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 type = Column (String)
115 hrn = Column (String)
116 gid = Column (String)
117 authority = Column (String)
118 peer_authority = Column (String)
119 pointer = Column (Integer, default=-1)
120 date_created = Column (DateTime)
121 last_updated = Column (DateTime)
122 # use the 'type' column to decide which subclass the object is of
123 __mapper_args__ = { 'polymorphic_on' : classtype }
125 fields = [ 'type', 'hrn', 'gid', 'authority', 'peer_authority' ]
126 def __init__ (self, type=None, hrn=None, gid=None, authority=None, peer_authority=None,
127 pointer=None, dict=None):
128 if type: self.type=type
131 if isinstance(gid, StringTypes): self.gid=gid
132 else: self.gid=gid.save_to_string(save_parents=True)
133 if authority: self.authority=authority
134 if peer_authority: self.peer_authority=peer_authority
135 if pointer: self.pointer=pointer
136 if dict: self.load_from_dict (dict)
139 result="[Record id=%s, type=%s, hrn=%s, authority=%s, pointer=%s" % \
140 (self.record_id, self.type, self.hrn, self.authority, self.pointer)
141 # skip the uniform '--- BEGIN CERTIFICATE --' stuff
142 if self.gid: result+=" gid=%s..."%self.gid[28:36]
143 else: result+=" nogid"
148 def validate_gid (self, key, gid):
149 if gid is None: return
150 elif isinstance(gid, StringTypes): return gid
151 else: return gid.save_to_string(save_parents=True)
153 # xxx - there might be smarter ways to handle get/set'ing gid using validation hooks
154 def get_gid_object (self):
155 if not self.gid: return None
156 else: return GID(string=self.gid)
158 def just_created (self):
160 self.date_created=now
161 self.last_updated=now
163 def just_updated (self):
165 self.last_updated=now
167 ##############################
168 class RegAuthority (RegRecord):
169 __tablename__ = 'authorities'
170 __mapper_args__ = { 'polymorphic_identity' : 'authority' }
171 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
173 # no proper data yet, just hack the typename
175 return RegRecord.__repr__(self).replace("Record","Authority")
177 ##############################
178 class RegSlice (RegRecord):
179 __tablename__ = 'slices'
180 __mapper_args__ = { 'polymorphic_identity' : 'slice' }
181 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
184 return RegRecord.__repr__(self).replace("Record","Slice")
186 ##############################
187 class RegNode (RegRecord):
188 __tablename__ = 'nodes'
189 __mapper_args__ = { 'polymorphic_identity' : 'node' }
190 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
193 return RegRecord.__repr__(self).replace("Record","Node")
195 ##############################
196 class RegUser (RegRecord):
197 __tablename__ = 'users'
198 # these objects will have type='user' in the records table
199 __mapper_args__ = { 'polymorphic_identity' : 'user' }
200 record_id = Column (Integer, ForeignKey ("records.record_id"), primary_key=True)
201 email = Column ('email', String)
202 # can't use name 'keys' here because when loading from xml we're getting
203 # a 'keys' tag, and assigning a list of strings in a reference column like this crashes
204 reg_keys = relationship ('RegKey', backref='reg_user')
206 def __init__ (self, **kwds):
207 # handle local settings
208 if 'email' in kwds: self.email=kwds.pop('email')
209 # fill in type if not previously set
210 if 'type' not in kwds: kwds['type']='user'
211 RegRecord.__init__(self, **kwds)
213 # append stuff at the end of the record __repr__
215 result = RegRecord.__repr__(self).replace("Record","User")
216 result.replace ("]"," email=%s"%self.email)
221 def validate_email(self, key, address):
222 assert '@' in address
225 def normalize_xml (self):
226 if hasattr(self,'keys'): self.reg_keys = [ RegKey (key) for key in self.keys ]
229 # xxx tocheck : not sure about eager loading of this one
230 # meaning, when querying the whole records, we expect there should
231 # be a single query to fetch all the keys
233 __tablename__ = 'keys'
234 key_id = Column (Integer, primary_key=True)
235 record_id = Column (Integer, ForeignKey ("records.record_id"))
236 key = Column (String)
237 pointer = Column (Integer, default = -1)
239 def __init__ (self, key, pointer=None):
241 if pointer: self.pointer=pointer
244 result="[key key=%s..."%self.key[8:16]
245 try: result += " user=%s"%self.user.record_id
246 except: result += " <orphan>"
250 ##############################
251 # although the db needs of course to be reachable,
252 # the schema management functions are here and not in alchemy
253 # because the actual details of the classes need to be known
254 # migrations: this code has no notion of the previous versions
255 # of the data model nor of migrations
256 # sfa.storage.migrations.db_init uses this when starting from
258 def init_tables(engine):
259 logger.info("Initializing db schema from current/latest model")
260 Base.metadata.create_all(engine)
262 def drop_tables(engine):
263 logger.info("Dropping tables from current/latest model")
264 Base.metadata.drop_all(engine)
266 ##############################
267 # create a record of the right type from either a dict or an xml string
268 def make_record (dict={}, xml=""):
269 if dict: return make_record_dict (dict)
270 elif xml: return make_record_xml (xml)
271 else: raise Exception("make_record has no input")
273 # convert an incoming record - typically from xmlrpc - into an object
274 def make_record_dict (record_dict):
275 assert ('type' in record_dict)
276 type=record_dict['type'].split('+')[0]
277 if type=='authority':
278 result=RegAuthority (dict=record_dict)
280 result=RegUser (dict=record_dict)
282 result=RegSlice (dict=record_dict)
284 result=RegNode (dict=record_dict)
286 logger.debug("Untyped RegRecord instance")
287 result=RegRecord (dict=record_dict)
288 logger.info ("converting dict into Reg* with type=%s"%type)
289 logger.info ("returning=%s"%result)
291 # register non-db attributes in an extensions field
294 def make_record_xml (xml):
295 xml_record = XML(xml)
296 xml_dict = xml_record.todict()
297 logger.info("load from xml, keys=%s"%xml_dict.keys())
298 return make_record_dict (xml_dict)