db_test.cc raw

   1  // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   2  // Use of this source code is governed by a BSD-style license that can be
   3  // found in the LICENSE file. See the AUTHORS file for names of contributors.
   4  
   5  #include "leveldb/db.h"
   6  
   7  #include <atomic>
   8  #include <string>
   9  
  10  #include "db/db_impl.h"
  11  #include "db/filename.h"
  12  #include "db/version_set.h"
  13  #include "db/write_batch_internal.h"
  14  #include "leveldb/cache.h"
  15  #include "leveldb/env.h"
  16  #include "leveldb/filter_policy.h"
  17  #include "leveldb/table.h"
  18  #include "port/port.h"
  19  #include "port/thread_annotations.h"
  20  #include "util/hash.h"
  21  #include "util/logging.h"
  22  #include "util/mutexlock.h"
  23  #include "util/testharness.h"
  24  #include "util/testutil.h"
  25  
  26  namespace leveldb {
  27  
  28  static std::string RandomString(Random* rnd, int len) {
  29    std::string r;
  30    test::RandomString(rnd, len, &r);
  31    return r;
  32  }
  33  
  34  static std::string RandomKey(Random* rnd) {
  35    int len =
  36        (rnd->OneIn(3) ? 1  // Short sometimes to encourage collisions
  37                       : (rnd->OneIn(100) ? rnd->Skewed(10) : rnd->Uniform(10)));
  38    return test::RandomKey(rnd, len);
  39  }
  40  
  41  namespace {
  42  class AtomicCounter {
  43   public:
  44    AtomicCounter() : count_(0) {}
  45    void Increment() { IncrementBy(1); }
  46    void IncrementBy(int count) LOCKS_EXCLUDED(mu_) {
  47      MutexLock l(&mu_);
  48      count_ += count;
  49    }
  50    int Read() LOCKS_EXCLUDED(mu_) {
  51      MutexLock l(&mu_);
  52      return count_;
  53    }
  54    void Reset() LOCKS_EXCLUDED(mu_) {
  55      MutexLock l(&mu_);
  56      count_ = 0;
  57    }
  58  
  59   private:
  60    port::Mutex mu_;
  61    int count_ GUARDED_BY(mu_);
  62  };
  63  
  64  void DelayMilliseconds(int millis) {
  65    Env::Default()->SleepForMicroseconds(millis * 1000);
  66  }
  67  }  // namespace
  68  
  69  // Test Env to override default Env behavior for testing.
  70  class TestEnv : public EnvWrapper {
  71   public:
  72    explicit TestEnv(Env* base) : EnvWrapper(base), ignore_dot_files_(false) {}
  73  
  74    void SetIgnoreDotFiles(bool ignored) { ignore_dot_files_ = ignored; }
  75  
  76    Status GetChildren(const std::string& dir,
  77                       std::vector<std::string>* result) override {
  78      Status s = target()->GetChildren(dir, result);
  79      if (!s.ok() || !ignore_dot_files_) {
  80        return s;
  81      }
  82  
  83      std::vector<std::string>::iterator it = result->begin();
  84      while (it != result->end()) {
  85        if ((*it == ".") || (*it == "..")) {
  86          it = result->erase(it);
  87        } else {
  88          ++it;
  89        }
  90      }
  91  
  92      return s;
  93    }
  94  
  95   private:
  96    bool ignore_dot_files_;
  97  };
  98  
  99  // Special Env used to delay background operations.
 100  class SpecialEnv : public EnvWrapper {
 101   public:
 102    // sstable/log Sync() calls are blocked while this pointer is non-null.
 103    std::atomic<bool> delay_data_sync_;
 104  
 105    // sstable/log Sync() calls return an error.
 106    std::atomic<bool> data_sync_error_;
 107  
 108    // Simulate no-space errors while this pointer is non-null.
 109    std::atomic<bool> no_space_;
 110  
 111    // Simulate non-writable file system while this pointer is non-null.
 112    std::atomic<bool> non_writable_;
 113  
 114    // Force sync of manifest files to fail while this pointer is non-null.
 115    std::atomic<bool> manifest_sync_error_;
 116  
 117    // Force write to manifest files to fail while this pointer is non-null.
 118    std::atomic<bool> manifest_write_error_;
 119  
 120    bool count_random_reads_;
 121    AtomicCounter random_read_counter_;
 122  
 123    explicit SpecialEnv(Env* base)
 124        : EnvWrapper(base),
 125          delay_data_sync_(false),
 126          data_sync_error_(false),
 127          no_space_(false),
 128          non_writable_(false),
 129          manifest_sync_error_(false),
 130          manifest_write_error_(false),
 131          count_random_reads_(false) {}
 132  
 133    Status NewWritableFile(const std::string& f, WritableFile** r) {
 134      class DataFile : public WritableFile {
 135       private:
 136        SpecialEnv* const env_;
 137        WritableFile* const base_;
 138  
 139       public:
 140        DataFile(SpecialEnv* env, WritableFile* base) : env_(env), base_(base) {}
 141        ~DataFile() { delete base_; }
 142        Status Append(const Slice& data) override {
 143          if (env_->no_space_.load(std::memory_order_acquire)) {
 144            // Drop writes on the floor
 145            return Status::OK();
 146          } else {
 147            return base_->Append(data);
 148          }
 149        }
 150        Status Close() override { return base_->Close(); }
 151        Status Flush() override { return base_->Flush(); }
 152        Status Sync() override {
 153          if (env_->data_sync_error_.load(std::memory_order_acquire)) {
 154            return Status::IOError("simulated data sync error");
 155          }
 156          while (env_->delay_data_sync_.load(std::memory_order_acquire)) {
 157            DelayMilliseconds(100);
 158          }
 159          return base_->Sync();
 160        }
 161        std::string GetName() const override { return ""; }
 162      };
 163      class ManifestFile : public WritableFile {
 164       private:
 165        SpecialEnv* env_;
 166        WritableFile* base_;
 167  
 168       public:
 169        ManifestFile(SpecialEnv* env, WritableFile* b) : env_(env), base_(b) {}
 170        ~ManifestFile() { delete base_; }
 171        Status Append(const Slice& data) override {
 172          if (env_->manifest_write_error_.load(std::memory_order_acquire)) {
 173            return Status::IOError("simulated writer error");
 174          } else {
 175            return base_->Append(data);
 176          }
 177        }
 178        Status Close() override { return base_->Close(); }
 179        Status Flush() override { return base_->Flush(); }
 180        Status Sync() override {
 181          if (env_->manifest_sync_error_.load(std::memory_order_acquire)) {
 182            return Status::IOError("simulated sync error");
 183          } else {
 184            return base_->Sync();
 185          }
 186        }
 187        std::string GetName() const override { return ""; }
 188      };
 189  
 190      if (non_writable_.load(std::memory_order_acquire)) {
 191        return Status::IOError("simulated write error");
 192      }
 193  
 194      Status s = target()->NewWritableFile(f, r);
 195      if (s.ok()) {
 196        if (strstr(f.c_str(), ".ldb") != nullptr ||
 197            strstr(f.c_str(), ".log") != nullptr) {
 198          *r = new DataFile(this, *r);
 199        } else if (strstr(f.c_str(), "MANIFEST") != nullptr) {
 200          *r = new ManifestFile(this, *r);
 201        }
 202      }
 203      return s;
 204    }
 205  
 206    Status NewRandomAccessFile(const std::string& f, RandomAccessFile** r) {
 207      class CountingFile : public RandomAccessFile {
 208       private:
 209        RandomAccessFile* target_;
 210        AtomicCounter* counter_;
 211  
 212       public:
 213        CountingFile(RandomAccessFile* target, AtomicCounter* counter)
 214            : target_(target), counter_(counter) {}
 215        ~CountingFile() override { delete target_; }
 216        Status Read(uint64_t offset, size_t n, Slice* result,
 217                    char* scratch) const override {
 218          counter_->Increment();
 219          return target_->Read(offset, n, result, scratch);
 220        }
 221        std::string GetName() const override { return ""; }
 222      };
 223  
 224      Status s = target()->NewRandomAccessFile(f, r);
 225      if (s.ok() && count_random_reads_) {
 226        *r = new CountingFile(*r, &random_read_counter_);
 227      }
 228      return s;
 229    }
 230  };
 231  
 232  class DBTest {
 233   public:
 234    std::string dbname_;
 235    SpecialEnv* env_;
 236    DB* db_;
 237  
 238    Options last_options_;
 239  
 240    DBTest() : env_(new SpecialEnv(Env::Default())), option_config_(kDefault) {
 241      filter_policy_ = NewBloomFilterPolicy(10);
 242      dbname_ = test::TmpDir() + "/db_test";
 243      DestroyDB(dbname_, Options());
 244      db_ = nullptr;
 245      Reopen();
 246    }
 247  
 248    ~DBTest() {
 249      delete db_;
 250      DestroyDB(dbname_, Options());
 251      delete env_;
 252      delete filter_policy_;
 253    }
 254  
 255    // Switch to a fresh database with the next option configuration to
 256    // test.  Return false if there are no more configurations to test.
 257    bool ChangeOptions() {
 258      option_config_++;
 259      if (option_config_ >= kEnd) {
 260        return false;
 261      } else {
 262        DestroyAndReopen();
 263        return true;
 264      }
 265    }
 266  
 267    // Return the current option configuration.
 268    Options CurrentOptions() {
 269      Options options;
 270      options.reuse_logs = false;
 271      switch (option_config_) {
 272        case kReuse:
 273          options.reuse_logs = true;
 274          break;
 275        case kFilter:
 276          options.filter_policy = filter_policy_;
 277          break;
 278        case kUncompressed:
 279          options.compression = kNoCompression;
 280          break;
 281        default:
 282          break;
 283      }
 284      return options;
 285    }
 286  
 287    DBImpl* dbfull() { return reinterpret_cast<DBImpl*>(db_); }
 288  
 289    void Reopen(Options* options = nullptr) { ASSERT_OK(TryReopen(options)); }
 290  
 291    void Close() {
 292      delete db_;
 293      db_ = nullptr;
 294    }
 295  
 296    void DestroyAndReopen(Options* options = nullptr) {
 297      delete db_;
 298      db_ = nullptr;
 299      DestroyDB(dbname_, Options());
 300      ASSERT_OK(TryReopen(options));
 301    }
 302  
 303    Status TryReopen(Options* options) {
 304      delete db_;
 305      db_ = nullptr;
 306      Options opts;
 307      if (options != nullptr) {
 308        opts = *options;
 309      } else {
 310        opts = CurrentOptions();
 311        opts.create_if_missing = true;
 312      }
 313      last_options_ = opts;
 314  
 315      return DB::Open(opts, dbname_, &db_);
 316    }
 317  
 318    Status Put(const std::string& k, const std::string& v) {
 319      return db_->Put(WriteOptions(), k, v);
 320    }
 321  
 322    Status Delete(const std::string& k) { return db_->Delete(WriteOptions(), k); }
 323  
 324    std::string Get(const std::string& k, const Snapshot* snapshot = nullptr) {
 325      ReadOptions options;
 326      options.snapshot = snapshot;
 327      std::string result;
 328      Status s = db_->Get(options, k, &result);
 329      if (s.IsNotFound()) {
 330        result = "NOT_FOUND";
 331      } else if (!s.ok()) {
 332        result = s.ToString();
 333      }
 334      return result;
 335    }
 336  
 337    // Return a string that contains all key,value pairs in order,
 338    // formatted like "(k1->v1)(k2->v2)".
 339    std::string Contents() {
 340      std::vector<std::string> forward;
 341      std::string result;
 342      Iterator* iter = db_->NewIterator(ReadOptions());
 343      for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
 344        std::string s = IterStatus(iter);
 345        result.push_back('(');
 346        result.append(s);
 347        result.push_back(')');
 348        forward.push_back(s);
 349      }
 350  
 351      // Check reverse iteration results are the reverse of forward results
 352      size_t matched = 0;
 353      for (iter->SeekToLast(); iter->Valid(); iter->Prev()) {
 354        ASSERT_LT(matched, forward.size());
 355        ASSERT_EQ(IterStatus(iter), forward[forward.size() - matched - 1]);
 356        matched++;
 357      }
 358      ASSERT_EQ(matched, forward.size());
 359  
 360      delete iter;
 361      return result;
 362    }
 363  
 364    std::string AllEntriesFor(const Slice& user_key) {
 365      Iterator* iter = dbfull()->TEST_NewInternalIterator();
 366      InternalKey target(user_key, kMaxSequenceNumber, kTypeValue);
 367      iter->Seek(target.Encode());
 368      std::string result;
 369      if (!iter->status().ok()) {
 370        result = iter->status().ToString();
 371      } else {
 372        result = "[ ";
 373        bool first = true;
 374        while (iter->Valid()) {
 375          ParsedInternalKey ikey;
 376          if (!ParseInternalKey(iter->key(), &ikey)) {
 377            result += "CORRUPTED";
 378          } else {
 379            if (last_options_.comparator->Compare(ikey.user_key, user_key) != 0) {
 380              break;
 381            }
 382            if (!first) {
 383              result += ", ";
 384            }
 385            first = false;
 386            switch (ikey.type) {
 387              case kTypeValue:
 388                result += iter->value().ToString();
 389                break;
 390              case kTypeDeletion:
 391                result += "DEL";
 392                break;
 393            }
 394          }
 395          iter->Next();
 396        }
 397        if (!first) {
 398          result += " ";
 399        }
 400        result += "]";
 401      }
 402      delete iter;
 403      return result;
 404    }
 405  
 406    int NumTableFilesAtLevel(int level) {
 407      std::string property;
 408      ASSERT_TRUE(db_->GetProperty(
 409          "leveldb.num-files-at-level" + NumberToString(level), &property));
 410      return std::stoi(property);
 411    }
 412  
 413    int TotalTableFiles() {
 414      int result = 0;
 415      for (int level = 0; level < config::kNumLevels; level++) {
 416        result += NumTableFilesAtLevel(level);
 417      }
 418      return result;
 419    }
 420  
 421    // Return spread of files per level
 422    std::string FilesPerLevel() {
 423      std::string result;
 424      int last_non_zero_offset = 0;
 425      for (int level = 0; level < config::kNumLevels; level++) {
 426        int f = NumTableFilesAtLevel(level);
 427        char buf[100];
 428        snprintf(buf, sizeof(buf), "%s%d", (level ? "," : ""), f);
 429        result += buf;
 430        if (f > 0) {
 431          last_non_zero_offset = result.size();
 432        }
 433      }
 434      result.resize(last_non_zero_offset);
 435      return result;
 436    }
 437  
 438    int CountFiles() {
 439      std::vector<std::string> files;
 440      env_->GetChildren(dbname_, &files);
 441      return static_cast<int>(files.size());
 442    }
 443  
 444    uint64_t Size(const Slice& start, const Slice& limit) {
 445      Range r(start, limit);
 446      uint64_t size;
 447      db_->GetApproximateSizes(&r, 1, &size);
 448      return size;
 449    }
 450  
 451    void Compact(const Slice& start, const Slice& limit) {
 452      db_->CompactRange(&start, &limit);
 453    }
 454  
 455    // Do n memtable compactions, each of which produces an sstable
 456    // covering the range [small_key,large_key].
 457    void MakeTables(int n, const std::string& small_key,
 458                    const std::string& large_key) {
 459      for (int i = 0; i < n; i++) {
 460        Put(small_key, "begin");
 461        Put(large_key, "end");
 462        dbfull()->TEST_CompactMemTable();
 463      }
 464    }
 465  
 466    // Prevent pushing of new sstables into deeper levels by adding
 467    // tables that cover a specified range to all levels.
 468    void FillLevels(const std::string& smallest, const std::string& largest) {
 469      MakeTables(config::kNumLevels, smallest, largest);
 470    }
 471  
 472    void DumpFileCounts(const char* label) {
 473      fprintf(stderr, "---\n%s:\n", label);
 474      fprintf(
 475          stderr, "maxoverlap: %lld\n",
 476          static_cast<long long>(dbfull()->TEST_MaxNextLevelOverlappingBytes()));
 477      for (int level = 0; level < config::kNumLevels; level++) {
 478        int num = NumTableFilesAtLevel(level);
 479        if (num > 0) {
 480          fprintf(stderr, "  level %3d : %d files\n", level, num);
 481        }
 482      }
 483    }
 484  
 485    std::string DumpSSTableList() {
 486      std::string property;
 487      db_->GetProperty("leveldb.sstables", &property);
 488      return property;
 489    }
 490  
 491    std::string IterStatus(Iterator* iter) {
 492      std::string result;
 493      if (iter->Valid()) {
 494        result = iter->key().ToString() + "->" + iter->value().ToString();
 495      } else {
 496        result = "(invalid)";
 497      }
 498      return result;
 499    }
 500  
 501    bool DeleteAnSSTFile() {
 502      std::vector<std::string> filenames;
 503      ASSERT_OK(env_->GetChildren(dbname_, &filenames));
 504      uint64_t number;
 505      FileType type;
 506      for (size_t i = 0; i < filenames.size(); i++) {
 507        if (ParseFileName(filenames[i], &number, &type) && type == kTableFile) {
 508          ASSERT_OK(env_->DeleteFile(TableFileName(dbname_, number)));
 509          return true;
 510        }
 511      }
 512      return false;
 513    }
 514  
 515    // Returns number of files renamed.
 516    int RenameLDBToSST() {
 517      std::vector<std::string> filenames;
 518      ASSERT_OK(env_->GetChildren(dbname_, &filenames));
 519      uint64_t number;
 520      FileType type;
 521      int files_renamed = 0;
 522      for (size_t i = 0; i < filenames.size(); i++) {
 523        if (ParseFileName(filenames[i], &number, &type) && type == kTableFile) {
 524          const std::string from = TableFileName(dbname_, number);
 525          const std::string to = SSTTableFileName(dbname_, number);
 526          ASSERT_OK(env_->RenameFile(from, to));
 527          files_renamed++;
 528        }
 529      }
 530      return files_renamed;
 531    }
 532  
 533   private:
 534    // Sequence of option configurations to try
 535    enum OptionConfig { kDefault, kReuse, kFilter, kUncompressed, kEnd };
 536  
 537    const FilterPolicy* filter_policy_;
 538    int option_config_;
 539  };
 540  
 541  TEST(DBTest, Empty) {
 542    do {
 543      ASSERT_TRUE(db_ != nullptr);
 544      ASSERT_EQ("NOT_FOUND", Get("foo"));
 545    } while (ChangeOptions());
 546  }
 547  
 548  TEST(DBTest, EmptyKey) {
 549    do {
 550      ASSERT_OK(Put("", "v1"));
 551      ASSERT_EQ("v1", Get(""));
 552      ASSERT_OK(Put("", "v2"));
 553      ASSERT_EQ("v2", Get(""));
 554    } while (ChangeOptions());
 555  }
 556  
 557  TEST(DBTest, EmptyValue) {
 558    do {
 559      ASSERT_OK(Put("key", "v1"));
 560      ASSERT_EQ("v1", Get("key"));
 561      ASSERT_OK(Put("key", ""));
 562      ASSERT_EQ("", Get("key"));
 563      ASSERT_OK(Put("key", "v2"));
 564      ASSERT_EQ("v2", Get("key"));
 565    } while (ChangeOptions());
 566  }
 567  
 568  TEST(DBTest, ReadWrite) {
 569    do {
 570      ASSERT_OK(Put("foo", "v1"));
 571      ASSERT_EQ("v1", Get("foo"));
 572      ASSERT_OK(Put("bar", "v2"));
 573      ASSERT_OK(Put("foo", "v3"));
 574      ASSERT_EQ("v3", Get("foo"));
 575      ASSERT_EQ("v2", Get("bar"));
 576    } while (ChangeOptions());
 577  }
 578  
 579  TEST(DBTest, PutDeleteGet) {
 580    do {
 581      ASSERT_OK(db_->Put(WriteOptions(), "foo", "v1"));
 582      ASSERT_EQ("v1", Get("foo"));
 583      ASSERT_OK(db_->Put(WriteOptions(), "foo", "v2"));
 584      ASSERT_EQ("v2", Get("foo"));
 585      ASSERT_OK(db_->Delete(WriteOptions(), "foo"));
 586      ASSERT_EQ("NOT_FOUND", Get("foo"));
 587    } while (ChangeOptions());
 588  }
 589  
 590  TEST(DBTest, GetFromImmutableLayer) {
 591    do {
 592      Options options = CurrentOptions();
 593      options.env = env_;
 594      options.write_buffer_size = 100000;  // Small write buffer
 595      Reopen(&options);
 596  
 597      ASSERT_OK(Put("foo", "v1"));
 598      ASSERT_EQ("v1", Get("foo"));
 599  
 600      // Block sync calls.
 601      env_->delay_data_sync_.store(true, std::memory_order_release);
 602      Put("k1", std::string(100000, 'x'));  // Fill memtable.
 603      Put("k2", std::string(100000, 'y'));  // Trigger compaction.
 604      ASSERT_EQ("v1", Get("foo"));
 605      // Release sync calls.
 606      env_->delay_data_sync_.store(false, std::memory_order_release);
 607    } while (ChangeOptions());
 608  }
 609  
 610  TEST(DBTest, GetFromVersions) {
 611    do {
 612      ASSERT_OK(Put("foo", "v1"));
 613      dbfull()->TEST_CompactMemTable();
 614      ASSERT_EQ("v1", Get("foo"));
 615    } while (ChangeOptions());
 616  }
 617  
 618  TEST(DBTest, GetMemUsage) {
 619    do {
 620      ASSERT_OK(Put("foo", "v1"));
 621      std::string val;
 622      ASSERT_TRUE(db_->GetProperty("leveldb.approximate-memory-usage", &val));
 623      int mem_usage = std::stoi(val);
 624      ASSERT_GT(mem_usage, 0);
 625      ASSERT_LT(mem_usage, 5 * 1024 * 1024);
 626    } while (ChangeOptions());
 627  }
 628  
 629  TEST(DBTest, GetSnapshot) {
 630    do {
 631      // Try with both a short key and a long key
 632      for (int i = 0; i < 2; i++) {
 633        std::string key = (i == 0) ? std::string("foo") : std::string(200, 'x');
 634        ASSERT_OK(Put(key, "v1"));
 635        const Snapshot* s1 = db_->GetSnapshot();
 636        ASSERT_OK(Put(key, "v2"));
 637        ASSERT_EQ("v2", Get(key));
 638        ASSERT_EQ("v1", Get(key, s1));
 639        dbfull()->TEST_CompactMemTable();
 640        ASSERT_EQ("v2", Get(key));
 641        ASSERT_EQ("v1", Get(key, s1));
 642        db_->ReleaseSnapshot(s1);
 643      }
 644    } while (ChangeOptions());
 645  }
 646  
 647  TEST(DBTest, GetIdenticalSnapshots) {
 648    do {
 649      // Try with both a short key and a long key
 650      for (int i = 0; i < 2; i++) {
 651        std::string key = (i == 0) ? std::string("foo") : std::string(200, 'x');
 652        ASSERT_OK(Put(key, "v1"));
 653        const Snapshot* s1 = db_->GetSnapshot();
 654        const Snapshot* s2 = db_->GetSnapshot();
 655        const Snapshot* s3 = db_->GetSnapshot();
 656        ASSERT_OK(Put(key, "v2"));
 657        ASSERT_EQ("v2", Get(key));
 658        ASSERT_EQ("v1", Get(key, s1));
 659        ASSERT_EQ("v1", Get(key, s2));
 660        ASSERT_EQ("v1", Get(key, s3));
 661        db_->ReleaseSnapshot(s1);
 662        dbfull()->TEST_CompactMemTable();
 663        ASSERT_EQ("v2", Get(key));
 664        ASSERT_EQ("v1", Get(key, s2));
 665        db_->ReleaseSnapshot(s2);
 666        ASSERT_EQ("v1", Get(key, s3));
 667        db_->ReleaseSnapshot(s3);
 668      }
 669    } while (ChangeOptions());
 670  }
 671  
 672  TEST(DBTest, IterateOverEmptySnapshot) {
 673    do {
 674      const Snapshot* snapshot = db_->GetSnapshot();
 675      ReadOptions read_options;
 676      read_options.snapshot = snapshot;
 677      ASSERT_OK(Put("foo", "v1"));
 678      ASSERT_OK(Put("foo", "v2"));
 679  
 680      Iterator* iterator1 = db_->NewIterator(read_options);
 681      iterator1->SeekToFirst();
 682      ASSERT_TRUE(!iterator1->Valid());
 683      delete iterator1;
 684  
 685      dbfull()->TEST_CompactMemTable();
 686  
 687      Iterator* iterator2 = db_->NewIterator(read_options);
 688      iterator2->SeekToFirst();
 689      ASSERT_TRUE(!iterator2->Valid());
 690      delete iterator2;
 691  
 692      db_->ReleaseSnapshot(snapshot);
 693    } while (ChangeOptions());
 694  }
 695  
 696  TEST(DBTest, GetLevel0Ordering) {
 697    do {
 698      // Check that we process level-0 files in correct order.  The code
 699      // below generates two level-0 files where the earlier one comes
 700      // before the later one in the level-0 file list since the earlier
 701      // one has a smaller "smallest" key.
 702      ASSERT_OK(Put("bar", "b"));
 703      ASSERT_OK(Put("foo", "v1"));
 704      dbfull()->TEST_CompactMemTable();
 705      ASSERT_OK(Put("foo", "v2"));
 706      dbfull()->TEST_CompactMemTable();
 707      ASSERT_EQ("v2", Get("foo"));
 708    } while (ChangeOptions());
 709  }
 710  
 711  TEST(DBTest, GetOrderedByLevels) {
 712    do {
 713      ASSERT_OK(Put("foo", "v1"));
 714      Compact("a", "z");
 715      ASSERT_EQ("v1", Get("foo"));
 716      ASSERT_OK(Put("foo", "v2"));
 717      ASSERT_EQ("v2", Get("foo"));
 718      dbfull()->TEST_CompactMemTable();
 719      ASSERT_EQ("v2", Get("foo"));
 720    } while (ChangeOptions());
 721  }
 722  
 723  TEST(DBTest, GetPicksCorrectFile) {
 724    do {
 725      // Arrange to have multiple files in a non-level-0 level.
 726      ASSERT_OK(Put("a", "va"));
 727      Compact("a", "b");
 728      ASSERT_OK(Put("x", "vx"));
 729      Compact("x", "y");
 730      ASSERT_OK(Put("f", "vf"));
 731      Compact("f", "g");
 732      ASSERT_EQ("va", Get("a"));
 733      ASSERT_EQ("vf", Get("f"));
 734      ASSERT_EQ("vx", Get("x"));
 735    } while (ChangeOptions());
 736  }
 737  
 738  TEST(DBTest, GetDoesNotTriggerSeekCompaction) {
 739    do {
 740      // Arrange for the following to happen:
 741      //   * sstable A in level 0
 742      //   * nothing in level 1
 743      //   * sstable B in level 2
 744      // Seek compaction is disabled in this fork, so repeated reads must
 745      // not change the level layout. A manual compaction must still work.
 746  
 747      // Step 1: First place sstables in levels 0 and 2
 748      int compaction_count = 0;
 749      while (NumTableFilesAtLevel(0) == 0 || NumTableFilesAtLevel(2) == 0) {
 750        ASSERT_LE(compaction_count, 100) << "could not fill levels 0 and 2";
 751        compaction_count++;
 752        Put("a", "begin");
 753        Put("z", "end");
 754        dbfull()->TEST_CompactMemTable();
 755      }
 756  
 757      // Step 2: clear level 1 if necessary.
 758      dbfull()->TEST_CompactRange(1, nullptr, nullptr);
 759      ASSERT_EQ(NumTableFilesAtLevel(0), 1);
 760      ASSERT_EQ(NumTableFilesAtLevel(1), 0);
 761      ASSERT_EQ(NumTableFilesAtLevel(2), 1);
 762  
 763      // Step 3: many read misses must not schedule any compaction.
 764      for (int i = 0; i < 1000; i++) {
 765        ASSERT_EQ("NOT_FOUND", Get("missing"));
 766      }
 767      DelayMilliseconds(1000);
 768      ASSERT_EQ(NumTableFilesAtLevel(0), 1);
 769      ASSERT_EQ(NumTableFilesAtLevel(1), 0);
 770      ASSERT_EQ(NumTableFilesAtLevel(2), 1);
 771  
 772      // Step 4: a manual compaction still moves the L0 file down.
 773      dbfull()->TEST_CompactRange(0, nullptr, nullptr);
 774      ASSERT_EQ(NumTableFilesAtLevel(0), 0);
 775    } while (ChangeOptions());
 776  }
 777  
 778  TEST(DBTest, IterEmpty) {
 779    Iterator* iter = db_->NewIterator(ReadOptions());
 780  
 781    iter->SeekToFirst();
 782    ASSERT_EQ(IterStatus(iter), "(invalid)");
 783  
 784    iter->SeekToLast();
 785    ASSERT_EQ(IterStatus(iter), "(invalid)");
 786  
 787    iter->Seek("foo");
 788    ASSERT_EQ(IterStatus(iter), "(invalid)");
 789  
 790    delete iter;
 791  }
 792  
 793  TEST(DBTest, IterSingle) {
 794    ASSERT_OK(Put("a", "va"));
 795    Iterator* iter = db_->NewIterator(ReadOptions());
 796  
 797    iter->SeekToFirst();
 798    ASSERT_EQ(IterStatus(iter), "a->va");
 799    iter->Next();
 800    ASSERT_EQ(IterStatus(iter), "(invalid)");
 801    iter->SeekToFirst();
 802    ASSERT_EQ(IterStatus(iter), "a->va");
 803    iter->Prev();
 804    ASSERT_EQ(IterStatus(iter), "(invalid)");
 805  
 806    iter->SeekToLast();
 807    ASSERT_EQ(IterStatus(iter), "a->va");
 808    iter->Next();
 809    ASSERT_EQ(IterStatus(iter), "(invalid)");
 810    iter->SeekToLast();
 811    ASSERT_EQ(IterStatus(iter), "a->va");
 812    iter->Prev();
 813    ASSERT_EQ(IterStatus(iter), "(invalid)");
 814  
 815    iter->Seek("");
 816    ASSERT_EQ(IterStatus(iter), "a->va");
 817    iter->Next();
 818    ASSERT_EQ(IterStatus(iter), "(invalid)");
 819  
 820    iter->Seek("a");
 821    ASSERT_EQ(IterStatus(iter), "a->va");
 822    iter->Next();
 823    ASSERT_EQ(IterStatus(iter), "(invalid)");
 824  
 825    iter->Seek("b");
 826    ASSERT_EQ(IterStatus(iter), "(invalid)");
 827  
 828    delete iter;
 829  }
 830  
 831  TEST(DBTest, IterMulti) {
 832    ASSERT_OK(Put("a", "va"));
 833    ASSERT_OK(Put("b", "vb"));
 834    ASSERT_OK(Put("c", "vc"));
 835    Iterator* iter = db_->NewIterator(ReadOptions());
 836  
 837    iter->SeekToFirst();
 838    ASSERT_EQ(IterStatus(iter), "a->va");
 839    iter->Next();
 840    ASSERT_EQ(IterStatus(iter), "b->vb");
 841    iter->Next();
 842    ASSERT_EQ(IterStatus(iter), "c->vc");
 843    iter->Next();
 844    ASSERT_EQ(IterStatus(iter), "(invalid)");
 845    iter->SeekToFirst();
 846    ASSERT_EQ(IterStatus(iter), "a->va");
 847    iter->Prev();
 848    ASSERT_EQ(IterStatus(iter), "(invalid)");
 849  
 850    iter->SeekToLast();
 851    ASSERT_EQ(IterStatus(iter), "c->vc");
 852    iter->Prev();
 853    ASSERT_EQ(IterStatus(iter), "b->vb");
 854    iter->Prev();
 855    ASSERT_EQ(IterStatus(iter), "a->va");
 856    iter->Prev();
 857    ASSERT_EQ(IterStatus(iter), "(invalid)");
 858    iter->SeekToLast();
 859    ASSERT_EQ(IterStatus(iter), "c->vc");
 860    iter->Next();
 861    ASSERT_EQ(IterStatus(iter), "(invalid)");
 862  
 863    iter->Seek("");
 864    ASSERT_EQ(IterStatus(iter), "a->va");
 865    iter->Seek("a");
 866    ASSERT_EQ(IterStatus(iter), "a->va");
 867    iter->Seek("ax");
 868    ASSERT_EQ(IterStatus(iter), "b->vb");
 869    iter->Seek("b");
 870    ASSERT_EQ(IterStatus(iter), "b->vb");
 871    iter->Seek("z");
 872    ASSERT_EQ(IterStatus(iter), "(invalid)");
 873  
 874    // Switch from reverse to forward
 875    iter->SeekToLast();
 876    iter->Prev();
 877    iter->Prev();
 878    iter->Next();
 879    ASSERT_EQ(IterStatus(iter), "b->vb");
 880  
 881    // Switch from forward to reverse
 882    iter->SeekToFirst();
 883    iter->Next();
 884    iter->Next();
 885    iter->Prev();
 886    ASSERT_EQ(IterStatus(iter), "b->vb");
 887  
 888    // Make sure iter stays at snapshot
 889    ASSERT_OK(Put("a", "va2"));
 890    ASSERT_OK(Put("a2", "va3"));
 891    ASSERT_OK(Put("b", "vb2"));
 892    ASSERT_OK(Put("c", "vc2"));
 893    ASSERT_OK(Delete("b"));
 894    iter->SeekToFirst();
 895    ASSERT_EQ(IterStatus(iter), "a->va");
 896    iter->Next();
 897    ASSERT_EQ(IterStatus(iter), "b->vb");
 898    iter->Next();
 899    ASSERT_EQ(IterStatus(iter), "c->vc");
 900    iter->Next();
 901    ASSERT_EQ(IterStatus(iter), "(invalid)");
 902    iter->SeekToLast();
 903    ASSERT_EQ(IterStatus(iter), "c->vc");
 904    iter->Prev();
 905    ASSERT_EQ(IterStatus(iter), "b->vb");
 906    iter->Prev();
 907    ASSERT_EQ(IterStatus(iter), "a->va");
 908    iter->Prev();
 909    ASSERT_EQ(IterStatus(iter), "(invalid)");
 910  
 911    delete iter;
 912  }
 913  
 914  TEST(DBTest, IterSmallAndLargeMix) {
 915    ASSERT_OK(Put("a", "va"));
 916    ASSERT_OK(Put("b", std::string(100000, 'b')));
 917    ASSERT_OK(Put("c", "vc"));
 918    ASSERT_OK(Put("d", std::string(100000, 'd')));
 919    ASSERT_OK(Put("e", std::string(100000, 'e')));
 920  
 921    Iterator* iter = db_->NewIterator(ReadOptions());
 922  
 923    iter->SeekToFirst();
 924    ASSERT_EQ(IterStatus(iter), "a->va");
 925    iter->Next();
 926    ASSERT_EQ(IterStatus(iter), "b->" + std::string(100000, 'b'));
 927    iter->Next();
 928    ASSERT_EQ(IterStatus(iter), "c->vc");
 929    iter->Next();
 930    ASSERT_EQ(IterStatus(iter), "d->" + std::string(100000, 'd'));
 931    iter->Next();
 932    ASSERT_EQ(IterStatus(iter), "e->" + std::string(100000, 'e'));
 933    iter->Next();
 934    ASSERT_EQ(IterStatus(iter), "(invalid)");
 935  
 936    iter->SeekToLast();
 937    ASSERT_EQ(IterStatus(iter), "e->" + std::string(100000, 'e'));
 938    iter->Prev();
 939    ASSERT_EQ(IterStatus(iter), "d->" + std::string(100000, 'd'));
 940    iter->Prev();
 941    ASSERT_EQ(IterStatus(iter), "c->vc");
 942    iter->Prev();
 943    ASSERT_EQ(IterStatus(iter), "b->" + std::string(100000, 'b'));
 944    iter->Prev();
 945    ASSERT_EQ(IterStatus(iter), "a->va");
 946    iter->Prev();
 947    ASSERT_EQ(IterStatus(iter), "(invalid)");
 948  
 949    delete iter;
 950  }
 951  
 952  TEST(DBTest, IterMultiWithDelete) {
 953    do {
 954      ASSERT_OK(Put("a", "va"));
 955      ASSERT_OK(Put("b", "vb"));
 956      ASSERT_OK(Put("c", "vc"));
 957      ASSERT_OK(Delete("b"));
 958      ASSERT_EQ("NOT_FOUND", Get("b"));
 959  
 960      Iterator* iter = db_->NewIterator(ReadOptions());
 961      iter->Seek("c");
 962      ASSERT_EQ(IterStatus(iter), "c->vc");
 963      iter->Prev();
 964      ASSERT_EQ(IterStatus(iter), "a->va");
 965      delete iter;
 966    } while (ChangeOptions());
 967  }
 968  
 969  TEST(DBTest, Recover) {
 970    do {
 971      ASSERT_OK(Put("foo", "v1"));
 972      ASSERT_OK(Put("baz", "v5"));
 973  
 974      Reopen();
 975      ASSERT_EQ("v1", Get("foo"));
 976  
 977      ASSERT_EQ("v1", Get("foo"));
 978      ASSERT_EQ("v5", Get("baz"));
 979      ASSERT_OK(Put("bar", "v2"));
 980      ASSERT_OK(Put("foo", "v3"));
 981  
 982      Reopen();
 983      ASSERT_EQ("v3", Get("foo"));
 984      ASSERT_OK(Put("foo", "v4"));
 985      ASSERT_EQ("v4", Get("foo"));
 986      ASSERT_EQ("v2", Get("bar"));
 987      ASSERT_EQ("v5", Get("baz"));
 988    } while (ChangeOptions());
 989  }
 990  
 991  TEST(DBTest, RecoveryWithEmptyLog) {
 992    do {
 993      ASSERT_OK(Put("foo", "v1"));
 994      ASSERT_OK(Put("foo", "v2"));
 995      Reopen();
 996      Reopen();
 997      ASSERT_OK(Put("foo", "v3"));
 998      Reopen();
 999      ASSERT_EQ("v3", Get("foo"));
1000    } while (ChangeOptions());
1001  }
1002  
1003  // Check that writes done during a memtable compaction are recovered
1004  // if the database is shutdown during the memtable compaction.
1005  TEST(DBTest, RecoverDuringMemtableCompaction) {
1006    do {
1007      Options options = CurrentOptions();
1008      options.env = env_;
1009      options.write_buffer_size = 1000000;
1010      Reopen(&options);
1011  
1012      // Trigger a long memtable compaction and reopen the database during it
1013      ASSERT_OK(Put("foo", "v1"));                         // Goes to 1st log file
1014      ASSERT_OK(Put("big1", std::string(10000000, 'x')));  // Fills memtable
1015      ASSERT_OK(Put("big2", std::string(1000, 'y')));      // Triggers compaction
1016      ASSERT_OK(Put("bar", "v2"));                         // Goes to new log file
1017  
1018      Reopen(&options);
1019      ASSERT_EQ("v1", Get("foo"));
1020      ASSERT_EQ("v2", Get("bar"));
1021      ASSERT_EQ(std::string(10000000, 'x'), Get("big1"));
1022      ASSERT_EQ(std::string(1000, 'y'), Get("big2"));
1023    } while (ChangeOptions());
1024  }
1025  
1026  static std::string Key(int i) {
1027    char buf[100];
1028    snprintf(buf, sizeof(buf), "key%06d", i);
1029    return std::string(buf);
1030  }
1031  
1032  TEST(DBTest, MinorCompactionsHappen) {
1033    Options options = CurrentOptions();
1034    options.write_buffer_size = 10000;
1035    Reopen(&options);
1036  
1037    const int N = 500;
1038  
1039    int starting_num_tables = TotalTableFiles();
1040    for (int i = 0; i < N; i++) {
1041      ASSERT_OK(Put(Key(i), Key(i) + std::string(1000, 'v')));
1042    }
1043    int ending_num_tables = TotalTableFiles();
1044    ASSERT_GT(ending_num_tables, starting_num_tables);
1045  
1046    for (int i = 0; i < N; i++) {
1047      ASSERT_EQ(Key(i) + std::string(1000, 'v'), Get(Key(i)));
1048    }
1049  
1050    Reopen();
1051  
1052    for (int i = 0; i < N; i++) {
1053      ASSERT_EQ(Key(i) + std::string(1000, 'v'), Get(Key(i)));
1054    }
1055  }
1056  
1057  TEST(DBTest, RecoverWithLargeLog) {
1058    {
1059      Options options = CurrentOptions();
1060      Reopen(&options);
1061      ASSERT_OK(Put("big1", std::string(200000, '1')));
1062      ASSERT_OK(Put("big2", std::string(200000, '2')));
1063      ASSERT_OK(Put("small3", std::string(10, '3')));
1064      ASSERT_OK(Put("small4", std::string(10, '4')));
1065      ASSERT_EQ(NumTableFilesAtLevel(0), 0);
1066    }
1067  
1068    // Make sure that if we re-open with a small write buffer size that
1069    // we flush table files in the middle of a large log file.
1070    Options options = CurrentOptions();
1071    options.write_buffer_size = 100000;
1072    Reopen(&options);
1073    ASSERT_EQ(NumTableFilesAtLevel(0), 3);
1074    ASSERT_EQ(std::string(200000, '1'), Get("big1"));
1075    ASSERT_EQ(std::string(200000, '2'), Get("big2"));
1076    ASSERT_EQ(std::string(10, '3'), Get("small3"));
1077    ASSERT_EQ(std::string(10, '4'), Get("small4"));
1078    ASSERT_GT(NumTableFilesAtLevel(0), 1);
1079  }
1080  
1081  TEST(DBTest, CompactionsGenerateMultipleFiles) {
1082    Options options = CurrentOptions();
1083    options.write_buffer_size = 100000000;  // Large write buffer
1084    Reopen(&options);
1085  
1086    Random rnd(301);
1087  
1088    // Write 8MB (80 values, each 100K)
1089    ASSERT_EQ(NumTableFilesAtLevel(0), 0);
1090    std::vector<std::string> values;
1091    for (int i = 0; i < 80; i++) {
1092      values.push_back(RandomString(&rnd, 100000));
1093      ASSERT_OK(Put(Key(i), values[i]));
1094    }
1095  
1096    // Reopening moves updates to level-0
1097    Reopen(&options);
1098    dbfull()->TEST_CompactRange(0, nullptr, nullptr);
1099  
1100    ASSERT_EQ(NumTableFilesAtLevel(0), 0);
1101    ASSERT_GT(NumTableFilesAtLevel(1), 1);
1102    for (int i = 0; i < 80; i++) {
1103      ASSERT_EQ(Get(Key(i)), values[i]);
1104    }
1105  }
1106  
1107  TEST(DBTest, RepeatedWritesToSameKey) {
1108    Options options = CurrentOptions();
1109    options.env = env_;
1110    options.write_buffer_size = 100000;  // Small write buffer
1111    Reopen(&options);
1112  
1113    // We must have at most one file per level except for level-0,
1114    // which may have up to kL0_StopWritesTrigger files.
1115    const int kMaxFiles = config::kNumLevels + config::kL0_StopWritesTrigger;
1116  
1117    Random rnd(301);
1118    std::string value = RandomString(&rnd, 2 * options.write_buffer_size);
1119    for (int i = 0; i < 5 * kMaxFiles; i++) {
1120      Put("key", value);
1121      ASSERT_LE(TotalTableFiles(), kMaxFiles);
1122      fprintf(stderr, "after %d: %d files\n", i + 1, TotalTableFiles());
1123    }
1124  }
1125  
1126  TEST(DBTest, SparseMerge) {
1127    Options options = CurrentOptions();
1128    options.compression = kNoCompression;
1129    Reopen(&options);
1130  
1131    FillLevels("A", "Z");
1132  
1133    // Suppose there is:
1134    //    small amount of data with prefix A
1135    //    large amount of data with prefix B
1136    //    small amount of data with prefix C
1137    // and that recent updates have made small changes to all three prefixes.
1138    // Check that we do not do a compaction that merges all of B in one shot.
1139    const std::string value(1000, 'x');
1140    Put("A", "va");
1141    // Write approximately 100MB of "B" values
1142    for (int i = 0; i < 100000; i++) {
1143      char key[100];
1144      snprintf(key, sizeof(key), "B%010d", i);
1145      Put(key, value);
1146    }
1147    Put("C", "vc");
1148    dbfull()->TEST_CompactMemTable();
1149    dbfull()->TEST_CompactRange(0, nullptr, nullptr);
1150  
1151    // Make sparse update
1152    Put("A", "va2");
1153    Put("B100", "bvalue2");
1154    Put("C", "vc2");
1155    dbfull()->TEST_CompactMemTable();
1156  
1157    // Compactions should not cause us to create a situation where
1158    // a file overlaps too much data at the next level.
1159    ASSERT_LE(dbfull()->TEST_MaxNextLevelOverlappingBytes(), 20 * 1048576);
1160    dbfull()->TEST_CompactRange(0, nullptr, nullptr);
1161    ASSERT_LE(dbfull()->TEST_MaxNextLevelOverlappingBytes(), 20 * 1048576);
1162    dbfull()->TEST_CompactRange(1, nullptr, nullptr);
1163    ASSERT_LE(dbfull()->TEST_MaxNextLevelOverlappingBytes(), 20 * 1048576);
1164  }
1165  
1166  static bool Between(uint64_t val, uint64_t low, uint64_t high) {
1167    bool result = (val >= low) && (val <= high);
1168    if (!result) {
1169      fprintf(stderr, "Value %llu is not in range [%llu, %llu]\n",
1170              (unsigned long long)(val), (unsigned long long)(low),
1171              (unsigned long long)(high));
1172    }
1173    return result;
1174  }
1175  
1176  TEST(DBTest, ApproximateSizes) {
1177    do {
1178      Options options = CurrentOptions();
1179      options.write_buffer_size = 100000000;  // Large write buffer
1180      options.compression = kNoCompression;
1181      DestroyAndReopen();
1182  
1183      ASSERT_TRUE(Between(Size("", "xyz"), 0, 0));
1184      Reopen(&options);
1185      ASSERT_TRUE(Between(Size("", "xyz"), 0, 0));
1186  
1187      // Write 8MB (80 values, each 100K)
1188      ASSERT_EQ(NumTableFilesAtLevel(0), 0);
1189      const int N = 80;
1190      static const int S1 = 100000;
1191      static const int S2 = 105000;  // Allow some expansion from metadata
1192      Random rnd(301);
1193      for (int i = 0; i < N; i++) {
1194        ASSERT_OK(Put(Key(i), RandomString(&rnd, S1)));
1195      }
1196  
1197      // 0 because GetApproximateSizes() does not account for memtable space
1198      ASSERT_TRUE(Between(Size("", Key(50)), 0, 0));
1199  
1200      if (options.reuse_logs) {
1201        // Recovery will reuse memtable, and GetApproximateSizes() does not
1202        // account for memtable usage;
1203        Reopen(&options);
1204        ASSERT_TRUE(Between(Size("", Key(50)), 0, 0));
1205        continue;
1206      }
1207  
1208      // Check sizes across recovery by reopening a few times
1209      for (int run = 0; run < 3; run++) {
1210        Reopen(&options);
1211  
1212        for (int compact_start = 0; compact_start < N; compact_start += 10) {
1213          for (int i = 0; i < N; i += 10) {
1214            ASSERT_TRUE(Between(Size("", Key(i)), S1 * i, S2 * i));
1215            ASSERT_TRUE(Between(Size("", Key(i) + ".suffix"), S1 * (i + 1),
1216                                S2 * (i + 1)));
1217            ASSERT_TRUE(Between(Size(Key(i), Key(i + 10)), S1 * 10, S2 * 10));
1218          }
1219          ASSERT_TRUE(Between(Size("", Key(50)), S1 * 50, S2 * 50));
1220          ASSERT_TRUE(Between(Size("", Key(50) + ".suffix"), S1 * 50, S2 * 50));
1221  
1222          std::string cstart_str = Key(compact_start);
1223          std::string cend_str = Key(compact_start + 9);
1224          Slice cstart = cstart_str;
1225          Slice cend = cend_str;
1226          dbfull()->TEST_CompactRange(0, &cstart, &cend);
1227        }
1228  
1229        ASSERT_EQ(NumTableFilesAtLevel(0), 0);
1230        ASSERT_GT(NumTableFilesAtLevel(1), 0);
1231      }
1232    } while (ChangeOptions());
1233  }
1234  
1235  TEST(DBTest, ApproximateSizes_MixOfSmallAndLarge) {
1236    do {
1237      Options options = CurrentOptions();
1238      options.compression = kNoCompression;
1239      Reopen();
1240  
1241      Random rnd(301);
1242      std::string big1 = RandomString(&rnd, 100000);
1243      ASSERT_OK(Put(Key(0), RandomString(&rnd, 10000)));
1244      ASSERT_OK(Put(Key(1), RandomString(&rnd, 10000)));
1245      ASSERT_OK(Put(Key(2), big1));
1246      ASSERT_OK(Put(Key(3), RandomString(&rnd, 10000)));
1247      ASSERT_OK(Put(Key(4), big1));
1248      ASSERT_OK(Put(Key(5), RandomString(&rnd, 10000)));
1249      ASSERT_OK(Put(Key(6), RandomString(&rnd, 300000)));
1250      ASSERT_OK(Put(Key(7), RandomString(&rnd, 10000)));
1251  
1252      if (options.reuse_logs) {
1253        // Need to force a memtable compaction since recovery does not do so.
1254        ASSERT_OK(dbfull()->TEST_CompactMemTable());
1255      }
1256  
1257      // Check sizes across recovery by reopening a few times
1258      for (int run = 0; run < 3; run++) {
1259        Reopen(&options);
1260  
1261        ASSERT_TRUE(Between(Size("", Key(0)), 0, 0));
1262        ASSERT_TRUE(Between(Size("", Key(1)), 10000, 11000));
1263        ASSERT_TRUE(Between(Size("", Key(2)), 20000, 21000));
1264        ASSERT_TRUE(Between(Size("", Key(3)), 120000, 121000));
1265        ASSERT_TRUE(Between(Size("", Key(4)), 130000, 131000));
1266        ASSERT_TRUE(Between(Size("", Key(5)), 230000, 231000));
1267        ASSERT_TRUE(Between(Size("", Key(6)), 240000, 241000));
1268        ASSERT_TRUE(Between(Size("", Key(7)), 540000, 541000));
1269        ASSERT_TRUE(Between(Size("", Key(8)), 550000, 560000));
1270  
1271        ASSERT_TRUE(Between(Size(Key(3), Key(5)), 110000, 111000));
1272  
1273        dbfull()->TEST_CompactRange(0, nullptr, nullptr);
1274      }
1275    } while (ChangeOptions());
1276  }
1277  
1278  TEST(DBTest, IteratorPinsRef) {
1279    Put("foo", "hello");
1280  
1281    // Get iterator that will yield the current contents of the DB.
1282    Iterator* iter = db_->NewIterator(ReadOptions());
1283  
1284    // Write to force compactions
1285    Put("foo", "newvalue1");
1286    for (int i = 0; i < 100; i++) {
1287      ASSERT_OK(Put(Key(i), Key(i) + std::string(100000, 'v')));  // 100K values
1288    }
1289    Put("foo", "newvalue2");
1290  
1291    iter->SeekToFirst();
1292    ASSERT_TRUE(iter->Valid());
1293    ASSERT_EQ("foo", iter->key().ToString());
1294    ASSERT_EQ("hello", iter->value().ToString());
1295    iter->Next();
1296    ASSERT_TRUE(!iter->Valid());
1297    delete iter;
1298  }
1299  
1300  TEST(DBTest, Snapshot) {
1301    do {
1302      Put("foo", "v1");
1303      const Snapshot* s1 = db_->GetSnapshot();
1304      Put("foo", "v2");
1305      const Snapshot* s2 = db_->GetSnapshot();
1306      Put("foo", "v3");
1307      const Snapshot* s3 = db_->GetSnapshot();
1308  
1309      Put("foo", "v4");
1310      ASSERT_EQ("v1", Get("foo", s1));
1311      ASSERT_EQ("v2", Get("foo", s2));
1312      ASSERT_EQ("v3", Get("foo", s3));
1313      ASSERT_EQ("v4", Get("foo"));
1314  
1315      db_->ReleaseSnapshot(s3);
1316      ASSERT_EQ("v1", Get("foo", s1));
1317      ASSERT_EQ("v2", Get("foo", s2));
1318      ASSERT_EQ("v4", Get("foo"));
1319  
1320      db_->ReleaseSnapshot(s1);
1321      ASSERT_EQ("v2", Get("foo", s2));
1322      ASSERT_EQ("v4", Get("foo"));
1323  
1324      db_->ReleaseSnapshot(s2);
1325      ASSERT_EQ("v4", Get("foo"));
1326    } while (ChangeOptions());
1327  }
1328  
1329  TEST(DBTest, HiddenValuesAreRemoved) {
1330    do {
1331      Random rnd(301);
1332      FillLevels("a", "z");
1333  
1334      std::string big = RandomString(&rnd, 50000);
1335      Put("foo", big);
1336      Put("pastfoo", "v");
1337      const Snapshot* snapshot = db_->GetSnapshot();
1338      Put("foo", "tiny");
1339      Put("pastfoo2", "v2");  // Advance sequence number one more
1340  
1341      ASSERT_OK(dbfull()->TEST_CompactMemTable());
1342      ASSERT_GT(NumTableFilesAtLevel(0), 0);
1343  
1344      ASSERT_EQ(big, Get("foo", snapshot));
1345      ASSERT_TRUE(Between(Size("", "pastfoo"), 50000, 60000));
1346      db_->ReleaseSnapshot(snapshot);
1347      ASSERT_EQ(AllEntriesFor("foo"), "[ tiny, " + big + " ]");
1348      Slice x("x");
1349      dbfull()->TEST_CompactRange(0, nullptr, &x);
1350      ASSERT_EQ(AllEntriesFor("foo"), "[ tiny ]");
1351      ASSERT_EQ(NumTableFilesAtLevel(0), 0);
1352      ASSERT_GE(NumTableFilesAtLevel(1), 1);
1353      dbfull()->TEST_CompactRange(1, nullptr, &x);
1354      ASSERT_EQ(AllEntriesFor("foo"), "[ tiny ]");
1355  
1356      ASSERT_TRUE(Between(Size("", "pastfoo"), 0, 1000));
1357    } while (ChangeOptions());
1358  }
1359  
1360  TEST(DBTest, DeletionMarkers1) {
1361    Put("foo", "v1");
1362    ASSERT_OK(dbfull()->TEST_CompactMemTable());
1363    const int last = config::kMaxMemCompactLevel;
1364    ASSERT_EQ(NumTableFilesAtLevel(last), 1);  // foo => v1 is now in last level
1365  
1366    // Place a table at level last-1 to prevent merging with preceding mutation
1367    Put("a", "begin");
1368    Put("z", "end");
1369    dbfull()->TEST_CompactMemTable();
1370    ASSERT_EQ(NumTableFilesAtLevel(last), 1);
1371    ASSERT_EQ(NumTableFilesAtLevel(last - 1), 1);
1372  
1373    Delete("foo");
1374    Put("foo", "v2");
1375    ASSERT_EQ(AllEntriesFor("foo"), "[ v2, DEL, v1 ]");
1376    ASSERT_OK(dbfull()->TEST_CompactMemTable());  // Moves to level last-2
1377    ASSERT_EQ(AllEntriesFor("foo"), "[ v2, DEL, v1 ]");
1378    Slice z("z");
1379    dbfull()->TEST_CompactRange(last - 2, nullptr, &z);
1380    // DEL eliminated, but v1 remains because we aren't compacting that level
1381    // (DEL can be eliminated because v2 hides v1).
1382    ASSERT_EQ(AllEntriesFor("foo"), "[ v2, v1 ]");
1383    dbfull()->TEST_CompactRange(last - 1, nullptr, nullptr);
1384    // Merging last-1 w/ last, so we are the base level for "foo", so
1385    // DEL is removed.  (as is v1).
1386    ASSERT_EQ(AllEntriesFor("foo"), "[ v2 ]");
1387  }
1388  
1389  TEST(DBTest, DeletionMarkers2) {
1390    Put("foo", "v1");
1391    ASSERT_OK(dbfull()->TEST_CompactMemTable());
1392    const int last = config::kMaxMemCompactLevel;
1393    ASSERT_EQ(NumTableFilesAtLevel(last), 1);  // foo => v1 is now in last level
1394  
1395    // Place a table at level last-1 to prevent merging with preceding mutation
1396    Put("a", "begin");
1397    Put("z", "end");
1398    dbfull()->TEST_CompactMemTable();
1399    ASSERT_EQ(NumTableFilesAtLevel(last), 1);
1400    ASSERT_EQ(NumTableFilesAtLevel(last - 1), 1);
1401  
1402    Delete("foo");
1403    ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v1 ]");
1404    ASSERT_OK(dbfull()->TEST_CompactMemTable());  // Moves to level last-2
1405    ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v1 ]");
1406    dbfull()->TEST_CompactRange(last - 2, nullptr, nullptr);
1407    // DEL kept: "last" file overlaps
1408    ASSERT_EQ(AllEntriesFor("foo"), "[ DEL, v1 ]");
1409    dbfull()->TEST_CompactRange(last - 1, nullptr, nullptr);
1410    // Merging last-1 w/ last, so we are the base level for "foo", so
1411    // DEL is removed.  (as is v1).
1412    ASSERT_EQ(AllEntriesFor("foo"), "[ ]");
1413  }
1414  
1415  TEST(DBTest, OverlapInLevel0) {
1416    do {
1417      ASSERT_EQ(config::kMaxMemCompactLevel, 2) << "Fix test to match config";
1418  
1419      // Fill levels 1 and 2 to disable the pushing of new memtables to levels >
1420      // 0.
1421      ASSERT_OK(Put("100", "v100"));
1422      ASSERT_OK(Put("999", "v999"));
1423      dbfull()->TEST_CompactMemTable();
1424      ASSERT_OK(Delete("100"));
1425      ASSERT_OK(Delete("999"));
1426      dbfull()->TEST_CompactMemTable();
1427      ASSERT_EQ("0,1,1", FilesPerLevel());
1428  
1429      // Make files spanning the following ranges in level-0:
1430      //  files[0]  200 .. 900
1431      //  files[1]  300 .. 500
1432      // Note that files are sorted by smallest key.
1433      ASSERT_OK(Put("300", "v300"));
1434      ASSERT_OK(Put("500", "v500"));
1435      dbfull()->TEST_CompactMemTable();
1436      ASSERT_OK(Put("200", "v200"));
1437      ASSERT_OK(Put("600", "v600"));
1438      ASSERT_OK(Put("900", "v900"));
1439      dbfull()->TEST_CompactMemTable();
1440      ASSERT_EQ("2,1,1", FilesPerLevel());
1441  
1442      // Compact away the placeholder files we created initially
1443      dbfull()->TEST_CompactRange(1, nullptr, nullptr);
1444      dbfull()->TEST_CompactRange(2, nullptr, nullptr);
1445      ASSERT_EQ("2", FilesPerLevel());
1446  
1447      // Do a memtable compaction.  Before bug-fix, the compaction would
1448      // not detect the overlap with level-0 files and would incorrectly place
1449      // the deletion in a deeper level.
1450      ASSERT_OK(Delete("600"));
1451      dbfull()->TEST_CompactMemTable();
1452      ASSERT_EQ("3", FilesPerLevel());
1453      ASSERT_EQ("NOT_FOUND", Get("600"));
1454    } while (ChangeOptions());
1455  }
1456  
1457  TEST(DBTest, L0_CompactionBug_Issue44_a) {
1458    Reopen();
1459    ASSERT_OK(Put("b", "v"));
1460    Reopen();
1461    ASSERT_OK(Delete("b"));
1462    ASSERT_OK(Delete("a"));
1463    Reopen();
1464    ASSERT_OK(Delete("a"));
1465    Reopen();
1466    ASSERT_OK(Put("a", "v"));
1467    Reopen();
1468    Reopen();
1469    ASSERT_EQ("(a->v)", Contents());
1470    DelayMilliseconds(1000);  // Wait for compaction to finish
1471    ASSERT_EQ("(a->v)", Contents());
1472  }
1473  
1474  TEST(DBTest, L0_CompactionBug_Issue44_b) {
1475    Reopen();
1476    Put("", "");
1477    Reopen();
1478    Delete("e");
1479    Put("", "");
1480    Reopen();
1481    Put("c", "cv");
1482    Reopen();
1483    Put("", "");
1484    Reopen();
1485    Put("", "");
1486    DelayMilliseconds(1000);  // Wait for compaction to finish
1487    Reopen();
1488    Put("d", "dv");
1489    Reopen();
1490    Put("", "");
1491    Reopen();
1492    Delete("d");
1493    Delete("b");
1494    Reopen();
1495    ASSERT_EQ("(->)(c->cv)", Contents());
1496    DelayMilliseconds(1000);  // Wait for compaction to finish
1497    ASSERT_EQ("(->)(c->cv)", Contents());
1498  }
1499  
1500  TEST(DBTest, Fflush_Issue474) {
1501    static const int kNum = 100000;
1502    Random rnd(test::RandomSeed());
1503    for (int i = 0; i < kNum; i++) {
1504      fflush(nullptr);
1505      ASSERT_OK(Put(RandomKey(&rnd), RandomString(&rnd, 100)));
1506    }
1507  }
1508  
1509  TEST(DBTest, ComparatorCheck) {
1510    class NewComparator : public Comparator {
1511     public:
1512      const char* Name() const override { return "leveldb.NewComparator"; }
1513      int Compare(const Slice& a, const Slice& b) const override {
1514        return BytewiseComparator()->Compare(a, b);
1515      }
1516      void FindShortestSeparator(std::string* s, const Slice& l) const override {
1517        BytewiseComparator()->FindShortestSeparator(s, l);
1518      }
1519      void FindShortSuccessor(std::string* key) const override {
1520        BytewiseComparator()->FindShortSuccessor(key);
1521      }
1522    };
1523    NewComparator cmp;
1524    Options new_options = CurrentOptions();
1525    new_options.comparator = &cmp;
1526    Status s = TryReopen(&new_options);
1527    ASSERT_TRUE(!s.ok());
1528    ASSERT_TRUE(s.ToString().find("comparator") != std::string::npos)
1529        << s.ToString();
1530  }
1531  
1532  TEST(DBTest, CustomComparator) {
1533    class NumberComparator : public Comparator {
1534     public:
1535      const char* Name() const override { return "test.NumberComparator"; }
1536      int Compare(const Slice& a, const Slice& b) const override {
1537        return ToNumber(a) - ToNumber(b);
1538      }
1539      void FindShortestSeparator(std::string* s, const Slice& l) const override {
1540        ToNumber(*s);  // Check format
1541        ToNumber(l);   // Check format
1542      }
1543      void FindShortSuccessor(std::string* key) const override {
1544        ToNumber(*key);  // Check format
1545      }
1546  
1547     private:
1548      static int ToNumber(const Slice& x) {
1549        // Check that there are no extra characters.
1550        ASSERT_TRUE(x.size() >= 2 && x[0] == '[' && x[x.size() - 1] == ']')
1551            << EscapeString(x);
1552        int val;
1553        char ignored;
1554        ASSERT_TRUE(sscanf(x.ToString().c_str(), "[%i]%c", &val, &ignored) == 1)
1555            << EscapeString(x);
1556        return val;
1557      }
1558    };
1559    NumberComparator cmp;
1560    Options new_options = CurrentOptions();
1561    new_options.create_if_missing = true;
1562    new_options.comparator = &cmp;
1563    new_options.filter_policy = nullptr;   // Cannot use bloom filters
1564    new_options.write_buffer_size = 1000;  // Compact more often
1565    DestroyAndReopen(&new_options);
1566    ASSERT_OK(Put("[10]", "ten"));
1567    ASSERT_OK(Put("[0x14]", "twenty"));
1568    for (int i = 0; i < 2; i++) {
1569      ASSERT_EQ("ten", Get("[10]"));
1570      ASSERT_EQ("ten", Get("[0xa]"));
1571      ASSERT_EQ("twenty", Get("[20]"));
1572      ASSERT_EQ("twenty", Get("[0x14]"));
1573      ASSERT_EQ("NOT_FOUND", Get("[15]"));
1574      ASSERT_EQ("NOT_FOUND", Get("[0xf]"));
1575      Compact("[0]", "[9999]");
1576    }
1577  
1578    for (int run = 0; run < 2; run++) {
1579      for (int i = 0; i < 1000; i++) {
1580        char buf[100];
1581        snprintf(buf, sizeof(buf), "[%d]", i * 10);
1582        ASSERT_OK(Put(buf, buf));
1583      }
1584      Compact("[0]", "[1000000]");
1585    }
1586  }
1587  
1588  TEST(DBTest, ManualCompaction) {
1589    ASSERT_EQ(config::kMaxMemCompactLevel, 2)
1590        << "Need to update this test to match kMaxMemCompactLevel";
1591  
1592    MakeTables(3, "p", "q");
1593    ASSERT_EQ("1,1,1", FilesPerLevel());
1594  
1595    // Compaction range falls before files
1596    Compact("", "c");
1597    ASSERT_EQ("1,1,1", FilesPerLevel());
1598  
1599    // Compaction range falls after files
1600    Compact("r", "z");
1601    ASSERT_EQ("1,1,1", FilesPerLevel());
1602  
1603    // Compaction range overlaps files
1604    Compact("p1", "p9");
1605    ASSERT_EQ("0,0,1", FilesPerLevel());
1606  
1607    // Populate a different range
1608    MakeTables(3, "c", "e");
1609    ASSERT_EQ("1,1,2", FilesPerLevel());
1610  
1611    // Compact just the new range
1612    Compact("b", "f");
1613    ASSERT_EQ("0,0,2", FilesPerLevel());
1614  
1615    // Compact all
1616    MakeTables(1, "a", "z");
1617    ASSERT_EQ("0,1,2", FilesPerLevel());
1618    db_->CompactRange(nullptr, nullptr);
1619    ASSERT_EQ("0,0,1", FilesPerLevel());
1620  }
1621  
1622  TEST(DBTest, DBOpen_Options) {
1623    std::string dbname = test::TmpDir() + "/db_options_test";
1624    DestroyDB(dbname, Options());
1625  
1626    // Does not exist, and create_if_missing == false: error
1627    DB* db = nullptr;
1628    Options opts;
1629    opts.create_if_missing = false;
1630    Status s = DB::Open(opts, dbname, &db);
1631    ASSERT_TRUE(strstr(s.ToString().c_str(), "does not exist") != nullptr);
1632    ASSERT_TRUE(db == nullptr);
1633  
1634    // Does not exist, and create_if_missing == true: OK
1635    opts.create_if_missing = true;
1636    s = DB::Open(opts, dbname, &db);
1637    ASSERT_OK(s);
1638    ASSERT_TRUE(db != nullptr);
1639  
1640    delete db;
1641    db = nullptr;
1642  
1643    // Does exist, and error_if_exists == true: error
1644    opts.create_if_missing = false;
1645    opts.error_if_exists = true;
1646    s = DB::Open(opts, dbname, &db);
1647    ASSERT_TRUE(strstr(s.ToString().c_str(), "exists") != nullptr);
1648    ASSERT_TRUE(db == nullptr);
1649  
1650    // Does exist, and error_if_exists == false: OK
1651    opts.create_if_missing = true;
1652    opts.error_if_exists = false;
1653    s = DB::Open(opts, dbname, &db);
1654    ASSERT_OK(s);
1655    ASSERT_TRUE(db != nullptr);
1656  
1657    delete db;
1658    db = nullptr;
1659  }
1660  
1661  TEST(DBTest, DestroyEmptyDir) {
1662    std::string dbname = test::TmpDir() + "/db_empty_dir";
1663    TestEnv env(Env::Default());
1664    env.DeleteDir(dbname);
1665    ASSERT_TRUE(!env.FileExists(dbname));
1666  
1667    Options opts;
1668    opts.env = &env;
1669  
1670    ASSERT_OK(env.CreateDir(dbname));
1671    ASSERT_TRUE(env.FileExists(dbname));
1672    std::vector<std::string> children;
1673    ASSERT_OK(env.GetChildren(dbname, &children));
1674    // The stock Env's do not filter out '.' and '..' special files.
1675    ASSERT_EQ(2, children.size());
1676    ASSERT_OK(DestroyDB(dbname, opts));
1677    ASSERT_TRUE(!env.FileExists(dbname));
1678  
1679    // Should also be destroyed if Env is filtering out dot files.
1680    env.SetIgnoreDotFiles(true);
1681    ASSERT_OK(env.CreateDir(dbname));
1682    ASSERT_TRUE(env.FileExists(dbname));
1683    ASSERT_OK(env.GetChildren(dbname, &children));
1684    ASSERT_EQ(0, children.size());
1685    ASSERT_OK(DestroyDB(dbname, opts));
1686    ASSERT_TRUE(!env.FileExists(dbname));
1687  }
1688  
1689  TEST(DBTest, DestroyOpenDB) {
1690    std::string dbname = test::TmpDir() + "/open_db_dir";
1691    env_->DeleteDir(dbname);
1692    ASSERT_TRUE(!env_->FileExists(dbname));
1693  
1694    Options opts;
1695    opts.create_if_missing = true;
1696    DB* db = nullptr;
1697    ASSERT_OK(DB::Open(opts, dbname, &db));
1698    ASSERT_TRUE(db != nullptr);
1699  
1700    // Must fail to destroy an open db.
1701    ASSERT_TRUE(env_->FileExists(dbname));
1702    ASSERT_TRUE(!DestroyDB(dbname, Options()).ok());
1703    ASSERT_TRUE(env_->FileExists(dbname));
1704  
1705    delete db;
1706    db = nullptr;
1707  
1708    // Should succeed destroying a closed db.
1709    ASSERT_OK(DestroyDB(dbname, Options()));
1710    ASSERT_TRUE(!env_->FileExists(dbname));
1711  }
1712  
1713  TEST(DBTest, Locking) {
1714    DB* db2 = nullptr;
1715    Status s = DB::Open(CurrentOptions(), dbname_, &db2);
1716    ASSERT_TRUE(!s.ok()) << "Locking did not prevent re-opening db";
1717  }
1718  
1719  // Check that number of files does not grow when we are out of space
1720  TEST(DBTest, NoSpace) {
1721    Options options = CurrentOptions();
1722    options.env = env_;
1723    Reopen(&options);
1724  
1725    ASSERT_OK(Put("foo", "v1"));
1726    ASSERT_EQ("v1", Get("foo"));
1727    Compact("a", "z");
1728    const int num_files = CountFiles();
1729    // Force out-of-space errors.
1730    env_->no_space_.store(true, std::memory_order_release);
1731    for (int i = 0; i < 10; i++) {
1732      for (int level = 0; level < config::kNumLevels - 1; level++) {
1733        dbfull()->TEST_CompactRange(level, nullptr, nullptr);
1734      }
1735    }
1736    env_->no_space_.store(false, std::memory_order_release);
1737    ASSERT_LT(CountFiles(), num_files + 3);
1738  }
1739  
1740  TEST(DBTest, NonWritableFileSystem) {
1741    Options options = CurrentOptions();
1742    options.write_buffer_size = 1000;
1743    options.env = env_;
1744    Reopen(&options);
1745    ASSERT_OK(Put("foo", "v1"));
1746    // Force errors for new files.
1747    env_->non_writable_.store(true, std::memory_order_release);
1748    std::string big(100000, 'x');
1749    int errors = 0;
1750    for (int i = 0; i < 20; i++) {
1751      fprintf(stderr, "iter %d; errors %d\n", i, errors);
1752      if (!Put("foo", big).ok()) {
1753        errors++;
1754        DelayMilliseconds(100);
1755      }
1756    }
1757    ASSERT_GT(errors, 0);
1758    env_->non_writable_.store(false, std::memory_order_release);
1759  }
1760  
1761  TEST(DBTest, WriteSyncError) {
1762    // Check that log sync errors cause the DB to disallow future writes.
1763  
1764    // (a) Cause log sync calls to fail
1765    Options options = CurrentOptions();
1766    options.env = env_;
1767    Reopen(&options);
1768    env_->data_sync_error_.store(true, std::memory_order_release);
1769  
1770    // (b) Normal write should succeed
1771    WriteOptions w;
1772    ASSERT_OK(db_->Put(w, "k1", "v1"));
1773    ASSERT_EQ("v1", Get("k1"));
1774  
1775    // (c) Do a sync write; should fail
1776    w.sync = true;
1777    ASSERT_TRUE(!db_->Put(w, "k2", "v2").ok());
1778    ASSERT_EQ("v1", Get("k1"));
1779    ASSERT_EQ("NOT_FOUND", Get("k2"));
1780  
1781    // (d) make sync behave normally
1782    env_->data_sync_error_.store(false, std::memory_order_release);
1783  
1784    // (e) Do a non-sync write; should fail
1785    w.sync = false;
1786    ASSERT_TRUE(!db_->Put(w, "k3", "v3").ok());
1787    ASSERT_EQ("v1", Get("k1"));
1788    ASSERT_EQ("NOT_FOUND", Get("k2"));
1789    ASSERT_EQ("NOT_FOUND", Get("k3"));
1790  }
1791  
1792  TEST(DBTest, ManifestWriteError) {
1793    // Test for the following problem:
1794    // (a) Compaction produces file F
1795    // (b) Log record containing F is written to MANIFEST file, but Sync() fails
1796    // (c) GC deletes F
1797    // (d) After reopening DB, reads fail since deleted F is named in log record
1798  
1799    // We iterate twice.  In the second iteration, everything is the
1800    // same except the log record never makes it to the MANIFEST file.
1801    for (int iter = 0; iter < 2; iter++) {
1802      std::atomic<bool>* error_type = (iter == 0) ? &env_->manifest_sync_error_
1803                                                  : &env_->manifest_write_error_;
1804  
1805      // Insert foo=>bar mapping
1806      Options options = CurrentOptions();
1807      options.env = env_;
1808      options.create_if_missing = true;
1809      options.error_if_exists = false;
1810      DestroyAndReopen(&options);
1811      ASSERT_OK(Put("foo", "bar"));
1812      ASSERT_EQ("bar", Get("foo"));
1813  
1814      // Memtable compaction (will succeed)
1815      dbfull()->TEST_CompactMemTable();
1816      ASSERT_EQ("bar", Get("foo"));
1817      const int last = config::kMaxMemCompactLevel;
1818      ASSERT_EQ(NumTableFilesAtLevel(last), 1);  // foo=>bar is now in last level
1819  
1820      // Merging compaction (will fail)
1821      error_type->store(true, std::memory_order_release);
1822      dbfull()->TEST_CompactRange(last, nullptr, nullptr);  // Should fail
1823      ASSERT_EQ("bar", Get("foo"));
1824  
1825      // Recovery: should not lose data
1826      error_type->store(false, std::memory_order_release);
1827      Reopen(&options);
1828      ASSERT_EQ("bar", Get("foo"));
1829    }
1830  }
1831  
1832  TEST(DBTest, MissingSSTFile) {
1833    ASSERT_OK(Put("foo", "bar"));
1834    ASSERT_EQ("bar", Get("foo"));
1835  
1836    // Dump the memtable to disk.
1837    dbfull()->TEST_CompactMemTable();
1838    ASSERT_EQ("bar", Get("foo"));
1839  
1840    Close();
1841    ASSERT_TRUE(DeleteAnSSTFile());
1842    Options options = CurrentOptions();
1843    options.paranoid_checks = true;
1844    Status s = TryReopen(&options);
1845    ASSERT_TRUE(!s.ok());
1846    ASSERT_TRUE(s.ToString().find("issing") != std::string::npos) << s.ToString();
1847  }
1848  
1849  TEST(DBTest, StillReadSST) {
1850    ASSERT_OK(Put("foo", "bar"));
1851    ASSERT_EQ("bar", Get("foo"));
1852  
1853    // Dump the memtable to disk.
1854    dbfull()->TEST_CompactMemTable();
1855    ASSERT_EQ("bar", Get("foo"));
1856    Close();
1857    ASSERT_GT(RenameLDBToSST(), 0);
1858    Options options = CurrentOptions();
1859    options.paranoid_checks = true;
1860    Status s = TryReopen(&options);
1861    ASSERT_TRUE(s.ok());
1862    ASSERT_EQ("bar", Get("foo"));
1863  }
1864  
1865  TEST(DBTest, FilesDeletedAfterCompaction) {
1866    ASSERT_OK(Put("foo", "v2"));
1867    Compact("a", "z");
1868    const int num_files = CountFiles();
1869    for (int i = 0; i < 10; i++) {
1870      ASSERT_OK(Put("foo", "v2"));
1871      Compact("a", "z");
1872    }
1873    ASSERT_EQ(CountFiles(), num_files);
1874  }
1875  
1876  TEST(DBTest, BloomFilter) {
1877    env_->count_random_reads_ = true;
1878    Options options = CurrentOptions();
1879    options.env = env_;
1880    options.block_cache = NewLRUCache(0);  // Prevent cache hits
1881    options.filter_policy = NewBloomFilterPolicy(10);
1882    Reopen(&options);
1883  
1884    // Populate multiple layers
1885    const int N = 10000;
1886    for (int i = 0; i < N; i++) {
1887      ASSERT_OK(Put(Key(i), Key(i)));
1888    }
1889    Compact("a", "z");
1890    for (int i = 0; i < N; i += 100) {
1891      ASSERT_OK(Put(Key(i), Key(i)));
1892    }
1893    dbfull()->TEST_CompactMemTable();
1894  
1895    // Prevent auto compactions triggered by seeks
1896    env_->delay_data_sync_.store(true, std::memory_order_release);
1897  
1898    // Lookup present keys.  Should rarely read from small sstable.
1899    env_->random_read_counter_.Reset();
1900    for (int i = 0; i < N; i++) {
1901      ASSERT_EQ(Key(i), Get(Key(i)));
1902    }
1903    int reads = env_->random_read_counter_.Read();
1904    fprintf(stderr, "%d present => %d reads\n", N, reads);
1905    ASSERT_GE(reads, N);
1906    ASSERT_LE(reads, N + 2 * N / 100);
1907  
1908    // Lookup present keys.  Should rarely read from either sstable.
1909    env_->random_read_counter_.Reset();
1910    for (int i = 0; i < N; i++) {
1911      ASSERT_EQ("NOT_FOUND", Get(Key(i) + ".missing"));
1912    }
1913    reads = env_->random_read_counter_.Read();
1914    fprintf(stderr, "%d missing => %d reads\n", N, reads);
1915    ASSERT_LE(reads, 3 * N / 100);
1916  
1917    env_->delay_data_sync_.store(false, std::memory_order_release);
1918    Close();
1919    delete options.block_cache;
1920    delete options.filter_policy;
1921  }
1922  
1923  // Multi-threaded test:
1924  namespace {
1925  
1926  static const int kNumThreads = 4;
1927  static const int kTestSeconds = 10;
1928  static const int kNumKeys = 1000;
1929  
1930  struct MTState {
1931    DBTest* test;
1932    std::atomic<bool> stop;
1933    std::atomic<int> counter[kNumThreads];
1934    std::atomic<bool> thread_done[kNumThreads];
1935  };
1936  
1937  struct MTThread {
1938    MTState* state;
1939    int id;
1940  };
1941  
1942  static void MTThreadBody(void* arg) {
1943    MTThread* t = reinterpret_cast<MTThread*>(arg);
1944    int id = t->id;
1945    DB* db = t->state->test->db_;
1946    int counter = 0;
1947    fprintf(stderr, "... starting thread %d\n", id);
1948    Random rnd(1000 + id);
1949    std::string value;
1950    char valbuf[1500];
1951    while (!t->state->stop.load(std::memory_order_acquire)) {
1952      t->state->counter[id].store(counter, std::memory_order_release);
1953  
1954      int key = rnd.Uniform(kNumKeys);
1955      char keybuf[20];
1956      snprintf(keybuf, sizeof(keybuf), "%016d", key);
1957  
1958      if (rnd.OneIn(2)) {
1959        // Write values of the form <key, my id, counter>.
1960        // We add some padding for force compactions.
1961        snprintf(valbuf, sizeof(valbuf), "%d.%d.%-1000d", key, id,
1962                 static_cast<int>(counter));
1963        ASSERT_OK(db->Put(WriteOptions(), Slice(keybuf), Slice(valbuf)));
1964      } else {
1965        // Read a value and verify that it matches the pattern written above.
1966        Status s = db->Get(ReadOptions(), Slice(keybuf), &value);
1967        if (s.IsNotFound()) {
1968          // Key has not yet been written
1969        } else {
1970          // Check that the writer thread counter is >= the counter in the value
1971          ASSERT_OK(s);
1972          int k, w, c;
1973          ASSERT_EQ(3, sscanf(value.c_str(), "%d.%d.%d", &k, &w, &c)) << value;
1974          ASSERT_EQ(k, key);
1975          ASSERT_GE(w, 0);
1976          ASSERT_LT(w, kNumThreads);
1977          ASSERT_LE(c, t->state->counter[w].load(std::memory_order_acquire));
1978        }
1979      }
1980      counter++;
1981    }
1982    t->state->thread_done[id].store(true, std::memory_order_release);
1983    fprintf(stderr, "... stopping thread %d after %d ops\n", id, counter);
1984  }
1985  
1986  }  // namespace
1987  
1988  TEST(DBTest, MultiThreaded) {
1989    do {
1990      // Initialize state
1991      MTState mt;
1992      mt.test = this;
1993      mt.stop.store(false, std::memory_order_release);
1994      for (int id = 0; id < kNumThreads; id++) {
1995        mt.counter[id].store(false, std::memory_order_release);
1996        mt.thread_done[id].store(false, std::memory_order_release);
1997      }
1998  
1999      // Start threads
2000      MTThread thread[kNumThreads];
2001      for (int id = 0; id < kNumThreads; id++) {
2002        thread[id].state = &mt;
2003        thread[id].id = id;
2004        env_->StartThread(MTThreadBody, &thread[id]);
2005      }
2006  
2007      // Let them run for a while
2008      DelayMilliseconds(kTestSeconds * 1000);
2009  
2010      // Stop the threads and wait for them to finish
2011      mt.stop.store(true, std::memory_order_release);
2012      for (int id = 0; id < kNumThreads; id++) {
2013        while (!mt.thread_done[id].load(std::memory_order_acquire)) {
2014          DelayMilliseconds(100);
2015        }
2016      }
2017    } while (ChangeOptions());
2018  }
2019  
2020  namespace {
2021  typedef std::map<std::string, std::string> KVMap;
2022  }
2023  
2024  class ModelDB : public DB {
2025   public:
2026    class ModelSnapshot : public Snapshot {
2027     public:
2028      KVMap map_;
2029    };
2030  
2031    explicit ModelDB(const Options& options) : options_(options) {}
2032    ~ModelDB() override = default;
2033    Status Put(const WriteOptions& o, const Slice& k, const Slice& v) override {
2034      return DB::Put(o, k, v);
2035    }
2036    Status Delete(const WriteOptions& o, const Slice& key) override {
2037      return DB::Delete(o, key);
2038    }
2039    Status Get(const ReadOptions& options, const Slice& key,
2040               std::string* value) override {
2041      assert(false);  // Not implemented
2042      return Status::NotFound(key);
2043    }
2044    Iterator* NewIterator(const ReadOptions& options) override {
2045      if (options.snapshot == nullptr) {
2046        KVMap* saved = new KVMap;
2047        *saved = map_;
2048        return new ModelIter(saved, true);
2049      } else {
2050        const KVMap* snapshot_state =
2051            &(reinterpret_cast<const ModelSnapshot*>(options.snapshot)->map_);
2052        return new ModelIter(snapshot_state, false);
2053      }
2054    }
2055    const Snapshot* GetSnapshot() override {
2056      ModelSnapshot* snapshot = new ModelSnapshot;
2057      snapshot->map_ = map_;
2058      return snapshot;
2059    }
2060  
2061    void ReleaseSnapshot(const Snapshot* snapshot) override {
2062      delete reinterpret_cast<const ModelSnapshot*>(snapshot);
2063    }
2064    Status Write(const WriteOptions& options, WriteBatch* batch) override {
2065      class Handler : public WriteBatch::Handler {
2066       public:
2067        KVMap* map_;
2068        void Put(const Slice& key, const Slice& value) override {
2069          (*map_)[key.ToString()] = value.ToString();
2070        }
2071        void Delete(const Slice& key) override { map_->erase(key.ToString()); }
2072      };
2073      Handler handler;
2074      handler.map_ = &map_;
2075      return batch->Iterate(&handler);
2076    }
2077  
2078    bool GetProperty(const Slice& property, std::string* value) override {
2079      return false;
2080    }
2081    void GetApproximateSizes(const Range* r, int n, uint64_t* sizes) override {
2082      for (int i = 0; i < n; i++) {
2083        sizes[i] = 0;
2084      }
2085    }
2086    void CompactRange(const Slice* start, const Slice* end) override {}
2087  
2088   private:
2089    class ModelIter : public Iterator {
2090     public:
2091      ModelIter(const KVMap* map, bool owned)
2092          : map_(map), owned_(owned), iter_(map_->end()) {}
2093      ~ModelIter() override {
2094        if (owned_) delete map_;
2095      }
2096      bool Valid() const override { return iter_ != map_->end(); }
2097      void SeekToFirst() override { iter_ = map_->begin(); }
2098      void SeekToLast() override {
2099        if (map_->empty()) {
2100          iter_ = map_->end();
2101        } else {
2102          iter_ = map_->find(map_->rbegin()->first);
2103        }
2104      }
2105      void Seek(const Slice& k) override {
2106        iter_ = map_->lower_bound(k.ToString());
2107      }
2108      void Next() override { ++iter_; }
2109      void Prev() override { --iter_; }
2110      Slice key() const override { return iter_->first; }
2111      Slice value() const override { return iter_->second; }
2112      Status status() const override { return Status::OK(); }
2113  
2114     private:
2115      const KVMap* const map_;
2116      const bool owned_;  // Do we own map_
2117      KVMap::const_iterator iter_;
2118    };
2119    const Options options_;
2120    KVMap map_;
2121  };
2122  
2123  static bool CompareIterators(int step, DB* model, DB* db,
2124                               const Snapshot* model_snap,
2125                               const Snapshot* db_snap) {
2126    ReadOptions options;
2127    options.snapshot = model_snap;
2128    Iterator* miter = model->NewIterator(options);
2129    options.snapshot = db_snap;
2130    Iterator* dbiter = db->NewIterator(options);
2131    bool ok = true;
2132    int count = 0;
2133    for (miter->SeekToFirst(), dbiter->SeekToFirst();
2134         ok && miter->Valid() && dbiter->Valid(); miter->Next(), dbiter->Next()) {
2135      count++;
2136      if (miter->key().compare(dbiter->key()) != 0) {
2137        fprintf(stderr, "step %d: Key mismatch: '%s' vs. '%s'\n", step,
2138                EscapeString(miter->key()).c_str(),
2139                EscapeString(dbiter->key()).c_str());
2140        ok = false;
2141        break;
2142      }
2143  
2144      if (miter->value().compare(dbiter->value()) != 0) {
2145        fprintf(stderr, "step %d: Value mismatch for key '%s': '%s' vs. '%s'\n",
2146                step, EscapeString(miter->key()).c_str(),
2147                EscapeString(miter->value()).c_str(),
2148                EscapeString(miter->value()).c_str());
2149        ok = false;
2150      }
2151    }
2152  
2153    if (ok) {
2154      if (miter->Valid() != dbiter->Valid()) {
2155        fprintf(stderr, "step %d: Mismatch at end of iterators: %d vs. %d\n",
2156                step, miter->Valid(), dbiter->Valid());
2157        ok = false;
2158      }
2159    }
2160    fprintf(stderr, "%d entries compared: ok=%d\n", count, ok);
2161    delete miter;
2162    delete dbiter;
2163    return ok;
2164  }
2165  
2166  TEST(DBTest, Randomized) {
2167    Random rnd(test::RandomSeed());
2168    do {
2169      ModelDB model(CurrentOptions());
2170      const int N = 10000;
2171      const Snapshot* model_snap = nullptr;
2172      const Snapshot* db_snap = nullptr;
2173      std::string k, v;
2174      for (int step = 0; step < N; step++) {
2175        if (step % 100 == 0) {
2176          fprintf(stderr, "Step %d of %d\n", step, N);
2177        }
2178        // TODO(sanjay): Test Get() works
2179        int p = rnd.Uniform(100);
2180        if (p < 45) {  // Put
2181          k = RandomKey(&rnd);
2182          v = RandomString(
2183              &rnd, rnd.OneIn(20) ? 100 + rnd.Uniform(100) : rnd.Uniform(8));
2184          ASSERT_OK(model.Put(WriteOptions(), k, v));
2185          ASSERT_OK(db_->Put(WriteOptions(), k, v));
2186  
2187        } else if (p < 90) {  // Delete
2188          k = RandomKey(&rnd);
2189          ASSERT_OK(model.Delete(WriteOptions(), k));
2190          ASSERT_OK(db_->Delete(WriteOptions(), k));
2191  
2192        } else {  // Multi-element batch
2193          WriteBatch b;
2194          const int num = rnd.Uniform(8);
2195          for (int i = 0; i < num; i++) {
2196            if (i == 0 || !rnd.OneIn(10)) {
2197              k = RandomKey(&rnd);
2198            } else {
2199              // Periodically reuse the same key from the previous iter, so
2200              // we have multiple entries in the write batch for the same key
2201            }
2202            if (rnd.OneIn(2)) {
2203              v = RandomString(&rnd, rnd.Uniform(10));
2204              b.Put(k, v);
2205            } else {
2206              b.Delete(k);
2207            }
2208          }
2209          ASSERT_OK(model.Write(WriteOptions(), &b));
2210          ASSERT_OK(db_->Write(WriteOptions(), &b));
2211        }
2212  
2213        if ((step % 100) == 0) {
2214          ASSERT_TRUE(CompareIterators(step, &model, db_, nullptr, nullptr));
2215          ASSERT_TRUE(CompareIterators(step, &model, db_, model_snap, db_snap));
2216          // Save a snapshot from each DB this time that we'll use next
2217          // time we compare things, to make sure the current state is
2218          // preserved with the snapshot
2219          if (model_snap != nullptr) model.ReleaseSnapshot(model_snap);
2220          if (db_snap != nullptr) db_->ReleaseSnapshot(db_snap);
2221  
2222          Reopen();
2223          ASSERT_TRUE(CompareIterators(step, &model, db_, nullptr, nullptr));
2224  
2225          model_snap = model.GetSnapshot();
2226          db_snap = db_->GetSnapshot();
2227        }
2228      }
2229      if (model_snap != nullptr) model.ReleaseSnapshot(model_snap);
2230      if (db_snap != nullptr) db_->ReleaseSnapshot(db_snap);
2231    } while (ChangeOptions());
2232  }
2233  
2234  std::string MakeKey(unsigned int num) {
2235    char buf[30];
2236    snprintf(buf, sizeof(buf), "%016u", num);
2237    return std::string(buf);
2238  }
2239  
2240  void BM_LogAndApply(int iters, int num_base_files) {
2241    std::string dbname = test::TmpDir() + "/leveldb_test_benchmark";
2242    DestroyDB(dbname, Options());
2243  
2244    DB* db = nullptr;
2245    Options opts;
2246    opts.create_if_missing = true;
2247    Status s = DB::Open(opts, dbname, &db);
2248    ASSERT_OK(s);
2249    ASSERT_TRUE(db != nullptr);
2250  
2251    delete db;
2252    db = nullptr;
2253  
2254    Env* env = Env::Default();
2255  
2256    port::Mutex mu;
2257    MutexLock l(&mu);
2258  
2259    InternalKeyComparator cmp(BytewiseComparator());
2260    Options options;
2261    VersionSet vset(dbname, &options, nullptr, &cmp);
2262    bool save_manifest;
2263    ASSERT_OK(vset.Recover(&save_manifest));
2264    VersionEdit vbase;
2265    uint64_t fnum = 1;
2266    for (int i = 0; i < num_base_files; i++) {
2267      InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
2268      InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
2269      vbase.AddFile(2, fnum++, 1 /* file size */, start, limit);
2270    }
2271    ASSERT_OK(vset.LogAndApply(&vbase, &mu));
2272  
2273    uint64_t start_micros = env->NowMicros();
2274  
2275    for (int i = 0; i < iters; i++) {
2276      VersionEdit vedit;
2277      vedit.DeleteFile(2, fnum);
2278      InternalKey start(MakeKey(2 * fnum), 1, kTypeValue);
2279      InternalKey limit(MakeKey(2 * fnum + 1), 1, kTypeDeletion);
2280      vedit.AddFile(2, fnum++, 1 /* file size */, start, limit);
2281      vset.LogAndApply(&vedit, &mu);
2282    }
2283    uint64_t stop_micros = env->NowMicros();
2284    unsigned int us = stop_micros - start_micros;
2285    char buf[16];
2286    snprintf(buf, sizeof(buf), "%d", num_base_files);
2287    fprintf(stderr,
2288            "BM_LogAndApply/%-6s   %8d iters : %9u us (%7.0f us / iter)\n", buf,
2289            iters, us, ((float)us) / iters);
2290  }
2291  
2292  }  // namespace leveldb
2293  
2294  int main(int argc, char** argv) {
2295    if (argc > 1 && std::string(argv[1]) == "--benchmark") {
2296      leveldb::BM_LogAndApply(1000, 1);
2297      leveldb::BM_LogAndApply(1000, 100);
2298      leveldb::BM_LogAndApply(1000, 10000);
2299      leveldb::BM_LogAndApply(100, 100000);
2300      return 0;
2301    }
2302  
2303    return leveldb::test::RunAllTests();
2304  }
2305