diff options
Diffstat (limited to 'src/leap/soledad/client/http_target/support.py')
| -rw-r--r-- | src/leap/soledad/client/http_target/support.py | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/leap/soledad/client/http_target/support.py b/src/leap/soledad/client/http_target/support.py new file mode 100644 index 00000000..d8d8e420 --- /dev/null +++ b/src/leap/soledad/client/http_target/support.py @@ -0,0 +1,220 @@ +# -*- coding: utf-8 -*- +# support.py +# Copyright (C) 2015 LEAP +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. +import warnings +import json + +from twisted.internet import defer +from twisted.web.client import _ReadBodyProtocol +from twisted.web.client import PartialDownloadError +from twisted.web._newclient import ResponseDone +from twisted.web._newclient import PotentialDataLoss + +from leap.soledad.common.l2db import errors +from leap.soledad.common.l2db.remote import http_errors + +# we want to make sure that HTTP errors will raise appropriate u1db errors, +# that is, fire errbacks with the appropriate failures, in the context of +# twisted. Because of that, we redefine the http body reader used by the HTTP +# client below. + + +class ReadBodyProtocol(_ReadBodyProtocol): + """ + From original Twisted implementation, focused on adding our error + handling and ensuring that the proper u1db error is raised. + """ + + def __init__(self, response, deferred): + """ + Initialize the protocol, additionally storing the response headers. + """ + _ReadBodyProtocol.__init__( + self, response.code, response.phrase, deferred) + self.headers = response.headers + + # ---8<--- snippet from u1db.remote.http_client, modified to use errbacks + def _error(self, respdic): + descr = respdic.get("error") + exc_cls = errors.wire_description_to_exc.get(descr) + if exc_cls is not None: + message = respdic.get("message") + self.deferred.errback(exc_cls(message)) + else: + self.deferred.errback( + errors.HTTPError(self.status, respdic, self.headers)) + # ---8<--- end of snippet from u1db.remote.http_client + + def connectionLost(self, reason): + """ + Deliver the accumulated response bytes to the waiting L{Deferred}, if + the response body has been completely received without error. + """ + if reason.check(ResponseDone): + + body = b''.join(self.dataBuffer) + + # ---8<--- snippet from u1db.remote.http_client + if self.status in (200, 201): + self.deferred.callback(body) + elif self.status in http_errors.ERROR_STATUSES: + try: + respdic = json.loads(body) + except ValueError: + self.deferred.errback( + errors.HTTPError(self.status, body, self.headers)) + else: + self._error(respdic) + # special cases + elif self.status == 503: + self.deferred.errback(errors.Unavailable(body, self.headers)) + else: + self.deferred.errback( + errors.HTTPError(self.status, body, self.headers)) + # ---8<--- end of snippet from u1db.remote.http_client + + elif reason.check(PotentialDataLoss): + self.deferred.errback( + PartialDownloadError(self.status, self.message, + b''.join(self.dataBuffer))) + else: + self.deferred.errback(reason) + + +def readBody(response, protocolClass=ReadBodyProtocol): + """ + Get the body of an L{IResponse} and return it as a byte string. + + This is a helper function for clients that don't want to incrementally + receive the body of an HTTP response. + + @param response: The HTTP response for which the body will be read. + @type response: L{IResponse} provider + + @return: A L{Deferred} which will fire with the body of the response. + Cancelling it will close the connection to the server immediately. + """ + def cancel(deferred): + """ + Cancel a L{readBody} call, close the connection to the HTTP server + immediately, if it is still open. + + @param deferred: The cancelled L{defer.Deferred}. + """ + abort = getAbort() + if abort is not None: + abort() + + d = defer.Deferred(cancel) + protocol = protocolClass(response, d) + + def getAbort(): + return getattr(protocol.transport, 'abortConnection', None) + + response.deliverBody(protocol) + + if protocol.transport is not None and getAbort() is None: + warnings.warn( + 'Using readBody with a transport that does not have an ' + 'abortConnection method', + category=DeprecationWarning, + stacklevel=2) + + return d + + +class RequestBody(object): + """ + This class is a helper to generate send and fetch requests. + The expected format is something like: + [ + {headers}, + {entry1}, + {...}, + {entryN}, + ] + """ + + def __init__(self, **header_dict): + """ + Creates a new RequestBody holding header information. + + :param header_dict: A dictionary with the headers. + :type header_dict: dict + """ + self.headers = header_dict + self.entries = [] + self.consumed = 0 + + def insert_info(self, **entry_dict): + """ + Dumps an entry into JSON format and add it to entries list. + Adds 'content' key on a new line if it's present. + + :param entry_dict: Entry as a dictionary + :type entry_dict: dict + """ + content = '' + if 'content' in entry_dict: + content = ',\r\n' + (entry_dict['content'] or '') + entry = json.dumps(entry_dict) + content + self.entries.append(entry) + + def pop(self, amount=10, leave_open=False): + """ + Removes entries and returns it formatted and ready + to be sent. + + :param amount: number of entries to pop and format + :type amount: int + + :param leave_open: flag to skip stream closing + :type amount: bool + + :return: formatted body ready to be sent + :rtype: str + """ + start = self.consumed == 0 + amount = min([len(self.entries), amount]) + entries = [self.entries.pop(0) for i in xrange(amount)] + self.consumed += amount + end = len(self.entries) == 0 if not leave_open else False + return self.entries_to_str(entries, start, end) + + def __str__(self): + return self.pop(len(self.entries)) + + def __len__(self): + return len(self.entries) + + def entries_to_str(self, entries=None, start=True, end=True): + """ + Format a list of entries into the body format expected + by the server. + + :param entries: entries to format + :type entries: list + + :return: formatted body ready to be sent + :rtype: str + """ + data = '' + if start: + data = '[\r\n' + json.dumps(self.headers) + data += ''.join(',\r\n' + entry for entry in entries) + if end: + data += '\r\n]' + return data |