# Copyright (c) 2009, Digital Enterprise Research Institute (DERI),
# NUI Galway
# All rights reserved.
# author: Cosmin Basca
# email: cosmin.basca@gmail.com
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with
# the distribution.
# * Neither the name of DERI nor the
# names of its contributors may be used to endorse or promote
# products derived from this software without specific prior
# written permission.
# THIS SOFTWARE IS PROVIDED BY DERI ''AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DERI BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
# OF THE POSSIBILITY OF SUCH DAMAGE.
# -*- coding: utf-8 -*-
from abc import ABCMeta, abstractmethod
from surf.plugin import Plugin
from surf.plugin.reader import RDFReader
__author__ = 'Cosmin Basca'
class InvalidResourceException(Exception):
def __init__(self,*args,**kwargs):
super(InvalidResourceException,self).__init__(self,*args,**kwargs)
[docs]class RDFWriter(Plugin):
"""
Super class for all surf Writer plugins.
"""
__metaclass__ = ABCMeta
def __init__(self, reader, *args, **kwargs):
super(RDFWriter, self).__init__(*args, **kwargs)
if isinstance(reader,RDFReader):
self.__reader = reader
else:
raise ValueError("The reader plugin must be of type RDFReader " +
"not %s" % type(reader))
reader = property(fget = lambda self: self.__reader)
@abstractmethod
def _clear(self,context=None):
pass
@abstractmethod
def _save(self, *resources):
pass
@abstractmethod
def _update(self, *resources):
pass
@abstractmethod
def _remove(self, *resources, **kwargs):
pass
@abstractmethod
def _size(self):
return -1
@abstractmethod
def _add_triple(self, s=None, p=None, o=None, context=None):
pass
@abstractmethod
def _set_triple(self, s=None, p=None, o=None, context=None):
pass
def _remove_triple(self, s=None, p=None, o=None, context=None):
pass
[docs] def clear(self, context=None):
"""
Remove all triples from the `store`.
If ``context`` is specified, only the specified context will be cleared.
"""
self._clear(context=context)
[docs] def save(self, *resources):
"""
Replace the ``*resources`` in store with their current state.
"""
for resource in resources:
if not hasattr(resource, "subject"):
raise InvalidResourceException("Arguments must be of type surf.resource.Resource")
self._save(*resources)
[docs] def update(self, *resources):
"""
Update the ``*resources`` to the `store` - persist.
"""
for resource in resources:
if not hasattr(resource, "subject"):
raise InvalidResourceException("Arguments must be of type surf.resource.Resource")
self._update(resource)
[docs] def remove(self, *resources, **kwargs):
"""
Completely remove the ``*resources`` from the `store`.
"""
# TODO: decide whether triples that are indirect belong to other
# resource should be removed as well)
for resource in resources:
if not hasattr(resource, "subject"):
raise InvalidResourceException("Arguments must be of type surf.resource.Resource")
self._remove(*resources, **kwargs)
[docs] def size(self):
"""
Return the number of `triples` in the current `store`.
"""
return self._size()
# triple level access methods
[docs] def add_triple(self, s=None, p=None, o=None, context=None):
"""
Add a triple to the `store`, in the specified ``context``.
`None` can be used as a wildcard.
"""
self._add_triple(s, p, o, context)
[docs] def set_triple(self, s=None, p=None, o=None, context=None):
"""
Replace a triple in the `store` and specified ``context``.
`None` can be used as a wildcard.
"""
self._set_triple(s,p,o,context)
[docs] def remove_triple(self, s=None, p=None, o=None, context=None):
"""
Remove a triple from the `store`, from the specified ``context``.
`None` can be used as a wildcard.
"""
self._remove_triple(s,p,o,context)
# management
[docs] def close(self):
"""
Close the `plugin`.
"""
pass
[docs] def index_triples(self,**kwargs):
"""
Perform `index` of the `triples` if such functionality is present.
Return `True` if operation successful.
"""
return False
[docs] def load_triples(self,**kwargs):
"""
Load `triples` from supported `sources` if such functionality is present.
Return `True` if operation successful.
"""
return False
class NoneWriter(RDFWriter):
def _set_triple(self, s=None, p=None, o=None, context=None):
pass
def _update(self, *resources):
pass
def _save(self, *resources):
pass
def _remove(self, *resources, **kwargs):
pass
def _clear(self, context=None):
pass
def _add_triple(self, s=None, p=None, o=None, context=None):
pass
def _size(self):
pass
