def create(self, *fields, **kw):
"""Creates a database instance and returns a reference to it
fields are tuples (field_name,field_type[,default_value])
field_name must not begin by _
field_type can be one of the values in the dictionary self.types
A keyword 'mode' can be specified:
'override' : if the base already exists, remove it and create
a new one
'open' : if the base already exists, open it
If mode is not set, if the base exists, raise IOError
In any case, if a directory of the same name exists, raise an
exception
"""
mode = kw.get('mode', None)
if os.path.exists(self.name):
if os.path.exists(self.info_name):
if mode == 'override':
pass
elif mode == 'open':
return self.open()
else:
raise IOError, "Base %s already exists" % self.name
else:
if mode != 'open':
raise IOError, "Directory %s already exists" % self.name
else:
raise IOError,"Mode 'open' : " \
"Directory %s already exists but no info file found" \
%self.name
self.field_names = [f[0] for f in fields]
self.fields = dict([(f[0], f[1]) for f in fields])
# set general info about field definition
buzhug_info.set_info(self, fields)
self.field_names = ['__id__', '__version__'] + self.field_names
self.fields['__id__'] = int
self.fields['__version__'] = int
# create the directory used for the base
if not os.path.exists(self.name):
os.mkdir(self.name)
# create index file
self._id_pos = IntegerFile(self.name, '_id_pos').create()
# create positions file
open(self.pos_name, 'wb').close()
self._pos = PositionFile(self).create()
# create the file holding a list of the deleted rows (the line number
# of deleted records in field files)
self._del_rows = DeletedRowsFile(self.name, "__del_rows__").create()
# create field files abstractions
self._file = {}
for f in self.field_names:
self._file[f] = self.file_types[self.fields[f]](self.name, f)
self._file[f].create()
# save information in files __info__ and __defaults__
buzhug_info.save_info(self)
# create class for records with all values set
self._full_rec = makeRecordClass(self, self.record_class,
self.field_names)
return self
def create(self,*fields,**kw):
"""Creates a database instance and returns a reference to it
fields are tuples (field_name,field_type[,default_value])
field_name must not begin by _
field_type can be one of the values in the dictionary self.types
A keyword 'mode' can be specified:
'override' : if the base already exists, remove it and create
a new one
'open' : if the base already exists, open it
If mode is not set, if the base exists, raise IOError
In any case, if a directory of the same name exists, raise an
exception
"""
mode = kw.get('mode',None)
if os.path.exists(self.name):
if os.path.exists(self.info_name):
if mode == 'override':
pass
elif mode == 'open':
return self.open()
else:
raise IOError,"Base %s already exists" %self.name
else:
if mode != 'open':
raise IOError,"Directory %s already exists" %self.name
else:
raise IOError,"Mode 'open' : " \
"Directory %s already exists but no info file found" \
%self.name
self.field_names = [ f[0] for f in fields ]
self.fields = dict([(f[0],f[1]) for f in fields])
# set general info about field definition
buzhug_info.set_info(self,fields)
self.field_names = ['__id__','__version__'] + self.field_names
self.fields['__id__'] = int
self.fields['__version__'] = int
# create the directory used for the base
if not os.path.exists(self.name):
os.mkdir(self.name)
# create index file
self._id_pos = IntegerFile(self.name,'_id_pos').create()
# create positions file
open(self.pos_name,'wb').close()
self._pos = PositionFile(self).create()
# create the file holding a list of the deleted rows (the line number
# of deleted records in field files)
self._del_rows = DeletedRowsFile(self.name,"__del_rows__").create()
# create field files abstractions
self._file = {}
for f in self.field_names:
self._file[f] = self.file_types[self.fields[f]](self.name,f)
self._file[f].create()
# save information in files __info__ and __defaults__
buzhug_info.save_info(self)
# create class for records with all values set
self._full_rec = makeRecordClass(self,self.record_class,self.field_names)
return self
def set_default(self, field_name, default):
"""Set a default value for a field"""
fields = []
for f in self.field_names[2:]:
if f == field_name:
fields.append((f, self.fields[f], default))
elif self.defaults[f] is None:
fields.append((f, self.fields[f]))
else:
fields.append((f, self.fields[f], self.defaults[f]))
buzhug_info.set_info(self, fields)
def set_default(self,field_name,default):
"""Set a default value for a field"""
fields = []
for f in self.field_names[2:]:
if f==field_name:
fields.append((f,self.fields[f],default))
elif self.defaults[f] is None:
fields.append((f,self.fields[f]))
else:
fields.append((f,self.fields[f],self.defaults[f]))
buzhug_info.set_info(self,fields)
