libkosokoso/kosokoso.py

343 lines
11 KiB
Python

import sqlalchemy as sa
from sqlalchemy.orm import declared_attr
from sqlalchemy.ext.associationproxy import association_proxy
# from sqlalchemy import text
import itertools
import logging
import pprint
import sys
# this will get overridden by init_base
Base = None
class TagBase(object):
def __init__(self, tag_text=None):
super(Tag, self).__init__()
self.text = tag_text
def __repr__(self):
return "kk_tag %s: %s" % (self.db_id, self.text)
def __eq__(self, other):
return self.text == other.text
db_id = sa.Column(sa.Integer, primary_key=True)
text = sa.Column(sa.Unicode(255), unique=True)
__tablename__ = "kk_tags"
# we disable batch to ensure that parents are inserted before
# children.
__mapper_args__ = {
# "primary_key": [db_id],
"batch": False
}
class TaggedObjectCollection(object):
__emulates__ = list
def __init__(self):
self.data = []
@sa.orm.collections.collection.internally_instrumented
def append(self, item, _sa_initiator=None):
"""This method is marked internally_instrumented to ensure
that sqlalchemy only notices the add when a TagAssociation
is used. If a class is added directly, we generate a
TagAssociation and re-call this method with the
association, which then triggers the append event.
hang on, shouldn't this all be handled by the
associationproxy?"""
if isinstance(item, TagAssociation):
try:
# logging.debug("adding assoc %s w/ %s" % (item,
# _sa_initiator))
# this has to be done first.
adapter = sa.orm.collections.collection_adapter(self)
item = adapter.fire_append_event(item, _sa_initiator)
if item.tracked_obj:
self.data.append(item)
else:
cls = self._get_class_by_tablename(item.target_table)
thingy = cls()
thingy.db_id = item.target_id
self.data.append(thingy)
# pprint.pprint(self.data)
except TypeError:
raise
else:
logging.debug("adding %s" % item)
# this seems kind of redundant.
assoc = TagAssociation()
assoc.target_id = item.db_id
assoc.target_table = item.__tablename__
assoc.tracked_obj = item
self.append(assoc, _sa_initiator)
def remove(self, item):
pass
# 'extend' is apparently taken?
def merge(self, iterable):
logging.debug('merge called')
for i in iterable:
for j in self.data:
if (i.target_table == j.target_table and
i.target_id == j.target_id):
logging.info(f'item {i} already in collection')
break
else:
logging.info(f'adding {i}')
self.append(i)
continue
def __iter__(self):
return iter(self.data)
def __len__(self):
return len(self.data)
def __eq__(self, other):
pass
# if not isinstance(other, TaggedObjectCollection):
# return False
# if len(self.data) ne len(other.data):
# return False
# s1 = sorted(self.data)
# s2 = sorted(other.data)
# for i in range(0, len(s1)):
# if s1[i] ne s2[i]:
# return False
# return True
def __repr__(self):
out = 'TaggedObjectCollection: ['
for i in self.data:
out += str(i) + '\n'
out += ']'
return out
def _get_class_by_tablename(self, tablename):
"""Return class reference mapped to table.
:param tablename: String with name of table.
:return: Class reference or None.
"""
for c in Base.registry._class_registry.values():
if getattr(c, '__tablename__', None) == tablename:
return c
# for c in Base._decl_class_registry.values():
# if (hasattr(c, '__tablename__')
# and c.__tablename__ == tablename):
# return c
collection = sa.orm.relationship("TagAssociation",
collection_class=TaggedObjectCollection,
enable_typechecks=True,
primaryjoin="TagAssociation.tag_id==Tag.db_id",
back_populates="tag_obj"
)
class TagAssociationBase(object):
__tablename__ = "kk_tag_associations"
db_id = sa.Column(sa.Integer, primary_key=True)
tag_id = sa.Column(sa.Integer, sa.ForeignKey("kk_tags.db_id"))
# target_table = sa.Column(sa.Unicode(255, convert_unicode=False))
target_table = sa.Column(sa.Unicode(255))
target_id = sa.Column(sa.Integer)
__mapper_args__ = {
"polymorphic_on": "target_table"
}
# at import time, Tag doesn't exist, so we use declared_attr to
# defer.
@declared_attr
def tag_obj(cls):
return sa.orm.relationship(Tag)
tag = association_proxy("tag_obj", "text")
tracked_obj = None
def __eq__(self, other):
if not isinstance(other, TagAssociation):
return False
return self.db_id == other.db_id
def __lt__(self, other):
if not isinstance(other, TagAssociation):
return False
k1 = str(self.tag_obj.text) + self.target_table + str(self.target_id)
k2 = str(other.tag_obj.text) + other.target_table + str(other.target_id)
return k1 < k2
# @property
# def parent(self):
# return getattr(self, "%s_parent" % self.target_table)
def __repr__(self):
return "tag assoc %s: [%s] %s:%s" % (self.db_id, self.tag_obj.text,
self.target_table, self.target_id)
class TaggableBase(object):
__abstract__ = True
@declared_attr
def kk_tag_associations(cls):
name = cls.__name__
table = cls.__tablename__
def cls_init(self, tag=None):
# traceback.print_stack()
# logging.debug("cls_init called, type %s".format(table))
super(TagAssociation, self).__init__()
self.target_table = table
# is this necessary? how does this get called?
if tag:
if isinstance(tag, Tag):
self.tag_obj = tag
else:
# logging.debug("cls init called with text %s" % tag)
self.tag_obj = Tag(tag)
assoc_cls = type(
f"{name}TagAssociation",
(TagAssociation, ),
dict(
__mapper_args__ = {
"polymorphic_identity": table,
"polymorphic_on": "target_table",
},
__init__ = cls_init,
)
)
cls.tags = association_proxy("kk_tag_associations", "tag")
return sa.orm.relationship(
assoc_cls,
primaryjoin=(
"and_(TagAssociation.target_table=='%s', "
"foreign(TagAssociation.target_id)==%s.db_id)"
%(table, name)),
)
def init_base(new_base):
"""Set up classes based on new_base."""
# based on https://stackoverflow.com/a/41927212
def init_cls(name, base):
current = globals()[name + 'Base']
new_ns = current.__dict__.copy()
del new_ns['__dict__']
new_ns = type(name, (new_base,), new_ns)
globals()[name] = new_ns
return {name: new_ns}
ret = {}
for c in ['Tag', 'TagAssociation', 'Taggable']:
ret.update(init_cls(c, new_base))
globals()['Base'] = new_base
return ret
@sa.event.listens_for(sa.orm.Session, 'before_flush')
def merge_text_tags(session, ctx, instances):
texts = {}
for i in session.new:
if isinstance(i, Tag):
t = session.query(Tag).filter_by(text=i.text).first()
if t:
logging.info(f'got t, merging')
i.db_id = t.db_id
t.collection.merge(i.collection)
# t = session.merge(i)
session.expunge(i)
elif i.text in texts:
logging.info('have text, not sure how to proceed.')
session.expunge(i)
else:
texts[i.text] = i
# @sa.event.listens_for(sa.orm.Session, "before_attach")
# def intercept(session, instance):
# if not isinstance(instance, Tag):
# logging.info(f'got non-tag {instance}')
# return
#
# # i guess this only returns stuff that's persistent?
# logging.info(f'have tag {instance}')
# t = session.query(Tag).filter_by(text=instance.text).first()
# if t:
# logging.info(f'have tag {instance}')
# instance.db_id = t.db_id
# session.merge(instance)
# return
# i'm not sure if this is necessary -- its purpose is to set the id on
# our new instance to ensure it matches the old instance. if this
# isn't done, it seems like the id might change, breaking old links.
# @sa.event.listens_for(sa.orm.Session, "before_flush")
# def enforce_unique_text(session, flush_context, instances):
# texts = []
# for i in session.new:
# if isinstance(i, Tag):
# t = session.query(Tag).filter_by(text=i.text).first()
# if t:
# logging.info(f'got t, merging')
# i.db_id = t.db_id
# session.merge(t)
# elif i.text in texts:
# logging.info('have text, not sure how to proceed.')
# else:
# texts.append(i.text)
# FIXME we could probably do this more effectively if we listen for
# the object event, not session.
# @sa.event.listens_for(sa.orm.Session, "before_flush")
# def delete_before_insert(session, context, instances):
# tags = []
# logging.info('calling delete_before_insert')
# for instance in session.dirty:
# if isinstance(instance, Tag):
# logging.info('have dirty tag')
# tags.append(instance.text)
# for instance in session.new:
# if not isinstance(instance, Tag):
# logging.info('got non-tag')
# continue
# # if not session.is_modified(instance):
# # continue
#
# logging.info(f'have tag {instance}')
# t = session.query(Tag).filter_by(text=instance.text).first()
# # conn = session.connection()
# # r = conn.execute(text("SELECT db_id FROM kk_tags WHERE text='%s'" %
# # instance.text))
# # apparently this is -1 if the query matches no rows
# # if r.rowcount > 0:
# if t:
# session.expunge(instance)
# else:
# logging.info('no row')
#
# # handle the case where we have multiples of the same tag in
# # new
# logging.info(f'{tags}')
# if instance.text in tags:
# session.expunge(instance)
# else:
# tags.append(instance.text)