Files
pyDevSup/weatherApp/weather.py
2015-01-04 12:25:59 -05:00

160 lines
3.9 KiB
Python

# -*- coding: utf-8 -*-
from __future__ import print_function
import socket, time, urllib2
from weakref import WeakValueDictionary
from devsup.hooks import addHook
from devsup.util import StoppableThread
from devsup.db import IOScanListBlock
try:
import pymetar
except ImportError:
print("The pymetar package could not be imported!")
raise
_isofmt = '%Y-%m-%d %H:%M:%SZ'
def iso2sec(str):
"""Convert the string returned by pymetar to posix time.
"""
rtime = time.mktime(time.strptime(str, _isofmt))
return rtime - (time.altzone if time.daylight else time.timezone)
_stations = WeakValueDictionary()
def getStation(name):
try:
return _stations[name]
except KeyError:
S = ReportScanner(name)
_stations[name] = S
return S
class DataWatcher(object):
"""Weather watcher device support.
field(INP,"weather KISP getTemperatureCelsius")
of
field(INP,"weather KISP showID")
"""
# disable automatic RVAL -> VAL conversion.
# We will update VAL ourselves.
raw = True
def __init__(self, rec, args):
station, name = args.split(None, 1)
self.staid = station
self.sta = getStation(station)
self.attr = name
self.last = None
if name.startswith('get'):
# Assume this is a method of pymetar.WeatherReport
self.allowScan = self.sta.scan.add
self.process = self.process_report
else:
# Our own internal info
self.allowScan = self.sta.intscan.add
self.process = getattr(self, name)
try:
rec.UDF = 0
except AttributeError:
pass
def detach(self, rec):
pass
def showID(self, rec, report):
rec.VAL = self.staid
def updatePeriod(self, rec, report):
rec.VAL = self.sta.updatePeriod/60.0
def process_report(self, rec, report):
if report is not None:
self.last = report
else:
report = self.last
if report is None:
rec.setSevr()
return
fn = getattr(self.last, self.attr)
newval = fn()
try:
rec.VAL = newval
except ValueError:
rec.setSevr()
try:
rec.UDF = 0
except AttributeError:
pass
if rec.TSE==-2:
rec.setTime(report._updatetime)
build = DataWatcher
class ReportScanner(StoppableThread):
"""Driver thread which occasionally polls for new metar data
"""
def __init__(self, station):
self.io = pymetar.ReportFetcher()
self.station = station
self.initPeriod = self.updatePeriod = 15*60.0
self.minPeriod = 10*60.0
self.maxPeriod = 2*60*60.0
self.lastUpdate = None # Time of last report
self.scan = IOScanListBlock() # I/O Intr scan for report data
self.intscan = IOScanListBlock() # scan for internal info
super(ReportScanner,self).__init__()
addHook('AfterIocRunning', self.start)
addHook('AtIocExit', self.join)
def run(self):
print("Starting scanner for ",self.station)
while self.shouldRun():
try:
report = self.io.FetchReport(self.station)
pymetar.ReportParser().ParseReport(report)
rtime = iso2sec(report.getISOTime())
report._updatetime = rtime
#print('update',report.getISOTime(),rtime,self.lastUpdate)
if self.lastUpdate is not None:
if self.lastUpdate >= rtime:
#print('No update, Wait a little longer next time')
self.updatePeriod = self.initPeriod
else: # self.lastUpdate < rtime
#print('Got an update')
self.updatePeriod = rtime - self.lastUpdate
self.updatePeriod = max(self.minPeriod, min(self.updatePeriod, self.maxPeriod))
self.updatePeriod += 15*60.0
self.scan.interrupt(reason=report)
else:
self.scan.interrupt(reason=report)
self.lastUpdate = rtime
except Exception as e:
print("download error for",self.station,":",e)
self.updatePeriod = self.initPeriod
self.intscan.interrupt()
#print('Waiting',self.updatePeriod)
self.sleep(self.updatePeriod)
print('Done')