-from types import StringTypes
+# $Id$
+# $URL$
+from types import StringTypes, IntType, LongType
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 the names of tables that reference this table's
# 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):
"""
def associate(self, *args):
"""
- Provides a means for high lvl api calls to associate objects
- using low lvl calls.
+ Provides a means for high level api calls to associate objects
+ using low level calls.
"""
if len(args) < 3:
else:
raise PLCInvalidArguemnt, "No such associate function associate_%s" % args[1]
- def validate_timestamp(self, timestamp, check_future = False):
- """
- Validates the specified GMT timestamp string (must be in
- %Y-%m-%d %H:%M:%S format) or number (seconds since UNIX epoch,
- i.e., 1970-01-01 00:00:00 GMT). If check_future is True,
- raises an exception if timestamp is not in the future. Returns
- a GMT timestamp string.
- """
-
- time_format = "%Y-%m-%d %H:%M:%S"
-
- if isinstance(timestamp, StringTypes):
- # calendar.timegm() is the inverse of time.gmtime()
- timestamp = calendar.timegm(time.strptime(timestamp, time_format))
-
- # Human readable timestamp string
- human = time.strftime(time_format, time.gmtime(timestamp))
-
- if check_future and timestamp < time.time():
- raise PLCInvalidArgument, "'%s' not in the future" % human
-
- return human
+ def validate_timestamp (self, timestamp):
+ return Timestamp.sql_validate(timestamp)
def add_object(self, classobj, join_table, columns = None):
"""
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
for this object, and are not marked as a read-only Parameter.
"""
- if obj is None:
- obj = self
+ if obj is None: obj = self
db_fields = self.api.db.fields(self.table_name)
- return dict(filter(lambda (key, value): \
- key in db_fields and \
- (key not in self.fields or \
- not isinstance(self.fields[key], Parameter) or \
- not self.fields[key].ro),
- obj.items()))
+ return dict ( [ (key,value) for (key,value) in 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.iteritems()
+ 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.iteritems():
+ 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 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.iteritems():
+ found=False
+ for i in range(len(dicts)):
+ candidate_dict=dicts[i]
+ if field in 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 cls.tags.keys():
+ api.db.do(cls.tagvalue_view_create_sql (tagname))
+ api.db.commit()
def __eq__(self, y):
"""
if not self.has_key(self.primary_key) 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 in (IntType, LongType) 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 = db_fields.keys()
+ values = [self.api.db.param(key, value) for (key, value) in db_fields.items()]
# Insert new row
sql = "INSERT INTO %s (%s) VALUES (%s)" % \
(self.table_name, ", ".join(keys), ", ".join(values))
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()
if columns is None:
columns = classobj.fields
+ tag_columns={}
else:
- columns = filter(lambda x: x in classobj.fields, columns)
- if not columns:
- raise PLCInvalidArgument, "No valid return fields specified"
+ (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):
"""
git://git.onelab.eu / plcapi.git / blobdiff