# ----------------------------------------------------------------------------
# This software is in the public domain, furnished "as is", without technical
# support, and with no warranty, express or implied, as to its usefulness for
# any purpose.
#
# offsetTime.py
# Handles Displaced Real Time for various applications
#
# Author: hansen/romberg
# ----------------------------------------------------------------------------
import string
import time
# Given the timeStr, return the offset (in seconds)
# from the current time.
# Also return the launchStr i.e. Programs launched from this
# offset application will use the launchStr as the -z argument.
# The offset will be positive for time in the future,
# negative for time in the past.
#
# May still want it to be normalized to the most recent midnight.
#
# NOTES about synchronizing:
# --With synchronizing on, the "current time" for all processes started
# within a given hour will be the same.
# This guarantees that GFE's have the same current time and ISC grid
# time stamps are syncrhonized and can be exchanged.
# Formatters launched from the GFE in this mode will be synchronized as
# well by setting the launchStr to use the time difference format
# (YYYYMMDD_HHMM,YYYYMMDD_HHMM).
# --This does not solve the problem in the general case.
# For example, if someone starts the GFE at 12:59 and someone
# else starts it at 1:01, they will have different offsets and
# current times.
# --With synchronizing off, when the process starts, the current time
# matches the drtTime in the command line. However, with synchronizing
# on, the current time will be offset by the fraction of the hour at
# which the process was started. Examples:
# Actual Starting time: 20040617_1230
# drtTime 20040616_0000
# Synchronizing off:
# GFE Spatial Editor at StartUp: 20040616_0000
# Synchronizing on:
# GFE Spatial Editor at StartUp: 20040616_0030
#
[docs]def determineDrtOffset(timeStr):
launchStr = timeStr
# Check for time difference
if timeStr.find(",") >= 0:
times = timeStr.split(",")
t1 = makeTime(times[0])
t2 = makeTime(times[1])
return t1-t2, launchStr
# Check for synchronized mode
synch = 0
if timeStr[0] == "S":
timeStr = timeStr[1:]
synch = 1
drt_t = makeTime(timeStr)
gm = time.gmtime()
cur_t = time.mktime(gm)
# Synchronize to most recent hour
# i.e. "truncate" cur_t to most recent hour.
if synch:
cur_t = time.mktime((gm[0], gm[1], gm[2], gm[3], 0, 0, 0, 0, 0))
curStr = '%4s%2s%2s_%2s00\n' % (repr(gm[0]), repr(gm[1]),
repr(gm[2]), repr(gm[3]))
curStr = curStr.replace(' ', '0')
launchStr = timeStr + "," + curStr
offset = drt_t - cur_t
return int(offset), launchStr
[docs]def makeTime(timeStr):
year = string.atoi(timeStr[0:4])
month = string.atoi(timeStr[4:6])
day = string.atoi(timeStr[6:8])
hour = string.atoi(timeStr[9:11])
minute = string.atoi(timeStr[11:13])
# Do not use daylight savings because gmtime is not in daylight
# savings time.
return time.mktime((year, month, day, hour, minute, 0, 0, 0, 0))