Method: PEROBS::BTree#open

Defined in:
lib/perobs/BTree.rb

#open(file_must_exist = false) ⇒ Object

Open the tree file.



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# File 'lib/perobs/BTree.rb', line 89

def open(file_must_exist = false)
  if @dirty_flag.is_locked?
    PEROBS.log.fatal "Index file #{@nodes.file_name} is already " +
      "locked"
  end
  if file_must_exist && !@nodes.file_exist?
    PEROBS.log.fatal "Index file #{@nodes.file_name} does not exist"
  end

  @node_cache.clear
  @nodes.open

  if @nodes.total_entries == 0
    # We've created a new nodes file
    node = BTreeNode::create(self)
  else
    # We are loading an existing tree.
    node = BTreeNode::load_and_link(self, @nodes.first_entry)
    @first_leaf = BTreeNode::load_and_link(
      self, @nodes.get_custom_data('first_leaf'))
    @last_leaf = BTreeNode::load_and_link(
      self, @nodes.get_custom_data('last_leaf'))
  end
  set_root(node)

  # Get the total number of entries that are stored in the tree.
  @size = @nodes.get_custom_data('btree_size')
end