Method CompactRange

src/leveldb/db/version_set.cc:1441–1472

}

Compaction* VersionSet::CompactRange(int level, const InternalKey* begin,
                                     const InternalKey* end) {
  std::vector<FileMetaData*> inputs;
  current_->GetOverlappingInputs(level, begin, end, &inputs);
  if (inputs.empty()) {
    return nullptr;
  }

  // Avoid compacting too much in one shot in case the range is large.
  // But we cannot do this for level-0 since level-0 files can overlap
  // and we must not pick one file and drop another older file if the
  // two files overlap.
  if (level > 0) {
    const uint64_t limit = MaxFileSizeForLevel(options_, level);
    uint64_t total = 0;
    for (size_t i = 0; i < inputs.size(); i++) {
      uint64_t s = inputs[i]->file_size;
      total += s;
      if (total >= limit) {
        inputs.resize(i + 1);
        break;
      }
    }
  }

  Compaction* c = new Compaction(options_, level);
  c->input_version_ = current_;
  c->input_version_->Ref();
  c->inputs_[0] = inputs;
  SetupOtherInputs(c);
  return c;
}

Compaction::Compaction(const Options* options, int level)
    : level_(level),