Task #9931: added non-blocking readlines method

LCS/PyCommon/subprocess.py

+import logging
 from datetime import datetime, timedelta
 from threading import Thread
 try:
@@ -5,6 +6,8 @@ try:
 except ImportError:
     from queue import Queue, Empty  # python 3.x
 
+logger = logging.getLogger()
+
 class PipeReader:
     '''
     helper class to do non-blocking readline calls to a subprocess stdput or stderr pipe.
@@ -24,7 +27,7 @@ class PipeReader:
         except Exception as e:
             logger.error(e)
 
-    def readline(self, timeout=None):
+    def __fill_line_buffer(self, timeout=None):
         start = datetime.now()
         while timeout==None or datetime.now() - start <= timedelta(seconds=timeout):
             try:
@@ -34,6 +37,9 @@ class PipeReader:
             except Empty:
                 pass
 
+    def readline(self, timeout=None):
+        self.__fill_line_buffer(timeout)
+
         endline_idx = self.__line_buffer.find('\n')
 
         if endline_idx > -1:
@@ -42,3 +48,12 @@ class PipeReader:
             return line
         return ''
 
+    def readlines(self, timeout=None):
+        self.__fill_line_buffer(timeout)
+
+        lines = self.__line_buffer.split('\n')
+        if lines and not lines[-1].endswith('\n'):
+            self.__line_buffer = lines[-1]
+            lines = lines[:-2]
+
+        return lines