--- /dev/null
+from types import StringTypes
+import time
+import calendar
+
+from PLC.Faults import *
+from PLC.Parameter import Parameter
+
+class Row(dict):
+ """
+ Representation of a row in a database table. To use, optionally
+ instantiate with a dict of values. Update as you would a
+ dict. Commit to the database with sync().
+ """
+
+ # Set this to the name of the table that stores the row.
+ 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.
+ primary_key = None
+
+ # 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 = {}
+
+ def __init__(self, api, fields = {}):
+ dict.__init__(self, fields)
+ self.api = api
+
+ def validate(self):
+ """
+ Validates values. Will validate a value with a custom function
+ if a function named 'validate_[key]' exists.
+ """
+
+ # 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) 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():
+ if value is not None and hasattr(self, 'validate_' + key):
+ validate = getattr(self, 'validate_' + key)
+ self[key] = validate(value)
+
+ 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 = filter(lambda x: isinstance(x, (int, long)), items)
+ strs = filter(lambda x: isinstance(x, StringTypes), items)
+ dicts = filter(lambda x: isinstance(x, dict), items)
+ return (ints, strs, dicts)
+ else:
+ raise PLCInvalidArgument, "Can only separate list types"
+
+
+ def associate(self, *args):
+ """
+ Provides a means for high lvl api calls to associate objects
+ using low lvl 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, 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 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.iteritems():
+ 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)
+
+ 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(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()))
+
+ 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)
+
+ def sync(self, commit = True, insert = None):
+ """
+ Flush changes back to the database.
+ """
+
+ # Validate all specified fields
+ self.validate()
+
+ # Filter out fields that cannot be set or updated directly
+ db_fields = self.db_fields()
+
+ # Parameterize for safety
+ keys = db_fields.keys()
+ values = [self.api.db.param(key, value) for (key, value) in db_fields.items()]
+
+ # 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 not self.has_key(self.primary_key) or \
+ keys == [self.primary_key] or \
+ insert is True:
+ # Insert new row
+ 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]))
+
+ 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(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
+ else:
+ columns = filter(lambda x: x in classobj.fields, columns)
+ if not columns:
+ raise PLCInvalidArgument, "No valid return fields specified"
+
+ self.columns = columns
+
+ def sync(self, commit = True):
+ """
+ Flush changes back to the database.
+ """
+
+ 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])
git://git.onelab.eu / plcapi.git / blobdiff