commit: fc8df8594e5d7b14f75adb080aa928a48c01a448
Author: Brian Dolbec <dolsen <AT> gentoo <DOT> org>
AuthorDate: Fri May 2 17:04:39 2014 +0000
Commit: Brian Dolbec <brian.dolbec <AT> gmail <DOT> com>
CommitDate: Tue Sep 30 00:42:25 2014 +0000
URL:
http://sources.gentoo.org/gitweb/?p=proj/portage.git;a=commit;h=fc8df859
sync/modules/rsync: Refactor legacy code
Split up the _sync() into logical chunks.
Replace out my* variables.
Move constants out of code, to top of the file.
---
pym/portage/sync/modules/rsync/rsync.py | 508 +++++++++++++++++---------------
1 file changed, 267 insertions(+), 241 deletions(-)
diff --git a/pym/portage/sync/modules/rsync/rsync.py
b/pym/portage/sync/modules/rsync/rsync.py
index d0ee886..76d83f2 100644
--- a/pym/portage/sync/modules/rsync/rsync.py
+++ b/pym/portage/sync/modules/rsync/rsync.py
@@ -24,6 +24,10 @@ from _emerge.UserQuery import UserQuery
from portage.sync.syncbase import SyncBase
+SERVER_OUT_OF_DATE = -1
+EXCEEDED_MAX_RETRIES = -2
+
+
class RsyncSync(SyncBase):
'''Rsync sync module'''
@@ -40,112 +44,47 @@ class RsyncSync(SyncBase):
def _sync(self):
'''Internal sync function which performs only the sync'''
- myopts = self.options.get('emerge_config').opts
- usersync_uid = self.options.get('usersync_uid', None)
- enter_invalid = '--ask-enter-invalid' in myopts
+ opts = self.options.get('emerge_config').opts
+ self.usersync_uid = self.options.get('usersync_uid', None)
+ enter_invalid = '--ask-enter-invalid' in opts
out = portage.output.EOutput()
syncuri = self.repo.sync_uri
- dosyncuri = syncuri
vcs_dirs = frozenset(VCS_DIRS)
vcs_dirs = vcs_dirs.intersection(os.listdir(self.repo.location))
-
for vcs_dir in vcs_dirs:
writemsg_level(("!!! %s appears to be under revision "
+ \
"control (contains %s).\n!!! Aborting rsync
sync.\n") % \
(self.repo.location, vcs_dir),
level=logging.ERROR, noiselevel=-1)
return (1, False)
- mytimeout=180
+ self.timeout=180
rsync_opts = []
if self.settings["PORTAGE_RSYNC_OPTS"] == "":
- portage.writemsg("PORTAGE_RSYNC_OPTS empty or unset,
using hardcoded defaults\n")
- rsync_opts.extend([
- "--recursive", # Recurse directories
- "--links", # Consider symlinks
- "--safe-links", # Ignore links outside of tree
- "--perms", # Preserve permissions
- "--times", # Preserive mod times
- "--omit-dir-times",
- "--compress", # Compress the data
transmitted
- "--force", # Force deletion on non-empty
dirs
- "--whole-file", # Don't do block transfers,
only entire files
- "--delete", # Delete files that aren't in
the master tree
- "--stats", # Show final statistics about
what was transfered
- "--human-readable",
- "--timeout="+str(mytimeout), # IO timeout if
not done in X seconds
- "--exclude=/distfiles", # Exclude distfiles
from consideration
- "--exclude=/local", # Exclude local
from consideration
- "--exclude=/packages", # Exclude packages
from consideration
- ])
-
- else:
- # The below validation is not needed when using the
above hardcoded
- # defaults.
-
- portage.writemsg("Using PORTAGE_RSYNC_OPTS instead of
hardcoded defaults\n", 1)
- rsync_opts.extend(portage.util.shlex_split(
- self.settings.get("PORTAGE_RSYNC_OPTS", "")))
- for opt in ("--recursive", "--times"):
- if opt not in rsync_opts:
- portage.writemsg(yellow("WARNING:") + "
adding required option " + \
- "%s not included in
PORTAGE_RSYNC_OPTS\n" % opt)
- rsync_opts.append(opt)
-
- for exclude in ("distfiles", "local", "packages"):
- opt = "--exclude=/%s" % exclude
- if opt not in rsync_opts:
- portage.writemsg(yellow("WARNING:") + \
- " adding required option %s not
included in " % opt + \
- "PORTAGE_RSYNC_OPTS (can be overridden
with --exclude='!')\n")
- rsync_opts.append(opt)
-
- if
syncuri.rstrip("/").endswith(".gentoo.org/gentoo-portage"):
- def rsync_opt_startswith(opt_prefix):
- for x in rsync_opts:
- if x.startswith(opt_prefix):
- return (1, False)
- return (0, False)
-
- if not rsync_opt_startswith("--timeout="):
- rsync_opts.append("--timeout=%d" %
mytimeout)
-
- for opt in ("--compress", "--whole-file"):
- if opt not in rsync_opts:
-
portage.writemsg(yellow("WARNING:") + " adding required option " + \
- "%s not included in
PORTAGE_RSYNC_OPTS\n" % opt)
- rsync_opts.append(opt)
-
- if "--quiet" in myopts:
- rsync_opts.append("--quiet") # Shut up a lot
+ rsync_opts = self._set_rsync_defaults()
else:
- rsync_opts.append("--verbose") # Print filelist
-
- if "--verbose" in myopts:
- rsync_opts.append("--progress") # Progress meter for
each file
-
- if "--debug" in myopts:
- rsync_opts.append("--checksum") # Force checksum on all
files
+ rsync_opts = self._validate_rsync_opts(rsync_opts,
syncuri)
+ self.rsync_opts = self._rsync_opts_extend(opts, rsync_opts)
# Real local timestamp file.
- servertimestampfile = os.path.join(
+ self.servertimestampfile = os.path.join(
self.repo.location, "metadata", "timestamp.chk")
- content = portage.util.grabfile(servertimestampfile)
- mytimestamp = 0
+ content = portage.util.grabfile(self.servertimestampfile)
+ timestamp = 0
if content:
try:
- mytimestamp =
time.mktime(time.strptime(content[0],
+ timestamp =
time.mktime(time.strptime(content[0],
TIMESTAMP_FORMAT))
except (OverflowError, ValueError):
pass
del content
try:
- rsync_initial_timeout = \
+ self.rsync_initial_timeout = \
int(self.settings.get("PORTAGE_RSYNC_INITIAL_TIMEOUT", "15"))
except ValueError:
- rsync_initial_timeout = 15
+ self.rsync_initial_timeout = 15
try:
maxretries=int(self.settings["PORTAGE_RSYNC_RETRIES"])
@@ -156,7 +95,7 @@ class RsyncSync(SyncBase):
retries=0
try:
- proto, user_name, hostname, port = re.split(
+ self.proto, user_name, hostname, port = re.split(
r"(rsync|ssh)://([^:/]+@)?(\[[:\da-fA-F]*\]|[^:/]*)(:[0-9]+)?",
syncuri, maxsplit=4)[1:5]
except ValueError:
@@ -164,7 +103,7 @@ class RsyncSync(SyncBase):
noiselevel=-1, level=logging.ERROR)
return (1, False)
- ssh_opts = self.settings.get("PORTAGE_SSH_OPTS")
+ self.ssh_opts = self.settings.get("PORTAGE_SSH_OPTS")
if port is None:
port=""
@@ -176,10 +115,10 @@ class RsyncSync(SyncBase):
# getaddrinfo needs the brackets stripped
getaddrinfo_host = hostname[1:-1]
updatecache_flg=True
- all_rsync_opts = set(rsync_opts)
- extra_rsync_opts = portage.util.shlex_split(
+ all_rsync_opts = set(self.rsync_opts)
+ self.extra_rsync_opts = portage.util.shlex_split(
self.settings.get("PORTAGE_RSYNC_EXTRA_OPTS",""))
- all_rsync_opts.update(extra_rsync_opts)
+ all_rsync_opts.update(self.extra_rsync_opts)
family = socket.AF_UNSPEC
if "-4" in all_rsync_opts or "--ipv4" in all_rsync_opts:
@@ -245,8 +184,6 @@ class RsyncSync(SyncBase):
if effective_maxretries < 0:
effective_maxretries = len(uris) - 1
- SERVER_OUT_OF_DATE = -1
- EXCEEDED_MAX_RETRIES = -2
while (1):
if uris:
dosyncuri = uris.pop()
@@ -267,7 +204,7 @@ class RsyncSync(SyncBase):
sys.exit(128 + signal.SIGINT)
self.logger(self.xterm_titles,
">>> Starting rsync with " + dosyncuri)
- if "--quiet" not in myopts:
+ if "--quiet" not in opts:
print(">>> Starting rsync with
"+dosyncuri+"...")
else:
self.logger(self.xterm_titles,
@@ -280,160 +217,9 @@ class RsyncSync(SyncBase):
if dosyncuri.startswith('ssh://'):
dosyncuri = dosyncuri[6:].replace('/', ':/', 1)
- if mytimestamp != 0 and "--quiet" not in myopts:
- print(">>> Checking server timestamp ...")
-
- rsynccommand = [self.bin_command] + rsync_opts +
extra_rsync_opts
-
- if proto == 'ssh' and ssh_opts:
- rsynccommand.append("--rsh=ssh " + ssh_opts)
-
- if "--debug" in myopts:
- print(rsynccommand)
-
- exitcode = os.EX_OK
- servertimestamp = 0
- # Even if there's no timestamp available locally, fetch
the
- # timestamp anyway as an initial probe to verify that
the server is
- # responsive. This protects us from hanging
indefinitely on a
- # connection attempt to an unresponsive server which
rsync's
- # --timeout option does not prevent.
- if True:
- # Temporary file for remote server timestamp
comparison.
- # NOTE: If FEATURES=usersync is enabled then
the tempfile
- # needs to be in a directory that's readable by
the usersync
- # user. We assume that PORTAGE_TMPDIR will
satisfy this
- # requirement, since that's not necessarily
true for the
- # default directory used by the tempfile module.
- if usersync_uid is not None:
- tmpdir = self.settings['PORTAGE_TMPDIR']
- else:
- # use default dir from tempfile module
- tmpdir = None
- fd, tmpservertimestampfile = \
- tempfile.mkstemp(dir=tmpdir)
- os.close(fd)
- if usersync_uid is not None:
-
portage.util.apply_permissions(tmpservertimestampfile,
- uid=usersync_uid)
- mycommand = rsynccommand[:]
- mycommand.append(dosyncuri.rstrip("/") + \
- "/metadata/timestamp.chk")
- mycommand.append(tmpservertimestampfile)
- content = None
- mypids = []
- try:
- # Timeout here in case the server is
unresponsive. The
- # --timeout rsync option doesn't apply
to the initial
- # connection attempt.
- try:
- if rsync_initial_timeout:
-
portage.exception.AlarmSignal.register(
-
rsync_initial_timeout)
-
-
mypids.extend(portage.process.spawn(
- mycommand,
returnpid=True,
-
**portage._native_kwargs(self.spawn_kwargs)))
- exitcode =
os.waitpid(mypids[0], 0)[1]
- if usersync_uid is not None:
-
portage.util.apply_permissions(tmpservertimestampfile,
- uid=os.getuid())
- content =
portage.grabfile(tmpservertimestampfile)
- finally:
- if rsync_initial_timeout:
-
portage.exception.AlarmSignal.unregister()
- try:
-
os.unlink(tmpservertimestampfile)
- except OSError:
- pass
- except portage.exception.AlarmSignal:
- # timed out
- print('timed out')
- # With waitpid and WNOHANG, only check
the
- # first element of the tuple since the
second
- # element may vary (bug #337465).
- if mypids and os.waitpid(mypids[0],
os.WNOHANG)[0] == 0:
- os.kill(mypids[0],
signal.SIGTERM)
- os.waitpid(mypids[0], 0)
- # This is the same code rsync uses for
timeout.
- exitcode = 30
- else:
- if exitcode != os.EX_OK:
- if exitcode & 0xff:
- exitcode = (exitcode &
0xff) << 8
- else:
- exitcode = exitcode >> 8
-
- if content:
- try:
- servertimestamp =
time.mktime(time.strptime(
- content[0],
TIMESTAMP_FORMAT))
- except (OverflowError, ValueError):
- pass
- del mycommand, mypids, content
- if exitcode == os.EX_OK:
- if (servertimestamp != 0) and (servertimestamp
== mytimestamp):
- self.logger(self.xterm_titles,
- ">>> Cancelling sync -- Already
current.")
- print()
- print(">>>")
- print(">>> Timestamps on the server and
in the local repository are the same.")
- print(">>> Cancelling all further sync
action. You are already up to date.")
- print(">>>")
- print(">>> In order to force sync,
remove '%s'." % servertimestampfile)
- print(">>>")
- print()
- return (exitcode, updatecache_flg)
- elif (servertimestamp != 0) and
(servertimestamp < mytimestamp):
- self.logger(self.xterm_titles,
- ">>> Server out of date: %s" %
dosyncuri)
- print()
- print(">>>")
- print(">>> SERVER OUT OF DATE: %s" %
dosyncuri)
- print(">>>")
- print(">>> In order to force sync,
remove '%s'." % servertimestampfile)
- print(">>>")
- print()
- exitcode = SERVER_OUT_OF_DATE
- elif (servertimestamp == 0) or (servertimestamp
> mytimestamp):
- # actual sync
- mycommand = rsynccommand +
[dosyncuri+"/", self.repo.location]
- exitcode = None
- try:
- exitcode =
portage.process.spawn(mycommand,
-
**portage._native_kwargs(self.spawn_kwargs))
- finally:
- if exitcode is None:
- # interrupted
- exitcode = 128 +
signal.SIGINT
-
- # 0 Success
- # 1 Syntax or usage error
- # 2 Protocol incompatibility
- # 5 Error starting
client-server protocol
- # 35 Timeout waiting for
daemon connection
- if exitcode not in (0, 1, 2, 5,
35):
- # If the exit code is
not among those listed above,
- # then we may have a
partial/inconsistent sync
- # state, so our
previously read timestamp as well
- # as the corresponding
file can no longer be
- # trusted.
- mytimestamp = 0
- try:
-
os.unlink(servertimestampfile)
- except OSError:
- pass
-
- if exitcode in [0,1,3,4,11,14,20,21]:
- break
- elif exitcode in [1,3,4,11,14,20,21]:
+ is_synced, exitcode = self._do_rsync(dosyncuri,
timestamp, opts)
+ if is_synced:
break
- else:
- # Code 2 indicates protocol incompatibility,
which is expected
- # for servers with protocol < 29 that don't
support
- # --prune-empty-directories. Retry for a
server that supports
- # at least rsync protocol version 29
(>=rsync-2.6.4).
- pass
retries=retries+1
@@ -445,9 +231,13 @@ class RsyncSync(SyncBase):
updatecache_flg=False
exitcode = EXCEEDED_MAX_RETRIES
break
+ self._process_exitcode(exitcode, dosyncuri, out, maxretries)
+ return (exitcode, updatecache_flg)
+
+ def _process_exitcode(self, exitcode, syncuri, out, maxretries):
if (exitcode==0):
- self.logger(self.xterm_titles, "=== Sync completed with
%s" % dosyncuri)
+ self.logger(self.xterm_titles, "=== Sync completed with
%s" % syncuri)
elif exitcode == SERVER_OUT_OF_DATE:
exitcode = 1
elif exitcode == EXCEEDED_MAX_RETRIES:
@@ -476,7 +266,6 @@ class RsyncSync(SyncBase):
msg.append("(and possibly your system's
filesystem) configuration.")
for line in msg:
out.eerror(line)
- return (exitcode, updatecache_flg)
def new(self, **kwargs):
@@ -491,3 +280,240 @@ class RsyncSync(SyncBase):
return (1, False)
return self._sync()
+
+ def _set_rsync_defaults(self):
+ portage.writemsg("PORTAGE_RSYNC_OPTS empty or unset, using
hardcoded defaults\n")
+ rsync_opts = [
+ "--recursive", # Recurse directories
+ "--links", # Consider symlinks
+ "--safe-links", # Ignore links outside of tree
+ "--perms", # Preserve permissions
+ "--times", # Preserive mod times
+ "--omit-dir-times",
+ "--compress", # Compress the data transmitted
+ "--force", # Force deletion on non-empty dirs
+ "--whole-file", # Don't do block transfers, only
entire files
+ "--delete", # Delete files that aren't in the
master tree
+ "--stats", # Show final statistics about what
was transfered
+ "--human-readable",
+ "--timeout="+str(self.timeout), # IO timeout if not
done in X seconds
+ "--exclude=/distfiles", # Exclude distfiles from
consideration
+ "--exclude=/local", # Exclude local from
consideration
+ "--exclude=/packages", # Exclude packages from
consideration
+ ]
+ return rsync_opts
+
+
+ def _validate_rsync_opts(self, rsync_opts, syncuri):
+ # The below validation is not needed when using the above
hardcoded
+ # defaults.
+
+ portage.writemsg("Using PORTAGE_RSYNC_OPTS instead of hardcoded
defaults\n", 1)
+ rsync_opts.extend(portage.util.shlex_split(
+ self.settings.get("PORTAGE_RSYNC_OPTS", "")))
+ for opt in ("--recursive", "--times"):
+ if opt not in rsync_opts:
+ portage.writemsg(yellow("WARNING:") + " adding
required option " + \
+ "%s not included in PORTAGE_RSYNC_OPTS\n" % opt)
+ rsync_opts.append(opt)
+
+ for exclude in ("distfiles", "local", "packages"):
+ opt = "--exclude=/%s" % exclude
+ if opt not in rsync_opts:
+ portage.writemsg(yellow("WARNING:") + \
+ " adding required option %s not included in "
% opt + \
+ "PORTAGE_RSYNC_OPTS (can be overridden with
--exclude='!')\n")
+ rsync_opts.append(opt)
+
+ if syncuri.rstrip("/").endswith(".gentoo.org/gentoo-portage"):
+ def rsync_opt_startswith(opt_prefix):
+ for x in rsync_opts:
+ if x.startswith(opt_prefix):
+ return (1, False)
+ return (0, False)
+
+ if not rsync_opt_startswith("--timeout="):
+ rsync_opts.append("--timeout=%d" % self.timeout)
+
+ for opt in ("--compress", "--whole-file"):
+ if opt not in rsync_opts:
+ portage.writemsg(yellow("WARNING:") + "
adding required option " + \
+ "%s not included in
PORTAGE_RSYNC_OPTS\n" % opt)
+ rsync_opts.append(opt)
+ return rsync_opts
+
+
+ @staticmethod
+ def _rsync_opts_extend(opts, rsync_opts):
+ if "--quiet" in opts:
+ rsync_opts.append("--quiet") # Shut up a lot
+ else:
+ rsync_opts.append("--verbose") # Print filelist
+
+ if "--verbose" in opts:
+ rsync_opts.append("--progress") # Progress meter for
each file
+
+ if "--debug" in opts:
+ rsync_opts.append("--checksum") # Force checksum on all
files
+ return rsync_opts
+
+
+ def _do_rsync(self, syncuri, timestamp, opts):
+ is_synced = False
+ if timestamp != 0 and "--quiet" not in opts:
+ print(">>> Checking server timestamp ...")
+
+ rsynccommand = [self.bin_command] + self.rsync_opts +
self.extra_rsync_opts
+
+ if self.proto == 'ssh' and self.ssh_opts:
+ rsynccommand.append("--rsh=ssh " + self.ssh_opts)
+
+ if "--debug" in opts:
+ print(rsynccommand)
+
+ exitcode = os.EX_OK
+ servertimestamp = 0
+ # Even if there's no timestamp available locally, fetch the
+ # timestamp anyway as an initial probe to verify that the
server is
+ # responsive. This protects us from hanging indefinitely on a
+ # connection attempt to an unresponsive server which rsync's
+ # --timeout option does not prevent.
+
+ #if True:
+ # Temporary file for remote server timestamp comparison.
+ # NOTE: If FEATURES=usersync is enabled then the tempfile
+ # needs to be in a directory that's readable by the usersync
+ # user. We assume that PORTAGE_TMPDIR will satisfy this
+ # requirement, since that's not necessarily true for the
+ # default directory used by the tempfile module.
+ if self.usersync_uid is not None:
+ tmpdir = self.settings['PORTAGE_TMPDIR']
+ else:
+ # use default dir from tempfile module
+ tmpdir = None
+ fd, tmpservertimestampfile = \
+ tempfile.mkstemp(dir=tmpdir)
+ os.close(fd)
+ if self.usersync_uid is not None:
+ portage.util.apply_permissions(tmpservertimestampfile,
+ uid=self.usersync_uid)
+ command = rsynccommand[:]
+ command.append(syncuri.rstrip("/") + \
+ "/metadata/timestamp.chk")
+ command.append(tmpservertimestampfile)
+ content = None
+ pids = []
+ try:
+ # Timeout here in case the server is unresponsive. The
+ # --timeout rsync option doesn't apply to the initial
+ # connection attempt.
+ try:
+ if self.rsync_initial_timeout:
+ portage.exception.AlarmSignal.register(
+ self.rsync_initial_timeout)
+
+ pids.extend(portage.process.spawn(
+ command, returnpid=True,
+
**portage._native_kwargs(self.spawn_kwargs)))
+ exitcode = os.waitpid(pids[0], 0)[1]
+ if self.usersync_uid is not None:
+
portage.util.apply_permissions(tmpservertimestampfile,
+ uid=os.getuid())
+ content =
portage.grabfile(tmpservertimestampfile)
+ finally:
+ if self.rsync_initial_timeout:
+
portage.exception.AlarmSignal.unregister()
+ try:
+ os.unlink(tmpservertimestampfile)
+ except OSError:
+ pass
+ except portage.exception.AlarmSignal:
+ # timed out
+ print('timed out')
+ # With waitpid and WNOHANG, only check the
+ # first element of the tuple since the second
+ # element may vary (bug #337465).
+ if pids and os.waitpid(pids[0], os.WNOHANG)[0] == 0:
+ os.kill(pids[0], signal.SIGTERM)
+ os.waitpid(pids[0], 0)
+ # This is the same code rsync uses for timeout.
+ exitcode = 30
+ else:
+ if exitcode != os.EX_OK:
+ if exitcode & 0xff:
+ exitcode = (exitcode & 0xff) << 8
+ else:
+ exitcode = exitcode >> 8
+
+ if content:
+ try:
+ servertimestamp = time.mktime(time.strptime(
+ content[0], TIMESTAMP_FORMAT))
+ except (OverflowError, ValueError):
+ pass
+ del command, pids, content
+
+ if exitcode == os.EX_OK:
+ if (servertimestamp != 0) and (servertimestamp ==
timestamp):
+ self.logger(self.xterm_titles,
+ ">>> Cancelling sync -- Already
current.")
+ print()
+ print(">>>")
+ print(">>> Timestamps on the server and in the
local repository are the same.")
+ print(">>> Cancelling all further sync action.
You are already up to date.")
+ print(">>>")
+ print(">>> In order to force sync, remove
'%s'." % self.servertimestampfile)
+ print(">>>")
+ print()
+ return is_synced, exitcode
+ elif (servertimestamp != 0) and (servertimestamp <
timestamp):
+ self.logger(self.xterm_titles,
+ ">>> Server out of date: %s" % syncuri)
+ print()
+ print(">>>")
+ print(">>> SERVER OUT OF DATE: %s" % syncuri)
+ print(">>>")
+ print(">>> In order to force sync, remove
'%s'." % self.servertimestampfile)
+ print(">>>")
+ print()
+ exitcode = SERVER_OUT_OF_DATE
+ elif (servertimestamp == 0) or (servertimestamp >
timestamp):
+ # actual sync
+ command = rsynccommand + [syncuri+"/",
self.repo.location]
+ exitcode = None
+ try:
+ exitcode =
portage.process.spawn(command,
+
**portage._native_kwargs(self.spawn_kwargs))
+ finally:
+ if exitcode is None:
+ # interrupted
+ exitcode = 128 + signal.SIGINT
+
+ # 0 Success
+ # 1 Syntax or usage error
+ # 2 Protocol incompatibility
+ # 5 Error starting client-server
protocol
+ # 35 Timeout waiting for daemon
connection
+ if exitcode not in (0, 1, 2, 5, 35):
+ # If the exit code is not among
those listed above,
+ # then we may have a
partial/inconsistent sync
+ # state, so our previously read
timestamp as well
+ # as the corresponding file can
no longer be
+ # trusted.
+ timestamp = 0
+ try:
+
os.unlink(self.servertimestampfile)
+ except OSError:
+ pass
+
+ if exitcode in [0,1,3,4,11,14,20,21]:
+ is_synced = True
+ elif exitcode in [1,3,4,11,14,20,21]:
+ is_synced = True
+ else:
+ # Code 2 indicates protocol incompatibility, which is
expected
+ # for servers with protocol < 29 that don't support
+ # --prune-empty-directories. Retry for a server that
supports
+ # at least rsync protocol version 29 (>=rsync-2.6.4).
+ pass
+ return is_synced, exitcode
