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			59 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			59 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| import datetime
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| from unittest import mock
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| 
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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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| 
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| from .models import Article
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| 
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| 
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| class QuerySetIteratorTests(TestCase):
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|     itersize_index_in_mock_args = 3
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| 
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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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| 
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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(
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|                     ValueError, "Chunk size must be strictly positive."
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|                 ):
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|                     Article.objects.iterator(chunk_size=size)
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| 
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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(
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|             "django.db.models.sql.compiler.cursor_iter", side_effect=cursor_iter
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|         ) 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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| 
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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(
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|             "django.db.models.sql.compiler.cursor_iter", side_effect=cursor_iter
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|         ) 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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| 
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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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