[repoapi] fold ClientConnection into Connection Connection replaces ClientConnection everywhere. Some notes: * testlib: .client_cnx and .repo_cnx become aliases of .cnx (we might not want to tell people to update their tests again for just no real benefit, so we'll live with these aliases for a while) * entity.as_rset must not be cached because we risk caching result sets having a Connection object as .req (helps unittest_breadcrumbs) * entity._cw_dont_cache_attributes loses its repo/request special paths and only keeps its storage/bfss user (this helps unittest_wfobjs) * moreover, entity.cw_instantiate and .cw_set stop overriding the attributes cache *after* the before_*_entity hooks have run, because there is no need to (it is now actually harmful to do it and unittest_hooks.test_html_tidy* tests remain green because of this) * rset._build_entity sticks its .req onto the entity just fetched from the cache, because otherwise it might carry a _cw that is a Connection object where a Request is expected (helps unittest_views_actions) * we get overall better cache usages (entity caches were split over Request + ClientConnection and Connection), hence the changes unittest_entity and unittest_wfobjs * void the ecache when providing the cnx to a request object Having the entity cache pre-filled when we bind it to the request object hurts because these entities are bound to Connection objects, that lack e.g. `.form` or `.add_js` and crash the views subsystem. Thus, the unittest_testlib.test_error_raised test will are kept green. Closes #3837233

"""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"

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)