EncodeKey(100));
 321   ASSERT_TRUE(cache_->Ref(h));
 322   ASSERT_EQ(101, DecodeValue(cache_->Value(h)));
 323   ASSERT_EQ(1U, cache_->GetUsage());
 324
 325   for (int i = 0; i < 3; ++i) {
 326     if (i > 0) {
 327       // First release (i == 1) corresponds to Ref(), second release (i == 2)
 328       // corresponds to Lookup(). Then, since all external refs are released,
 329       // the below insertions should push out the cache entry.
 330       cache_->Release(h);
 331     }
 332     // double cache size because the usage bit in block cache prevents 100 from
 333     // being evicted in the first kCacheSize iterations
 334     for (int j = 0; j < 2 * kCacheSize + 100; j++) {
 335       Insert(1000 + j, 2000 + j);
 336     }
 337     if (i < 2) {
 338       ASSERT_EQ(101, Lookup(100));
 339     }
 340   }
 341   ASSERT_EQ(-1, Lookup(100));
 342 }
 343
 344 TEST_P(CacheTest, EvictionPolicyRef) {
 345   Insert(100, 101);
 346   Insert(101, 102);
 347   Insert(102, 103);
 348   Insert(103, 104);
 349   Insert(200, 101);
 350   Insert(201, 102);
 351   Insert(202, 103);
 352   Insert(203, 104);
 353   Cache::Handle* h201 = cache_->Lookup(EncodeKey(200));
 354   Cache::Handle* h202 = cache_->Lookup(EncodeKey(201));
 355   Cache::Handle* h203 = cache_->Lookup(EncodeKey(202));
 356   Cache::Handle* h204 = cache_->Lookup(EncodeKey(203));
 357   Insert(300, 101);
 358   Insert(301, 102);
 359   Insert(302, 103);
 360   Insert(303, 104);
 361
 362   // Insert entries much more than Cache capacity
 363   for (int i = 0; i < kCacheSize + 100; i++) {
 364     Insert(1000 + i, 2000 + i);
 365   }
 366
 367   // Check whether the entries inserted in the beginning
 368   // are evicted. Ones without extra ref are evicted and
 369   // those with are not.
 370   ASSERT_EQ(-1, Lookup(100));
 371   ASSERT_EQ(-1, Lookup(101));
 372   ASSERT_EQ(-1, Lookup(102));
 373   ASSERT_EQ(-1, Lookup(103));
 374
 375   ASSERT_EQ(-1, Lookup(300));
 376   ASSERT_EQ(-1, Lookup(301));
 377   ASSERT_EQ(-1, Lookup(302));
 378   ASSERT_EQ(-1, Lookup(303));
 379
 380   ASSERT_EQ(101, Lookup(200));
 381   ASSERT_EQ(102, Lookup(201));
 382   ASSERT_EQ(103, Lookup(202));
 383   ASSERT_EQ(104, Lookup(203));
 384
 385   // Cleaning up all the handles
 386   cache_->Release(h201);
 387   cache_->Release(h202);
 388   cache_->Release(h203);
 389   cache_->Release(h204);
 390 }
 391
 392 TEST_P(CacheTest, EvictEmptyCache) {
 393   // Insert item large than capacity to trigger eviction on empty cache.
 394   auto cache = NewCache(1, 0, false);
 395   ASSERT_OK(cache->Insert("foo", nullptr, 10, dumbDeleter));
 396 }
 397
 398 TEST_P(CacheTest, EraseFromDeleter) {
 399   // Have deleter which will erase item from cache, which will re-enter
 400   // the cache at that point.
 401   std::shared_ptr<Cache> cache = NewCache(10, 0, false);
 402   ASSERT_OK(cache->Insert("foo", nullptr, 1, dumbDeleter));
 403   ASSERT_OK(cache->Insert("bar", cache.get(), 1, eraseDeleter));
 404   cache->Erase("bar");
 405   ASSERT_EQ(nullptr, cache->Lookup("foo"));
 406   ASSERT_EQ(nullptr, cache->Lookup("bar"));
 407 }
 408
 409 TEST_P(CacheTest, ErasedHandleState) {
 410   // insert a key and get two handles
 411   Insert(100, 1000);
 412   Cache::Handle* h1 = cache_->Lookup(EncodeKey(100));
 413   Cache::Handle* h2 = cache_->Lookup(EncodeKey(100));
 414   ASSERT_EQ(h1, h2);
 415   ASSERT_EQ(DecodeValue(cache_->Value(h1)), 1000);
 416   ASSERT_EQ(DecodeValue(cache_->Value(h2)), 1000);
 417
 418   // delete the key from the cache
 419   Erase(100);
 420   // can no longer find in the cache
 421   ASSERT_EQ(-1, Lookup(100));
 422
 423   // release one handle
 424   cache_->Release(h1);
 425   // still can't find in cache
 426   ASSERT_EQ(-1, Lookup(100));
 427
 428   cache_->Release(h2);
 429 }
 430
 431 TEST_P(CacheTest, HeavyEntries) {
 432   // Add a bunch of light and heavy entries and then count the combined
 433   // size of items still in the cache, which must be approximately the
 434   // same as the total capacity.
 435   const int kLight = 1;
 436   const int kHeavy = 10;
 437   int added = 0;
 438   int index = 0;
 439   while (added < 2*kCacheSize) {
 440     const int weight = (index & 1) ? kLight : kHeavy;
 441     Insert(index, 1000+index, weight);
 442     added += weight;
 443     index++;
 444   }
 445
 446   int cached_weight = 0;
 447   for (int i = 0; i < index; i++) {
 448     const int weight = (i & 1 ? kLight : kHeavy);
 449     int r = Lookup(i);
 450     if (r >= 0) {
 451       cached_weight += weight;
 452       ASSERT_EQ(1000+i, r);
 453     }
 454   }
 455   ASSERT_LE(cached_weight, kCacheSize + kCacheSize/10);
 456 }
 457
 458 TEST_P(CacheTest, NewId) {
 459   uint64_t a = cache_->NewId();
 460   uint64_t b = cache_->NewId();
 461   ASSERT_NE(a, b);
 462 }
 463
 464
 465 class Value {
 466  public:
 467   explicit Value(size_t v) : v_(v) { }
 468
 469   size_t v_;
 470 };
 471
 472 namespace {
 473 void deleter(const Slice& /*key*/, void* value) {
 474   delete static_cast<Value *>(value);
 475 }
 476 }  // namespace
 477
 478 TEST_P(CacheTest, ReleaseAndErase) {
 479   std::shared_ptr<Cache> cache = NewCache(5, 0, false);
 480   Cache::Handle* handle;
 481   Status s = cache->Insert(EncodeKey(100), EncodeValue(100), 1,
 482                            &CacheTest::Deleter, &handle);
 483   ASSERT_TRUE(s.ok());
 484   ASSERT_EQ(5U, cache->GetCapacity());
 485   ASSERT_EQ(1U, cache->GetUsage());
 486   ASSERT_EQ(0U, deleted_keys_.size());
 487   auto erased = cache->Release(handle, true);
 488   ASSERT_TRUE(erased);
 489   // This tests that deleter has been called
 490   ASSERT_EQ(1U, deleted_keys_.size());
 491 }
 492
 493 TEST_P(CacheTest, ReleaseWithoutErase) {
 494   std::shared_ptr<Cache> cache = NewCache(5, 0, false);
 495   Cache::Handle* handle;
 496   Status s = cache->Insert(EncodeKey(100), EncodeValue(100), 1,
 497                            &CacheTest::Deleter, &handle);
 498   ASSERT_TRUE(s.ok());
 499   ASSERT_EQ(5U, cache->GetCapacity());
 500   ASSERT_EQ(1U, cache->GetUsage());
 501   ASSERT_EQ(0U, deleted_keys_.size());
 502   auto erased = cache->Release(handle);
 503   ASSERT_FALSE(erased);
 504   // This tests that deleter is not called. When cache has free capacity it is
 505   // not expected to immediately erase the released items.
 506   ASSERT_EQ(0U, deleted_keys_.size());
 507 }
 508
 509 TEST_P(CacheTest, SetCapacity) {
 510   // test1: increase capacity
 511   // lets create a cache with capacity 5,
 512   // then, insert 5 elements, then increase capacity
 513   // to 10, returned capacity should be 10, usage=5
 514   std::shared_ptr<Cache> cache = NewCache(5, 0, false);
 515   std::vector<Cache::Handle*> handles(10);
 516   // Insert 5 entries, but not releasing.
 517   for (size_t i = 0; i < 5; i++) {
 518     std::string key = ToString(i+1);
 519     Status s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
 520     ASSERT_TRUE(s.ok());
 521   }
 522   ASSERT_EQ(5U, cache->GetCapacity());
 523   ASSERT_EQ(5U, cache->GetUsage());
 524   cache->SetCapacity(10);
 525   ASSERT_EQ(10U, cache->GetCapacity());
 526   ASSERT_EQ(5U, cache->GetUsage());
 527
 528   // test2: decrease capacity
 529   // insert 5 more elements to cache, then release 5,
 530   // then decrease capacity to 7, final capacity should be 7
 531   // and usage should be 7
 532   for (size_t i = 5; i < 10; i++) {
 533     std::string key = ToString(i+1);
 534     Status s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
 535     ASSERT_TRUE(s.ok());
 536   }
 537   ASSERT_EQ(10U, cache->GetCapacity());
 538   ASSERT_EQ(10U, cache->GetUsage());
 539   for (size_t i = 0; i < 5; i++) {
 540     cache->Release(handles[i]);
 541   }
 542   ASSERT_EQ(10U, cache->GetCapacity());
 543   ASSERT_EQ(10U, cache->GetUsage());
 544   cache->SetCapacity(7);
 545   ASSERT_EQ(7, cache->GetCapacity());
 546   ASSERT_EQ(7, cache->GetUsage());
 547
 548   // release remaining 5 to keep valgrind happy
 549   for (size_t i = 5; i < 10; i++) {
 550     cache->Release(handles[i]);
 551   }
 552 }
 553
 554 TEST_P(CacheTest, SetStrictCapacityLimit) {
 555   // test1: set the flag to false. Insert more keys than capacity. See if they
 556   // all go through.
 557   std::shared_ptr<Cache> cache = NewLRUCache(5, 0, false);
 558   std::vector<Cache::Handle*> handles(10);
 559   Status s;
 560   for (size_t i = 0; i < 10; i++) {
 561     std::string key = ToString(i + 1);
 562     s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
 563     ASSERT_OK(s);
 564     ASSERT_NE(nullptr, handles[i]);
 565   }
 566
 567   // test2: set the flag to true. Insert and check if it fails.
 568   std::string extra_key = "extra";
 569   Value* extra_value = new Value(0);
 570   cache->SetStrictCapacityLimit(true);
 571   Cache::Handle* handle;
 572   s = cache->Insert(extra_key, extra_value, 1, &deleter, &handle);
 573   ASSERT_TRUE(s.IsIncomplete());
 574   ASSERT_EQ(nullptr, handle);
 575
 576   for (size_t i = 0; i < 10; i++) {
 577     cache->Release(handles[i]);
 578   }
 579
 580   // test3: init with flag being true.
 581   std::shared_ptr<Cache> cache2 = NewLRUCache(5, 0, true);
 582   for (size_t i = 0; i < 5; i++) {
 583     std::string key = ToString(i + 1);
 584     s = cache2->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
 585     ASSERT_OK(s);
 586     ASSERT_NE(nullptr, handles[i]);
 587   }
 588   s = cache2->Insert(extra_key, extra_value, 1, &deleter, &handle);
 589   ASSERT_TRUE(s.IsIncomplete());
 590   ASSERT_EQ(nullptr, handle);
 591   // test insert without handle
 592   s = cache2->Insert(extra_key, extra_value, 1, &deleter);
 593   // AS if the key have been inserted into cache but get evicted immediately.
 594   ASSERT_OK(s);
 595   ASSERT_EQ(5, cache->GetUsage());
 596   ASSERT_EQ(nullptr, cache2->Lookup(extra_key));
 597
 598   for (size_t i = 0; i < 5; i++) {
 599     cache2->Release(handles[i]);
 600   }
 601 }
 602
 603 TEST_P(CacheTest, OverCapacity) {
 604   size_t n = 10;
 605
 606   // a LRUCache with n entries and one shard only
 607   std::shared_ptr<Cache> cache = NewCache(n, 0, false);
 608
 609   std::vector<Cache::Handle*> handles(n+1);
 610
 611   // Insert n+1 entries, but not releasing.
 612   for (size_t i = 0; i < n + 1; i++) {
 613     std::string key = ToString(i+1);
 614     Status s = cache->Insert(key, new Value(i + 1), 1, &deleter, &handles[i]);
 615     ASSERT_TRUE(s.ok());
 616   }
 617
 618   // Guess what's in the cache now?
 619   for (size_t i = 0; i < n + 1; i++) {
 620     std::string key = ToString(i+1);
 621     auto h = cache->Lookup(key);
 622     ASSERT_TRUE(h != nullptr);
 623     if (h) cache->Release(h);
 624   }
 625
 626   // the cache is over capacity since nothing could be evicted
 627   ASSERT_EQ(n + 1U, cache->GetUsage());
 628   for (size_t i = 0; i < n + 1; i++) {
 629     cache->Release(handles[i]);
 630   }
 631   // Make sure eviction is triggered.
 632   cache->SetCapacity(n);
 633
 634   // cache is under capacity now since elements were released
 635   ASSERT_EQ(n, cache->GetUsage());
 636
 637   // element 0 is evicted and the rest is there
 638   // This is consistent with the LRU policy since the element 0
 639   // was released first
 640   for (size_t i = 0; i < n + 1; i++) {
 641     std::string key = ToString(i+1);
 642     auto h = cache->Lookup(key);
 643     if (h) {
 644       ASSERT_NE(i, 0U);
 645       cache->Release(h);
 646     } else {
 647       ASSERT_EQ(i, 0U);
 648     }
 649   }
 650 }
 651
 652 namespace {
 653 std::vector<std::pair<int, int>> callback_state;
 654 void callback(void* entry, size_t charge) {
 655   callback_state.push_back({DecodeValue(entry), static_cast<int>(charge)});
 656 }
 657 };
 658
 659 TEST_P(CacheTest, ApplyToAllCacheEntiresTest) {
 660   std::vector<std::pair<int, int>> inserted;
 661   callback_state.clear();
 662
 663   for (int i = 0; i < 10; ++i) {
 664     Insert(i, i * 2, i + 1);
 665     inserted.push_back({i * 2, i + 1});
 666   }
 667   cache_->ApplyToAllCacheEntries(callback, true);
 668
 669   std::sort(inserted.begin(), inserted.end());
 670   std::sort(callback_state.begin(), callback_state.end());
 671   ASSERT_TRUE(inserted == callback_state);
 672 }
 673
 674 TEST_P(CacheTest, DefaultShardBits) {
 675   // test1: set the flag to false. Insert more keys than capacity. See if they
 676   // all go through.
 677   std::shared_ptr<Cache> cache = NewCache(16 * 1024L * 1024L);
 678   ShardedCache* sc = dynamic_cast<ShardedCache*>(cache.get());
 679   ASSERT_EQ(5, sc->GetNumShardBits());
 680
 681   cache = NewLRUCache(511 * 1024L, -1, true);
 682   sc = dynamic_cast<ShardedCache*>(cache.get());
 683   ASSERT_EQ(0, sc->GetNumShardBits());
 684
 685   cache = NewLRUCache(1024L * 1024L * 1024L, -1, true);
 686   sc = dynamic_cast<ShardedCache*>(cache.get());
 687   ASSERT_EQ(6, sc->GetNumShardBits());
 688 }
 689
 690 #ifdef SUPPORT_CLOCK_CACHE
 691 shared_ptr<Cache> (*new_clock_cache_func)(size_t, int, bool) = NewClockCache;
 692 INSTANTIATE_TEST_CASE_P(CacheTestInstance, CacheTest,
 693                         testing::Values(kLRU, kClock));
 694 #else
 695 INSTANTIATE_TEST_CASE_P(CacheTestInstance, CacheTest, testing::Values(kLRU));
 696 #endif  // SUPPORT_CLOCK_CACHE
 697
 698 }  // namespace rocksdb
 699
 700 int main(int argc, char** argv) {
 701   ::testing::InitGoogleTest(&argc, argv);
 702   return RUN_ALL_TESTS();
 703 }