Automatically resume after a failed initial backup. (Patch from Josh Nisly)

git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup@950 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

trunk/rdiff-backup/CHANGELOG

 New in v1.2.2 (????/??/??)
 ---------------------------
 
+Automatically resume after a failed initial backup. (Patch from Josh Nisly)
+
 Improve compatibility between Unix and remote native Windows client. It is now
 possible to use SSH daemons other than Putty on Windows. (Andrew Ferguson)
 

trunk/rdiff-backup/rdiff_backup/Main.py

@@ -380,6 +380,44 @@ def backup_check_dirs(rpin, rpout):
 		Log.FatalError("Source %s is not a directory" % rpin.path)
 	Globals.rbdir = rpout.append_path("rdiff-backup-data")
 
+def check_failed_initial_backup():
+	"""Returns true if it looks like initial backup failed."""
+	if Globals.rbdir.lstat():
+		rbdir_files = Globals.rbdir.listdir()
+		mirror_markers = filter(lambda x: x.startswith("current_mirror"),
+								rbdir_files)
+		error_logs = filter(lambda x: x.startswith("error_log"),
+							rbdir_files)
+		metadata_mirrors = filter(lambda x: x.startswith("mirror_metadata"),
+								rbdir_files)
+		# If we have no current_mirror marker, and the increments directory
+		# is empty, we most likely have a failed backup.
+		return not mirror_markers and len(error_logs) <= 1 and \
+				len(metadata_mirrors) <= 1
+	return False
+
+def fix_failed_initial_backup():
+	"""Clear Globals.rbdir after a failed initial backup"""
+	Log("Found interrupted initial backup. Removing...",  2)
+	rbdir_files = Globals.rbdir.listdir()
+	# Try to delete the increments dir first
+	if 'increments' in rbdir_files:
+		rbdir_files.remove('increments')
+		rp = Globals.rbdir.append('increments')
+		try:
+			rp.conn.rpath.delete_dir_no_files(rp)
+		except rpath.RPathException:
+			Log("Increments dir contains files.", 4)
+			return
+		except Security.Violation:
+			Log("Server doesn't support resuming.", 2)
+			return
+	
+	for file_name in rbdir_files:
+		rp = Globals.rbdir.append_path(file_name)
+		if not rp.isdir(): # Only remove files, not folders
+			rp.delete()
+
 def backup_set_rbdir(rpin, rpout):
 	"""Initialize data dir and logging"""
 	global incdir
@@ -400,6 +438,8 @@ exists, but does not look like a rdiff-backup directory.  Running
 rdiff-backup like this could mess up what is currently in it.  If you
 want to update or overwrite it, run rdiff-backup with the --force
 option.""" % rpout.path)
+	elif check_failed_initial_backup():
+		fix_failed_initial_backup()
 
 	if not Globals.rbdir.lstat(): Globals.rbdir.mkdir()
 	SetConnections.UpdateGlobal('rbdir', Globals.rbdir)

trunk/rdiff-backup/rdiff_backup/Security.py

@@ -45,7 +45,8 @@ file_requests = {'os.listdir':0, 'rpath.make_file_dict':0, 'os.chmod':0,
 				 'os.chown':0, 'os.remove':0, 'os.removedirs':0,
 				 'os.rename':0, 'os.renames':0, 'os.rmdir':0, 'os.unlink':0,
 				 'os.utime':0, 'os.lchown':0, 'os.link':1, 'os.symlink':1,
-				 'os.mkdir':0, 'os.makedirs':0}
+				 'os.mkdir':0, 'os.makedirs':0,
+				 'rpath.delete_dir_no_files':0}
 				 
 def initialize(action, cmdpairs):
 	"""Initialize allowable request list and chroot"""
@@ -180,6 +181,7 @@ def set_allowed_requests(sec_level):
 	if sec_level == "all":
 		l.extend(["os.mkdir", "os.chown", "os.lchown", "os.rename",
 				  "os.unlink", "os.remove", "os.chmod", "os.makedirs",
+				  "rpath.delete_dir_no_files",
 				  "backup.DestinationStruct.patch",
 				  "restore.TargetStruct.get_initial_iter",
 				  "restore.TargetStruct.patch",

trunk/rdiff-backup/rdiff_backup/rpath.py

@@ -372,6 +372,14 @@ def get_incfile_info(basename):
 	else: basestr = ".".join(dotsplit[:-2])
 	return (compressed, timestring, ext, basestr)
 
+def delete_dir_no_files(rp):
+	"""Deletes the directory at rp.path if empty. Raises if the
+	directory contains files."""
+	assert rp.isdir()
+	if rp.contains_files():
+		raise RPathException("Directory contains files.")
+	rp.delete()
+
 
 class RORPath:
 	"""Read Only RPath - carry information about a path
@@ -1047,6 +1055,21 @@ class RPath(RORPath):
 		else: self.conn.os.unlink(self.path)
 		self.setdata()
 
+	def contains_files(self):
+		"""Returns true if self (or subdir) contains any regular files."""
+		log.Log("Determining if directory contains files: %s" % self.path, 7)
+		if not self.isdir():
+			return False
+		dir_entries = self.listdir()
+		for entry in dir_entries:
+			child_rp = self.append(entry)
+			if not child_rp.isdir():
+				return True
+			else:
+				if child_rp.contains_files():
+					return True
+		return False
+
 	def quote(self):
 		"""Return quoted self.path for use with os.system()"""
 		return '"%s"' % self.regex_chars_to_quote.sub(