diff options
Diffstat (limited to 'freebase-api/freebase/api/session.py')
| -rw-r--r-- | freebase-api/freebase/api/session.py | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/freebase-api/freebase/api/session.py b/freebase-api/freebase/api/session.py new file mode 100644 index 0000000..fc32676 --- /dev/null +++ b/freebase-api/freebase/api/session.py @@ -0,0 +1,524 @@ +# ======================================================================== +# Copyright (c) 2007, Metaweb Technologies, Inc. +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions +# are met: +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following +# disclaimer in the documentation and/or other materials provided +# with the distribution. +# +# THIS SOFTWARE IS PROVIDED BY METAWEB TECHNOLOGIES AND CONTRIBUTORS +# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL METAWEB +# TECHNOLOGIES OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +# POSSIBILITY OF SUCH DAMAGE. +# ======================================================================== + +# +# declarations for external metaweb api. +# +# +# from metaweb.api import HTTPMetawebSession +# +# mss = HTTPMetawebSession('sandbox.freebase.com') +# print mss.mqlread([dict(name=None, type='/type/type')]) +# +# +# + +__all__ = ['MetawebError', 'MetawebSession', 'HTTPMetawebSession', 'attrdict'] +__version__ = '0.1' + +import os, sys, re +import urllib2 +import cookielib +import simplejson +from urllib import quote as urlquote +import pprint +import socket +import logging + +try: + import httplib2 + from httplib2cookie import CookiefulHttp +except ImportError: + httplib2 = None + CookiefulHttp = None + print ('freebase.api: you can install httplib2 for better performance') + +import simplejson.encoder +# remove whitespace from json encoded output +simplejson.JSONEncoder.item_separator = ',' +simplejson.JSONEncoder.key_separator = ':' +# don't escape slashes, we're not pasting into script tags here. +if simplejson.encoder.ESCAPE_DCT.get('/', None) == r'\/': + simplejson.encoder.ESCAPE_DCT['/'] = '/' + +def urlencode_weak(s): + return urlquote(s, safe=',/:$') + + +# from http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/361668 +class attrdict(dict): + """A dict whose items can also be accessed as member variables. + + >>> d = attrdict(a=1, b=2) + >>> d['c'] = 3 + >>> print d.a, d.b, d.c + 1 2 3 + >>> d.b = 10 + >>> print d['b'] + 10 + + # but be careful, it's easy to hide methods + >>> print d.get('c') + 3 + >>> d['get'] = 4 + >>> print d.get('a') + Traceback (most recent call last): + TypeError: 'int' object is not callable + """ + def __init__(self, *args, **kwargs): + dict.__init__(self, *args, **kwargs) + self.__dict__ = self + + + +# TODO expose the common parts of the result envelope +class MetawebError(Exception): + """ + an error report from the metaweb service. + """ + pass + + + +# TODO right now this is a completely unnecessary superclass. +# is there enough common behavior between session types +# to justify it? +class MetawebSession(object): + """ + MetawebSession is the base class for MetawebSession, subclassed for + different connection types. Only http is available externally. + + This is more of an interface than a class + """ + + # interface definition here... + + +# from httplib2 +NORMALIZE_SPACE = re.compile(r'(?:\r\n)?[ \t]+') +def _normalize_headers(headers): + return dict([ (key.lower(), NORMALIZE_SPACE.sub(value, ' ').strip()) for (key, value) in headers.iteritems()]) + + +class HTTPMetawebSession(MetawebSession): + """ + a MetawebSession is a request/response queue. + + this version uses the HTTP api, and is synchronous. + """ + # share cookies across sessions, so that different sessions can + # see each other's writes immediately. + _default_cookiejar = cookielib.CookieJar() + + def __init__(self, service_url, username=None, password=None, prev_session=None, cookiejar=None, cookiefile=None): + """ + create a new MetawebSession for interacting with the Metaweb. + + a new session will inherit state from prev_session if present, + """ + super(HTTPMetawebSession, self).__init__() + + self.log = logging.getLogger() + + assert not service_url.endswith('/') + if not '/' in service_url: # plain host:port + service_url = 'http://' + service_url + + self.service_url = service_url + + self.username = username + self.password = password + + self.tid = None + + if prev_session: + self.service_url = prev.service_url + + if cookiefile is not None: + cookiejar = self.open_cookie_file(cookiefile) + + if cookiejar is not None: + self.cookiejar = cookiejar + elif prev_session: + self.cookiejar = prev_session.cookiejar + else: + self.cookiejar = self._default_cookiejar + + if CookiefulHttp is not None: + self.httpclient = CookiefulHttp(cookiejar=self.cookiejar) + else: + cookiespy = urllib2.HTTPCookieProcessor(self.cookiejar) + self.opener = urllib2.build_opener(cookiespy) + + + def open_cookie_file(self, cookiefile=None): + if cookiefile is None or cookiefile == '': + if os.environ.has_key('HOME'): + cookiefile = os.path.join(os.environ['HOME'], '.pyfreebase/cookiejar') + else: + raise MetawebError("no cookiefile specified and no $HOME/.pyfreebase directory" % cookiefile) + + cookiejar = cookielib.LWPCookieJar(cookiefile) + if os.path.exists(cookiefile): + cookiejar.load(ignore_discard=True) + + return cookiejar + + + def _httpreq(self, service_path, method='GET', body=None, form=None, + headers=None): + """ + make an http request to the service. + + form arguments are encoded in the url, even for POST, if a non-form + content-type is given for the body. + + returns a pair (resp, body) + + resp is the response object and may be different depending + on whether urllib2 or httplib2 is in use? + """ + + if method == 'POST': + assert body is not None or form is not None + elif method == 'GET': + assert body is None + else: + assert 0, 'unknown method %s' % method + + url = self.service_url + service_path + + if headers is None: + headers = {} + else: + headers = _normalize_headers(headers) + + # XXX This is a lousy way to parse Content-Type, where is + # the library? + ct = headers.get('content-type', None) + if ct is not None: + ct = ct.split(';')[0] + + if body is not None: + # if body is provided, content-type had better be too + assert ct is not None + + if form is not None: + qstr = '&'.join(['%s=%s' % (urlencode_weak(k), urlencode_weak(v)) + for k,v in form.items()]) + if method == 'POST': + # put the args on the url if we're putting something else + # in the body. this is used to add args to raw uploads. + if body is not None: + url += '?' + qstr + else: + if ct is None: + # XXX encoding and stuff + ct = 'application/x-www-form-urlencoded' + headers['content-type'] = ct + + if ct == 'multipart/form-encoded': + # XXX fixme + raise NotImplementedError + elif ct == 'application/x-www-form-urlencoded': + body = qstr + else: + # for all methods other than POST, use the url + url += '?' + qstr + + + # assure the service that this isn't a CSRF form submission + headers['x-metaweb-request'] = 'Python' + + if 'user-agent' not in headers: + headers['user-agent'] = 'python freebase.api-%s' % __version__ + + #if self.tid is not None: + # headers['x-metaweb-tid'] = self.tid + + ####### DEBUG MESSAGE - should check log level before generating + if form is None: + formstr = '' + else: + formstr = 'FORM:\n ' + '\n '.join(['%s=%s' % (k,v) + for k,v in form.items()]) + if headers is None: + headerstr = '' + else: + headerstr = 'HEADERS:\n ' + '\n '.join([('%s: %s' % (k,v)) + for k,v in headers.items()]) + self.log.debug('%s %s%s%s', method, url, formstr, headerstr) + ####### + + if CookiefulHttp is not None: + return self._httplib2_request(url, method, body, headers) + else: + return self._urllib2_request(url, method, body, headers) + + + def _raise_service_error(self, status, ctype, body): + is_jsbody = (e.info().type.endswith('javascript') + or e.info().type.endswith('json')) + if str(status) == '400' and is_jsbody: + r = self._loadjson(body) + msg = r.messages[0] + raise MetawebError(u'%s %s %r' % (msg.get('code',''), msg.message, msg.info)) + + raise MetawebError, 'request failed: %s: %r %r' % (url, str(e), body) + + def _urllib2_request(self, url, method, body, headers): + req = urllib2.Request(url, body, headers) + + try: + resp = self.opener.open(req) + + except socket.error, e: + self.log.error('SOCKET FAILURE: %s', e.fp.read()) + raise MetawebError, 'failed contacting %s: %s' % (url, str(e)) + + except urllib2.HTTPError, e: + _raise_service_error(e.code, e.info().type, e.fp.read()) + + for header in resp.info().headers: + self.log.debug('HTTP HEADER %s', header) + name, value = re.split("[:\n\r]", header, 1) + if name.lower() == 'x-metaweb-tid': + self.tid = value.strip() + + return (resp, resp.read()) + + def _httplib2_request(self, url, method, body, headers): + try: + resp, content = self.httpclient.request(url, method=method, + body=body, headers=headers) + except socket.error, e: + self.log.error('SOCKET FAILURE: %s', e.fp.read()) + raise MetawebError, 'failed contacting %s: %s' % (url, str(e)) + + except httplib2.HttpLib2ErrorWithResponse, e: + self._raise_service_error(resp.status, resp['content-type'], content) + except httplib2.HttpLib2Error, e: + raise MetawebError(u'HTTP error: %s' % (e,)) + + #tid = resp.get('x-metaweb-tid', None) + + return (resp, content) + + + def _httpreq_json(self, *args, **kws): + resp, body = self._httpreq(*args, **kws) + return self._loadjson(body) + + def _loadjson(self, json): + # TODO really this should be accomplished by hooking + # simplejson to create attrdicts instead of dicts. + def struct2attrdict(st): + """ + copy a json structure, turning all dicts into attrdicts. + + copying descends instances of dict and list, including subclasses. + """ + if isinstance(st, dict): + return attrdict([(k,struct2attrdict(v)) for k,v in st.items()]) + if isinstance(st, list): + return [struct2attrdict(li) for li in st] + return st + + if json == '': + self.log.error('the empty string is not valid json') + raise MetawebError('the empty string is not valid json') + + try: + r = simplejson.loads(json) + except ValueError, e: + self.log.error('error parsing json string %r' % json) + raise MetawebError, 'error parsing JSON string: %s' % e + + return struct2attrdict(r) + + def _check_mqlerror(self, r): + if r.code != '/api/status/ok': + for msg in r.messages: + self.log.error('mql error: %s %s %r' % (msg.code, msg.message, msg.get('query', None))) + raise MetawebError, 'query failed: %s %r' % (r.messages[0].code, r.messages[0].get('query', None)) + + def _mqlresult(self, r): + self._check_mqlerror(r) + + # should check log level to avoid redundant simplejson.dumps + rstr = simplejson.dumps(r.result, indent=2) + if rstr[0] == '{': + rstr = rstr[1:-2] + self.log.info('result: %s', rstr) + + return r.result + + + + def login(self): + """sign in to the service""" + + assert self.username is not None + assert self.password is not None + + self.log.debug('LOGIN USERNAME: %s', self.username) + + try: + r = self._httpreq_json('/api/account/login', 'POST', + form=dict(username=self.username, + password=self.password)) + except urllib2.HTTPError, e: + raise MetawebError("login error: %s", e) + + if r.code != '/api/status/ok': + raise MetawebError(u'%s %r' % (r.get('code',''), r.messages)) + + self.log.debug('LOGIN RESP: %r', r) + self.log.debug('LOGIN COOKIES: %s', self.cookiejar) + + + def mqlreaditer(self, sq): + """read a structure query""" + + cursor = True + + while 1: + subq = dict(query=[sq], cursor=cursor, escape=False) + qstr = simplejson.dumps(subq) + + service = '/api/service/mqlread' + + r = self._httpreq_json(service, form=dict(query=qstr)) + + for item in self._mqlresult(r): + yield item + + if r['cursor']: + cursor = r['cursor'] + self.log.info('CONTINUING with %s', cursor) + else: + return + + def mqlread(self, sq): + """read a structure query""" + subq = dict(query=sq, escape=False) + if isinstance(sq, list): + subq['cursor'] = True + + service = '/api/service/mqlread' + + # should check log level to avoid redundant simplejson.dumps + self.log.info('%s: %s', + service, + simplejson.dumps(sq, indent=2)[1:-2]) + + qstr = simplejson.dumps(subq) + r = self._httpreq_json(service, form=dict(query=qstr)) + + return self._mqlresult(r) + + def trans(self, guid): + """translate blob from guid """ + url = '/api/trans/raw' + urlquote(guid) + + self.log.info(url) + + resp, body = self._httpreq(url) + + self.log.info('%d bytes' % len(body)) + + return body + + def mqlwrite(self, sq): + """do a mql write""" + query = dict(query=sq, escape=False) + qstr = simplejson.dumps(query) + + self.log.debug('MQLWRITE: %s', qstr) + + service = '/api/service/mqlwrite' + + # should check log level to avoid redundant simplejson.dumps + self.log.info('%s: %s', + service, + simplejson.dumps(sq, indent=2)[1:-2]) + + r = self._httpreq_json(service, 'POST', + form=dict(query=qstr)) + + self.log.debug('MQLWRITE RESP: %r', r) + return self._mqlresult(r) + + def mqlflush(self): + """ask the service not to hand us old data""" + self.log.debug('MQLFLUSH') + + service = '/api/service/mqlwrite' + r = self._httpreq_json(service, 'POST', form={}) + + self._check_mqlerror(r) + return r + + def upload(self, body, content_type, document_id=False): + """upload to the metaweb""" + + service = '/api/service/upload' + + self.log.info('POST %s: %s (%d bytes)', + service, content_type, len(body)) + + + headers = {} + if content_type is not None: + headers['content-type'] = content_type + + form = None + if document_id is not False: + if document_id is None: + form = { 'document': '' } + else: + form = { 'document': document_id } + + # note the use of both body and form. + # form parameters get encoded into the URL in this case + r = self._httpreq_json(service, 'POST', + headers=headers, body=body, form=form) + return self._mqlresult(r) + + +if __name__ == '__main__': + console = logging.StreamHandler() + console.setLevel(logging.DEBUG) + + mss = HTTPMetawebSession('sandbox.freebase.com') + + self.mss.log.setLevel(logging.DEBUG) + self.mss.log.addHandler(console) + + + print mss.mqlread([dict(name=None, type='/type/type')]) |