[Rake-devel] rake speedup for several thousand tasks

[Niklas von Öhsen]

Hi there,

I just got acquainted to rake and want to use it to automate
some scientific calculations (I think, its great!). This involves 
definition of several thousand tasks. I found that the usual rake "file" 
and "task" syntax is quite slow for this. Thus I added new methods for a 
faster task definition. The original time needed for the definition of 
about 7000 file tasks with one additional dependence was 150 sec. Using 
the code below this goes down to 1.2 sec. A speedup of more than 10000% :-)
It sacrifices flexibility and beauty of syntax to raw speed, but if that 
is what you need ...

Maybe this interesting for somebody out there? Feel free to use it.

Niklas



# enhance rake task definition for large numbers of tasks
#
# normal rake usage:
#	file "name" => "dependency" do |x|
#	    do_something(x)
#  end
#
#This gets slow for a few thousand tasks, due to argument handling.
#
# fast definition for string arguments:
#
#  quickfile "name", "dependency" do |x|
#     do_something(x)
#	end

class Task

	def enhancedep(dep, &block)
		@prerequisites << dep
		@actions << block if block_given?
		self
	end

	class << self
		

		#makes faster task definition possible.
		def define_quicktask(name, dep, &block)
			if (String === name) and (String === dep)
				lookup(name).enhancedep(dep,&block)
				else
				
				raise "use quicktask only with strings"
			end
		end

	end

end

# Define a task with a string name and one string dependency
# This has improved performance over "task"
def quicktask(name,dep,&block)
	Task.define_quicktask(name,dep,&block)
end

# Define a file task with a string name and one string dependency
# see quicktask
def quickfile(name,dep,&block)
	FileTask.define_quicktask(name,dep,&block)
end






-- 
------------------------------------------------------------
Niklas von Öhsen