# -*- coding: utf-8 -*-
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# This file is part of Inspirehep.
# Copyright (C) 2016 CERN.
#
# Inspirehep is free software; you can redistribute it
# and/or modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of the
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# General Public License for more details.
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# Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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from __future__ import absolute_import, print_function
from .nothing import NOTHING
from .utils import get_obj_at_key_path
[docs]class BaseComparator(object):
"""Abstract base class for Entity Comparison."""
def __init__(self, l1, l2):
"""
Args:
l1: First list of entities.
l2: Second list of entities.
"""
self.l1 = l1
self.l2 = l2
self.matches = set()
self.process_lists()
[docs] def process_lists(self):
"""Do any preprocessing of the lists."""
for l1_idx, obj1 in enumerate(self.l1):
for l2_idx, obj2 in enumerate(self.l2):
if self.equal(obj1, obj2):
self.matches.add((l1_idx, l2_idx))
[docs] def equal(self, obj1, obj2):
"""Implementation of object equality."""
raise NotImplementedError()
[docs] def get_matches(self, src, src_idx):
"""Get elements equal to the idx'th in src from the other list.
e.g. get_matches(self, 'l1', 0) will return all elements from self.l2
matching with self.l1[0]
"""
if src not in ('l1', 'l2'):
raise ValueError('Must have one of "l1" or "l2" as src')
if src == 'l1':
target_list = self.l2
else:
target_list = self.l1
comparator = {
'l1': lambda s_idx, t_idx: (s_idx, t_idx) in self.matches,
'l2': lambda s_idx, t_idx: (t_idx, s_idx) in self.matches,
}[src]
return [(trg_idx, obj) for trg_idx, obj in enumerate(target_list)
if comparator(src_idx, trg_idx)]
[docs]class PrimaryKeyComparator(BaseComparator):
"""Considers two objects as equal if they have the same primary key.
If two objects have at least one of the configured primary_key_fields equal
then they are equal. A primary key field can be any of:
string: Two objects are equal if the values at the given key paths
are equal. Example:
For 'key1.key2' the objects are equal if
obj1['key1']['key2'] == obj2['key1']['key2'].
list: Two objects are equal if all the values at the key paths
in the list are equal. Example:
For ['key1', 'key2.key3'] the objects are equal if
obj1['key1'] == obj2['key1'] and
obj1['key2']['key3'] == obj2['key2']['key3'].
For normalizing the fields in the objects to be compared, one can add
a normalization function for each field in the normalization_functions
dict.
Example:
Setting the normalization_functions field to:
``{'key1': str.lower}``
would normalize
obj1 = {'key1': 'ID123'} and obj2 = {'key1': 'id123'} to
obj1 = {'key1': 'id123'} and obj2 = {'key1': 'id123'}
"""
primary_key_fields = ['pk']
normalization_functions = {}
def _have_field_equal(self, obj1, obj2, field):
key_path = tuple(k for k in field.split('.') if k)
o1 = get_obj_at_key_path(obj1, key_path, NOTHING)
o2 = get_obj_at_key_path(obj2, key_path, NOTHING)
if o1 == NOTHING or o2 == NOTHING:
return False
fn = self.normalization_functions.get(field, lambda x: x)
return fn(o1) == fn(o2)
def equal(self, obj1, obj2):
if obj1 == obj2:
return True
for field_set in self.primary_key_fields:
if not isinstance(field_set, list):
field_set = [field_set]
checks = [self._have_field_equal(obj1, obj2, field)
for field in field_set]
if all(checks):
return True
return False
[docs]class DefaultComparator(BaseComparator):
"""Two objects are the same entity if they are fully equal."""
def equal(self, obj1, obj2):
return obj1 == obj2
