bool DBImpl::GetProperty()

in db/db_impl.cc [1387:1447]

• 58 lines of code
• 14 McCabe index (conditional complexity)

bool DBImpl::GetProperty(const Slice& property, std::string* value) {
  value->clear();

  MutexLock l(&mutex_);
  Slice in = property;
  Slice prefix("leveldb.");
  if (!in.starts_with(prefix)) return false;
  in.remove_prefix(prefix.size());

  if (in.starts_with("num-files-at-level")) {
    in.remove_prefix(strlen("num-files-at-level"));
    uint64_t level;
    bool ok = ConsumeDecimalNumber(&in, &level) && in.empty();
    if (!ok || level >= config::kNumLevels) {
      return false;
    } else {
      char buf[100];
      std::snprintf(buf, sizeof(buf), "%d",
                    versions_->NumLevelFiles(static_cast<int>(level)));
      *value = buf;
      return true;
    }
  } else if (in == "stats") {
    char buf[200];
    std::snprintf(buf, sizeof(buf),
                  "                               Compactions\n"
                  "Level  Files Size(MB) Time(sec) Read(MB) Write(MB)\n"
                  "--------------------------------------------------\n");
    value->append(buf);
    for (int level = 0; level < config::kNumLevels; level++) {
      int files = versions_->NumLevelFiles(level);
      if (stats_[level].micros > 0 || files > 0) {
        std::snprintf(buf, sizeof(buf), "%3d %8d %8.0f %9.0f %8.0f %9.0f\n",
                      level, files, versions_->NumLevelBytes(level) / 1048576.0,
                      stats_[level].micros / 1e6,
                      stats_[level].bytes_read / 1048576.0,
                      stats_[level].bytes_written / 1048576.0);
        value->append(buf);
      }
    }
    return true;
  } else if (in == "sstables") {
    *value = versions_->current()->DebugString();
    return true;
  } else if (in == "approximate-memory-usage") {
    size_t total_usage = options_.block_cache->TotalCharge();
    if (mem_) {
      total_usage += mem_->ApproximateMemoryUsage();
    }
    if (imm_) {
      total_usage += imm_->ApproximateMemoryUsage();
    }
    char buf[50];
    std::snprintf(buf, sizeof(buf), "%llu",
                  static_cast<unsigned long long>(total_usage));
    value->append(buf);
    return true;
  }

  return false;
}