1 from types import StringTypes
2 from datetime import datetime
4 from sqlalchemy import Column, Integer, String, DateTime
5 from sqlalchemy import Table, Column, MetaData, join, ForeignKey
6 from sqlalchemy.orm import relationship, backref
7 from sqlalchemy.orm import column_property
8 from sqlalchemy.orm import object_mapper
9 from sqlalchemy.orm import validates
10 from sqlalchemy.ext.declarative import declarative_base
12 from sfa.util.sfalogging import logger
13 from sfa.util.xml import XML
15 from sfa.trust.gid import GID
17 ##############################
18 Base=declarative_base()
23 # historically the front end to the db dealt with dicts, so the code was only dealing with dicts
24 # sqlalchemy however offers an object interface, meaning that you write obj.id instead of obj['id']
25 # which is admittedly much nicer
26 # however we still need to deal with dictionaries if only for the xmlrpc layer
28 # here are a few utilities for this
30 # (*) first off, when an old pieve of code needs to be used as-is, if only temporarily, the simplest trick
31 # is to use obj.__dict__
32 # this behaves exactly like required, i.e. obj.__dict__['field']='new value' does change obj.field
33 # however this depends on sqlalchemy's implementation so it should be avoided
35 # (*) second, when an object needs to be exposed to the xmlrpc layer, we need to convert it into a dict
36 # remember though that writing the resulting dictionary won't change the object
37 # essentially obj.__dict__ would be fine too, except that we want to discard alchemy private keys starting with '_'
38 # 2 ways are provided for that:
41 # the former dict(obj) relies on __iter__() and next() below, and does not rely on the fields names
42 # although it seems to work fine, I've found cases where it issues a weird python error that I could not get right
43 # so the latter obj.todict() seems more reliable but more hacky as is relies on the form of fields, so this can probably be improved
45 # (*) finally for converting a dictionary into an sqlalchemy object, we provide
46 # obj.load_from_dict(dict)
50 self._i = iter(object_mapper(self).columns)
53 n = self._i.next().name
54 return n, getattr(self, n)
57 keys=[k for k in d.keys() if not k.startswith('_')]
58 return dict ( [ (k,d[k]) for k in keys ] )
59 def load_from_dict (self, d):
60 for (k,v) in d.iteritems():
62 if isinstance(v, StringTypes) and v.lower() in ['true']: v=True
63 if isinstance(v, StringTypes) and v.lower() in ['false']: v=False
66 # in addition we provide convenience for converting to and from xml records
67 # for this purpose only, we need the subclasses to define 'fields' as either
68 # a list or a dictionary
69 def xml_fields (self):
71 if isinstance(fields,dict): fields=fields.keys()
74 def save_as_xml (self):
75 # xxx not sure about the scope here
76 input_dict = dict( [ (key, getattr(self.key), ) for key in self.xml_fields() if getattr(self,key,None) ] )
77 xml_record=XML("<record />")
78 xml_record.parse_dict (input_dict)
79 return xml_record.toxml()
81 def dump(self, dump_parents=False):
82 for key in self.fields:
83 if key == 'gid' and self.gid:
84 gid = GID(string=self.gid)
86 gid.dump(8, dump_parents)
87 elif getattr(self,key,None):
88 print " %s: %s" % (key, getattr(self,key))
90 # # only intended for debugging
91 # def inspect (self, logger, message=""):
92 # logger.info("%s -- Inspecting AlchemyObj -- attrs"%message)
94 # if not k.startswith('_'):
95 # logger.info (" %s: %s"%(k,getattr(self,k)))
96 # logger.info("%s -- Inspecting AlchemyObj -- __dict__"%message)
98 # for (k,v) in d.iteritems():
99 # logger.info("[%s]=%s"%(k,v))
102 ##############################
103 # various kinds of records are implemented as an inheritance hierarchy
104 # RegRecord is the base class for all actual variants
105 # a first draft was using 'type' as the discriminator for the inheritance
106 # but we had to define another more internal column (classtype) so we
107 # accomodate variants in types like authority+am and the like
109 class RegRecord (Base,AlchemyObj):
110 __tablename__ = 'records'
111 record_id = Column (Integer, primary_key=True)
112 # this is the discriminator that tells which class to use
113 classtype = Column (String)
114 # in a first version type was the discriminator
115 # but that could not accomodate for 'authority+sa' and the like
116 type = Column (String)
117 hrn = Column (String)
118 gid = Column (String)
119 authority = Column (String)
120 peer_authority = Column (String)
121 pointer = Column (Integer, default=-1)
122 date_created = Column (DateTime)
123 last_updated = Column (DateTime)
124 # use the 'type' column to decide which subclass the object is of
125 __mapper_args__ = { 'polymorphic_on' : classtype }
127 fields = [ 'type', 'hrn', 'gid', 'authority', 'peer_authority' ]
128 def __init__ (self, type=None, hrn=None, gid=None, authority=None, peer_authority=None,
129 pointer=None, dict=None):
130 if type: self.type=type
133 if isinstance(gid, StringTypes): self.gid=gid
134 else: self.gid=gid.save_to_string(save_parents=True)
135 if authority: self.authority=authority
136 if peer_authority: self.peer_authority=peer_authority
137 if pointer: self.pointer=pointer
138 if dict: self.load_from_dict (dict)
141 result="<Record id=%s, type=%s, hrn=%s, authority=%s, pointer=%s" % \
142 (self.record_id, self.type, self.hrn, self.authority, self.pointer)
143 # skip the uniform '--- BEGIN CERTIFICATE --' stuff
144 if self.gid: result+=" gid=%s..."%self.gid[28:36]
145 else: result+=" nogid"
150 def validate_gid (self, key, gid):
151 if gid is None: return
152 elif isinstance(gid, StringTypes): return gid
153 else: return gid.save_to_string(save_parents=True)
155 # xxx - there might be smarter ways to handle get/set'ing gid using validation hooks
156 def get_gid_object (self):
157 if not self.gid: return None
158 else: return GID(string=self.gid)
160 def just_created (self):
162 self.date_created=now
163 self.last_updated=now
165 def just_updated (self):
167 self.last_updated=now
169 ##############################
170 # all subclasses define a convenience constructor with a default value for type,
171 # and when applicable a way to define local fields in a kwd=value argument
173 class RegAuthority (RegRecord):
174 __tablename__ = 'authorities'
175 __mapper_args__ = { 'polymorphic_identity' : 'authority' }
176 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
178 def __init__ (self, **kwds):
179 # fill in type if not previously set
180 if 'type' not in kwds: kwds['type']='authority'
181 # base class constructor
182 RegRecord.__init__(self, **kwds)
184 # no proper data yet, just hack the typename
186 return RegRecord.__repr__(self).replace("Record","Authority")
189 class RegSlice (RegRecord):
190 __tablename__ = 'slices'
191 __mapper_args__ = { 'polymorphic_identity' : 'slice' }
192 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
194 def __init__ (self, **kwds):
195 if 'type' not in kwds: kwds['type']='slice'
196 RegRecord.__init__(self, **kwds)
199 return RegRecord.__repr__(self).replace("Record","Slice")
202 class RegNode (RegRecord):
203 __tablename__ = 'nodes'
204 __mapper_args__ = { 'polymorphic_identity' : 'node' }
205 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
207 def __init__ (self, **kwds):
208 if 'type' not in kwds: kwds['type']='node'
209 RegRecord.__init__(self, **kwds)
212 return RegRecord.__repr__(self).replace("Record","Node")
215 class RegUser (RegRecord):
216 __tablename__ = 'users'
217 # these objects will have type='user' in the records table
218 __mapper_args__ = { 'polymorphic_identity' : 'user' }
219 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
220 email = Column ('email', String)
221 # can't use name 'keys' here because when loading from xml we're getting
222 # a 'keys' tag, and assigning a list of strings in a reference column like this crashes
223 reg_keys = relationship ('RegKey', backref='reg_user',
224 cascade="all, delete, delete-orphan")
226 # so we can use RegUser (email=.., hrn=..) and the like
227 def __init__ (self, **kwds):
228 # handle local settings
229 if 'email' in kwds: self.email=kwds.pop('email')
230 if 'type' not in kwds: kwds['type']='user'
231 RegRecord.__init__(self, **kwds)
233 # append stuff at the end of the record __repr__
235 result = RegRecord.__repr__(self).replace("Record","User")
236 result.replace (">"," email=%s"%self.email)
241 def validate_email(self, key, address):
242 assert '@' in address
245 # xxx this might be temporary
246 def normalize_xml (self):
247 if hasattr(self,'keys'): self.reg_keys = [ RegKey (key) for key in self.keys ]
250 # xxx tocheck : not sure about eager loading of this one
251 # meaning, when querying the whole records, we expect there should
252 # be a single query to fetch all the keys
253 # or, is it enough that we issue a single query to retrieve all the keys
255 __tablename__ = 'keys'
256 key_id = Column (Integer, primary_key=True)
257 record_id = Column (Integer, ForeignKey ("records.record_id"))
258 key = Column (String)
259 pointer = Column (Integer, default = -1)
261 def __init__ (self, key, pointer=None):
263 if pointer: self.pointer=pointer
266 result="<key id=%s key=%s..."%(self.key_id,self.key[8:16],)
267 try: result += " user=%s"%self.reg_user.record_id
268 except: result += " no-user"
272 ##############################
273 # although the db needs of course to be reachable for the following functions
274 # the schema management functions are here and not in alchemy
275 # because the actual details of the classes need to be known
276 # migrations: this code has no notion of the previous versions
277 # of the data model nor of migrations
278 # sfa.storage.migrations.db_init uses this when starting from
280 def init_tables(engine):
281 logger.info("Initializing db schema from current/latest model")
282 Base.metadata.create_all(engine)
284 def drop_tables(engine):
285 logger.info("Dropping tables from current/latest model")
286 Base.metadata.drop_all(engine)
288 ##############################
289 # create a record of the right type from either a dict or an xml string
290 def make_record (dict={}, xml=""):
291 if dict: return make_record_dict (dict)
292 elif xml: return make_record_xml (xml)
293 else: raise Exception("make_record has no input")
295 # convert an incoming record - typically from xmlrpc - into an object
296 def make_record_dict (record_dict):
297 assert ('type' in record_dict)
298 type=record_dict['type'].split('+')[0]
299 if type=='authority':
300 result=RegAuthority (dict=record_dict)
302 result=RegUser (dict=record_dict)
304 result=RegSlice (dict=record_dict)
306 result=RegNode (dict=record_dict)
308 logger.debug("Untyped RegRecord instance")
309 result=RegRecord (dict=record_dict)
310 logger.info ("converting dict into Reg* with type=%s"%type)
311 logger.info ("returning=%s"%result)
313 # register non-db attributes in an extensions field
316 def make_record_xml (xml):
317 xml_record = XML(xml)
318 xml_dict = xml_record.todict()
319 logger.info("load from xml, keys=%s"%xml_dict.keys())
320 return make_record_dict (xml_dict)