mirror of
https://github.com/janeczku/calibre-web
synced 2024-11-28 20:39:59 +00:00
119 lines
4.6 KiB
Python
119 lines
4.6 KiB
Python
# orm/sync.py
|
|
# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""private module containing functions used for copying data
|
|
between instances based on join conditions.
|
|
|
|
"""
|
|
|
|
from . import exc, util as orm_util, attributes
|
|
|
|
|
|
def populate(source, source_mapper, dest, dest_mapper,
|
|
synchronize_pairs, uowcommit, flag_cascaded_pks):
|
|
source_dict = source.dict
|
|
dest_dict = dest.dict
|
|
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
# inline of source_mapper._get_state_attr_by_column
|
|
prop = source_mapper._columntoproperty[l]
|
|
value = source.manager[prop.key].impl.get(source, source_dict,
|
|
attributes.PASSIVE_OFF)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, dest_mapper, r)
|
|
|
|
try:
|
|
# inline of dest_mapper._set_state_attr_by_column
|
|
prop = dest_mapper._columntoproperty[r]
|
|
dest.manager[prop.key].impl.set(dest, dest_dict, value, None)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(True, source_mapper, l, dest_mapper, r)
|
|
|
|
# technically the "r.primary_key" check isn't
|
|
# needed here, but we check for this condition to limit
|
|
# how often this logic is invoked for memory/performance
|
|
# reasons, since we only need this info for a primary key
|
|
# destination.
|
|
if flag_cascaded_pks and l.primary_key and \
|
|
r.primary_key and \
|
|
r.references(l):
|
|
uowcommit.attributes[("pk_cascaded", dest, r)] = True
|
|
|
|
|
|
def clear(dest, dest_mapper, synchronize_pairs):
|
|
for l, r in synchronize_pairs:
|
|
if r.primary_key:
|
|
raise AssertionError(
|
|
"Dependency rule tried to blank-out primary key "
|
|
"column '%s' on instance '%s'" %
|
|
(r, orm_util.state_str(dest))
|
|
)
|
|
try:
|
|
dest_mapper._set_state_attr_by_column(dest, dest.dict, r, None)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(True, None, l, dest_mapper, r)
|
|
|
|
|
|
def update(source, source_mapper, dest, old_prefix, synchronize_pairs):
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
oldvalue = source_mapper._get_committed_attr_by_column(
|
|
source.obj(), l)
|
|
value = source_mapper._get_state_attr_by_column(
|
|
source, source.dict, l)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, None, r)
|
|
dest[r.key] = value
|
|
dest[old_prefix + r.key] = oldvalue
|
|
|
|
|
|
def populate_dict(source, source_mapper, dict_, synchronize_pairs):
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
value = source_mapper._get_state_attr_by_column(
|
|
source, source.dict, l)
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, None, r)
|
|
|
|
dict_[r.key] = value
|
|
|
|
|
|
def source_modified(uowcommit, source, source_mapper, synchronize_pairs):
|
|
"""return true if the source object has changes from an old to a
|
|
new value on the given synchronize pairs
|
|
|
|
"""
|
|
for l, r in synchronize_pairs:
|
|
try:
|
|
prop = source_mapper._columntoproperty[l]
|
|
except exc.UnmappedColumnError:
|
|
_raise_col_to_prop(False, source_mapper, l, None, r)
|
|
history = uowcommit.get_attribute_history(source, prop.key,
|
|
attributes.PASSIVE_NO_INITIALIZE)
|
|
if bool(history.deleted):
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
|
|
def _raise_col_to_prop(isdest, source_mapper, source_column,
|
|
dest_mapper, dest_column):
|
|
if isdest:
|
|
raise exc.UnmappedColumnError("Can't execute sync rule for "
|
|
"destination column '%s'; mapper '%s' does not map "
|
|
"this column. Try using an explicit `foreign_keys` "
|
|
"collection which does not include this column (or use "
|
|
"a viewonly=True relation)." % (dest_column,
|
|
dest_mapper))
|
|
else:
|
|
raise exc.UnmappedColumnError("Can't execute sync rule for "
|
|
"source column '%s'; mapper '%s' does not map this "
|
|
"column. Try using an explicit `foreign_keys` "
|
|
"collection which does not include destination column "
|
|
"'%s' (or use a viewonly=True relation)."
|
|
% (source_column, source_mapper, dest_column))
|