parse output from Popen PIPE every poll to make sure the pipe buffer never fills. Moved polling to 250ms. Moved output to an array to facilitate changes

Author: Tim Vaillancourt

MongoBackup/Common/LocalCommand.py

@@ -10,7 +10,7 @@ def __init__(self, command, command_flags=[], verbose=False):
         self.command_flags = command_flags
         self.verbose       = verbose
 
-        self.output   = ""
+        self.output   = []
         self.stdout   = None
         self.stderr   = None
         self._process = None
@@ -26,7 +26,8 @@ def parse_output(self):
                 output = self.stdout.strip()
                 if output == "" and self.stderr.strip() != "":
                     output = self.stderr.strip()
-                self.output = "\n\t".join(output.split("\n"))
+                if not output == "":
+                    self.output.append("\n\t".join(output.split("\n")))
             except Exception, e:
                 raise Exception, "Error parsing output: %s" % e, None
         return self.output
@@ -35,22 +36,22 @@ def run(self):
         try:
             self._process = Popen(self.command_line, stdout=PIPE, stderr=PIPE)
             while self._process.poll() is None:
-                sleep(0.5)
+                self.parse_output()
+                sleep(0.25)
         except Exception, e:
             raise e
 
-        self.parse_output()
         if self._process.returncode != 0:
             raise Exception, "%s command failed with exit code %i! Stderr output:\n%s" % (
                 self.command,
                 self._process.returncode,
                 self.stderr.strip()
             ), None
         elif self.verbose:
-            if self.output == "":
-                logging.debug("%s command completed" % (self.command))
+            if len(self.output) > 0:
+                logging.debug("%s command completed with output:\n\t%s" % (self.command, "\n".join(self.output)))
             else:
-                logging.debug("%s command completed with output:\n\t%s" % (self.command, self.output))
+                logging.debug("%s command completed" % (self.command))
 
     def close(self):
         if self._process: