Mercurial > libervia-backend
diff src/tmp/wokkel/rsm.py @ 1266:9141bde7ff31
use sat.tmp.wokkel as a buffer module until the changes are integrated to wokkel
author | souliane <souliane@mailoo.org> |
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date | Mon, 15 Dec 2014 12:46:58 +0100 |
parents | |
children | 7d9ff14a2d9d |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/tmp/wokkel/rsm.py Mon Dec 15 12:46:58 2014 +0100 @@ -0,0 +1,349 @@ +# -*- test-case-name: wokkel.test.test_rsm -*- +# +# Copyright (c) Adrien Cossa. +# See LICENSE for details. + +""" +XMPP Result Set Management protocol. + +This protocol is specified in +U{XEP-0059<http://xmpp.org/extensions/xep-0059.html>}. +""" + +from twisted.python import log +from twisted.words.xish import domish + +import pubsub +import copy + + +# RSM namespace +NS_RSM = 'http://jabber.org/protocol/rsm' + + +class RSMRequest(): + """ + A Result Set Management request. + + @ivar max: limit on the number of retrieved items. + @itype max: C{int} or C{unicode} + + @ivar index: starting index of the requested page. + @itype index: C{int} or C{unicode} + + @ivar after: ID of the element immediately preceding the page. + @itype after: C{unicode} + + @ivar before: ID of the element immediately following the page. + @itype before: C{unicode} + """ + + max = 10 + index = None + after = None + before = None + + def __init__(self, max=None, index=None, after=None, before=None): + if max is not None: + max = int(max) + assert(max >= 0) + self.max = max + + if index is not None: + assert(after is None and before is None) + index = int(index) + assert(index >= 0) + self.index = index + + if after is not None: + assert(before is None) + assert(isinstance(after, unicode)) + self.after = after + + if before is not None: + assert(isinstance(before, unicode)) + self.before = before + + @classmethod + def parse(cls, element): + """Parse the given request element. + + @param element: request containing a set element. + @type element: L{domish.Element} + + @return: RSMRequest instance. + @rtype: L{RSMRequest} + """ + try: + set_elt = domish.generateElementsQNamed(element.elements(), + name="set", + uri=NS_RSM).next() + except StopIteration: + return None + + request = RSMRequest() + for elt in list(set_elt.elements()): + if elt.name in ('before', 'after'): + setattr(request, elt.name, ''.join(elt.children)) + elif elt.name in ('max', 'index'): + setattr(request, elt.name, int(''.join(elt.children))) + + if request.max is None: + log.err("RSM request is missing its 'max' element!") + + return request + + def render(self, element=None): + """Render a RSM page request, eventually embed it in the given element. + + @param element: request element. + @type element: L{domish.Element} + + @return: RSM request element. + @rtype: L{domish.Element} + """ + if element and element.name == 'pubsub' and hasattr(element, 'items'): + element.items.attributes['max_items'] = unicode(self.max) + + set_elt = domish.Element((NS_RSM, 'set')) + set_elt.addElement('max').addContent(unicode(self.max)) + + if self.index is not None: + set_elt.addElement('index').addContent(unicode(self.index)) + + if self.before is not None: + if self.before == '': # request the last page + set_elt.addElement('before') + else: + set_elt.addElement('before').addContent(self.before) + + if self.after is not None: + set_elt.addElement('after').addContent(self.after) + + if element: + element.addChild(set_elt) + + return set_elt + + +class RSMResponse(): + """ + A Result Set Management response. + + @ivar count: total number of items. + @itype count: C{int} + + @ivar index: starting index of the returned page. + @itype index: C{int} + + @ivar first: ID of the first element of the returned page. + @itype first: C{unicode} + + @ivar last: ID of the last element of the returned page. + @itype last: C{unicode} + """ + + count = 0 + index = None + first = None + last = None + + def __init__(self, count=None, index=None, first=None, last=None): + if count is not None: + assert(isinstance(count, int) and count >= 0) + self.count = count + + if index is not None: + assert(isinstance(index, int) and index >= 0) + self.index = index + assert(isinstance(first, unicode)) + self.first = first + assert(isinstance(last, unicode)) + self.last = last + else: + assert(first is None and last is None) + + @classmethod + def parse(cls, element): + """Parse the given response element. + + @param element: response element. + @type element: L{domish.Element} + + @return: RSMResponse instance. + @rtype: L{RSMResponse} + """ + try: + set_elt = domish.generateElementsQNamed(element.elements(), + name="set", + uri=NS_RSM).next() + except StopIteration: + return None + + response = RSMResponse() + for elt in list(set_elt.elements()): + if elt.name in ('first', 'last'): + setattr(response, elt.name, ''.join(elt.children)) + if elt.name == 'first': + response.index = int(elt.getAttribute("index")) + elif elt.name == 'count': + response.count = int(''.join(elt.children)) + + if response.count is None: + log.err("RSM response is missing its 'count' element!") + + return response + + def render(self, parent=None): + """Render a RSM page response, eventually embed it in the given element. + + @param element: response element. + @type element: L{domish.Element} + + @return: RSM request element. + @rtype: L{domish.Element} + """ + set_elt = domish.Element((NS_RSM, 'set')) + set_elt.addElement('count').addContent(unicode(self.count)) + + if self.index is not None: + first_elt = set_elt.addElement('first') + first_elt.addContent(self.first) + first_elt['index'] = unicode(self.index) + + set_elt.addElement('last').addContent(self.last) + + if parent: + parent.addChild(set_elt) + + return set_elt + + def toDict(self): + """Return a dict representation of the object. + + @return: a dict of strings. + @rtype: C{dict} binding C{unicode} to C{unicode} + """ + result = {} + for attr in ('count', 'index', 'first', 'last'): + value = getattr(self, attr) + if value is not None: + result[attr] = unicode(value) + return result + + +class PubSubRequest(pubsub.PubSubRequest): + """PubSubRequest extension to handle RSM. + + @ivar rsm: RSM request instance. + @type rsm: L{RSMRequest} + """ + + rsm = None + + def __init__(self, verb=None): + pubsub.PubSubRequest.__init__(self, verb) + self._parameters = copy.deepcopy(pubsub.PubSubRequest._parameters) + self._parameters['items'].append('rsm') + + def _parse_rsm(self, verbElement): + self.rsm = RSMRequest.parse(verbElement.parent) + + def _render_rsm(self, verbElement): + if self.rsm: + self.rsm.render(verbElement.parent) + + +class PubSubClient(pubsub.PubSubClient): + """PubSubClient extension to handle RSM.""" + + _rsm_responses = {} + + def items(self, service, nodeIdentifier, maxItems=None, itemIdentifiers=None, + subscriptionIdentifier=None, sender=None, ext_data=None): + """ + Retrieve previously published items from a publish subscribe node. + + @param service: The publish subscribe service that keeps the node. + @type service: L{JID<twisted.words.protocols.jabber.jid.JID>} + + @param nodeIdentifier: The identifier of the node. + @type nodeIdentifier: C{unicode} + + @param maxItems: Optional limit on the number of retrieved items. + @type maxItems: C{int} + + @param itemIdentifiers: Identifiers of the items to be retrieved. + @type itemIdentifiers: C{set} + + @param subscriptionIdentifier: Optional subscription identifier. In + case the node has been subscribed to multiple times, this narrows + the results to the specific subscription. + @type subscriptionIdentifier: C{unicode} + + @param ext_data: extension data. + @type ext_data: L{dict} + + @return: a Deferred that fires a C{list} of L{domish.Element}. + @rtype: L{defer.Deferred} + """ + request = PubSubRequest('items') # that's a rsm.PubSubRequest instance + request.recipient = service + request.nodeIdentifier = nodeIdentifier + if maxItems: + request.maxItems = str(int(maxItems)) + request.subscriptionIdentifier = subscriptionIdentifier + request.sender = sender + request.itemIdentifiers = itemIdentifiers + if ext_data and 'rsm' in ext_data: + request.rsm = ext_data['rsm'] + + def cb(iq): + items = [] + if iq.pubsub.items: + for element in iq.pubsub.items.elements(): + if element.uri == pubsub.NS_PUBSUB and element.name == 'item': + items.append(element) + + if request.rsm: + response = RSMResponse.parse(iq.pubsub) + if response is not None: + self._rsm_responses[ext_data['id']] = response + return items + + d = request.send(self.xmlstream) + d.addCallback(cb) + return d + + def getRSMResponse(self, id): + """ + Post-retrieve the RSM response data after items retrieval is done. + + @param id: extension data ID + @type id: C{unicode} + + @return: dict representation of the RSM response. + @rtype: C{dict} of C{unicode} + """ + # This method exists to not modify the return value of self.items. + if id not in self._rsm_responses: + return {} + result = self._rsm_responses[id].toDict() + del self._rsm_responses[id] + return result + + +class PubSubService(pubsub.PubSubService): + """PubSubService extension to handle RSM.""" + + _request_class = PubSubRequest + + def _toResponse_items(self, result, resource, request): + response = pubsub.PubSubService._toResponse_items(self, result, + resource, request) + set_elts = [elt for elt in result if elt.name == 'set'] + if set_elts: + assert(len(set_elts) == 1) + response.addChild(set_elts[0]) + + return response