Assemble similar stuffs into a validation method

Currently, controllers have similar stuffs to validate
query parameter either to limit the listing result or
to make a marker starts with next to it.

This patch intoduces a validation method 'get_validated_param'
for those stuffs to get a pre-validated value with some parameters
(e.g. default, limit) to keep the code clean.

Change-Id: Ia5e939ee342bf4fb8533f1aa97419f5aad9b7fe1

swift3/controllers/bucket.py

@@ -45,11 +45,9 @@ class BucketController(Controller):
         """
         Handle GET Bucket (List Objects) request
         """
-        if 'max-keys' in req.params:
-            if req.params.get('max-keys').isdigit() is False:
-                raise InvalidArgument('max-keys', req.params['max-keys'])
 
-        max_keys = int(req.params.get('max-keys', CONF.max_bucket_listing))
+        max_keys = req.get_validated_param('max-keys', CONF.max_bucket_listing)
+        # TODO: Separate max_bucket_listing and default_bucket_listing
         max_keys = min(max_keys, CONF.max_bucket_listing)
 
         encoding_type = req.params.get('encoding-type')

swift3/controllers/multi_upload.py

@@ -145,20 +145,8 @@ class UploadsController(Controller):
 
         keymarker = req.params.get('key-marker', '')
         uploadid = req.params.get('upload-id-marker', '')
-        maxuploads = DEFAULT_MAX_UPLOADS
-
-        if 'max-uploads' in req.params:
-            try:
-                maxuploads = int(req.params['max-uploads'])
-                if maxuploads < 0 or DEFAULT_MAX_UPLOADS < maxuploads:
-                    err_msg = 'Argument max-uploads must be an integer ' \
-                              'between 0 and %d' % DEFAULT_MAX_UPLOADS
-                    raise InvalidArgument('max-uploads', maxuploads, err_msg)
-            except ValueError:
-                err_msg = 'Provided max-uploads not an integer or within ' \
-                          'integer range'
-                raise InvalidArgument('max-uploads', req.params['max-uploads'],
-                                      err_msg)
+        maxuploads = req.get_validated_param(
+            'max-uploads', DEFAULT_MAX_UPLOADS, DEFAULT_MAX_UPLOADS)
 
         query = {
             'format': 'json',
@@ -296,39 +284,10 @@ class UploadController(Controller):
         upload_id = req.params['uploadId']
         _check_upload_info(req, self.app, upload_id)
 
-        maxparts = DEFAULT_MAX_PARTS
-        part_num_marker = 0
-
-        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)
+        maxparts = req.get_validated_param(
+            'max-parts', DEFAULT_MAX_PARTS, CONF.max_parts)
+        part_num_marker = req.get_validated_param(
+            'part-number-marker', 0, CONF.max_parts)
 
         query = {
             'format': 'json',

swift3/request.py

@@ -652,6 +652,24 @@ class Request(swob.Request):
         return self._get_response(app, method, container, obj,
                                   headers, body, query)
 
+    def get_validated_param(self, param, default, limit=None):
+        value = default
+        if param in self.params:
+            try:
+                value = int(self.params[param])
+                if value < 0 or (limit is not None and limit < value):
+                    err_msg = 'Argument %s must be an integer between 0 and' \
+                              ' %d' % (param, limit)
+                    raise InvalidArgument(param,
+                                          self.params[param],
+                                          err_msg)
+            except ValueError:
+                err_msg = 'Provided %s not an integer or within ' \
+                          'integer range' % param
+                raise InvalidArgument(param, self.params[param],
+                                      err_msg)
+        return value
+
 
 class S3AclRequest(Request):
     """

swift3/test/unit/test_request.py

@@ -24,6 +24,7 @@ from swift3.test.unit.test_middleware import Swift3TestCase
 from swift3.cfg import CONF
 from swift3.request import Request as S3_Request
 from swift3.request import S3AclRequest
+from swift3.response import InvalidArgument
 
 
 Fake_ACL_MAP = {
@@ -160,6 +161,24 @@ class TestRequest(Swift3TestCase):
         permission = args[1]
         self.assertEqual(permission, 'READ')
 
+    def test_get_validate_param(self):
+        def create_s3request_with_param(param, value):
+            req = Request.blank(
+                '/bucket?%s=%s' % (param, value),
+                environ={'REQUEST_METHOD': 'GET'},
+                headers={'Authorization': 'AWS test:tester:hmac'})
+            return S3_Request(req.environ, True)
+
+        s3req = create_s3request_with_param('max-keys', '1')
+
+        # a param in the range
+        self.assertEquals(s3req.get_validated_param('max-keys', 1000, 1000), 1)
+        self.assertEquals(s3req.get_validated_param('max-keys', 0, 1), 1)
+
+        # a param in the out of the range
+        with self.assertRaises(InvalidArgument):
+            s3req.get_validated_param('max-keys', 0, 0)
+
 
 if __name__ == '__main__':
     unittest.main()