//  Copyright (c) 2013, Facebook, Inc.  All rights reserved.
//  This source code is licensed under the BSD-style license found in the
//  LICENSE file in the root directory of this source tree. An additional grant
//  of patent rights can be found in the PATENTS file in the same directory.
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

#include "db/db_test_util.h"
#include "port/stack_trace.h"

namespace rocksdb {

static int cfilter_count = 0;

// This is a static filter used for filtering
// kvs during the compaction process.
static std::string NEW_VALUE = "NewValue";

class DBTestCompactionFilter : public DBTestBase {
 public:
  DBTestCompactionFilter() : DBTestBase("/db_compaction_filter_test") {}
};

class KeepFilter : public CompactionFilter {
 public:
  virtual bool Filter(int level, const Slice& key, const Slice& value,
                      std::string* new_value, bool* value_changed) const
      override {
    cfilter_count++;
    return false;
  }

  virtual const char* Name() const override { return "KeepFilter"; }
};

class DeleteFilter : public CompactionFilter {
 public:
  virtual bool Filter(int level, const Slice& key, const Slice& value,
                      std::string* new_value, bool* value_changed) const
      override {
    cfilter_count++;
    return true;
  }

  virtual const char* Name() const override { return "DeleteFilter"; }
};

class DeleteISFilter : public CompactionFilter {
 public:
  virtual bool Filter(int level, const Slice& key, const Slice& value,
                      std::string* new_value,
                      bool* value_changed) const override {
    cfilter_count++;
    int i = std::stoi(key.ToString());
    if (i > 5 && i <= 105) {
      return true;
    }
    return false;
  }

  virtual bool IgnoreSnapshots() const override { return true; }

  virtual const char* Name() const override { return "DeleteFilter"; }
};

class DelayFilter : public CompactionFilter {
 public:
  explicit DelayFilter(DBTestBase* d) : db_test(d) {}
  virtual bool Filter(int level, const Slice& key, const Slice& value,
                      std::string* new_value,
                      bool* value_changed) const override {
    db_test->env_->addon_time_.fetch_add(1000);
    return true;
  }

  virtual const char* Name() const override { return "DelayFilter"; }

 private:
  DBTestBase* db_test;
};

class ConditionalFilter : public CompactionFilter {
 public:
  explicit ConditionalFilter(const std::string* filtered_value)
      : filtered_value_(filtered_value) {}
  virtual bool Filter(int level, const Slice& key, const Slice& value,
                      std::string* new_value,
                      bool* value_changed) const override {
    return value.ToString() == *filtered_value_;
  }

  virtual const char* Name() const override { return "ConditionalFilter"; }

 private:
  const std::string* filtered_value_;
};

class ChangeFilter : public CompactionFilter {
 public:
  explicit ChangeFilter() {}

  virtual bool Filter(int level, const Slice& key, const Slice& value,
                      std::string* new_value, bool* value_changed) const
      override {
    assert(new_value != nullptr);
    *new_value = NEW_VALUE;
    *value_changed = true;
    return false;
  }

  virtual const char* Name() const override { return "ChangeFilter"; }
};

class KeepFilterFactory : public CompactionFilterFactory {
 public:
  explicit KeepFilterFactory(bool check_context = false,
                             bool check_context_cf_id = false)
      : check_context_(check_context),
        check_context_cf_id_(check_context_cf_id),
        compaction_filter_created_(false) {}

  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
      const CompactionFilter::Context& context) override {
    if (check_context_) {
      EXPECT_EQ(expect_full_compaction_.load(), context.is_full_compaction);
      EXPECT_EQ(expect_manual_compaction_.load(), context.is_manual_compaction);
    }
    if (check_context_cf_id_) {
      EXPECT_EQ(expect_cf_id_.load(), context.column_family_id);
    }
    compaction_filter_created_ = true;
    return std::unique_ptr<CompactionFilter>(new KeepFilter());
  }

  bool compaction_filter_created() const { return compaction_filter_created_; }

  virtual const char* Name() const override { return "KeepFilterFactory"; }
  bool check_context_;
  bool check_context_cf_id_;
  std::atomic_bool expect_full_compaction_;
  std::atomic_bool expect_manual_compaction_;
  std::atomic<uint32_t> expect_cf_id_;
  bool compaction_filter_created_;
};

class DeleteFilterFactory : public CompactionFilterFactory {
 public:
  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
      const CompactionFilter::Context& context) override {
    if (context.is_manual_compaction) {
      return std::unique_ptr<CompactionFilter>(new DeleteFilter());
    } else {
      return std::unique_ptr<CompactionFilter>(nullptr);
    }
  }

  virtual const char* Name() const override { return "DeleteFilterFactory"; }
};

// Delete Filter Factory which ignores snapshots
class DeleteISFilterFactory : public CompactionFilterFactory {
 public:
  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
      const CompactionFilter::Context& context) override {
    if (context.is_manual_compaction) {
      return std::unique_ptr<CompactionFilter>(new DeleteISFilter());
    } else {
      return std::unique_ptr<CompactionFilter>(nullptr);
    }
  }

  virtual const char* Name() const override { return "DeleteFilterFactory"; }
};

class DelayFilterFactory : public CompactionFilterFactory {
 public:
  explicit DelayFilterFactory(DBTestBase* d) : db_test(d) {}
  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
      const CompactionFilter::Context& context) override {
    return std::unique_ptr<CompactionFilter>(new DelayFilter(db_test));
  }

  virtual const char* Name() const override { return "DelayFilterFactory"; }

 private:
  DBTestBase* db_test;
};

class ConditionalFilterFactory : public CompactionFilterFactory {
 public:
  explicit ConditionalFilterFactory(const Slice& filtered_value)
      : filtered_value_(filtered_value.ToString()) {}

  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
      const CompactionFilter::Context& context) override {
    return std::unique_ptr<CompactionFilter>(
        new ConditionalFilter(&filtered_value_));
  }

  virtual const char* Name() const override {
    return "ConditionalFilterFactory";
  }

 private:
  std::string filtered_value_;
};

class ChangeFilterFactory : public CompactionFilterFactory {
 public:
  explicit ChangeFilterFactory() {}

  virtual std::unique_ptr<CompactionFilter> CreateCompactionFilter(
      const CompactionFilter::Context& context) override {
    return std::unique_ptr<CompactionFilter>(new ChangeFilter());
  }

  virtual const char* Name() const override { return "ChangeFilterFactory"; }
};

#ifndef ROCKSDB_LITE
TEST_F(DBTestCompactionFilter, CompactionFilter) {
  Options options = CurrentOptions();
  options.max_open_files = -1;
  options.num_levels = 3;
  options.compaction_filter_factory = std::make_shared<KeepFilterFactory>();
  options = CurrentOptions(options);
  CreateAndReopenWithCF({"pikachu"}, options);

  // Write 100K keys, these are written to a few files in L0.
  const std::string value(10, 'x');
  for (int i = 0; i < 100000; i++) {
    char key[100];
    snprintf(key, sizeof(key), "B%010d", i);
    Put(1, key, value);
  }
  ASSERT_OK(Flush(1));

  // Push all files to the highest level L2. Verify that
  // the compaction is each level invokes the filter for
  // all the keys in that level.
  cfilter_count = 0;
  dbfull()->TEST_CompactRange(0, nullptr, nullptr, handles_[1]);
  ASSERT_EQ(cfilter_count, 100000);
  cfilter_count = 0;
  dbfull()->TEST_CompactRange(1, nullptr, nullptr, handles_[1]);
  ASSERT_EQ(cfilter_count, 100000);

  ASSERT_EQ(NumTableFilesAtLevel(0, 1), 0);
  ASSERT_EQ(NumTableFilesAtLevel(1, 1), 0);
  ASSERT_NE(NumTableFilesAtLevel(2, 1), 0);
  cfilter_count = 0;

  // All the files are in the lowest level.
  // Verify that all but the 100001st record
  // has sequence number zero. The 100001st record
  // is at the tip of this snapshot and cannot
  // be zeroed out.
  int count = 0;
  int total = 0;
  Arena arena;
  {
    ScopedArenaIterator iter(
        dbfull()->NewInternalIterator(&arena, handles_[1]));
    iter->SeekToFirst();
    ASSERT_OK(iter->status());
    while (iter->Valid()) {
      ParsedInternalKey ikey(Slice(), 0, kTypeValue);
      ikey.sequence = -1;
      ASSERT_EQ(ParseInternalKey(iter->key(), &ikey), true);
      total++;
      if (ikey.sequence != 0) {
        count++;
      }
      iter->Next();
    }
  }
  ASSERT_EQ(total, 100000);
  ASSERT_EQ(count, 1);

  // overwrite all the 100K keys once again.
  for (int i = 0; i < 100000; i++) {
    char key[100];
    snprintf(key, sizeof(key), "B%010d", i);
    ASSERT_OK(Put(1, key, value));
  }
  ASSERT_OK(Flush(1));

  // push all files to the highest level L2. This
  // means that all keys should pass at least once
  // via the compaction filter
  cfilter_count = 0;
  dbfull()->TEST_CompactRange(0, nullptr, nullptr, handles_[1]);
  ASSERT_EQ(cfilter_count, 100000);
  cfilter_count = 0;
  dbfull()->TEST_CompactRange(1, nullptr, nullptr, handles_[1]);
  ASSERT_EQ(cfilter_count, 100000);
  ASSERT_EQ(NumTableFilesAtLevel(0, 1), 0);
  ASSERT_EQ(NumTableFilesAtLevel(1, 1), 0);
  ASSERT_NE(NumTableFilesAtLevel(2, 1), 0);

  // create a new database with the compaction
  // filter in such a way that it deletes all keys
  options.compaction_filter_factory = std::make_shared<DeleteFilterFactory>();
  options.create_if_missing = true;
  DestroyAndReopen(options);
  CreateAndReopenWithCF({"pikachu"}, options);

  // write all the keys once again.
  for (int i = 0; i < 100000; i++) {
    char key[100];
    snprintf(key, sizeof(key), "B%010d", i);
    ASSERT_OK(Put(1, key, value));
  }
  ASSERT_OK(Flush(1));
  ASSERT_NE(NumTableFilesAtLevel(0, 1), 0);
  ASSERT_EQ(NumTableFilesAtLevel(1, 1), 0);
  ASSERT_EQ(NumTableFilesAtLevel(2, 1), 0);

  // Push all files to the highest level L2. This
  // triggers the compaction filter to delete all keys,
  // verify that at the end of the compaction process,
  // nothing is left.
  cfilter_count = 0;
  dbfull()->TEST_CompactRange(0, nullptr, nullptr, handles_[1]);
  ASSERT_EQ(cfilter_count, 100000);
  cfilter_count = 0;
  dbfull()->TEST_CompactRange(1, nullptr, nullptr, handles_[1]);
  ASSERT_EQ(cfilter_count, 0);
  ASSERT_EQ(NumTableFilesAtLevel(0, 1), 0);
  ASSERT_EQ(NumTableFilesAtLevel(1, 1), 0);

  {
    // Scan the entire database to ensure that nothing is left
    std::unique_ptr<Iterator> iter(
        db_->NewIterator(ReadOptions(), handles_[1]));
    iter->SeekToFirst();
    count = 0;
    while (iter->Valid()) {
      count++;
      iter->Next();
    }
    ASSERT_EQ(count, 0);
  }

  // The sequence number of the remaining record
  // is not zeroed out even though it is at the
  // level Lmax because this record is at the tip
  count = 0;
  {
    ScopedArenaIterator iter(
        dbfull()->NewInternalIterator(&arena, handles_[1]));
    iter->SeekToFirst();
    ASSERT_OK(iter->status());
    while (iter->Valid()) {
      ParsedInternalKey ikey(Slice(), 0, kTypeValue);
      ASSERT_EQ(ParseInternalKey(iter->key(), &ikey), true);
      ASSERT_NE(ikey.sequence, (unsigned)0);
      count++;
      iter->Next();
    }
    ASSERT_EQ(count, 0);
  }
}

// Tests the edge case where compaction does not produce any output -- all
// entries are deleted. The compaction should create bunch of 'DeleteFile'
// entries in VersionEdit, but none of the 'AddFile's.
TEST_F(DBTestCompactionFilter, CompactionFilterDeletesAll) {
  Options options;
  options.compaction_filter_factory = std::make_shared<DeleteFilterFactory>();
  options.disable_auto_compactions = true;
  options.create_if_missing = true;
  options = CurrentOptions(options);
  DestroyAndReopen(options);

  // put some data
  for (int table = 0; table < 4; ++table) {
    for (int i = 0; i < 10 + table; ++i) {
      Put(ToString(table * 100 + i), "val");
    }
    Flush();
  }

  // this will produce empty file (delete compaction filter)
  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
  ASSERT_EQ(0U, CountLiveFiles());

  Reopen(options);

  Iterator* itr = db_->NewIterator(ReadOptions());
  itr->SeekToFirst();
  // empty db
  ASSERT_TRUE(!itr->Valid());

  delete itr;
}
#endif  // ROCKSDB_LITE

TEST_F(DBTestCompactionFilter, CompactionFilterWithValueChange) {
  do {
    Options options;
    options.num_levels = 3;
    options.compaction_filter_factory =
      std::make_shared<ChangeFilterFactory>();
    options = CurrentOptions(options);
    CreateAndReopenWithCF({"pikachu"}, options);

    // Write 100K+1 keys, these are written to a few files
    // in L0. We do this so that the current snapshot points
    // to the 100001 key.The compaction filter is  not invoked
    // on keys that are visible via a snapshot because we
    // anyways cannot delete it.
    const std::string value(10, 'x');
    for (int i = 0; i < 100001; i++) {
      char key[100];
      snprintf(key, sizeof(key), "B%010d", i);
      Put(1, key, value);
    }

    // push all files to  lower levels
    ASSERT_OK(Flush(1));
    if (option_config_ != kUniversalCompactionMultiLevel &&
        option_config_ != kUniversalSubcompactions) {
      dbfull()->TEST_CompactRange(0, nullptr, nullptr, handles_[1]);
      dbfull()->TEST_CompactRange(1, nullptr, nullptr, handles_[1]);
    } else {
      dbfull()->CompactRange(CompactRangeOptions(), handles_[1], nullptr,
                             nullptr);
    }

    // re-write all data again
    for (int i = 0; i < 100001; i++) {
      char key[100];
      snprintf(key, sizeof(key), "B%010d", i);
      Put(1, key, value);
    }

    // push all files to  lower levels. This should
    // invoke the compaction filter for all 100000 keys.
    ASSERT_OK(Flush(1));
    if (option_config_ != kUniversalCompactionMultiLevel &&
        option_config_ != kUniversalSubcompactions) {
      dbfull()->TEST_CompactRange(0, nullptr, nullptr, handles_[1]);
      dbfull()->TEST_CompactRange(1, nullptr, nullptr, handles_[1]);
    } else {
      dbfull()->CompactRange(CompactRangeOptions(), handles_[1], nullptr,
                             nullptr);
    }

    // verify that all keys now have the new value that
    // was set by the compaction process.
    for (int i = 0; i < 100001; i++) {
      char key[100];
      snprintf(key, sizeof(key), "B%010d", i);
      std::string newvalue = Get(1, key);
      ASSERT_EQ(newvalue.compare(NEW_VALUE), 0);
    }
  } while (ChangeCompactOptions());
}

TEST_F(DBTestCompactionFilter, CompactionFilterWithMergeOperator) {
  std::string one, two, three, four;
  PutFixed64(&one, 1);
  PutFixed64(&two, 2);
  PutFixed64(&three, 3);
  PutFixed64(&four, 4);

  Options options;
  options = CurrentOptions(options);
  options.create_if_missing = true;
  options.merge_operator = MergeOperators::CreateUInt64AddOperator();
  options.num_levels = 3;
  // Filter out keys with value is 2.
  options.compaction_filter_factory =
      std::make_shared<ConditionalFilterFactory>(two);
  DestroyAndReopen(options);

  // In the same compaction, a value type needs to be deleted based on
  // compaction filter, and there is a merge type for the key. compaction
  // filter result is ignored.
  ASSERT_OK(db_->Put(WriteOptions(), "foo", two));
  ASSERT_OK(Flush());
  ASSERT_OK(db_->Merge(WriteOptions(), "foo", one));
  ASSERT_OK(Flush());
  std::string newvalue = Get("foo");
  ASSERT_EQ(newvalue, three);
  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  newvalue = Get("foo");
  ASSERT_EQ(newvalue, three);

  // value key can be deleted based on compaction filter, leaving only
  // merge keys.
  ASSERT_OK(db_->Put(WriteOptions(), "bar", two));
  ASSERT_OK(Flush());
  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  newvalue = Get("bar");
  ASSERT_EQ("NOT_FOUND", newvalue);
  ASSERT_OK(db_->Merge(WriteOptions(), "bar", two));
  ASSERT_OK(Flush());
  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  newvalue = Get("bar");
  ASSERT_EQ(two, two);

  // Compaction filter never applies to merge keys.
  ASSERT_OK(db_->Put(WriteOptions(), "foobar", one));
  ASSERT_OK(Flush());
  ASSERT_OK(db_->Merge(WriteOptions(), "foobar", two));
  ASSERT_OK(Flush());
  newvalue = Get("foobar");
  ASSERT_EQ(newvalue, three);
  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  newvalue = Get("foobar");
  ASSERT_EQ(newvalue, three);

  // In the same compaction, both of value type and merge type keys need to be
  // deleted based on compaction filter, and there is a merge type for the key.
  // For both keys, compaction filter results are ignored.
  ASSERT_OK(db_->Put(WriteOptions(), "barfoo", two));
  ASSERT_OK(Flush());
  ASSERT_OK(db_->Merge(WriteOptions(), "barfoo", two));
  ASSERT_OK(Flush());
  newvalue = Get("barfoo");
  ASSERT_EQ(newvalue, four);
  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  newvalue = Get("barfoo");
  ASSERT_EQ(newvalue, four);
}

#ifndef ROCKSDB_LITE
TEST_F(DBTestCompactionFilter, CompactionFilterContextManual) {
  KeepFilterFactory* filter = new KeepFilterFactory(true, true);

  Options options = CurrentOptions();
  options.compaction_style = kCompactionStyleUniversal;
  options.compaction_filter_factory.reset(filter);
  options.compression = kNoCompression;
  options.level0_file_num_compaction_trigger = 8;
  Reopen(options);
  int num_keys_per_file = 400;
  for (int j = 0; j < 3; j++) {
    // Write several keys.
    const std::string value(10, 'x');
    for (int i = 0; i < num_keys_per_file; i++) {
      char key[100];
      snprintf(key, sizeof(key), "B%08d%02d", i, j);
      Put(key, value);
    }
    dbfull()->TEST_FlushMemTable();
    // Make sure next file is much smaller so automatic compaction will not
    // be triggered.
    num_keys_per_file /= 2;
  }
  dbfull()->TEST_WaitForCompact();

  // Force a manual compaction
  cfilter_count = 0;
  filter->expect_manual_compaction_.store(true);
  filter->expect_full_compaction_.store(true);
  filter->expect_cf_id_.store(0);
  dbfull()->CompactRange(CompactRangeOptions(), nullptr, nullptr);
  ASSERT_EQ(cfilter_count, 700);
  ASSERT_EQ(NumSortedRuns(0), 1);
  ASSERT_TRUE(filter->compaction_filter_created());

  // Verify total number of keys is correct after manual compaction.
  {
    int count = 0;
    int total = 0;
    Arena arena;
    ScopedArenaIterator iter(dbfull()->NewInternalIterator(&arena));
    iter->SeekToFirst();
    ASSERT_OK(iter->status());
    while (iter->Valid()) {
      ParsedInternalKey ikey(Slice(), 0, kTypeValue);
      ikey.sequence = -1;
      ASSERT_EQ(ParseInternalKey(iter->key(), &ikey), true);
      total++;
      if (ikey.sequence != 0) {
        count++;
      }
      iter->Next();
    }
    ASSERT_EQ(total, 700);
    ASSERT_EQ(count, 1);
  }
}
#endif  // ROCKSDB_LITE

TEST_F(DBTestCompactionFilter, CompactionFilterContextCfId) {
  KeepFilterFactory* filter = new KeepFilterFactory(false, true);
  filter->expect_cf_id_.store(1);

  Options options = CurrentOptions();
  options.compaction_filter_factory.reset(filter);
  options.compression = kNoCompression;
  options.level0_file_num_compaction_trigger = 2;
  CreateAndReopenWithCF({"pikachu"}, options);

  int num_keys_per_file = 400;
  for (int j = 0; j < 3; j++) {
    // Write several keys.
    const std::string value(10, 'x');
    for (int i = 0; i < num_keys_per_file; i++) {
      char key[100];
      snprintf(key, sizeof(key), "B%08d%02d", i, j);
      Put(1, key, value);
    }
    Flush(1);
    // Make sure next file is much smaller so automatic compaction will not
    // be triggered.
    num_keys_per_file /= 2;
  }
  dbfull()->TEST_WaitForCompact();

  ASSERT_TRUE(filter->compaction_filter_created());
}

#ifndef ROCKSDB_LITE
// Compaction filters should only be applied to records that are newer than the
// latest snapshot. This test inserts records and applies a delete filter.
TEST_F(DBTestCompactionFilter, CompactionFilterSnapshot) {
  Options options;
  options.compaction_filter_factory = std::make_shared<DeleteFilterFactory>();
  options.disable_auto_compactions = true;
  options.create_if_missing = true;
  options = CurrentOptions(options);
  DestroyAndReopen(options);

  // Put some data.
  const Snapshot* snapshot = nullptr;
  for (int table = 0; table < 4; ++table) {
    for (int i = 0; i < 10; ++i) {
      Put(ToString(table * 100 + i), "val");
    }
    Flush();

    if (table == 0) {
      snapshot = db_->GetSnapshot();
    }
  }
  assert(snapshot != nullptr);

  cfilter_count = 0;
  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
  // The filter should delete 10 records.
  ASSERT_EQ(30U, cfilter_count);

  // Release the snapshot and compact again -> now all records should be
  // removed.
  db_->ReleaseSnapshot(snapshot);
  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
  ASSERT_EQ(0U, CountLiveFiles());
}

// Compaction filters should only be applied to records that are newer than the
// latest snapshot. However, if the compaction filter asks to ignore snapshots
// records newer than the snapshot will also be processed
TEST_F(DBTestCompactionFilter, CompactionFilterIgnoreSnapshot) {
  std::string five = ToString(5);
  Options options;
  options.compaction_filter_factory = std::make_shared<DeleteISFilterFactory>();
  options.disable_auto_compactions = true;
  options.create_if_missing = true;
  options = CurrentOptions(options);
  DestroyAndReopen(options);

  // Put some data.
  const Snapshot* snapshot = nullptr;
  for (int table = 0; table < 4; ++table) {
    for (int i = 0; i < 10; ++i) {
      Put(ToString(table * 100 + i), "val");
    }
    Flush();

    if (table == 0) {
      snapshot = db_->GetSnapshot();
    }
  }
  assert(snapshot != nullptr);

  cfilter_count = 0;
  ASSERT_OK(db_->CompactRange(CompactRangeOptions(), nullptr, nullptr));
  // The filter should delete 40 records.
  ASSERT_EQ(40U, cfilter_count);

  {
    // Scan the entire database as of the snapshot to ensure
    // that nothing is left
    ReadOptions read_options;
    read_options.snapshot = snapshot;
    std::unique_ptr<Iterator> iter(db_->NewIterator(read_options));
    iter->SeekToFirst();
    int count = 0;
    while (iter->Valid()) {
      count++;
      iter->Next();
    }
    ASSERT_EQ(count, 6);
    read_options.snapshot = 0;
    std::unique_ptr<Iterator> iter1(db_->NewIterator(read_options));
    iter1->SeekToFirst();
    count = 0;
    while (iter1->Valid()) {
      count++;
      iter1->Next();
    }
    // We have deleted 10 keys from 40 using the compaction filter
    //  Keys 6-9 before the snapshot and 100-105 after the snapshot
    ASSERT_EQ(count, 30);
  }

  // Release the snapshot and compact again -> now all records should be
  // removed.
  db_->ReleaseSnapshot(snapshot);
}
#endif  // ROCKSDB_LITE

}  // namespace rocksdb

int main(int argc, char** argv) {
  rocksdb::port::InstallStackTraceHandler();
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}
