@check_if_uptodate¶

@check_if_uptodate (dependency_checking_function)¶

Purpose:

Checks to see if a job is up to date, and needs to be run.

Usually used in conjunction with @parallel()

Example:

from ruffus import *
import os
def check_file_exists(input_file, output_file):
    if not os.path.exists(output_file):
        return True, "Missing file %s" % output_file
    else:
        return False, "File %s exists" % output_file

@parallel([[None, "a.1"]])
@check_if_uptodate(check_file_exists)
def create_if_necessary(input_file, output_file):
    open(output_file, "w")

pipeline_run([create_if_necessary])

Is equivalent to:

from ruffus import *
@files(None, "a.1")
def create_if_necessary(input_file, output_file):
    open(output_file, "w")

pipeline_run([create_if_necessary])

Both produce the same output:

Task = create_if_necessary
    Job = [null, "a.1"] completed

Parameters:

dependency_checking_function:

returns two parameters: if job needs to be run, and a message explaining why

dependency_checking_func() needs to handle the same number of parameters as the task function e.g. input_file and output_file above.