4 from PLC.Timestamp import Timestamp
5 from PLC.Faults import *
6 from PLC.Parameter import Parameter
11 Representation of a row in a database table. To use, optionally
12 instantiate with a dict of values. Update as you would a
13 dict. Commit to the database with sync().
16 # Set this to the name of the table that stores the row.
17 # e.g. table_name = "nodes"
20 # Set this to the name of the primary key of the table. It is
21 # assumed that the this key is a sequence if it is not set when
23 # e.g. primary_key="node_id"
26 # Set this to the names of tables that reference this table's
30 # Set this to a dict of the valid fields of this object and their
31 # types. Not all fields (e.g., joined fields) may be updated via
35 # The name of the view that extends objects with tags
36 # e.g. view_tags_name = "view_node_tags"
39 # Set this to the set of tags that can be returned by the Get function
42 def __init__(self, api, fields = {}):
43 dict.__init__(self, fields)
45 # run the class_init initializer once
47 if not hasattr(cls,'class_inited'):
49 cls.class_inited=True # actual value does not matter
53 Validates values. Will validate a value with a custom function
54 if a function named 'validate_[key]' exists.
57 # Warn about mandatory fields
58 mandatory_fields = self.api.db.fields(self.table_name, notnull = True, hasdef = False)
59 for field in mandatory_fields:
60 if field not in self or self[field] is None:
61 raise PLCInvalidArgument(field + " must be specified and cannot be unset in class %s"%self.__class__.__name__)
63 # Validate values before committing
64 for key, value in self.items():
65 if value is not None and hasattr(self, 'validate_' + key):
66 validate = getattr(self, 'validate_' + key)
67 self[key] = validate(value)
69 def separate_types(self, items):
71 Separate a list of different typed objects.
72 Return a list for each type (ints, strs and dicts)
75 if isinstance(items, (list, tuple, set)):
76 ints = [x for x in items if isinstance(x, int)]
77 strs = [x for x in items if isinstance(x, str)]
78 dicts = [x for x in items if isinstance(x, dict)]
79 return (ints, strs, dicts)
81 raise PLCInvalidArgument("Can only separate list types")
84 def associate(self, *args):
86 Provides a means for high level api calls to associate objects
87 using low level calls.
91 raise PLCInvalidArgumentCount("auth, field, value must be specified")
92 elif hasattr(self, 'associate_' + args[1]):
93 associate = getattr(self, 'associate_'+args[1])
96 raise PLCInvalidArguemnt("No such associate function associate_%s" % args[1])
98 def validate_timestamp (self, timestamp):
99 return Timestamp.sql_validate(timestamp)
101 def add_object(self, classobj, join_table, columns = None):
103 Returns a function that can be used to associate this object
107 def add(self, obj, columns = None, commit = True):
109 Associate with the specified object.
112 # Various sanity checks
113 assert isinstance(self, Row)
114 assert self.primary_key in self
115 assert join_table in self.join_tables
116 assert isinstance(obj, classobj)
117 assert isinstance(obj, Row)
118 assert obj.primary_key in obj
119 assert join_table in obj.join_tables
121 # By default, just insert the primary keys of each object
122 # into the join table.
124 columns = {self.primary_key: self[self.primary_key],
125 obj.primary_key: obj[obj.primary_key]}
128 for name, value in columns.items():
129 params.append(self.api.db.param(name, value))
131 self.api.db.do("INSERT INTO %s (%s) VALUES(%s)" % \
132 (join_table, ", ".join(columns), ", ".join(params)),
140 add_object = classmethod(add_object)
142 def remove_object(self, classobj, join_table):
144 Returns a function that can be used to disassociate this
148 def remove(self, obj, commit = True):
150 Disassociate from the specified object.
153 assert isinstance(self, Row)
154 assert self.primary_key in self
155 assert join_table in self.join_tables
156 assert isinstance(obj, classobj)
157 assert isinstance(obj, Row)
158 assert obj.primary_key in obj
159 assert join_table in obj.join_tables
161 self_id = self[self.primary_key]
162 obj_id = obj[obj.primary_key]
164 self.api.db.do("DELETE FROM %s WHERE %s = %s AND %s = %s" % \
166 self.primary_key, self.api.db.param('self_id', self_id),
167 obj.primary_key, self.api.db.param('obj_id', obj_id)),
175 remove_object = classmethod(remove_object)
177 # convenience: check in dict (self.fields or self.tags) that a key is writable
179 def is_writable (key,value,dict):
180 # if not mentioned, assume it's writable (e.g. deleted ...)
181 if key not in dict: return True
182 # if mentioned but not linked to a Parameter object, idem
183 if not isinstance(dict[key], Parameter): return True
184 # if not marked ro, it's writable
185 if not dict[key].ro: return True
188 def db_fields(self, obj = None):
190 Return only those fields that can be set or updated directly
191 (i.e., those fields that are in the primary table (table_name)
192 for this object, and are not marked as a read-only Parameter.
198 db_fields = self.api.db.fields(self.table_name)
199 return dict ( [ (key, value) for (key, value) in list(obj.items())
200 if key in db_fields and
201 Row.is_writable(key, value, self.fields) ] )
203 def tag_fields (self, obj=None):
205 Return the fields of obj that are mentioned in tags
207 if obj is None: obj=self
209 return dict ( [ (key,value) for (key,value) in obj.items()
210 if key in self.tags and Row.is_writable(key,value,self.tags) ] )
212 # takes as input a list of columns, sort native fields from tags
213 # returns 2 dicts and one list : fields, tags, rejected
215 def parse_columns (cls, columns):
216 (fields,tags,rejected)=({},{},[])
217 for column in columns:
218 if column in cls.fields: fields[column]=cls.fields[column]
219 elif column in cls.tags: tags[column]=cls.tags[column]
220 else: rejected.append(column)
221 return (fields,tags,rejected)
223 # compute the 'accepts' part of a method, from a list of column names, and a fields dict
224 # use exclude=True to exclude the column names instead
225 # typically accepted_fields (Node.fields,['hostname','model',...])
227 def accepted_fields (update_columns, fields_dict, exclude=False):
229 for (k,v) in fields_dict.items():
230 if (not exclude and k in update_columns) or (exclude and k not in update_columns):
234 # filter out user-provided fields that are not part of the declared acceptance list
235 # keep it separate from split_fields for simplicity
236 # typically check_fields (<user_provided_dict>,{'hostname':Parameter(str,...),'model':Parameter(..)...})
238 def check_fields (user_dict, accepted_fields):
239 # avoid the simple, but silent, version
240 # return dict ([ (k,v) for (k,v) in user_dict.items() if k in accepted_fields ])
242 for (k,v) in list(user_dict.items()):
243 if k in accepted_fields: result[k]=v
244 else: raise PLCInvalidArgument ('Trying to set/change unaccepted key %s'%k)
247 # given a dict (typically passed to an Update method), we check and sort
248 # them against a list of dicts, e.g. [Node.fields, Node.related_fields]
249 # return is a list that contains n+1 dicts, last one has the rejected fields
251 def split_fields (fields, dicts):
253 for x in dicts: result.append({})
255 for (field,value) in fields.items():
257 for i in range(len(dicts)):
258 candidate_dict=dicts[i]
259 if field in list(candidate_dict.keys()):
260 result[i][field]=value
263 if not found: rejected[field]=value
264 result.append(rejected)
267 ### class initialization : create tag-dependent cross view if needed
269 def tagvalue_view_name (cls, tagname):
270 return "tagvalue_view_%s_%s"%(cls.primary_key,tagname)
273 def tagvalue_view_create_sql (cls,tagname):
275 returns a SQL sentence that creates a view named after the primary_key and tagname,
277 (*) column 1: primary_key
278 (*) column 2: actual tag value, renamed into tagname
281 if not cls.view_tags_name:
282 raise Exception('WARNING: class %s needs to set view_tags_name'%cls.__name__)
284 table_name=cls.table_name
285 primary_key=cls.primary_key
286 view_tags_name=cls.view_tags_name
287 tagvalue_view_name=cls.tagvalue_view_name(tagname)
288 return 'CREATE OR REPLACE VIEW %(tagvalue_view_name)s ' \
289 'as SELECT %(table_name)s.%(primary_key)s,%(view_tags_name)s.value as "%(tagname)s" ' \
290 'from %(table_name)s right join %(view_tags_name)s using (%(primary_key)s) ' \
291 'WHERE tagname = \'%(tagname)s\';'%locals()
294 def class_init (cls,api):
295 cls.tagvalue_views_create (api)
298 def tagvalue_views_create (cls,api):
299 if not cls.tags: return
300 for tagname in list(cls.tags.keys()):
301 api.db.do(cls.tagvalue_view_create_sql (tagname))
309 # Filter out fields that cannot be set or updated directly
310 # (and thus would not affect equality for the purposes of
311 # deciding if we should sync() or not).
313 y = self.db_fields(y)
314 return dict.__eq__(x, y)
316 # validate becomes optional on sept. 2010
317 # we find it useful to use DeletePerson on duplicated entries
318 def sync(self, commit = True, insert = None, validate=True):
320 Flush changes back to the database.
323 # Validate all specified fields
324 if validate: self.validate()
326 # Filter out fields that cannot be set or updated directly
327 db_fields = self.db_fields()
329 # Parameterize for safety
330 keys = list(db_fields.keys())
331 values = [self.api.db.param(key, value) for (key, value) in list(db_fields.items())]
333 # If the primary key (usually an auto-incrementing serial
334 # identifier) has not been specified, or the primary key is the
335 # only field in the table, or insert has been forced.
336 if self.primary_key not in self or \
337 keys == [self.primary_key] or \
340 # If primary key id is a serial int and it isnt included, get next id
341 if (self.fields[self.primary_key].type is int
342 and self.primary_key not in self):
343 pk_id = self.api.db.next_id(self.table_name, self.primary_key)
344 self[self.primary_key] = pk_id
345 db_fields[self.primary_key] = pk_id
346 keys = list(db_fields.keys())
347 values = [self.api.db.param(key, value) for (key, value) in list(db_fields.items())]
349 sql = "INSERT INTO %s (%s) VALUES (%s)" % \
350 (self.table_name, ", ".join(keys), ", ".join(values))
352 # Update existing row
353 columns = ["%s = %s" % (key, value) for (key, value) in zip(keys, values)]
354 sql = "UPDATE {} SET {} WHERE {} = {}"\
355 .format(self.table_name,
358 self.api.db.param(self.primary_key, self[self.primary_key]))
360 self.api.db.do(sql, db_fields)
365 def delete(self, commit = True):
367 Delete row from its primary table, and from any tables that
371 assert self.primary_key in self
373 for table in self.join_tables + [self.table_name]:
374 if isinstance(table, tuple):
378 key = self.primary_key
380 sql = "DELETE FROM %s WHERE %s = %s" % \
382 self.api.db.param(self.primary_key, self[self.primary_key]))
384 self.api.db.do(sql, self)
391 Representation of row(s) in a database table.
394 def __init__(self, api, classobj, columns = None):
396 self.classobj = classobj
400 columns = classobj.fields
403 (columns,tag_columns,rejected) = classobj.parse_columns(columns)
404 if not columns and not tag_columns:
405 raise PLCInvalidArgument("No valid return fields specified for class %s"%classobj.__name__)
407 raise PLCInvalidArgument("unknown column(s) specified %r in %s"%(rejected,classobj.__name__))
409 self.columns = columns
410 self.tag_columns = tag_columns
412 def sync(self, commit = True):
414 Flush changes back to the database.
420 def selectall(self, sql, params = None):
422 Given a list of rows from the database, fill ourselves with
426 for row in self.api.db.selectall(sql, params):
427 obj = self.classobj(self.api, row)
430 def dict(self, key_field = None):
432 Return ourself as a dict keyed on key_field.
435 if key_field is None:
436 key_field = self.classobj.primary_key
438 return dict([(obj[key_field], obj) for obj in self])