[repo, undo] Finish repository-side implementation of the undo feature (closes #893940)
1) Changes API for undo_transaction in order to raise an exception:
the previous API returned a sequence of error, the user of the API
needed to be careful to check explicitly. We change this for it to
raise an UndoException with the list of errors as an attribute.
2) The server-side support for undoing update actions is finished
3) The configuration for `undo-support` is now a simple boolean
Beware of the costs, both in DB space and in number of requests
on the RDBMS backend, once this feture is activated.
4) Adds a txuuid param/attribute to the existing NoSuchTransaction
exception.
"""twisted server for CubicWeb web instances
:organization: Logilab
:copyright: 2001-2011 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""
__docformat__ = "restructuredtext en"
from cubicweb.web.http_headers import Headers
class HTTPResponse(object):
"""An object representing an HTTP Response to be sent to the client.
"""
def __init__(self, twisted_request, code=None, headers=None, stream=None):
self._headers_out = headers
self._twreq = twisted_request
self._stream = stream
self._code = code
self._init_headers()
self._finalize()
def _init_headers(self):
if self._headers_out is None:
return
# initialize headers
for k, values in self._headers_out.getAllRawHeaders():
self._twreq.responseHeaders.setRawHeaders(k, values)
# add content-length if not present
if (self._headers_out.getHeader('content-length') is None
and self._stream is not None):
self._twreq.setHeader('content-length', len(self._stream))
def _finalize(self):
# we must set code before writing anything, else it's too late
if self._code is not None:
self._twreq.setResponseCode(self._code)
if self._stream is not None:
self._twreq.write(str(self._stream))
self._twreq.finish()
def __repr__(self):
return "<%s.%s code=%d>" % (self.__module__, self.__class__.__name__, self._code)
def not_modified_response(twisted_request, headers_in):
headers_out = Headers()
for header in (
# Required from sec 10.3.5:
'date', 'etag', 'content-location', 'expires',
'cache-control', 'vary',
# Others:
'server', 'proxy-authenticate', 'www-authenticate', 'warning'):
value = headers_in.getRawHeaders(header)
if value is not None:
headers_out.setRawHeaders(header, value)
return HTTPResponse(twisted_request=twisted_request,
headers=headers_out)