3 from types import StringTypes, IntType, LongType
7 from PLC.Faults import *
8 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, check_future = False):
101 Validates the specified GMT timestamp string (must be in
102 %Y-%m-%d %H:%M:%S format) or number (seconds since UNIX epoch,
103 i.e., 1970-01-01 00:00:00 GMT). If check_future is True,
104 raises an exception if timestamp is not in the future. Returns
105 a GMT timestamp string.
108 time_format = "%Y-%m-%d %H:%M:%S"
110 if isinstance(timestamp, StringTypes):
111 # calendar.timegm() is the inverse of time.gmtime()
112 timestamp = calendar.timegm(time.strptime(timestamp, time_format))
114 # Human readable timestamp string
115 human = time.strftime(time_format, time.gmtime(timestamp))
117 if check_future and timestamp < time.time():
118 raise PLCInvalidArgument, "'%s' not in the future" % human
122 def add_object(self, classobj, join_table, columns = None):
124 Returns a function that can be used to associate this object
128 def add(self, obj, columns = None, commit = True):
130 Associate with the specified object.
133 # Various sanity checks
134 assert isinstance(self, Row)
135 assert self.primary_key in self
136 assert join_table in self.join_tables
137 assert isinstance(obj, classobj)
138 assert isinstance(obj, Row)
139 assert obj.primary_key in obj
140 assert join_table in obj.join_tables
142 # By default, just insert the primary keys of each object
143 # into the join table.
145 columns = {self.primary_key: self[self.primary_key],
146 obj.primary_key: obj[obj.primary_key]}
149 for name, value in columns.iteritems():
150 params.append(self.api.db.param(name, value))
152 self.api.db.do("INSERT INTO %s (%s) VALUES(%s)" % \
153 (join_table, ", ".join(columns), ", ".join(params)),
161 add_object = classmethod(add_object)
163 def remove_object(self, classobj, join_table):
165 Returns a function that can be used to disassociate this
169 def remove(self, obj, commit = True):
171 Disassociate from the specified object.
174 assert isinstance(self, Row)
175 assert self.primary_key in self
176 assert join_table in self.join_tables
177 assert isinstance(obj, classobj)
178 assert isinstance(obj, Row)
179 assert obj.primary_key in obj
180 assert join_table in obj.join_tables
182 self_id = self[self.primary_key]
183 obj_id = obj[obj.primary_key]
185 self.api.db.do("DELETE FROM %s WHERE %s = %s AND %s = %s" % \
187 self.primary_key, self.api.db.param('self_id', self_id),
188 obj.primary_key, self.api.db.param('obj_id', obj_id)),
196 remove_object = classmethod(remove_object)
198 # convenience: check in dict (self.fields or self.tags) that a key is writable
200 def is_writable (key,value,dict):
201 # if not mentioned, assume it's writable (e.g. deleted ...)
202 if key not in dict: return True
203 # if mentioned but not linked to a Parameter object, idem
204 if not isinstance(dict[key], Parameter): return True
205 # if not marked ro, it's writable
206 if not dict[key].ro: return True
209 def db_fields(self, obj = None):
211 Return only those fields that can be set or updated directly
212 (i.e., those fields that are in the primary table (table_name)
213 for this object, and are not marked as a read-only Parameter.
216 if obj is None: obj = self
218 db_fields = self.api.db.fields(self.table_name)
219 return dict ( [ (key,value) for (key,value) in obj.items()
220 if key in db_fields and
221 Row.is_writable(key,value,self.fields) ] )
223 def tag_fields (self, obj=None):
225 Return the fields of obj that are mentioned in tags
227 if obj is None: obj=self
229 return dict ( [ (key,value) for (key,value) in obj.iteritems()
230 if key in self.tags and Row.is_writable(key,value,self.tags) ] )
232 # takes as input a list of columns, sort native fields from tags
233 # returns 2 dicts and one list : fields, tags, rejected
235 def parse_columns (cls, columns):
236 (fields,tags,rejected)=({},{},[])
237 for column in columns:
238 if column in cls.fields: fields[column]=cls.fields[column]
239 elif column in cls.tags: tags[column]=cls.tags[column]
240 else: rejected.append(column)
241 return (fields,tags,rejected)
243 # compute the 'accepts' part of a method, from a list of column names, and a fields dict
244 # use exclude=True to exclude the column names instead
245 # typically accepted_fields (Node.fields,['hostname','model',...])
247 def accepted_fields (update_columns, fields_dict, exclude=False):
249 for (k,v) in fields_dict.iteritems():
250 if (not exclude and k in update_columns) or (exclude and k not in update_columns):
254 # filter out user-provided fields that are not part of the declared acceptance list
255 # keep it separate from split_fields for simplicity
256 # typically check_fields (<user_provided_dict>,{'hostname':Parameter(str,...),'model':Parameter(..)...})
258 def check_fields (user_dict, accepted_fields):
259 # avoid the simple, but silent, version
260 # return dict ([ (k,v) for (k,v) in user_dict.items() if k in accepted_fields ])
262 for (k,v) in user_dict.items():
263 if k in accepted_fields: result[k]=v
264 else: raise PLCInvalidArgument ('Trying to set/change unaccepted key %s'%k)
267 # given a dict (typically passed to an Update method), we check and sort
268 # them against a list of dicts, e.g. [Node.fields, Node.related_fields]
269 # return is a list that contains n+1 dicts, last one has the rejected fields
271 def split_fields (fields, dicts):
273 for x in dicts: result.append({})
275 for (field,value) in fields.iteritems():
277 for i in range(len(dicts)):
278 candidate_dict=dicts[i]
279 if field in candidate_dict.keys():
280 result[i][field]=value
283 if not found: rejected[field]=value
284 result.append(rejected)
287 ### class initialization : create tag-dependent cross view if needed
289 def tagvalue_view_name (cls, tagname):
290 return "tagvalue_view_%s_%s"%(cls.primary_key,tagname)
293 def tagvalue_view_create_sql (cls,tagname):
295 returns a SQL sentence that creates a view named after the primary_key and tagname,
297 (*) column 1: primary_key
298 (*) column 2: actual tag value, renamed into tagname
301 if not cls.view_tags_name:
302 raise Exception, 'WARNING: class %s needs to set view_tags_name'%cls.__name__
304 table_name=cls.table_name
305 primary_key=cls.primary_key
306 view_tags_name=cls.view_tags_name
307 tagvalue_view_name=cls.tagvalue_view_name(tagname)
308 return 'CREATE OR REPLACE VIEW %(tagvalue_view_name)s ' \
309 'as SELECT %(table_name)s.%(primary_key)s,%(view_tags_name)s.value as "%(tagname)s" ' \
310 'from %(table_name)s right join %(view_tags_name)s using (%(primary_key)s) ' \
311 'WHERE tagname = \'%(tagname)s\';'%locals()
314 def class_init (cls,api):
315 cls.tagvalue_views_create (api)
318 def tagvalue_views_create (cls,api):
319 if not cls.tags: return
320 for tagname in cls.tags.keys():
321 api.db.do(cls.tagvalue_view_create_sql (tagname))
329 # Filter out fields that cannot be set or updated directly
330 # (and thus would not affect equality for the purposes of
331 # deciding if we should sync() or not).
333 y = self.db_fields(y)
334 return dict.__eq__(x, y)
336 def sync(self, commit = True, insert = None):
338 Flush changes back to the database.
341 # Validate all specified fields
344 # Filter out fields that cannot be set or updated directly
345 db_fields = self.db_fields()
347 # Parameterize for safety
348 keys = db_fields.keys()
349 values = [self.api.db.param(key, value) for (key, value) in db_fields.items()]
351 # If the primary key (usually an auto-incrementing serial
352 # identifier) has not been specified, or the primary key is the
353 # only field in the table, or insert has been forced.
354 if not self.has_key(self.primary_key) or \
355 keys == [self.primary_key] or \
358 # If primary key id is a serial int and it isnt included, get next id
359 if self.fields[self.primary_key].type in (IntType, LongType) and \
360 self.primary_key not in self:
361 pk_id = self.api.db.next_id(self.table_name, self.primary_key)
362 self[self.primary_key] = pk_id
363 db_fields[self.primary_key] = pk_id
364 keys = db_fields.keys()
365 values = [self.api.db.param(key, value) for (key, value) in db_fields.items()]
367 sql = "INSERT INTO %s (%s) VALUES (%s)" % \
368 (self.table_name, ", ".join(keys), ", ".join(values))
370 # Update existing row
371 columns = ["%s = %s" % (key, value) for (key, value) in zip(keys, values)]
372 sql = "UPDATE %s SET " % self.table_name + \
373 ", ".join(columns) + \
376 self.api.db.param(self.primary_key, self[self.primary_key]))
378 self.api.db.do(sql, db_fields)
383 def delete(self, commit = True):
385 Delete row from its primary table, and from any tables that
389 assert self.primary_key in self
391 for table in self.join_tables + [self.table_name]:
392 if isinstance(table, tuple):
396 key = self.primary_key
398 sql = "DELETE FROM %s WHERE %s = %s" % \
400 self.api.db.param(self.primary_key, self[self.primary_key]))
402 self.api.db.do(sql, self)
409 Representation of row(s) in a database table.
412 def __init__(self, api, classobj, columns = None):
414 self.classobj = classobj
418 columns = classobj.fields
421 (columns,tag_columns,rejected) = classobj.parse_columns(columns)
422 if not columns and not tag_columns:
423 raise PLCInvalidArgument, "No valid return fields specified for class %s"%classobj.__name__
425 raise PLCInvalidArgument, "unknown column(s) specified %r in %s"%(rejected,classobj.__name__)
427 self.columns = columns
428 self.tag_columns = tag_columns
430 def sync(self, commit = True):
432 Flush changes back to the database.
438 def selectall(self, sql, params = None):
440 Given a list of rows from the database, fill ourselves with
444 for row in self.api.db.selectall(sql, params):
445 obj = self.classobj(self.api, row)
448 def dict(self, key_field = None):
450 Return ourself as a dict keyed on key_field.
453 if key_field is None:
454 key_field = self.classobj.primary_key
456 return dict([(obj[key_field], obj) for obj in self])