@@ -87,6 +87,7 @@ class Config(object):

     website_error = ""

     website_endpoint = "http://%(bucket)s.s3-website-%(location)s.amazonaws.com/"

     additional_destinations = []

+    cache_file = ""

     ## Creating a singleton

     def __new__(self, configfile = None):

@@ -9,6 +9,7 @@ from S3Uri import S3Uri

 from SortedDict import SortedDict

 from Utils import *

 from Exceptions import ParameterError

+from HashCache import HashCache

 from logging import debug, info, warning, error

@@ -137,7 +138,7 @@ def handle_exclude_include_walk(root, dirs, files):

             debug(u"PASS: %s" % (file))

 def fetch_local_list(args, recursive = None):

-    def _get_filelist_local(loc_list, local_uri):

+    def _get_filelist_local(loc_list, local_uri, cache):

         info(u"Compiling list of local files...")

         if local_uri.isdir():

             local_base = deunicodise(local_uri.basename())

@@ -180,11 +181,30 @@ def fetch_local_list(args, recursive = None):

                     ## TODO: Possibly more to save here...

                 }

 		if 'md5' in cfg.sync_checks:

-		    md5 = loc_list.get_md5(relative_file)

+                    md5 = cache.md5(sr.st_dev, sr.st_ino, sr.st_mtime, sr.st_size)

+		    if md5 is None:

+                        md5 = loc_list.get_md5(relative_file) # this does the file I/O

+			cache.add(sr.st_dev, sr.st_ino, sr.st_mtime, sr.st_size, md5)

 		    loc_list.record_hardlink(relative_file, sr.st_dev, sr.st_ino, md5)

         return loc_list, single_file

+    def _maintain_cache(cache, local_list):

+        if cfg.cache_file:

+            cache.mark_all_for_purge()

+	    for i in local_list.keys():

+                cache.unmark_for_purge(local_list[i]['dev'], local_list[i]['inode'], local_list[i]['mtime'], local_list[i]['size'])

+            cache.purge()

+	    cache.save(cfg.cache_file)

+

     cfg = Config()

+

+    cache = HashCache()

+    if cfg.cache_file:

+        try:

+            cache.load(cfg.cache_file)

+	except IOError:

+	    info(u"No cache file found, creating it.")

+    

     local_uris = []

     local_list = SortedDict(ignore_case = False)

     single_file = False

@@ -204,7 +224,7 @@ def fetch_local_list(args, recursive = None):

         local_uris.append(uri)

     for uri in local_uris:

-        list_for_uri, single_file = _get_filelist_local(local_list, uri)

+        list_for_uri, single_file = _get_filelist_local(local_list, uri, cache)

     ## Single file is True if and only if the user

     ## specified one local URI and that URI represents

@@ -214,6 +234,8 @@ def fetch_local_list(args, recursive = None):

     if len(local_list) > 1:

         single_file = False

+    _maintain_cache(cache, local_list)

+

     return local_list, single_file

 def fetch_remote_list(args, require_attribs = False, recursive = None):

new file mode 100644

@@ -0,0 +1,52 @@

+import cPickle as pickle

+

+class HashCache(object):

+    def __init__(self):

+        self.inodes = dict()

+    

+    def add(self, dev, inode, mtime, size, md5):

+        if dev not in self.inodes:

+            self.inodes[dev] = dict()

+        if inode not in self.inodes[dev]:

+            self.inodes[dev][inode] = dict()

+        self.inodes[dev][inode][mtime] = dict(md5=md5, size=size)

+

+    def md5(self, dev, inode, mtime, size):

+        try:

+            d = self.inodes[dev][inode][mtime]

+            if d['size'] != size:

+                return None

+        except:

+            return None

+        return d['md5']

+

+    def mark_all_for_purge(self):

+        for d in self.inodes.keys():

+            for i in self.inodes[d].keys():

+                for c in self.inodes[d][i].keys():

+                    self.inodes[d][i][c]['purge'] = True

+

+    def unmark_for_purge(self, dev, inode, mtime, size):

+        d = self.inodes[dev][inode][mtime]

+        if d['size'] == size and 'purge' in d:

+            del self.inodes[dev][inode][mtime]['purge']

+

+    def purge(self):

+        for d in self.inodes.keys():

+            for i in self.inodes[d].keys():

+                for m in self.inodes[d][i].keys():

+                    if 'purge' in self.inodes[d][i][m]:

+                        del self.inodes[d][i]

+    

+    def save(self, f):

+        d = dict(inodes=self.inodes, version=1)

+        f = open(f, 'w')

+        p = pickle.dump(d, f)

+        f.close()

+

+    def load(self, f):

+        f = open(f, 'r')

+        d = pickle.load(f)

+        f.close()

+        if d.get('version') == 1 and 'inodes' in d:

+            self.inodes = d['inodes']

@@ -1671,6 +1671,7 @@ def main():

     optparser.add_option("-d", "--debug", dest="verbosity", action="store_const", const=logging.DEBUG, help="Enable debug output.")

     optparser.add_option(      "--version", dest="show_version", action="store_true", help="Show s3cmd version (%s) and exit." % (PkgInfo.version))

     optparser.add_option("-F", "--follow-symlinks", dest="follow_symlinks", action="store_true", default=False, help="Follow symbolic links as if they are regular files")

+    optparser.add_option(      "--cache-file", dest="cache_file", action="store", default="",  metavar="FILE", help="Cache FILE containing local source MD5 values")

     optparser.set_usage(optparser.usage + " COMMAND [parameters]")

     optparser.set_description('S3cmd is a tool for managing objects in '+