@@ -46,8 +46,10 @@ class ThreadPool(object):

 class MultiPartUpload(object):

-    MAX_CHUNK_SIZE = 5368709120 # 5GB

+    MIN_CHUNK_SIZE_MB = 5       # 5MB

+    MAX_CHUNK_SIZE_MB = 5120    # 5GB

     MAX_CHUNKS = 100

+    MAX_FILE_SIZE = 42949672960 # 5TB

     def __init__(self, s3, file, uri):

         self.s3 = s3

@@ -355,7 +355,7 @@ class S3(object):

         multipart = False

         if self.config.enable_multipart:

-            if size > 2 * self.config.multipart_chunk_size:

+            if size > self.config.multipart_chunk_size:

                 multipart = True

         if multipart:

@@ -746,10 +746,7 @@ class S3(object):

         bucket, key, upload_id = upload.initiate_multipart_upload()

         num_threads = self.config.multipart_num_threads

-        chunk_size = self.config.multipart_chunk_size or MultiPartUpload.MIN_CHUNK_SIZE

-

-        if chunk_size > MultiPartUpload.MAX_CHUNK_SIZE:

-            raise RuntimeError("Chunk size is too large (%i bytes, max %i). Please adjust with --multipart-chunk-size=SIZE." % (size, MultiPartUpload.MAX_CHUNK_SIZE))

+        chunk_size = self.config.multipart_chunk_size

         file.seek(0)

         upload.upload_all_parts(num_threads, chunk_size)

@@ -1527,7 +1527,7 @@ def main():

     optparser.add_option(      "--verbatim", dest="urlencoding_mode", action="store_const", const="verbatim", help="Use the S3 name as given on the command line. No pre-processing, encoding, etc. Use with caution!")

     optparser.add_option(      "--disable-multipart", dest="enable_multipart", action="store_false", help="Disable multipart upload on files bigger than --multipart-chunk-size")

-    optparser.add_option(      "--multipart-chunk-size", dest="multipart_chunk_size", action="store", metavar="SIZE", help="Size of each chunk of a multipart upload. Files bigger than 2*SIZE are automatically uploaded as multithreaded-multipart, smaller files are uploaded using the traditional method. SIZE is in Bytes.")

+    optparser.add_option(      "--multipart-chunk-size", dest="multipart_chunk_size", type="int", action="store", metavar="SIZE", help="Size of each chunk of a multipart upload. Files bigger than SIZE are automatically uploaded as multithreaded-multipart, smaller files are uploaded using the traditional method. SIZE is in Mega-Bytes, default chunk size is %defaultMB, minimum allowed chunk size is 5MB, maximum is 5GB.")

     optparser.add_option(      "--list-md5", dest="list_md5", action="store_true", help="Include MD5 sums in bucket listings (only for 'ls' command).")

     optparser.add_option("-H", "--human-readable-sizes", dest="human_readable_sizes", action="store_true", help="Print sizes in human readable form (eg 1kB instead of 1234).")

@@ -1652,6 +1652,12 @@ def main():

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

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

+    ## Check multipart chunk constraints

+    if cfg.multipart_chunk_size < MultiPartUpload.MIN_CHUNK_SIZE_MB:

+        raise ParameterError("Chunk size %d MB is too small, must be >= %d MB. Please adjust --multipart-chunk-size" % (cfg.multipart_chunk_size, MultiPartUpload.MIN_CHUNK_SIZE_MB))

+    if cfg.multipart_chunk_size > MultiPartUpload.MAX_CHUNK_SIZE_MB:

+        raise ParameterError("Chunk size %d MB is too large, must be <= %d MB. Please adjust --multipart-chunk-size" % (cfg.multipart_chunk_size, MultiPartUpload.MAX_CHUNK_SIZE_MB))

+

     ## CloudFront's cf_enable and Config's enable share the same --enable switch

     options.cf_enable = options.enable

@@ -1789,6 +1795,7 @@ if __name__ == '__main__':

         from S3.CloudFront import Cmd as CfCmd

         from S3.CloudFront import CloudFront

         from S3.FileLists import *

+        from S3.MultiPart import MultiPartUpload

         main()

         sys.exit(0)