C++ TileIndex::left_child方法代码示例

bool Channel::read_tile_or_closest_ancestor(TileIndex ti, TileIndex &ret_index, Tile &ret) const {
  Locker lock(*this);  // Lock self and hold lock until exiting this method
  ChannelInfo info;
  bool success = read_info(info);
  if (!success) {
    if (verbosity) log_f("read_tile_or_closest_ancestor: can't read info");
    return false;
  }
  TileIndex root = info.nonnegative_root_tile_index;

  if (ti.is_ancestor_of(root)) {
    ret_index = root;
  } else {
    if (ti != root && !root.is_ancestor_of(ti)) {
      // Tile isn't under root
      return false;
    }
    
    assert(tile_exists(root));
    ret_index = root;
    while (ret_index != ti) {
      TileIndex child = ti.start_time() < ret_index.left_child().end_time() ? ret_index.left_child() : ret_index.right_child();
      if (!tile_exists(child)) break;
      ret_index = child;
    }
  }
  // ret_index now holds closest ancestor to ti (or ti itself if it exists)  
    
  assert(read_tile(ret_index, ret));
  return true;
}

TileIndex Channel::find_child_overlapping_time(TileIndex ti, double t, int desired_level) const {
  assert(!ti.is_null());
  // Start at root tile and move downwards

  while (ti.level > desired_level) {
    // Select correct child
    TileIndex child = t < ti.left_child().end_time() ? ti.left_child() : ti.right_child();
    
    if (child.is_null() || !tile_exists(child)) break;
    ti = child;
  }

  return ti;
}

TileIndex Channel::split_tile_if_needed(TileIndex ti, Tile &tile) {
  TileIndex new_root_index = TileIndex::null();
  if (tile.binary_length() <= m_max_tile_size) return new_root_index;
  Tile children[2];
  TileIndex child_indexes[2];
  if (verbosity) log_f("split_tile_if_needed: splitting tile %s", ti.to_string().c_str());

  // If we're splitting an "all" tile, it means that until now the channel has only had one tile's worth of
  // data, and that a proper root tile location couldn't be selected.  Select a new root tile now.
  if (ti.is_nonnegative_all()) {
    // TODO: this breaks if all samples are at one time
    ti = new_root_index = TileIndex::index_containing(Range(tile.first_sample_time(), tile.last_sample_time()));
    if (verbosity) log_f("split_tile_if_needed: Moving root tile to %s", ti.to_string().c_str());
  }
  
  child_indexes[0]= ti.left_child();
  child_indexes[1]= ti.right_child();

  double split_time = ti.right_child().start_time();
  split_samples(tile.double_samples, split_time, children[0], children[1]);
  split_samples(tile.string_samples, split_time, children[0], children[1]);

  for (int i = 0; i < 2; i++) {
    assert(!has_tile(child_indexes[i]));
    assert(split_tile_if_needed(child_indexes[i], children[i]) == TileIndex::null());
    write_tile(child_indexes[i], children[i]);
  }
  create_parent_tile_from_children(ti, tile, children);
  return new_root_index;
}

void Channel::create_parent_tile_from_children(TileIndex parent_index, Tile &parent, Tile children[]) {
  // Subsample the children to create the parent
  // when do we want to show original values?
  // when do we want to do a real low-pass filter?
  // do we need to filter more than just the child tiles? e.g. gaussian beyond the tile border
  if (verbosity) log_f("Channel: creating parent %s from children %s, %s",
                       parent_index.to_string().c_str(),
                       parent_index.left_child().to_string().c_str(),
                       parent_index.right_child().to_string().c_str());

  combine_samples(BT_CHANNEL_DOUBLE_SAMPLES, parent_index, parent.double_samples, children[0].double_samples, children[1].double_samples);
  if (children[0].double_samples.size() + children[1].double_samples.size()) assert(parent.double_samples.size());

  combine_samples(BT_CHANNEL_STRING_SAMPLES, parent_index, parent.string_samples, children[0].string_samples, children[1].string_samples);
  if (children[0].string_samples.size() + children[1].string_samples.size()) assert(parent.string_samples.size());

  parent.ranges = children[0].ranges;
  parent.ranges.add(children[1].ranges);
}

std::string Channel::dump_tile_summaries_internal(TileIndex ti, int level) const {
  Tile tile;
  if (!read_tile(ti, tile)) return "";
  std::string ret = string_printf("%*s%d.%d: %zd samples\n", level, "", ti.level, ti.offset, tile.double_samples.size());
  return ret + dump_tile_summaries_internal(ti.left_child(), level+1) + dump_tile_summaries_internal(ti.right_child(), level+1);
}

void Channel::add_data_internal(const std::vector<DataSample<T> > &data, DataRanges *channel_ranges) {
  if (!data.size()) return;
  // Sanity check
  if (data[0].time < 0) throw std::runtime_error("Unimplemented feature: adding data with negative time");
  for (unsigned i = 0; i < data.size()-1; i++) {
    if (data[i].time > data[i+1].time) throw std::runtime_error("Attempt to add data that is not sorted by ascending time");
  }

  //	regenerate = empty set
  Locker lock(*this);  // Lock self and hold lock until exiting this method
  std::set<TileIndex> to_regenerate;

  ChannelInfo info;
  bool success = read_info(info);
  if (!success) {
    // New channel
    info.magic = ChannelInfo::MAGIC;
    info.version = 0x00010000;
    info.times = Range(data[0].time, data.back().time);
    info.nonnegative_root_tile_index = TileIndex::nonnegative_all();
    create_tile(TileIndex::nonnegative_all());
    info.negative_root_tile_index = TileIndex::null();
  } else {
    info.times.add(Range(data[0].time, data.back().time));
    // If we're not the all-tile, see if we need to move the root upwards
    if (info.nonnegative_root_tile_index != TileIndex::nonnegative_all()) {
      TileIndex new_nonnegative_root_tile_index = TileIndex::index_containing(info.times);
      if (new_nonnegative_root_tile_index.level > info.nonnegative_root_tile_index.level) {
	// Root index changed.  Confirm new root is parent or more distant ancestor of old root
	assert(new_nonnegative_root_tile_index.is_ancestor_of(info.nonnegative_root_tile_index));
	// Trigger regeneration from old root's parent, up through new root
	to_regenerate.insert(info.nonnegative_root_tile_index.parent());
	move_root_upwards(new_nonnegative_root_tile_index, info.nonnegative_root_tile_index);
	info.nonnegative_root_tile_index = new_nonnegative_root_tile_index;
      }
    }
  }

  unsigned i=0;

  while (i < data.size()) {
    TileIndex ti= find_lowest_child_overlapping_time(info.nonnegative_root_tile_index, data[i].time);
    assert(!ti.is_null());

    Tile tile;
    assert(read_tile(ti, tile));
    const DataSample<T> *begin = &data[i];
    while (i < data.size() && ti.contains_time(data[i].time)) i++;
    const DataSample<T> *end = &data[i];
    tile.insert_samples(begin, end);
    
    TileIndex new_root = split_tile_if_needed(ti, tile);
    if (new_root != TileIndex::null()) {
      assert(ti == TileIndex::nonnegative_all());
      if (verbosity) log_f("Channel: %s changing root from %s to %s",
                           descriptor().c_str(), ti.to_string().c_str(),
                           new_root.to_string().c_str());
      info.nonnegative_root_tile_index = new_root;
      delete_tile(ti); // Delete old root
      ti = new_root;
    }
    write_tile(ti, tile);
    if (ti == info.nonnegative_root_tile_index && channel_ranges) { *channel_ranges = tile.ranges; }
    if (ti != info.nonnegative_root_tile_index) to_regenerate.insert(ti.parent());
  }
  
  // Regenerate from lowest level to highest
  while (!to_regenerate.empty()) {
    TileIndex ti = *to_regenerate.begin();
    to_regenerate.erase(to_regenerate.begin());
    Tile regenerated, children[2];
    assert(read_tile(ti.left_child(), children[0]));
    assert(read_tile(ti.right_child(), children[1]));
    create_parent_tile_from_children(ti, regenerated, children);
    write_tile(ti, regenerated);
    if (ti == info.nonnegative_root_tile_index && channel_ranges) { *channel_ranges = regenerated.ranges; }
    if (ti != info.nonnegative_root_tile_index) to_regenerate.insert(ti.parent());
  }
  write_info(info);
}