Attempt at fix for #387 (#388)

* Attempt at fix for #387

* Made the return statements a bit more concise

logger/readers/test_udp_reader.py

@@ -21,6 +21,21 @@
                b'\xff\xa2',
                b'\xff\xa3']
 
+SAMPLE_DATA_EOL = [
+"$INGGA,074633.951958,4914.2813714,N,00457.4807581,W,4,,0.616,-95.296,M,,M,,*67\n$INGGA,074634.054429,4914.2813739,N,00457.4807665,W,4,,0.616,-95.296,M,,M,,*61\n",
+"$INGGA,074634.151923,4914.2813762,N,00457.4807746,W,4,,0.616,-95.297,M,,M,,*6D\n",
+"$INGGA,074634.351497,4914.2813879,N,00457.4807920,W,4,,0.616,-95.293,M,,M,,*62"
+]
+
+SAMPLE_DATA_EOL_OUTPUT = [
+    [
+        "$INGGA,074633.951958,4914.2813714,N,00457.4807581,W,4,,0.616,-95.296,M,,M,,*67",
+        "$INGGA,074634.054429,4914.2813739,N,00457.4807665,W,4,,0.616,-95.296,M,,M,,*61"
+    ],
+    "$INGGA,074634.151923,4914.2813762,N,00457.4807746,W,4,,0.616,-95.297,M,,M,,*6D",
+    "$INGGA,074634.351497,4914.2813879,N,00457.4807920,W,4,,0.616,-95.293,M,,M,,*62"
+]
+
 # We're going to set MAXSIZE to 1K before writing this, and the fragmentation
 # marker is 10 bytes long.  The first record here should fragment cleanly into
 # all a's, all b's, and all c's, then get reassembled by the reader
@@ -84,6 +99,23 @@ def read_udp(self, interface, port, data, mc_group=None, encoding='utf-8', delay
             self.assertTrue(False, 'UDPReader timed out in test - is port '
                             '%s:%s open?' % (interface, port))
 
+    ############################
+    # Read with eol
+    def read_udp_eol(self, interface, port, data, mc_group=None, encoding='utf-8', delay=0):
+        time.sleep(delay)
+        try:
+            reader = UDPReader(interface=interface, port=port, mc_group=mc_group, encoding=encoding,
+                               eol='\n', this_is_a_test=True)
+            for line in data:
+                time.sleep(delay)
+                logging.debug('UDPReader reading...')
+                result = reader.read()
+                self.assertEqual(line, result)
+        except ReaderTimeout:
+            self.assertTrue(False, 'UDPReader timed out in test - is port '
+                            '%s:%s open?' % (interface, port))
+
+
     ############################
     # UNICAST
     def test_unicast(self):
@@ -107,6 +139,27 @@ def test_unicast(self):
         # Silence the alarm
         signal.alarm(0)
 
+    def test_unicast_with_eol(self):
+        port = 8000
+        dest = 'localhost'
+
+        w_thread = threading.Thread(target=self.write_udp, name='write_thread',
+                                    args=(dest, port, SAMPLE_DATA_EOL),
+                                    kwargs={'interval': 0.1, 'delay': 0.2})
+
+        # Set timeout we can catch if things are taking too long
+        signal.signal(signal.SIGALRM, self._handler)
+        signal.alarm(1)
+
+        w_thread.start()
+        self.read_udp_eol(dest, port, SAMPLE_DATA_EOL_OUTPUT)
+
+        # Make sure everyone has terminated
+        w_thread.join()
+
+        # Silence the alarm
+        signal.alarm(0)
+
     ############################
     # UNICAST raw/binary
     def test_unicast_binary(self):

logger/readers/udp_reader.py

@@ -42,7 +42,7 @@ class UDPReader(Reader):
     ############################
     def __init__(self, interface=None, port=None, mc_group=None,
                  reuseaddr=False, reuseport=False,
-                 encoding='utf-8', encoding_errors='ignore',
+                 encoding='utf-8', encoding_errors='ignore', eol=None,
                  this_is_a_test=False):
         """
         ```
@@ -63,14 +63,16 @@ def __init__(self, interface=None, port=None, mc_group=None,
         reuseport    Specifies wether we set SO_REUSEPORT on the created socket.  If
                      you don't know you need this, don't enable it.
 
-        encoding - 'utf-8' by default. If empty or None, do not attempt any decoding
-                and return raw bytes. Other possible encodings are listed in online
-                documentation here:
-                https://docs.python.org/3/library/codecs.html#standard-encodings
+        encoding     'utf-8' by default. If empty or None, do not attempt any decoding
+                     and return raw bytes. Other possible encodings are listed in
+                     online documentation here:
+                     https://docs. python.org/3/library/codecs.html#standard-encodings
 
-        encoding_errors - 'ignore' by default. Other error strategies are 'strict',
-                'replace', and 'backslashreplace', described here:
-                https://docs.python.org/3/howto/unicode.html#encodings
+        encoding_errors 'ignore' by default. Other error strategies are 'strict',
+                        'replace', and 'backslashreplace', described here:
+                        https://docs.python.org/3/howto/unicode.html#encodings
+
+        eol          split the record by the eol character if present.
 
         this_is_a_test - If True, recognize that this is being called in a unittest, so
                 don't output warnings about not using loopback addresses.
@@ -117,6 +119,8 @@ def __init__(self, interface=None, port=None, mc_group=None,
         self.reuseaddr = reuseaddr
         self.reuseport = reuseport
 
+        self.eol = eol
+
         self.this_is_a_test = this_is_a_test
 
         # socket gets initialized on-demand in read()
@@ -213,4 +217,14 @@ def read(self):
                 break
 
         # we've got a whole record in our record_buffer, decode it
-        return self._decode_bytes(record_buffer)
+
+        # if eol == None, return the record as is
+        if not self.eol:
+            return self._decode_bytes(record_buffer)
+
+        # otherwise split the record by the eol
+        decoded_records = self._decode_bytes(record_buffer).rstrip(self.eol).split(self.eol)
+
+        # if there was only one record, return just the first element in the
+        # list, otherwise return the whole list.
+        return decoded_records[0] if len(decoded_records) == 1 else decoded_records