From: Its Me <itsme213@...>
Date: 2004-04-22T06:34:09+09:00
Subject: rexml - extreme speed issue

I am having extreme speed issues with some simple rexml code and want to
know if I am doing something findamentally wrong. The source xml document
has a few thousand elements, attributes are not used much, text nodes are
present. I need to do some surgery on the tree, walking sequentially through
the initial very flat tree and moving things into a 3-level structure based
on known target levels for the element types. Just takes a single pass, and
does include some delete_element and add_element calls.The main method is:

@doc = REXML::Document.new @infile

target_level_0_nodes = ["A", "B", "C"]
target_level_1_nodes = ["a", "b", "c"]
target_level_2_nodes = ["x","y", "z"]

def relocate_siblings ()
  root = @doc.root
  level_0 = nil
  level_1 = nil
  level_2 = nil
  root.each_element do |curr|
    p curr
    if target_level_0_nodes.include? curr.name
      level_0 = curr
    else
      if target_level_1_nodes.include? curr.name
        curr.parent.delete_element(curr)
        level_0.add_element(curr)
        level_1 = curr
      else
        curr.parent.delete_element(curr)
        level_1.add_element(curr)
        level_2 = curr
      end
    end
  end
end

This runs excruciatingly slowly, literally taking seconds between printing
nodes. I could edit the tree in XMLSpy just marginally slower. The disk is
not awfully busy, CPU is at right about 100%.

Help!! What am I doing wrong?

I do not want to have to deal with XSLT!