def __init__(self, fn, section, updateCycle=7):
self._config = CP.RawConfigParser()
self._fs = PyAFS()
self._fn = fn
self._section = section
if not self._fs.fileExists(fn):
# Config does not yet exist
# Write the default version
self._config.add_section(section)
self._config.set(section, 'DATA_UPDATE_CYCLE_DAYS', updateCycle)
self._config.set(section, "DATA_DOWNLOAD_DATE", "NEVER")
self._config.write(self._fs.requestFile(fn, 'w'))
else:
# File exists
self._config.readfp(self._fs.requestFile(self._fn, 'r'))
if not self._config.has_section(section):
# Only the section does not yet exists
# Add the content
self._config.add_section(section)
self._config.set(section, 'DATA_UPDATE_CYCLE_DAYS', updateCycle)
self._config.set(section, "DATA_DOWNLOAD_DATE", "NEVER")
self._config.write(self._fs.requestFile(fn, 'w'))
# Read the current data set from file
self._config.readfp(self._fs.requestFile(self._fn, 'r'))
self._updateCycle = self._config.getfloat(self._section, "DATA_UPDATE_CYCLE_DAYS")
self._timeString = self._config.get(self._section, "DATA_DOWNLOAD_DATE")
class PyAUpdateCycle:
"""
A simple data update cycle.
This class provides a simple way to realize an
update cycle for data, which need to be re-initialized
periodically.
Parameters
----------
fn : string
The name of the file (within PyAFS), which
is used to store the settings.
section : string
The section within the config file used
to store the settings.
updateCycle : float or int
The number of days defining the update cycle.
"""
def __init__(self, fn, section, updateCycle=7):
self._config = CP.RawConfigParser()
self._fs = PyAFS()
self._fn = fn
self._section = section
if not self._fs.fileExists(fn):
# Config does not yet exist
# Write the default version
self._config.add_section(section)
self._config.set(section, 'DATA_UPDATE_CYCLE_DAYS', updateCycle)
self._config.set(section, "DATA_DOWNLOAD_DATE", "NEVER")
self._config.write(self._fs.requestFile(fn, 'w'))
else:
# File exists
self._config.readfp(self._fs.requestFile(self._fn, 'r'))
if not self._config.has_section(section):
# Only the section does not yet exists
# Add the content
self._config.add_section(section)
self._config.set(section, 'DATA_UPDATE_CYCLE_DAYS', updateCycle)
self._config.set(section, "DATA_DOWNLOAD_DATE", "NEVER")
self._config.write(self._fs.requestFile(fn, 'w'))
# Read the current data set from file
self._config.readfp(self._fs.requestFile(self._fn, 'r'))
self._updateCycle = self._config.getfloat(self._section, "DATA_UPDATE_CYCLE_DAYS")
self._timeString = self._config.get(self._section, "DATA_DOWNLOAD_DATE")
def dataAge(self):
"""
Determine the "age" of the data.
Returns
-------
age : float
The time since last data update
in days. None, if no age can be
determined, e.g., if data have
never been downloaded.
"""
if self._timeString == "NEVER":
return None
downloadTime = DT.datetime.strptime(self._timeString, "%Y-%m-%d %H:%M")
delta = DT.datetime.now() - downloadTime
# Convert into days
ddays = (delta.total_seconds()/86400.)
return ddays
def needsUpdate(self):
"""
Determine whether data need to be updated.
Returns
-------
Update flag : boolean
True if data need update and False
otherwise.
"""
if self._updateCycle < 0:
# Updating switched off
return False
age = self.dataAge()
if age is None:
return True
if age > self._updateCycle:
return True
return False
def _setDownloadDate(self, ddate=None):
"""
Set the download date.
Parameters
----------
ddate : datetime object, optional
The time of last update. If not
specified, the current time is
used.
"""
if ddate is None:
ddate = DT.datetime.now()
self._config.set(self._section, "DATA_DOWNLOAD_DATE", \
ddate.strftime("%Y-%m-%d %H:%M"))
self._config.write(self._fs.requestFile(self._fn, 'w'))
self._timeString = self._config.get(self._section, "DATA_DOWNLOAD_DATE")
def changeDownloadCycle(self, c):
"""
Change the time after which the data are updated.
By default, the data will be updated if they are older
than the given update cycle.
This method allows you to change that cycle.
Parameters
----------
c : float or None
The new update cycle in days. If `None` is
provided, updating is switched off.
"""
if c is not None:
if c < 0.0:
raise(PE.PyAValError("Update cycle needs to be a positive number of days."))
self._updateCycle = c
else:
self._updateCycle = -1.0
self._config.set(self._section, "DATA_UPDATE_CYCLE_DAYS", self._updateCycle)
self._config.write(self._fs.requestFile(self._fn, 'w'))
def _update(self, func, *args, **kwargs):
"""
Initiate data update
The download date is updated automatically.
Parameters
----------
func : callable
Function to call to carry out the update.
The function will be called with *args and
**kwargs as parameters.
"""
func(*args, **kwargs)
self._setDownloadDate()
