Support extension data

api/extension_data.py

@@ -0,0 +1,62 @@
+from .database import *
+
+
+def get_all_extension_data_keys(name: str) -> list[str]:
+    result: list[str] = []
+    for row in read_all(name, 'select key from extension_data'):
+        result.append(row['key'])
+    return result
+
+
+def get_all_extension_data(name: str) -> dict[str, Any]:
+    result: dict[str, Any] = {}
+    for row in read_all(name, 'select key, value from extension_data'):
+        result[row['key']] = row['value']
+    return result
+
+
+def get_extension_data(name: str, key: str) -> str | None:
+    if key == None or key == '':
+        return None
+    row = try_read(name, f"select value from extension_data where key = '{key}'")
+    if row == None:
+        return None
+    return row['value']
+
+
+def _set_extension_data(name: str, cs: ChangeSet) -> DbChangeSet:
+    op = cs.operations[0]
+    key, new_val = op['key'], op['value']
+
+    f_new_val = f"'{new_val}'" if new_val != None else 'null'
+
+    old_val = get_extension_data(name, key)
+    f_old_val = f"'{old_val}'" if old_val != None else 'null'
+
+    redo_sql = f"delete from extension_data where key = '{key}';"
+    if new_val != None:
+        redo_sql += f"insert into extension_data (key, value) values ('{key}', {f_new_val});"
+
+    undo_sql = f"delete from extension_data where key = '{key}';"
+    if old_val != None:
+        undo_sql += f"insert into extension_data (key, value) values ('{key}', {f_old_val});"
+
+    redo_cs = g_update_prefix | { 'type': 'extension_data', 'key': key, 'value': new_val }
+    undo_cs = g_update_prefix | { 'type': 'extension_data', 'key': key, 'value': old_val }
+
+    return DbChangeSet(redo_sql, undo_sql, [redo_cs], [undo_cs])
+
+
+def set_extension_data(name: str, cs: ChangeSet) -> ChangeSet:
+    if len(cs.operations) != 1:
+        return ChangeSet()
+
+    op = cs.operations[0]
+    if 'key' not in op or 'value' not in op:
+        return ChangeSet()
+
+    key = op['key']
+    if key == None or key == '':
+        return ChangeSet()
+
+    return execute_command(name, _set_extension_data(name, cs))