Adds to Melange a tags framework based on taggable-mixin.
The taggable-mixin allowed only tag per Datastore model. This is extended
framework allows any arbitrary number of tags per Datastore model. Also,
now one can define different models for different Tag types which are all
inherited from the base Tag model provided by taggable-mixin.
The GHOPTask model makes use of 2 tags per model, one for difficulty and the
other for task_type, both using the tags framework.
Reviewed by: Paweł Sołyga
import os
import sys
if os.name == 'posix':
def become_daemon(our_home_dir='.', out_log='/dev/null',
err_log='/dev/null', umask=022):
"Robustly turn into a UNIX daemon, running in our_home_dir."
# First fork
try:
if os.fork() > 0:
sys.exit(0) # kill off parent
except OSError, e:
sys.stderr.write("fork #1 failed: (%d) %s\n" % (e.errno, e.strerror))
sys.exit(1)
os.setsid()
os.chdir(our_home_dir)
os.umask(umask)
# Second fork
try:
if os.fork() > 0:
os._exit(0)
except OSError, e:
sys.stderr.write("fork #2 failed: (%d) %s\n" % (e.errno, e.strerror))
os._exit(1)
si = open('/dev/null', 'r')
so = open(out_log, 'a+', 0)
se = open(err_log, 'a+', 0)
os.dup2(si.fileno(), sys.stdin.fileno())
os.dup2(so.fileno(), sys.stdout.fileno())
os.dup2(se.fileno(), sys.stderr.fileno())
# Set custom file descriptors so that they get proper buffering.
sys.stdout, sys.stderr = so, se
else:
def become_daemon(our_home_dir='.', out_log=None, err_log=None, umask=022):
"""
If we're not running under a POSIX system, just simulate the daemon
mode by doing redirections and directory changing.
"""
os.chdir(our_home_dir)
os.umask(umask)
sys.stdin.close()
sys.stdout.close()
sys.stderr.close()
if err_log:
sys.stderr = open(err_log, 'a', 0)
else:
sys.stderr = NullDevice()
if out_log:
sys.stdout = open(out_log, 'a', 0)
else:
sys.stdout = NullDevice()
class NullDevice:
"A writeable object that writes to nowhere -- like /dev/null."
def write(self, s):
pass