1 from types import StringTypes, IntType, LongType
5 from PLC.Timestamp import Timestamp
6 from PLC.Faults import *
7 from PLC.Parameter import Parameter
12 Representation of a row in a database table. To use, optionally
13 instantiate with a dict of values. Update as you would a
14 dict. Commit to the database with sync().
17 # Set this to the name of the table that stores the row.
18 # e.g. table_name = "nodes"
21 # Set this to the name of the primary key of the table. It is
22 # assumed that the this key is a sequence if it is not set when
24 # e.g. primary_key="node_id"
27 # Set this to the names of tables that reference this table's
31 # Set this to a dict of the valid fields of this object and their
32 # types. Not all fields (e.g., joined fields) may be updated via
36 # The name of the view that extends objects with tags
37 # e.g. view_tags_name = "view_node_tags"
40 # Set this to the set of tags that can be returned by the Get function
43 def __init__(self, api, fields = {}):
44 dict.__init__(self, fields)
46 # run the class_init initializer once
48 if not hasattr(cls,'class_inited'):
50 cls.class_inited=True # actual value does not matter
54 Validates values. Will validate a value with a custom function
55 if a function named 'validate_[key]' exists.
58 # Warn about mandatory fields
59 mandatory_fields = self.api.db.fields(self.table_name, notnull = True, hasdef = False)
60 for field in mandatory_fields:
61 if not self.has_key(field) or self[field] is None:
62 raise PLCInvalidArgument, field + " must be specified and cannot be unset in class %s"%self.__class__.__name__
64 # Validate values before committing
65 for key, value in self.iteritems():
66 if value is not None and hasattr(self, 'validate_' + key):
67 validate = getattr(self, 'validate_' + key)
68 self[key] = validate(value)
70 def separate_types(self, items):
72 Separate a list of different typed objects.
73 Return a list for each type (ints, strs and dicts)
76 if isinstance(items, (list, tuple, set)):
77 ints = filter(lambda x: isinstance(x, (int, long)), items)
78 strs = filter(lambda x: isinstance(x, StringTypes), items)
79 dicts = filter(lambda x: isinstance(x, dict), items)
80 return (ints, strs, dicts)
82 raise PLCInvalidArgument, "Can only separate list types"
85 def associate(self, *args):
87 Provides a means for high level api calls to associate objects
88 using low level calls.
92 raise PLCInvalidArgumentCount, "auth, field, value must be specified"
93 elif hasattr(self, 'associate_' + args[1]):
94 associate = getattr(self, 'associate_'+args[1])
97 raise PLCInvalidArguemnt, "No such associate function associate_%s" % args[1]
99 def validate_timestamp (self, timestamp):
100 return Timestamp.sql_validate(timestamp)
102 def add_object(self, classobj, join_table, columns = None):
104 Returns a function that can be used to associate this object
108 def add(self, obj, columns = None, commit = True):
110 Associate with the specified object.
113 # Various sanity checks
114 assert isinstance(self, Row)
115 assert self.primary_key in self
116 assert join_table in self.join_tables
117 assert isinstance(obj, classobj)
118 assert isinstance(obj, Row)
119 assert obj.primary_key in obj
120 assert join_table in obj.join_tables
122 # By default, just insert the primary keys of each object
123 # into the join table.
125 columns = {self.primary_key: self[self.primary_key],
126 obj.primary_key: obj[obj.primary_key]}
129 for name, value in columns.iteritems():
130 params.append(self.api.db.param(name, value))
132 self.api.db.do("INSERT INTO %s (%s) VALUES(%s)" % \
133 (join_table, ", ".join(columns), ", ".join(params)),
141 add_object = classmethod(add_object)
143 def remove_object(self, classobj, join_table):
145 Returns a function that can be used to disassociate this
149 def remove(self, obj, commit = True):
151 Disassociate from the specified object.
154 assert isinstance(self, Row)
155 assert self.primary_key in self
156 assert join_table in self.join_tables
157 assert isinstance(obj, classobj)
158 assert isinstance(obj, Row)
159 assert obj.primary_key in obj
160 assert join_table in obj.join_tables
162 self_id = self[self.primary_key]
163 obj_id = obj[obj.primary_key]
165 self.api.db.do("DELETE FROM %s WHERE %s = %s AND %s = %s" % \
167 self.primary_key, self.api.db.param('self_id', self_id),
168 obj.primary_key, self.api.db.param('obj_id', obj_id)),
176 remove_object = classmethod(remove_object)
178 # convenience: check in dict (self.fields or self.tags) that a key is writable
180 def is_writable (key,value,dict):
181 # if not mentioned, assume it's writable (e.g. deleted ...)
182 if key not in dict: return True
183 # if mentioned but not linked to a Parameter object, idem
184 if not isinstance(dict[key], Parameter): return True
185 # if not marked ro, it's writable
186 if not dict[key].ro: return True
189 def db_fields(self, obj = None):
191 Return only those fields that can be set or updated directly
192 (i.e., those fields that are in the primary table (table_name)
193 for this object, and are not marked as a read-only Parameter.
199 db_fields = self.api.db.fields(self.table_name)
200 return dict ( [ (key, value) for (key, value) in obj.items()
201 if key in db_fields and
202 Row.is_writable(key, value, self.fields) ] )
204 def tag_fields (self, obj=None):
206 Return the fields of obj that are mentioned in tags
208 if obj is None: obj=self
210 return dict ( [ (key,value) for (key,value) in obj.iteritems()
211 if key in self.tags and Row.is_writable(key,value,self.tags) ] )
213 # takes as input a list of columns, sort native fields from tags
214 # returns 2 dicts and one list : fields, tags, rejected
216 def parse_columns (cls, columns):
217 (fields,tags,rejected)=({},{},[])
218 for column in columns:
219 if column in cls.fields: fields[column]=cls.fields[column]
220 elif column in cls.tags: tags[column]=cls.tags[column]
221 else: rejected.append(column)
222 return (fields,tags,rejected)
224 # compute the 'accepts' part of a method, from a list of column names, and a fields dict
225 # use exclude=True to exclude the column names instead
226 # typically accepted_fields (Node.fields,['hostname','model',...])
228 def accepted_fields (update_columns, fields_dict, exclude=False):
230 for (k,v) in fields_dict.iteritems():
231 if (not exclude and k in update_columns) or (exclude and k not in update_columns):
235 # filter out user-provided fields that are not part of the declared acceptance list
236 # keep it separate from split_fields for simplicity
237 # typically check_fields (<user_provided_dict>,{'hostname':Parameter(str,...),'model':Parameter(..)...})
239 def check_fields (user_dict, accepted_fields):
240 # avoid the simple, but silent, version
241 # return dict ([ (k,v) for (k,v) in user_dict.items() if k in accepted_fields ])
243 for (k,v) in user_dict.items():
244 if k in accepted_fields: result[k]=v
245 else: raise PLCInvalidArgument ('Trying to set/change unaccepted key %s'%k)
248 # given a dict (typically passed to an Update method), we check and sort
249 # them against a list of dicts, e.g. [Node.fields, Node.related_fields]
250 # return is a list that contains n+1 dicts, last one has the rejected fields
252 def split_fields (fields, dicts):
254 for x in dicts: result.append({})
256 for (field,value) in fields.iteritems():
258 for i in range(len(dicts)):
259 candidate_dict=dicts[i]
260 if field in candidate_dict.keys():
261 result[i][field]=value
264 if not found: rejected[field]=value
265 result.append(rejected)
268 ### class initialization : create tag-dependent cross view if needed
270 def tagvalue_view_name (cls, tagname):
271 return "tagvalue_view_%s_%s"%(cls.primary_key,tagname)
274 def tagvalue_view_create_sql (cls,tagname):
276 returns a SQL sentence that creates a view named after the primary_key and tagname,
278 (*) column 1: primary_key
279 (*) column 2: actual tag value, renamed into tagname
282 if not cls.view_tags_name:
283 raise Exception, 'WARNING: class %s needs to set view_tags_name'%cls.__name__
285 table_name=cls.table_name
286 primary_key=cls.primary_key
287 view_tags_name=cls.view_tags_name
288 tagvalue_view_name=cls.tagvalue_view_name(tagname)
289 return 'CREATE OR REPLACE VIEW %(tagvalue_view_name)s ' \
290 'as SELECT %(table_name)s.%(primary_key)s,%(view_tags_name)s.value as "%(tagname)s" ' \
291 'from %(table_name)s right join %(view_tags_name)s using (%(primary_key)s) ' \
292 'WHERE tagname = \'%(tagname)s\';'%locals()
295 def class_init (cls,api):
296 cls.tagvalue_views_create (api)
299 def tagvalue_views_create (cls,api):
300 if not cls.tags: return
301 for tagname in cls.tags.keys():
302 api.db.do(cls.tagvalue_view_create_sql (tagname))
310 # Filter out fields that cannot be set or updated directly
311 # (and thus would not affect equality for the purposes of
312 # deciding if we should sync() or not).
314 y = self.db_fields(y)
315 return dict.__eq__(x, y)
317 # validate becomes optional on sept. 2010
318 # we find it useful to use DeletePerson on duplicated entries
319 def sync(self, commit = True, insert = None, validate=True):
321 Flush changes back to the database.
324 # Validate all specified fields
325 if validate: self.validate()
327 # Filter out fields that cannot be set or updated directly
328 db_fields = self.db_fields()
330 # Parameterize for safety
331 keys = db_fields.keys()
332 values = [self.api.db.param(key, value) for (key, value) in db_fields.items()]
334 # If the primary key (usually an auto-incrementing serial
335 # identifier) has not been specified, or the primary key is the
336 # only field in the table, or insert has been forced.
337 if not self.has_key(self.primary_key) or \
338 keys == [self.primary_key] or \
341 # If primary key id is a serial int and it isnt included, get next id
342 if self.fields[self.primary_key].type in (IntType, LongType) and \
343 self.primary_key not in self:
344 pk_id = self.api.db.next_id(self.table_name, self.primary_key)
345 self[self.primary_key] = pk_id
346 db_fields[self.primary_key] = pk_id
347 keys = db_fields.keys()
348 values = [self.api.db.param(key, value) for (key, value) in db_fields.items()]
350 sql = "INSERT INTO %s (%s) VALUES (%s)" % \
351 (self.table_name, ", ".join(keys), ", ".join(values))
353 # Update existing row
354 columns = ["%s = %s" % (key, value) for (key, value) in zip(keys, values)]
355 sql = "UPDATE {} SET {} WHERE {} = {}"\
356 .format(self.table_name,
359 self.api.db.param(self.primary_key, self[self.primary_key]))
361 self.api.db.do(sql, db_fields)
366 def delete(self, commit = True):
368 Delete row from its primary table, and from any tables that
372 assert self.primary_key in self
374 for table in self.join_tables + [self.table_name]:
375 if isinstance(table, tuple):
379 key = self.primary_key
381 sql = "DELETE FROM %s WHERE %s = %s" % \
383 self.api.db.param(self.primary_key, self[self.primary_key]))
385 self.api.db.do(sql, self)
392 Representation of row(s) in a database table.
395 def __init__(self, api, classobj, columns = None):
397 self.classobj = classobj
401 columns = classobj.fields
404 (columns,tag_columns,rejected) = classobj.parse_columns(columns)
405 if not columns and not tag_columns:
406 raise PLCInvalidArgument, "No valid return fields specified for class %s"%classobj.__name__
408 raise PLCInvalidArgument, "unknown column(s) specified %r in %s"%(rejected,classobj.__name__)
410 self.columns = columns
411 self.tag_columns = tag_columns
413 def sync(self, commit = True):
415 Flush changes back to the database.
421 def selectall(self, sql, params = None):
423 Given a list of rows from the database, fill ourselves with
427 for row in self.api.db.selectall(sql, params):
428 obj = self.classobj(self.api, row)
431 def dict(self, key_field = None):
433 Return ourself as a dict keyed on key_field.
436 if key_field is None:
437 key_field = self.classobj.primary_key
439 return dict([(obj[key_field], obj) for obj in self])