+import time
+import calendar
+
+from PLC.Timestamp import Timestamp
from PLC.Faults import *
from PLC.Parameter import Parameter
+
class Row(dict):
"""
Representation of a row in a database table. To use, optionally
"""
# Set this to the name of the table that stores the row.
+ # e.g. table_name = "nodes"
table_name = None
# Set this to the name of the primary key of the table. It is
# assumed that the this key is a sequence if it is not set when
# sync() is called.
+ # e.g. primary_key="node_id"
primary_key = None
- # Set this to a dict of the valid fields of this object. Not all
- # fields (e.g., joined fields) may be updated via sync().
+ # Set this to the names of tables that reference this table's
+ # primary key.
+ join_tables = []
+
+ # Set this to a dict of the valid fields of this object and their
+ # types. Not all fields (e.g., joined fields) may be updated via
+ # sync().
fields = {}
+ # The name of the view that extends objects with tags
+ # e.g. view_tags_name = "view_node_tags"
+ view_tags_name = None
+
+ # Set this to the set of tags that can be returned by the Get function
+ tags = {}
+
+ def __init__(self, api, fields = {}):
+ dict.__init__(self, fields)
+ self.api = api
+ # run the class_init initializer once
+ cls=self.__class__
+ if not hasattr(cls,'class_inited'):
+ cls.class_init (api)
+ cls.class_inited=True # actual value does not matter
+
def validate(self):
"""
Validates values. Will validate a value with a custom function
# Warn about mandatory fields
mandatory_fields = self.api.db.fields(self.table_name, notnull = True, hasdef = False)
for field in mandatory_fields:
- if not self.has_key(field):
- raise PLCInvalidArgument, field + " must be specified"
+ if field not in self or self[field] is None:
+ raise PLCInvalidArgument(field + " must be specified and cannot be unset in class %s"%self.__class__.__name__)
# Validate values before committing
- for key, value in self.iteritems():
+ for key, value in self.items():
if value is not None and hasattr(self, 'validate_' + key):
validate = getattr(self, 'validate_' + key)
self[key] = validate(value)
- def sync(self, commit = True):
+ def separate_types(self, items):
+ """
+ Separate a list of different typed objects.
+ Return a list for each type (ints, strs and dicts)
+ """
+
+ if isinstance(items, (list, tuple, set)):
+ ints = [x for x in items if isinstance(x, int)]
+ strs = [x for x in items if isinstance(x, str)]
+ dicts = [x for x in items if isinstance(x, dict)]
+ return (ints, strs, dicts)
+ else:
+ raise PLCInvalidArgument("Can only separate list types")
+
+
+ def associate(self, *args):
+ """
+ Provides a means for high level api calls to associate objects
+ using low level calls.
+ """
+
+ if len(args) < 3:
+ raise PLCInvalidArgumentCount("auth, field, value must be specified")
+ elif hasattr(self, 'associate_' + args[1]):
+ associate = getattr(self, 'associate_'+args[1])
+ associate(*args)
+ else:
+ raise PLCInvalidArguemnt("No such associate function associate_%s" % args[1])
+
+ def validate_timestamp (self, timestamp):
+ return Timestamp.sql_validate(timestamp)
+
+ def add_object(self, classobj, join_table, columns = None):
+ """
+ Returns a function that can be used to associate this object
+ with another.
+ """
+
+ def add(self, obj, columns = None, commit = True):
+ """
+ Associate with the specified object.
+ """
+
+ # Various sanity checks
+ assert isinstance(self, Row)
+ assert self.primary_key in self
+ assert join_table in self.join_tables
+ assert isinstance(obj, classobj)
+ assert isinstance(obj, Row)
+ assert obj.primary_key in obj
+ assert join_table in obj.join_tables
+
+ # By default, just insert the primary keys of each object
+ # into the join table.
+ if columns is None:
+ columns = {self.primary_key: self[self.primary_key],
+ obj.primary_key: obj[obj.primary_key]}
+
+ params = []
+ for name, value in columns.items():
+ params.append(self.api.db.param(name, value))
+
+ self.api.db.do("INSERT INTO %s (%s) VALUES(%s)" % \
+ (join_table, ", ".join(columns), ", ".join(params)),
+ columns)
+
+ if commit:
+ self.api.db.commit()
+
+ return add
+
+ add_object = classmethod(add_object)
+
+ def remove_object(self, classobj, join_table):
+ """
+ Returns a function that can be used to disassociate this
+ object with another.
+ """
+
+ def remove(self, obj, commit = True):
+ """
+ Disassociate from the specified object.
+ """
+
+ assert isinstance(self, Row)
+ assert self.primary_key in self
+ assert join_table in self.join_tables
+ assert isinstance(obj, classobj)
+ assert isinstance(obj, Row)
+ assert obj.primary_key in obj
+ assert join_table in obj.join_tables
+
+ self_id = self[self.primary_key]
+ obj_id = obj[obj.primary_key]
+
+ self.api.db.do("DELETE FROM %s WHERE %s = %s AND %s = %s" % \
+ (join_table,
+ self.primary_key, self.api.db.param('self_id', self_id),
+ obj.primary_key, self.api.db.param('obj_id', obj_id)),
+ locals())
+
+ if commit:
+ self.api.db.commit()
+
+ return remove
+
+ remove_object = classmethod(remove_object)
+
+ # convenience: check in dict (self.fields or self.tags) that a key is writable
+ @staticmethod
+ def is_writable (key,value,dict):
+ # if not mentioned, assume it's writable (e.g. deleted ...)
+ if key not in dict: return True
+ # if mentioned but not linked to a Parameter object, idem
+ if not isinstance(dict[key], Parameter): return True
+ # if not marked ro, it's writable
+ if not dict[key].ro: return True
+ return False
+
+ def db_fields(self, obj = None):
+ """
+ Return only those fields that can be set or updated directly
+ (i.e., those fields that are in the primary table (table_name)
+ for this object, and are not marked as a read-only Parameter.
+ """
+
+ if obj is None:
+ obj = self
+
+ db_fields = self.api.db.fields(self.table_name)
+ return dict ( [ (key, value) for (key, value) in list(obj.items())
+ if key in db_fields and
+ Row.is_writable(key, value, self.fields) ] )
+
+ def tag_fields (self, obj=None):
+ """
+ Return the fields of obj that are mentioned in tags
+ """
+ if obj is None: obj=self
+
+ return dict ( [ (key,value) for (key,value) in obj.items()
+ if key in self.tags and Row.is_writable(key,value,self.tags) ] )
+
+ # takes as input a list of columns, sort native fields from tags
+ # returns 2 dicts and one list : fields, tags, rejected
+ @classmethod
+ def parse_columns (cls, columns):
+ (fields,tags,rejected)=({},{},[])
+ for column in columns:
+ if column in cls.fields: fields[column]=cls.fields[column]
+ elif column in cls.tags: tags[column]=cls.tags[column]
+ else: rejected.append(column)
+ return (fields,tags,rejected)
+
+ # compute the 'accepts' part of a method, from a list of column names, and a fields dict
+ # use exclude=True to exclude the column names instead
+ # typically accepted_fields (Node.fields,['hostname','model',...])
+ @staticmethod
+ def accepted_fields (update_columns, fields_dict, exclude=False):
+ result={}
+ for (k,v) in fields_dict.items():
+ if (not exclude and k in update_columns) or (exclude and k not in update_columns):
+ result[k]=v
+ return result
+
+ # filter out user-provided fields that are not part of the declared acceptance list
+ # keep it separate from split_fields for simplicity
+ # typically check_fields (<user_provided_dict>,{'hostname':Parameter(str,...),'model':Parameter(..)...})
+ @staticmethod
+ def check_fields (user_dict, accepted_fields):
+# avoid the simple, but silent, version
+# return dict ([ (k,v) for (k,v) in user_dict.items() if k in accepted_fields ])
+ result={}
+ for (k,v) in list(user_dict.items()):
+ if k in accepted_fields: result[k]=v
+ else: raise PLCInvalidArgument ('Trying to set/change unaccepted key %s'%k)
+ return result
+
+ # given a dict (typically passed to an Update method), we check and sort
+ # them against a list of dicts, e.g. [Node.fields, Node.related_fields]
+ # return is a list that contains n+1 dicts, last one has the rejected fields
+ @staticmethod
+ def split_fields (fields, dicts):
+ result=[]
+ for x in dicts: result.append({})
+ rejected={}
+ for (field,value) in fields.items():
+ found=False
+ for i in range(len(dicts)):
+ candidate_dict=dicts[i]
+ if field in list(candidate_dict.keys()):
+ result[i][field]=value
+ found=True
+ break
+ if not found: rejected[field]=value
+ result.append(rejected)
+ return result
+
+ ### class initialization : create tag-dependent cross view if needed
+ @classmethod
+ def tagvalue_view_name (cls, tagname):
+ return "tagvalue_view_%s_%s"%(cls.primary_key,tagname)
+
+ @classmethod
+ def tagvalue_view_create_sql (cls,tagname):
+ """
+ returns a SQL sentence that creates a view named after the primary_key and tagname,
+ with 2 columns
+ (*) column 1: primary_key
+ (*) column 2: actual tag value, renamed into tagname
+ """
+
+ if not cls.view_tags_name:
+ raise Exception('WARNING: class %s needs to set view_tags_name'%cls.__name__)
+
+ table_name=cls.table_name
+ primary_key=cls.primary_key
+ view_tags_name=cls.view_tags_name
+ tagvalue_view_name=cls.tagvalue_view_name(tagname)
+ return 'CREATE OR REPLACE VIEW %(tagvalue_view_name)s ' \
+ 'as SELECT %(table_name)s.%(primary_key)s,%(view_tags_name)s.value as "%(tagname)s" ' \
+ 'from %(table_name)s right join %(view_tags_name)s using (%(primary_key)s) ' \
+ 'WHERE tagname = \'%(tagname)s\';'%locals()
+
+ @classmethod
+ def class_init (cls,api):
+ cls.tagvalue_views_create (api)
+
+ @classmethod
+ def tagvalue_views_create (cls,api):
+ if not cls.tags: return
+ for tagname in list(cls.tags.keys()):
+ api.db.do(cls.tagvalue_view_create_sql (tagname))
+ api.db.commit()
+
+ def __eq__(self, y):
+ """
+ Compare two objects.
+ """
+
+ # Filter out fields that cannot be set or updated directly
+ # (and thus would not affect equality for the purposes of
+ # deciding if we should sync() or not).
+ x = self.db_fields()
+ y = self.db_fields(y)
+ return dict.__eq__(x, y)
+
+ # validate becomes optional on sept. 2010
+ # we find it useful to use DeletePerson on duplicated entries
+ def sync(self, commit = True, insert = None, validate=True):
"""
Flush changes back to the database.
"""
# Validate all specified fields
- self.validate()
+ if validate: self.validate()
# Filter out fields that cannot be set or updated directly
- all_fields = self.api.db.fields(self.table_name)
- fields = dict(filter(lambda (key, value): \
- key in all_fields and \
- (key not in self.fields or \
- not isinstance(self.fields[key], Parameter) or \
- not self.fields[key].ro),
- self.items()))
+ db_fields = self.db_fields()
# Parameterize for safety
- keys = fields.keys()
- values = [self.api.db.param(key, value) for (key, value) in fields.items()]
+ keys = list(db_fields.keys())
+ values = [self.api.db.param(key, value) for (key, value) in list(db_fields.items())]
- if not self.has_key(self.primary_key):
+ # If the primary key (usually an auto-incrementing serial
+ # identifier) has not been specified, or the primary key is the
+ # only field in the table, or insert has been forced.
+ if self.primary_key not in self or \
+ keys == [self.primary_key] or \
+ insert is True:
+
+ # If primary key id is a serial int and it isnt included, get next id
+ if (self.fields[self.primary_key].type is int
+ and self.primary_key not in self):
+ pk_id = self.api.db.next_id(self.table_name, self.primary_key)
+ self[self.primary_key] = pk_id
+ db_fields[self.primary_key] = pk_id
+ keys = list(db_fields.keys())
+ values = [self.api.db.param(key, value) for (key, value) in list(db_fields.items())]
# Insert new row
- sql = "INSERT INTO %s (%s) VALUES (%s);" % \
+ sql = "INSERT INTO %s (%s) VALUES (%s)" % \
(self.table_name, ", ".join(keys), ", ".join(values))
else:
# Update existing row
columns = ["%s = %s" % (key, value) for (key, value) in zip(keys, values)]
- sql = "UPDATE %s SET " % self.table_name + \
- ", ".join(columns) + \
- " WHERE %s = %s" % \
- (self.primary_key,
- self.api.db.param(self.primary_key, self[self.primary_key]))
+ sql = "UPDATE {} SET {} WHERE {} = {}"\
+ .format(self.table_name,
+ ", ".join(columns),
+ self.primary_key,
+ self.api.db.param(self.primary_key, self[self.primary_key]))
- self.api.db.do(sql, fields)
+ self.api.db.do(sql, db_fields)
- if not self.has_key(self.primary_key):
- self[self.primary_key] = self.api.db.last_insert_id(self.table_name, self.primary_key)
+ if commit:
+ self.api.db.commit()
+
+ def delete(self, commit = True):
+ """
+ Delete row from its primary table, and from any tables that
+ reference it.
+ """
+
+ assert self.primary_key in self
+
+ for table in self.join_tables + [self.table_name]:
+ if isinstance(table, tuple):
+ key = table[1]
+ table = table[0]
+ else:
+ key = self.primary_key
+
+ sql = "DELETE FROM %s WHERE %s = %s" % \
+ (table, key,
+ self.api.db.param(self.primary_key, self[self.primary_key]))
+
+ self.api.db.do(sql, self)
if commit:
self.api.db.commit()
-class Table(dict):
+class Table(list):
"""
Representation of row(s) in a database table.
"""
+ def __init__(self, api, classobj, columns = None):
+ self.api = api
+ self.classobj = classobj
+ self.rows = {}
+
+ if columns is None:
+ columns = classobj.fields
+ tag_columns={}
+ else:
+ (columns,tag_columns,rejected) = classobj.parse_columns(columns)
+ if not columns and not tag_columns:
+ raise PLCInvalidArgument("No valid return fields specified for class %s"%classobj.__name__)
+ if rejected:
+ raise PLCInvalidArgument("unknown column(s) specified %r in %s"%(rejected,classobj.__name__))
+
+ self.columns = columns
+ self.tag_columns = tag_columns
+
def sync(self, commit = True):
"""
Flush changes back to the database.
"""
- for row in self.values():
+ for row in self:
row.sync(commit)
+
+ def selectall(self, sql, params = None):
+ """
+ Given a list of rows from the database, fill ourselves with
+ Row objects.
+ """
+
+ for row in self.api.db.selectall(sql, params):
+ obj = self.classobj(self.api, row)
+ self.append(obj)
+
+ def dict(self, key_field = None):
+ """
+ Return ourself as a dict keyed on key_field.
+ """
+
+ if key_field is None:
+ key_field = self.classobj.primary_key
+
+ return dict([(obj[key_field], obj) for obj in self])