Fix max-parts, part-number-marker, and encoding-type in queries of List Parts

I've fixed ToDo in qeuries of  List Part.

encoding-type: Requests Amazon S3 to encode the response and specifies the encoding method to use.
max-parts: Sets the maximum number of parts to return in the response body.
part-number-marker: Specifies the part after which listing should begin. Only parts with higher part numbers will be listed.

For details, refer to the following.
http://docs.aws.amazon.com/AmazonS3/latest/API/mpUploadListParts.html

Change-Id: I1a3b3a0aba188fcb928e89e78ad8859dbecca2e8

swift3/controllers/multi_upload.py

@@ -56,6 +56,7 @@ from swift3.exception import BadSwiftRequest
 from swift3.utils import LOGGER, unique_id, MULTIUPLOAD_SUFFIX
 from swift3.etree import Element, SubElement, fromstring, tostring, \
     XMLSyntaxError, DocumentInvalid
+from swift3.cfg import CONF
 
 DEFAULT_MAX_PARTS = 1000
 DEFAULT_MAX_UPLOADS = 1000
@@ -280,6 +281,13 @@ class UploadController(Controller):
         """
         Handles List Parts.
         """
+        def filter_part_num_marker(o):
+            try:
+                num = int(os.path.basename(o['name']))
+                return num > part_num_marker
+            except ValueError:
+                return False
+
         encoding_type = req.params.get('encoding-type')
         if encoding_type is not None and encoding_type != 'url':
             err_msg = 'Invalid Encoding Method specified in Request'
@@ -288,11 +296,43 @@ class UploadController(Controller):
         upload_id = req.params['uploadId']
         _check_upload_info(req, self.app, upload_id)
 
+        maxparts = DEFAULT_MAX_PARTS
         part_num_marker = 0
 
-        # TODO: add support for max-parts and part-number-marker queries.
+        if 'max-parts' in req.params:
+            try:
+                maxparts = int(req.params['max-parts'])
+                if maxparts < 0 or CONF.max_parts < maxparts:
+                    err_msg = 'Argument max-parts must be an integer between 0 and' \
+                              ' %d' % CONF.max_parts
+                    raise InvalidArgument('max-parts',
+                                          req.params['max-parts'],
+                                          err_msg)
+            except ValueError:
+                err_msg = 'Provided max-parts not an integer or within ' \
+                          'integer range'
+                raise InvalidArgument('max-parts', req.params['max-parts'],
+                                      err_msg)
+
+        if 'part-number-marker' in req.params:
+            try:
+                part_num_marker = int(req.params['part-number-marker'])
+                if part_num_marker < 0 or CONF.max_parts < part_num_marker:
+                    err_msg = 'Argument part-number-marker must be an integer ' \
+                              'between 0 and %d' % CONF.max_parts
+                    raise InvalidArgument('part-number-marker',
+                                          req.params['part-number-marker'],
+                                          err_msg)
+            except ValueError:
+                err_msg = 'Provided part-number-marker not an integer or ' \
+                          'within integer range'
+                raise InvalidArgument('part-number-marker',
+                                      req.params['part-number-marker'],
+                                      err_msg)
+
         query = {
             'format': 'json',
+            'limit': maxparts + 1,
             'prefix': '%s/%s/' % (req.object_name, upload_id),
             'delimiter': '/'
         }
@@ -304,11 +344,24 @@ class UploadController(Controller):
 
         last_part = 0
 
-        # pylint: disable-msg=E1103
-        objects.sort(key=lambda o: int(o['name'].split('/')[-1]))
+        # If the caller requested a list starting at a specific part number,
+        # construct a sub-set of the object list.
+        objList = filter(filter_part_num_marker, objects)
 
-        if len(objects) > 0:
-            o = objects[-1]
+        # pylint: disable-msg=E1103
+        objList.sort(key=lambda o: int(o['name'].split('/')[-1]))
+
+        if len(objList) > maxparts:
+            objList = objList[:maxparts]
+            truncated = True
+        else:
+            truncated = False
+        # TODO: We have to retrieve object list again when truncated is True
+        # and some objects filtered by invalid name because there could be no
+        # enough objects for limit defined by maxparts.
+
+        if objList:
+            o = objList[-1]
             last_part = os.path.basename(o['name'])
 
         result_elem = Element('ListPartsResult')
@@ -326,11 +379,14 @@ class UploadController(Controller):
         SubElement(result_elem, 'StorageClass').text = 'STANDARD'
         SubElement(result_elem, 'PartNumberMarker').text = str(part_num_marker)
         SubElement(result_elem, 'NextPartNumberMarker').text = str(last_part)
-        SubElement(result_elem, 'MaxParts').text = str(DEFAULT_MAX_PARTS)
-        # TODO: add support for EncodingType
-        SubElement(result_elem, 'IsTruncated').text = 'false'
+        SubElement(result_elem, 'MaxParts').text = str(maxparts)
+        if 'encoding-type' in req.params:
+            SubElement(result_elem, 'EncodingType').text = \
+                req.params['encoding-type']
+        SubElement(result_elem, 'IsTruncated').text = \
+            'true' if truncated else 'false'
 
-        for i in objects:
+        for i in objList:
             part_elem = SubElement(result_elem, 'Part')
             SubElement(part_elem, 'PartNumber').text = i['name'].split('/')[-1]
             SubElement(part_elem, 'LastModified').text = \