Updates to descriptor

dfindexeddb/leveldb/descriptor.py

@@ -365,7 +365,8 @@ def GetVersions(self) -> Generator[LevelDBVersion, None, None]:
     current_log = None
 
     for version_edit in self.GetVersionEdits():
-      current_log = f'{version_edit.log_number:06d}.log'
+      if version_edit.log_number:
+        current_log = f'{version_edit.log_number:06d}.log'
 
       for new_file in version_edit.new_files:
         active_files[new_file.level][f'{new_file.number:06d}.ldb'] = new_file
@@ -380,3 +381,8 @@ def GetVersions(self) -> Generator[LevelDBVersion, None, None]:
           deleted_files=dict(deleted_files),
           version_edit_offset=version_edit.offset,
           last_sequence=version_edit.last_sequence)
+
+  def GetLatestVersion(self) -> LevelDBVersion:
+    """Returns the latest LevelDBVersion instance."""
+    *_, latest = self.GetVersions()
+    return latest

tests/dfindexeddb/leveldb/descriptor.py

@@ -57,3 +57,38 @@ def test_versionedit(self):
     self.assertEqual(version_edits[1].compact_pointers, [])
     self.assertEqual(version_edits[1].new_files, [])
     self.assertEqual(version_edits[1].deleted_files, [])
+
+  def test_versions(self):
+    """Tests the GetVersions method."""
+    manifest_file = descriptor.FileReader(
+        './test_data/leveldb/100k keys delete/MANIFEST-000002')
+    versions = list(manifest_file.GetVersions())
+    self.assertEqual(len(versions), 3)
+    self.assertEqual(versions[0].active_files, {})
+    self.assertEqual(versions[0].deleted_files, {})
+    self.assertEqual(versions[0].current_log, None)
+    self.assertEqual(versions[0].last_sequence, None)
+
+    self.assertEqual(len(versions[2].active_files), 1)
+    self.assertIn(2, versions[2].active_files)
+    self.assertIn('000005.ldb', versions[2].active_files[2])
+    self.assertEqual(versions[2].deleted_files, {})
+    self.assertEqual(versions[2].current_log, '000004.log')
+    self.assertEqual(versions[2].last_sequence, 85673)
+
+  def test_latestversion(self):
+    """Tests the GetLatestVersion method."""
+    manifest_file = descriptor.FileReader(
+        './test_data/leveldb/100k keys delete/MANIFEST-000002')
+    latest_version = manifest_file.GetLatestVersion()
+
+    self.assertEqual(len(latest_version.active_files), 1)
+    self.assertIn(2, latest_version.active_files)
+    self.assertIn('000005.ldb', latest_version.active_files[2])
+    self.assertEqual(latest_version.deleted_files, {})
+    self.assertEqual(latest_version.current_log, '000004.log')
+    self.assertEqual(latest_version.last_sequence, 85673)
+
+
+if __name__ == '__main__':
+  unittest.main()