From c08f5986a99e76fbe81d217a534b2171c6253cc8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Sat, 2 Apr 2016 23:51:37 +0200
Subject: [PATCH] backup: use constants for queue control strings

---
 qubes/backup.py | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/qubes/backup.py b/qubes/backup.py
index 9961eb2b..3fdb8c66 100644
--- a/qubes/backup.py
+++ b/qubes/backup.py
@@ -41,6 +41,10 @@ from multiprocessing import Queue, Process
 import qubes
 import qubes.core2migration
 
+QUEUE_ERROR = "ERROR"
+
+QUEUE_FINISHED = "FINISHED"
+
 HEADER_FILENAME = 'backup-header'
 DEFAULT_CRYPTO_ALGORITHM = 'aes-256-cbc'
 DEFAULT_HMAC_ALGORITHM = 'SHA512'
@@ -191,7 +195,7 @@ class SendWorker(Process):
         os.chdir(self.base_dir)
 
         for filename in iter(self.queue.get, None):
-            if filename == "FINISHED" or filename == "ERROR":
+            if filename in (QUEUE_FINISHED, QUEUE_ERROR):
                 break
 
             self.log.debug("Sending file {}".format(filename))
@@ -759,7 +763,7 @@ class Backup(object):
                             pass
                         tar_sparse.wait()
                         hmac.wait()
-                        to_send.put("ERROR")
+                        to_send.put(QUEUE_ERROR)
                         send_proc.join()
                         shutil.rmtree(self.tmpdir)
                         raise BackupCanceledError("Backup canceled")
@@ -813,7 +817,7 @@ class Backup(object):
             self._current_vm_bytes = 0
             self._send_progress_update()
 
-        self._queue_put_with_check(send_proc, vmproc, to_send, "FINISHED")
+        self._queue_put_with_check(send_proc, vmproc, to_send, QUEUE_FINISHED)
         send_proc.join()
         shutil.rmtree(self.tmpdir)
 
@@ -1013,7 +1017,7 @@ class ExtractWorker2(Process):
         filename = None
 
         for filename in iter(self.queue.get, None):
-            if filename == "FINISHED" or filename == "ERROR":
+            if filename in (QUEUE_FINISHED, QUEUE_ERROR):
                 break
 
             self.log.debug("Extracting file " + filename)
@@ -1128,7 +1132,7 @@ class ExtractWorker2(Process):
         os.unlink(self.restore_pipe)
 
         if self.tar2_process is not None:
-            if filename == "ERROR":
+            if filename == QUEUE_ERROR:
                 self.tar2_process.terminate()
                 self.tar2_process.wait()
             elif self.tar2_process.wait() != 0:
@@ -1169,7 +1173,7 @@ class ExtractWorker3(ExtractWorker2):
 
         input_pipe = None
         for filename in iter(self.queue.get, None):
-            if filename == "FINISHED" or filename == "ERROR":
+            if filename in (QUEUE_FINISHED, QUEUE_ERROR):
                 break
 
             self.log.debug("Extracting file " + filename)
@@ -1274,7 +1278,7 @@ class ExtractWorker3(ExtractWorker2):
 
         if self.tar2_process is not None:
             input_pipe.close()
-            if filename == "ERROR":
+            if filename == QUEUE_ERROR:
                 if self.decryptor_process:
                     self.decryptor_process.terminate()
                     self.decryptor_process.wait()
@@ -1608,7 +1612,7 @@ class BackupRestore(object):
     def _start_inner_extraction_worker(self, queue):
         """Start a worker process, extracting inner layer of bacup archive,
         extract them to :py:attr:`tmpdir`.
-        End the data by pushing "FINISHED" or "ERROR" to the queue.
+        End the data by pushing QUEUE_FINISHED or QUEUE_ERROR to the queue.
 
         :param queue :py:class:`Queue` object to handle files from
         """
@@ -1652,7 +1656,7 @@ class BackupRestore(object):
             self._verify_hmac("qubes.xml.000", "qubes.xml.000.hmac")
             queue = Queue()
             queue.put("qubes.xml.000")
-            queue.put("FINISHED")
+            queue.put(QUEUE_FINISHED)
 
         extract_proc = self._start_inner_extraction_worker(queue)
         extract_proc.join()
@@ -1761,11 +1765,11 @@ class BackupRestore(object):
                 raise qubes.exc.QubesException(
                     "Premature end of archive, the last file was %s" % filename)
         except:
-            to_extract.put("ERROR")
+            to_extract.put(QUEUE_ERROR)
             extract_proc.join()
             raise
         else:
-            to_extract.put("FINISHED")
+            to_extract.put(QUEUE_FINISHED)
 
         self.log.debug("Waiting for the extraction process to finish...")
         extract_proc.join()