@@ -30,6 +30,7 @@ class Config(object):

     send_chunk = 4096

     recv_chunk = 4096

     list_md5 = False

+    md5_xattr = None

     human_readable_sizes = False

     extra_headers = SortedDict(ignore_case = True)

     force = False

@@ -16,6 +16,12 @@ import base64

 import errno

 import urllib

+try:

+    import xattr

+    have_xattr = True

+except:

+    have_xattr = False

+

 from logging import debug, info, warning, error

@@ -227,6 +233,18 @@ def mktmpfile(prefix = "/tmp/tmpfile-", randchars = 20):

 __all__.append("mktmpfile")

 def hash_file_md5(filename):

+    md5_xattr = Config.Config().md5_xattr

+    if have_xattr and md5_xattr is not None:

+        try:

+            md5sum = xattr.get(filename, md5_xattr, namespace=xattr.NS_USER)

+            debug("xattr.get(%s, %s) returned %s" % (filename, md5_xattr, md5sum))

+            return md5sum

+        except:

+            pass

+    return hash_file_md5_io(filename)

+__all__.append("hash_file_md5")

+

+def hash_file_md5_io(filename):

     h = md5()

     f = open(filename, "rb")

     while True:

@@ -237,7 +255,6 @@ def hash_file_md5(filename):

         h.update(data)

     f.close()

     return h.hexdigest()

-__all__.append("hash_file_md5")

 def mkdir_with_parents(dir_name):

     """

@@ -12,6 +12,7 @@ import re

 from subprocess import Popen, PIPE, STDOUT

 import locale

 import pwd

+import xattr

 count_pass = 0

 count_fail = 0

@@ -25,8 +26,10 @@ verbose = False

 if os.name == "posix":

     have_wget = True

+    have_md5sum = True

 elif os.name == "nt":

     have_wget = False

+    have_md5sum = False

 else:

     print "Unknown platform: %s" % os.name

     sys.exit(1)

@@ -404,6 +407,15 @@ test_s3cmd("Don't check MD5", ['sync', 'testsuite/', 's3://%s/xyz/' % bucket(1),

 test_s3cmd("Check MD5", ['sync', 'testsuite/', 's3://%s/xyz/' % bucket(1), '--no-encrypt', '--check-md5'],

     must_find = [ "cksum1.txt" ])

+## ====== Check MD5 sum on Sync with Extended Attributes

+if 'xattr' in sys.modules.keys() and have_md5sum:

+    os.system("echo 1234566789012 > testsuite/checksum/cksum4.txt")

+    test_s3cmd("Overwrite cksum1.txt", ['put', 'testsuite/checksum/cksum4.txt', 's3://%s/xyz/checksum/cksum1.txt' % bucket(1), '--no-encrypt' ])

+    os.system("rm testsuite/checksum/cksum4.txt")

+    os.system("attr -s md5sum -V $(md5sum testsuite/checksum/cksum1.txt | awk '{print $1}') testsuite/checksum/cksum1.txt > /dev/null")

+    test_s3cmd("Check MD5 with xattr", ['sync', 'testsuite/', 's3://%s/xyz/' % bucket(1), '--no-encrypt', '--check-md5', '--xattr=md5sum'],

+               must_find = [ "cksum1.txt" ])

+

 ## ====== Rename within S3

 test_s3cmd("Rename within S3", ['mv', '%s/xyz/etc/logo.png' % pbucket(1), '%s/xyz/etc2/Logo.PNG' % pbucket(1)],

@@ -26,6 +26,8 @@ import socket

 import shutil

 import tempfile

 import S3.Exceptions

+try: import xattr

+except: pass

 from copy import copy

 from optparse import OptionParser, Option, OptionValueError, IndentedHelpFormatter

@@ -1806,6 +1808,8 @@ def main():

     optparser.add_option(      "--skip-existing", dest="skip_existing", action="store_true", help="Skip over files that exist at the destination (only for [get] and [sync] commands).")

     optparser.add_option("-r", "--recursive", dest="recursive", action="store_true", help="Recursive upload, download or removal.")

     optparser.add_option(      "--check-md5", dest="check_md5", action="store_true", help="Check MD5 sums when comparing files for [sync]. (default)")

+    if 'xattr' in sys.modules.keys():

+        optparser.add_option  ("--xattr", dest="md5_xattr", metavar="ATTR", action="store", default=None, help="If possible, use extended file attribute ATTR from the user namespace containing the md5sum for the file, instead of calculating it [sync].")

     optparser.add_option(      "--no-check-md5", dest="check_md5", action="store_false", help="Do not check MD5 sums when comparing files for [sync]. Only size will be compared. May significantly speed up transfer but may also miss some changed files.")

     optparser.add_option("-P", "--acl-public", dest="acl_public", action="store_true", help="Store objects with ACL allowing read for anyone.")

     optparser.add_option(      "--acl-private", dest="acl_public", action="store_false", help="Store objects with default ACL allowing access for you only.")

@@ -1988,6 +1992,7 @@ def main():

     ## Special handling for tri-state options (True, False, None)

     cfg.update_option("enable", options.enable)

     cfg.update_option("acl_public", options.acl_public)

+    cfg.update_option("md5_xattr", options.md5_xattr)

     ## Check multipart chunk constraints

     if cfg.multipart_chunk_size_mb < MultiPartUpload.MIN_CHUNK_SIZE_MB:

@@ -165,6 +165,9 @@ Check MD5 sums when comparing files for [sync]. (default)

 \fB\-\-no\-check\-md5\fR

 Do not check MD5 sums when comparing files for [sync]. Only size will be compared. May significantly speed up transfer but may also miss some changed files.

 .TP

+\fB-\-xattr\fR=ATTR

+If possible, use extended file attribute ATTR from the user namespace containing the md5sum for the file, instead of calculating it [sync].

+.TP

 \fB\-P\fR, \fB\-\-acl\-public\fR

 Store objects with ACL allowing read for anyone.

 .TP