openstack/deb-python-falcon
Code Issues Proposed changes

feat(req+resp): Add support for Content-Range units other than 'bytes'

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In RFC 2616 it says that "The only range unit defined by HTTP/1.1 is
"bytes". HTTP/1.1 implementations MAY ignore ranges specified using
other units.". Current falcon implementation only accepts 'bytes',
which does not work with some client implementations using different
range units. For example, dojo/store/JsonRest requires the server to
support 'items' as range unit.

Add a request property 'range_unit', which contains the range-unit
parsed from Range header. It enhances format_range to accept a range
unit as optional parameter in range tuple. This range unit default is
set to 'bytes' to not break current API.

Closes #570
This commit is contained in:
Peter Adam
2015-07-15 13:15:23 +02:00
committed by Kurt Griffiths
parent 960c23613c
commit 581f23bc83
5 changed files with 78 additions and 21 deletions
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32
falcon/request.py
View File

@@ -158,6 +158,8 @@ class Request(object):
Only continous ranges are supported (e.g., "bytes=0-0,-1" would
result in an HTTPBadRequest exception when the attribute is
accessed.)
range_unit (str): Unit of the range parsed from the value of the
Range header, or ``None`` if the header is missing
if_match (str): Value of the If-Match header, or ``None`` if the
header is missing.
if_none_match (str): Value of the If-None-Match header, or ``None``
@@ -371,20 +373,20 @@ class Request(object):
def range(self):
try:
value = self.env['HTTP_RANGE']
if value.startswith('bytes='):
value = value[6:]
if '=' in value:
unit, sep, req_range = value.partition('=')
else:
msg = "The value must be prefixed with 'bytes='"
msg = "The value must be prefixed with a range unit, e.g. 'bytes='"
raise HTTPInvalidHeader(msg, 'Range')
except KeyError:
return None
if ',' in value:
msg = 'The value must be a continuous byte range.'
if ',' in req_range:
msg = 'The value must be a continuous range.'
raise HTTPInvalidHeader(msg, 'Range')
try:
first, sep, last = value.partition('-')
first, sep, last = req_range.partition('-')
if not sep:
raise ValueError()
@@ -394,16 +396,30 @@ class Request(object):
elif last:
return (-int(last), -1)
else:
msg = 'The byte offsets are missing.'
msg = 'The range offsets are missing.'
raise HTTPInvalidHeader(msg, 'Range')
except ValueError:
href = 'http://goo.gl/zZ6Ey'
href_text = 'HTTP/1.1 Range Requests'
msg = ('It must be a byte range formatted according to RFC 2616.')
msg = ('It must be a range formatted according to RFC 7233.')
raise HTTPInvalidHeader(msg, 'Range', href=href,
href_text=href_text)
@property
def range_unit(self):
try:
value = self.env['HTTP_RANGE']
if '=' in value:
unit, sep, req_range = value.partition('=')
return unit
else:
msg = "The value must be prefixed with a range unit, e.g. 'bytes='"
raise HTTPInvalidHeader(msg, 'Range')
except KeyError:
return None
@property
def app(self):
return self.env.get('SCRIPT_NAME', '')

9
falcon/response.py
View File

@@ -509,10 +509,11 @@ class Response(object):
'Content-Range',
"""A tuple to use in constructing a value for the Content-Range header.
The tuple has the form (*start*, *end*, *length*), where *start* and
*end* designate the byte range (inclusive), and *length* is the
total number of bytes, or '\*' if unknown. You may pass ``int``'s for
these numbers (no need to convert to ``str`` beforehand).
The tuple has the form (*start*, *end*, *length*, [*unit*]), where *start* and
*end* designate the range (inclusive), and *length* is the
total length, or '\*' if unknown. You may pass ``int``'s for
these numbers (no need to convert to ``str`` beforehand). The optional value
*unit* describes the range unit and defaults to 'bytes'
Note:
You only need to use the alternate form, 'bytes \*/1234', for

8
falcon/response_helpers.py
View File

@@ -51,12 +51,16 @@ def format_range(value):
Args:
value: ``tuple`` passed to `req.range`
"""
# PERF: Concatenation is faster than % string formatting as well
# as ''.join() in this case.
return ('bytes ' +
if len(value) == 4:
unit = value[3] + ' '
else:
unit = 'bytes '
return (unit +
str(value[0]) + '-' +
str(value[1]) + '/' +
str(value[2]))

22
tests/test_headers.py
View File

@@ -64,8 +64,11 @@ class HeaderHelpersResource:
resp.location = '/things/87'
resp.content_location = '/things/78'
# bytes 0-499/10240
resp.content_range = (0, 499, 10 * 1024)
if req.range_unit is None or req.range_unit == 'bytes':
# bytes 0-499/10240
resp.content_range = (0, 499, 10 * 1024)
else:
resp.content_range = (0, 25, 100, req.range_unit)
self.resp = resp
@@ -347,6 +350,21 @@ class TestHeaders(testing.TestBase):
self.assertIn(('content-range', 'bytes 0-499/10240'),
self.srmock.headers)
resp.content_range = (0, 499, 10 * 1024, 'bytes')
self.assertEqual('bytes 0-499/10240', resp.content_range)
self.assertIn(('content-range', 'bytes 0-499/10240'),
self.srmock.headers)
req_headers = {
'Range': 'items=0-25',
}
self.simulate_request(self.test_route, headers=req_headers)
resp.content_range = (0, 25, 100, 'items')
self.assertEqual('items 0-25/100', resp.content_range)
self.assertIn(('content-range', 'items 0-25/100'),
self.srmock.headers)
# Check for duplicate headers
hist = defaultdict(lambda: 0)
for name, value in self.srmock.headers:

28
tests/test_req_vars.py
View File

@@ -403,6 +403,24 @@ class TestReqVars(testing.TestBase):
req = Request(testing.create_environ())
self.assertIs(req.range, None)
def test_range_unit(self):
headers = {'Range': 'bytes=10-'}
req = Request(testing.create_environ(headers=headers))
self.assertEqual(req.range, (10, -1))
self.assertEqual(req.range_unit, 'bytes')
headers = {'Range': 'items=10-'}
req = Request(testing.create_environ(headers=headers))
self.assertEqual(req.range, (10, -1))
self.assertEqual(req.range_unit, 'items')
headers = {'Range': ''}
req = Request(testing.create_environ(headers=headers))
self.assertRaises(falcon.HTTPInvalidHeader, lambda: req.range_unit)
req = Request(testing.create_environ())
self.assertIs(req.range_unit, None)
def test_range_invalid(self):
headers = {'Range': 'bytes=10240'}
req = Request(testing.create_environ(headers=headers))
@@ -410,7 +428,7 @@ class TestReqVars(testing.TestBase):
headers = {'Range': 'bytes=-'}
expected_desc = ('The value provided for the Range header is '
'invalid. The byte offsets are missing.')
'invalid. The range offsets are missing.')
self._test_error_details(headers, 'range',
falcon.HTTPInvalidHeader,
'Invalid header value', expected_desc)
@@ -461,8 +479,8 @@ class TestReqVars(testing.TestBase):
headers = {'Range': 'bytes=x-y'}
expected_desc = ('The value provided for the Range header is '
'invalid. It must be a byte range formatted '
'according to RFC 2616.')
'invalid. It must be a range formatted '
'according to RFC 7233.')
self._test_error_details(headers, 'range',
falcon.HTTPInvalidHeader,
'Invalid header value', expected_desc)
@@ -470,7 +488,7 @@ class TestReqVars(testing.TestBase):
headers = {'Range': 'bytes=0-0,-1'}
expected_desc = ('The value provided for the Range '
'header is invalid. The value must be a '
'continuous byte range.')
'continuous range.')
self._test_error_details(headers, 'range',
falcon.HTTPInvalidHeader,
'Invalid header value', expected_desc)
@@ -478,7 +496,7 @@ class TestReqVars(testing.TestBase):
headers = {'Range': '10-'}
expected_desc = ("The value provided for the Range "
"header is invalid. The value must be "
"prefixed with 'bytes='")
"prefixed with a range unit, e.g. 'bytes='")
self._test_error_details(headers, 'range',
falcon.HTTPInvalidHeader,
'Invalid header value', expected_desc)