Merge pull request #24 from kerel-fs/aprs/+AmbigousTimeError

Add user-defined exception AmbigousTimeError

ogn/aprs_parser.py

@@ -1,8 +1,10 @@
+from datetime import datetime
+
 from .model import Beacon, AircraftBeacon, ReceiverBeacon
 from ogn.exceptions import AprsParseError
 
 
-def parse_aprs(packet):
+def parse_aprs(packet, reference_date=datetime.utcnow()):
     if not isinstance(packet, str):
         raise TypeError("Expected packet to be str, got %s" % type(packet))
     elif packet == "":
@@ -11,7 +13,7 @@ def parse_aprs(packet):
         return None
 
     beacon = Beacon()
-    beacon.parse(packet)
+    beacon.parse(packet, reference_date)
 
     # symboltable / symbolcodes used by OGN:
     # I&: used as receiver

ogn/aprs_utils.py

@@ -1,6 +1,8 @@
 from datetime import datetime, timedelta
 import math
 
+from ogn.exceptions import AmbigousTimeError
+
 
 kmh2kts = 0.539957
 feet2m = 0.3048
@@ -18,18 +20,19 @@ def dmsToDeg(dms):
     return d + m
 
 
-def createTimestamp(hhmmss, reference=datetime.utcnow(), validate=False):
+def createTimestamp(hhmmss, reference):
-    hh = int(hhmmss[0:2])
+    packet_time = datetime.strptime(hhmmss, '%H%M%S').time()
-    mm = int(hhmmss[2:4])
+    timestamp = datetime.combine(reference, packet_time)
-    ss = int(hhmmss[4:6])
 
-    if (reference.hour == 23) & (hh == 0):
+    if reference.hour == 23 and timestamp.hour == 0:
-        reference = reference + timedelta(days=1)
+        timestamp = timestamp + timedelta(days=1)
-    elif (reference.hour == 0) & (hh == 23):
+    elif reference.hour == 0 and timestamp.hour == 23:
-        reference = reference - timedelta(days=1)
+        timestamp = timestamp - timedelta(days=1)
-    elif validate and abs(reference.hour - hh) > 1:
+
-        raise Exception("Time difference is too big. Reference time:%s - timestamp:%s" % (reference, hhmmss))
+    if reference - timestamp > timedelta(hours=1):
-    return datetime(reference.year, reference.month, reference.day, hh, mm, ss)
+        raise AmbigousTimeError(reference, packet_time)
+
+    return timestamp
 
 
 def create_aprs_login(user_name, pass_code, app_name, app_version, aprs_filter=None):

ogn/exceptions.py

@@ -1,20 +1,34 @@
 """
 exception definitions
 """
+from datetime import datetime
 
 
 class AprsParseError(Exception):
     """Parse error while parsing an aprs packet."""
     def __init__(self, aprs_string):
-        self.message = "This is not a valid APRS string: %s" % aprs_string
-        super(AprsParseError, self).__init__(self.message)
         self.aprs_string = aprs_string
 
+        self.message = "This is not a valid APRS string: {}".format(aprs_string)
+        super(AprsParseError, self).__init__(self.message)
+
 
 class OgnParseError(Exception):
-    """Parse error while parsing an aprs packet substring"""
+    """Parse error while parsing an aprs packet substring."""
     def __init__(self, substring, expected_type):
-        self.message = "For type %s this is not a valid token: %s" % (expected_type, substring)
-        super(OgnParseError, self).__init__(self.message)
         self.substring = substring
         self.expected_type = expected_type
+
+        self.message = "For type {} this is not a valid token: {}".format(expected_type, substring)
+        super(OgnParseError, self).__init__(self.message)
+
+
+class AmbigousTimeError(Exception):
+    """Timstamp from the past/future, can't fully reconstruct datetime from timestamp."""
+    def __init__(self, reference, packet_time):
+        self.reference = reference
+        self.packet_time = packet_time
+        self.timedelta = reference - datetime.combine(reference, packet_time)
+
+        self.message = "Can't reconstruct timstamp, {:.0f}s from past.".format(self.timedelta.total_seconds())
+        super(AmbigousTimeError, self).__init__(self.message)

ogn/gateway/client.py

@@ -5,7 +5,7 @@ from time import time
 from ogn.gateway import settings
 from ogn.aprs_parser import parse_aprs
 from ogn.aprs_utils import create_aprs_login
-from ogn.exceptions import AprsParseError, OgnParseError
+from ogn.exceptions import AprsParseError, OgnParseError, AmbigousTimeError
 
 
 class ognGateway:
@@ -83,6 +83,9 @@ class ognGateway:
         except OgnParseError:
             self.logger.error('OgnParseError while parsing line: {}'.format(line), exc_info=True)
             return
+        except AmbigousTimeError as e:
+            self.logger.error('Drop packet, {:.0f}s from past.'.format(e.timedelta.total_seconds()))
+            return
 
         if beacon is not None:
             self.process_beacon(beacon)

ogn/model/beacon.py

@@ -1,4 +1,5 @@
 import re
+from datetime import datetime
 
 from sqlalchemy import Column, String, Integer, Float, DateTime
 from sqlalchemy.ext.declarative import AbstractConcreteBase
@@ -29,7 +30,7 @@ class Beacon(AbstractConcreteBase, Base):
     altitude = Column(Integer)
     comment = None
 
-    def parse(self, text):
+    def parse(self, text, reference_date=datetime.utcnow()):
         result = re_pattern_aprs.match(text)
         if result is None:
             raise AprsParseError(text)
@@ -37,7 +38,7 @@ class Beacon(AbstractConcreteBase, Base):
         self.name = result.group(1)
         self.receiver_name = result.group(2)
 
-        self.timestamp = createTimestamp(result.group(3))
+        self.timestamp = createTimestamp(result.group(3), reference_date)
 
         self.latitude = dmsToDeg(float(result.group(4)) / 100)
         if result.group(5) == "S":

tests/test_aprs_parser.py

@@ -1,4 +1,5 @@
 import unittest
+from datetime import datetime
 
 from ogn.aprs_parser import parse_aprs
 from ogn.exceptions import AprsParseError, OgnParseError
@@ -8,7 +9,7 @@ class TestStringMethods(unittest.TestCase):
     def test_valid_beacons(self):
         with open('tests/valid_beacons.txt') as f:
             for line in f:
-                parse_aprs(line)
+                parse_aprs(line, datetime(2015, 4, 10, 17, 0))
 
     def test_fail_none(self):
         with self.assertRaises(TypeError):
@@ -24,11 +25,13 @@ class TestStringMethods(unittest.TestCase):
 
     def test_incomplete_device_string(self):
         with self.assertRaises(OgnParseError):
-            parse_aprs("ICA4B0E3A>APRS,qAS,Letzi:/072319h4711.75N\\00802.59E^327/149/A=006498 id154B0E3A -395")
+            parse_aprs("ICA4B0E3A>APRS,qAS,Letzi:/072319h4711.75N\\00802.59E^327/149/A=006498 id154B0E3A -395",
+                       datetime(2015, 4, 10, 7, 24))
 
     def test_incomplete_receiver_string(self):
         with self.assertRaises(OgnParseError):
-            parse_aprs("Lachens>APRS,TCPIP*,qAC,GLIDERN2:/165334h4344.70NI00639.19E&/A=005435 v0.2.1 CPU:0.3 RAM:1764.4/21")
+            parse_aprs("Lachens>APRS,TCPIP*,qAC,GLIDERN2:/165334h4344.70NI00639.19E&/A=005435 v0.2.1 CPU:0.3 RAM:1764.4/21",
+                       datetime(2015, 4, 10, 16, 54))
 
 
 if __name__ == '__main__':

tests/test_aprs_utils.py

@@ -2,6 +2,7 @@ import unittest
 from datetime import datetime
 
 from ogn.aprs_utils import dmsToDeg, createTimestamp, create_aprs_login
+from ogn.exceptions import AmbigousTimeError
 
 
 class TestStringMethods(unittest.TestCase):
@@ -18,8 +19,8 @@ class TestStringMethods(unittest.TestCase):
         self.assertEqual(timestamp, datetime(2015, 10, 16, 0, 0, 1))
 
     def test_createTimestamp_big_difference(self):
-        with self.assertRaises(Exception):
+        with self.assertRaises(AmbigousTimeError):
-            createTimestamp('123456', reference=datetime(2015, 10, 15, 23, 59, 59), validate=True)
+            createTimestamp('123456', reference=datetime(2015, 10, 15, 23, 59, 59))
 
     def test_create_aprs_login(self):
         basic_login = create_aprs_login('klaus', -1, 'myApp', '0.1')

tests/valid_beacons.txt

@@ -1,17 +1,17 @@
 # aprsc 2.0.14-g28c5a6a 10 Apr 2015 18:58:47 GMT GLIDERN1 37.187.40.234:14580
-FLRDDA5BA>APRS,qAS,LFMX:/160829h4415.41N/00600.03E'342/049/A=005524 id0ADDA5BA -454fpm -1.1rot 8.8dB 0e +51.2kHz gps4x5
+FLRDDA5BA>APRS,qAS,LFMX:/165829h4415.41N/00600.03E'342/049/A=005524 id0ADDA5BA -454fpm -1.1rot 8.8dB 0e +51.2kHz gps4x5
-ICA4B0E3A>APRS,qAS,Letzi:/072319h4711.75N\00802.59E^327/149/A=006498 id154B0E3A -3959fpm +0.5rot 9.0dB 0e -6.3kHz gps1x3
+ICA4B0E3A>APRS,qAS,Letzi:/165319h4711.75N\00802.59E^327/149/A=006498 id154B0E3A -3959fpm +0.5rot 9.0dB 0e -6.3kHz gps1x3
 Lachens>APRS,TCPIP*,qAC,GLIDERN2:/165334h4344.70NI00639.19E&/A=005435 v0.2.1 CPU:0.3 RAM:1764.4/2121.4MB NTP:2.8ms/+4.9ppm +47.0C RF:+0.70dB
-LFGU>APRS,TCPIP*,qAC,GLIDERN2:/190556h4907.63NI00706.41E&/A=000833 v0.2.0 CPU:0.9 RAM:281.3/458.9MB NTP:0.5ms/-19.1ppm +53.0C RF:+0.70dB
+LFGU>APRS,TCPIP*,qAC,GLIDERN2:/165556h4907.63NI00706.41E&/A=000833 v0.2.0 CPU:0.9 RAM:281.3/458.9MB NTP:0.5ms/-19.1ppm +53.0C RF:+0.70dB
-FLRDDB091>APRS,qAS,Letzi:/195831h4740.04N/00806.01EX152/124/A=004881 id06DD8E80 +198fpm +0.0rot 6.5dB 13e +4.0kHz gps3x4
+FLRDDB091>APRS,qAS,Letzi:/165831h4740.04N/00806.01EX152/124/A=004881 id06DD8E80 +198fpm +0.0rot 6.5dB 13e +4.0kHz gps3x4
-LSGS>APRS,TCPIP*,qAC,GLIDERN1:/195345h4613.25NI00719.68E&/A=001581 CPU:0.7 RAM:247.9/456.4MB NTP:0.7ms/-11.4ppm +44.4C RF:+53+71.9ppm/+0.4dB
+LSGS>APRS,TCPIP*,qAC,GLIDERN1:/165345h4613.25NI00719.68E&/A=001581 CPU:0.7 RAM:247.9/456.4MB NTP:0.7ms/-11.4ppm +44.4C RF:+53+71.9ppm/+0.4dB
 FLRDDDD33>APRS,qAS,LFNF:/165341h4344.27N/00547.41E'/A=000886 id06DDDD33 +020fpm +0.0rot 20.8dB 0e -14.3kHz gps3x4
 FLRDDE026>APRS,qAS,LFNF:/165341h4358.58N/00553.89E'204/055/A=005048 id06DDE026 +257fpm +0.1rot 7.2dB 0e -0.8kHz gps4x7
 ICA484A9C>APRS,qAS,LFMX:/165341h4403.50N/00559.67E'/A=001460 id05484A9C +000fpm +0.0rot 18.0dB 0e +3.5kHz gps4x7
 WolvesSW>APRS,TCPIP*,qAC,GLIDERN2:/165343h5232.23NI00210.91W&/A=000377 CPU:1.5 RAM:159.9/458.7MB NTP:6.6ms/-36.7ppm +45.5C RF:+130-0.4ppm/-0.1dB
-Oxford>APRS,TCPIP*,qAC,GLIDERN1:/190533h5142.96NI00109.68W&/A=000380 v0.1.3 CPU:0.9 RAM:268.8/458.6MB NTP:0.5ms/-45.9ppm +60.5C RF:+55+2.9ppm/+1.54dB
+Oxford>APRS,TCPIP*,qAC,GLIDERN1:/165533h5142.96NI00109.68W&/A=000380 v0.1.3 CPU:0.9 RAM:268.8/458.6MB NTP:0.5ms/-45.9ppm +60.5C RF:+55+2.9ppm/+1.54dB
-OGNE95A16>APRS,qAS,Sylwek:/203641h5001.94N/01956.91E'270/004/A=000000 id07E95A16 +000fpm +0.1rot 37.8dB 0e -0.4kHz
+OGNE95A16>APRS,qAS,Sylwek:/165641h5001.94N/01956.91E'270/004/A=000000 id07E95A16 +000fpm +0.1rot 37.8dB 0e -0.4kHz
-Salland>APRS,TCPIP*,qAC,GLIDERN2:/201426h5227.93NI00620.03E&/A=000049 v0.2.2 CPU:0.7 RAM:659.3/916.9MB NTP:2.5ms/-75.0ppm RF:+0.41dB
+Salland>APRS,TCPIP*,qAC,GLIDERN2:/165426h5227.93NI00620.03E&/A=000049 v0.2.2 CPU:0.7 RAM:659.3/916.9MB NTP:2.5ms/-75.0ppm RF:+0.41dB
-LSGS>APRS,TCPIP*,qAC,GLIDERN1:/195345h4613.25NI00719.68E&/A=001581 CPU:0.7 RAM:247.9/456.4MB NTP:0.7ms/-11.4ppm +44.4C RF:+53+71.9ppm/+0.4dB
+LSGS>APRS,TCPIP*,qAC,GLIDERN1:/165345h4613.25NI00719.68E&/A=001581 CPU:0.7 RAM:247.9/456.4MB NTP:0.7ms/-11.4ppm +44.4C RF:+53+71.9ppm/+0.4dB
-Drenstein>APRS,TCPIP*,qAC,GLIDERN1:/203011h5147.51NI00744.45E&/A=000213 v0.2.2 CPU:0.8 RAM:695.7/4025.5MB NTP:16000.0ms/+0.0ppm +63.0C
+Drenstein>APRS,TCPIP*,qAC,GLIDERN1:/165011h5147.51NI00744.45E&/A=000213 v0.2.2 CPU:0.8 RAM:695.7/4025.5MB NTP:16000.0ms/+0.0ppm +63.0C
-ZK-GSC>APRS,qAS,Omarama:/210202h4429.25S/16959.33E'/A=001407 id05C821EA +020fpm +0.0rot 16.8dB 0e -3.1kHz gps1x3 hear1084 hearB597 hearB598
+ZK-GSC>APRS,qAS,Omarama:/165202h4429.25S/16959.33E'/A=001407 id05C821EA +020fpm +0.0rot 16.8dB 0e -3.1kHz gps1x3 hear1084 hearB597 hearB598