53 lines
2.1 KiB
Python
53 lines
2.1 KiB
Python
import datetime
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from unittest import mock
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from django.db import connections
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from django.db.models.sql.compiler import cursor_iter
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from django.test import TestCase
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from .models import Article
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class QuerySetIteratorTests(TestCase):
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itersize_index_in_mock_args = 3
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@classmethod
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def setUpTestData(cls):
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Article.objects.create(name='Article 1', created=datetime.datetime.now())
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Article.objects.create(name='Article 2', created=datetime.datetime.now())
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def test_iterator_invalid_chunk_size(self):
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for size in (0, -1):
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with self.subTest(size=size):
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with self.assertRaisesMessage(ValueError, 'Chunk size must be strictly positive.'):
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Article.objects.iterator(chunk_size=size)
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def test_default_iterator_chunk_size(self):
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qs = Article.objects.iterator()
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with mock.patch('django.db.models.sql.compiler.cursor_iter', side_effect=cursor_iter) as cursor_iter_mock:
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next(qs)
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self.assertEqual(cursor_iter_mock.call_count, 1)
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mock_args, _mock_kwargs = cursor_iter_mock.call_args
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self.assertEqual(mock_args[self.itersize_index_in_mock_args], 2000)
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def test_iterator_chunk_size(self):
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batch_size = 3
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qs = Article.objects.iterator(chunk_size=batch_size)
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with mock.patch('django.db.models.sql.compiler.cursor_iter', side_effect=cursor_iter) as cursor_iter_mock:
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next(qs)
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self.assertEqual(cursor_iter_mock.call_count, 1)
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mock_args, _mock_kwargs = cursor_iter_mock.call_args
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self.assertEqual(mock_args[self.itersize_index_in_mock_args], batch_size)
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def test_no_chunked_reads(self):
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"""
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If the database backend doesn't support chunked reads, then the
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result of SQLCompiler.execute_sql() is a list.
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"""
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qs = Article.objects.all()
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compiler = qs.query.get_compiler(using=qs.db)
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features = connections[qs.db].features
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with mock.patch.object(features, 'can_use_chunked_reads', False):
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result = compiler.execute_sql(chunked_fetch=True)
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self.assertIsInstance(result, list)
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