bpo-27645: Add support for native backup facility of SQLite (GH-4238)

1 files changed, 162 insertions, 0 deletions

diff --git a/Lib/sqlite3/test/backup.py b/Lib/sqlite3/test/backup.py
new file mode 100644
index 0000000000..784702fb46
--- /dev/null
+++ b/Lib/sqlite3/test/backup.py
@@ -0,0 +1,162 @@
+import sqlite3 as sqlite
+import unittest
+
+
+@unittest.skipIf(sqlite.sqlite_version_info < (3, 6, 11), "Backup API not supported")
+class BackupTests(unittest.TestCase):
+    def setUp(self):
+        cx = self.cx = sqlite.connect(":memory:")
+        cx.execute('CREATE TABLE foo (key INTEGER)')
+        cx.executemany('INSERT INTO foo (key) VALUES (?)', [(3,), (4,)])
+        cx.commit()
+
+    def tearDown(self):
+        self.cx.close()
+
+    def verify_backup(self, bckcx):
+        result = bckcx.execute("SELECT key FROM foo ORDER BY key").fetchall()
+        self.assertEqual(result[0][0], 3)
+        self.assertEqual(result[1][0], 4)
+
+    def test_bad_target_none(self):
+        with self.assertRaises(TypeError):
+            self.cx.backup(None)
+
+    def test_bad_target_filename(self):
+        with self.assertRaises(TypeError):
+            self.cx.backup('some_file_name.db')
+
+    def test_bad_target_same_connection(self):
+        with self.assertRaises(ValueError):
+            self.cx.backup(self.cx)
+
+    def test_bad_target_closed_connection(self):
+        bck = sqlite.connect(':memory:')
+        bck.close()
+        with self.assertRaises(sqlite.ProgrammingError):
+            self.cx.backup(bck)
+
+    def test_bad_target_in_transaction(self):
+        bck = sqlite.connect(':memory:')
+        bck.execute('CREATE TABLE bar (key INTEGER)')
+        bck.executemany('INSERT INTO bar (key) VALUES (?)', [(3,), (4,)])
+        with self.assertRaises(sqlite.OperationalError) as cm:
+            self.cx.backup(bck)
+        if sqlite.sqlite_version_info < (3, 8, 7):
+            self.assertEqual(str(cm.exception), 'target is in transaction')
+
+    def test_keyword_only_args(self):
+        with self.assertRaises(TypeError):
+            with sqlite.connect(':memory:') as bck:
+                self.cx.backup(bck, 1)
+
+    def test_simple(self):
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck)
+            self.verify_backup(bck)
+
+    def test_progress(self):
+        journal = []
+
+        def progress(status, remaining, total):
+            journal.append(status)
+
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, pages=1, progress=progress)
+            self.verify_backup(bck)
+
+        self.assertEqual(len(journal), 2)
+        self.assertEqual(journal[0], sqlite.SQLITE_OK)
+        self.assertEqual(journal[1], sqlite.SQLITE_DONE)
+
+    def test_progress_all_pages_at_once_1(self):
+        journal = []
+
+        def progress(status, remaining, total):
+            journal.append(remaining)
+
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, progress=progress)
+            self.verify_backup(bck)
+
+        self.assertEqual(len(journal), 1)
+        self.assertEqual(journal[0], 0)
+
+    def test_progress_all_pages_at_once_2(self):
+        journal = []
+
+        def progress(status, remaining, total):
+            journal.append(remaining)
+
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, pages=-1, progress=progress)
+            self.verify_backup(bck)
+
+        self.assertEqual(len(journal), 1)
+        self.assertEqual(journal[0], 0)
+
+    def test_non_callable_progress(self):
+        with self.assertRaises(TypeError) as cm:
+            with sqlite.connect(':memory:') as bck:
+                self.cx.backup(bck, pages=1, progress='bar')
+        self.assertEqual(str(cm.exception), 'progress argument must be a callable')
+
+    def test_modifying_progress(self):
+        journal = []
+
+        def progress(status, remaining, total):
+            if not journal:
+                self.cx.execute('INSERT INTO foo (key) VALUES (?)', (remaining+1000,))
+                self.cx.commit()
+            journal.append(remaining)
+
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, pages=1, progress=progress)
+            self.verify_backup(bck)
+
+            result = bck.execute("SELECT key FROM foo"
+                                 " WHERE key >= 1000"
+                                 " ORDER BY key").fetchall()
+            self.assertEqual(result[0][0], 1001)
+
+        self.assertEqual(len(journal), 3)
+        self.assertEqual(journal[0], 1)
+        self.assertEqual(journal[1], 1)
+        self.assertEqual(journal[2], 0)
+
+    def test_failing_progress(self):
+        def progress(status, remaining, total):
+            raise SystemError('nearly out of space')
+
+        with self.assertRaises(SystemError) as err:
+            with sqlite.connect(':memory:') as bck:
+                self.cx.backup(bck, progress=progress)
+        self.assertEqual(str(err.exception), 'nearly out of space')
+
+    def test_database_source_name(self):
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, name='main')
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, name='temp')
+        with self.assertRaises(sqlite.OperationalError) as cm:
+            with sqlite.connect(':memory:') as bck:
+                self.cx.backup(bck, name='non-existing')
+        self.assertIn(
+            str(cm.exception),
+            ['SQL logic error', 'SQL logic error or missing database']
+        )
+
+        self.cx.execute("ATTACH DATABASE ':memory:' AS attached_db")
+        self.cx.execute('CREATE TABLE attached_db.foo (key INTEGER)')
+        self.cx.executemany('INSERT INTO attached_db.foo (key) VALUES (?)', [(3,), (4,)])
+        self.cx.commit()
+        with sqlite.connect(':memory:') as bck:
+            self.cx.backup(bck, name='attached_db')
+            self.verify_backup(bck)
+
+
+def suite():
+    return unittest.makeSuite(BackupTests)
+
+if __name__ == "__main__":
+    unittest.main()