Add a default execution time limit to writes

datasette/database.py

@@ -247,17 +247,29 @@ class Database:
         return_all=False,
         returning_limit=EXECUTE_WRITE_RETURNING_LIMIT,
         transaction=True,
+        time_limit_ms=2000,
     ):
         self._check_not_closed()
         if returning_limit < 0:
             raise ValueError("returning_limit must be >= 0")
 
-        def _inner(conn):
+        def execute_sql(conn):
             cursor = conn.execute(sql, params or [])
             return ExecuteWriteResult.from_cursor(
                 cursor, return_all=return_all, returning_limit=returning_limit
             )
 
+        def _inner(conn):
+            try:
+                if time_limit_ms is None:
+                    return execute_sql(conn)
+                with sqlite_timelimit(conn, time_limit_ms):
+                    return execute_sql(conn)
+            except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
+                if e.args == ("interrupted",):
+                    raise QueryInterrupted(e, sql, params)
+                raise
+
         with trace("sql", database=self.name, sql=sql.strip(), params=params):
             results = await self.execute_write_fn(
                 _inner, block=block, request=request, transaction=transaction

datasette/views/execute_write.py

@@ -1,6 +1,7 @@
 import re
 from urllib.parse import urlencode
 
+from datasette.database import QueryInterrupted
 from datasette.resources import DatabaseResource
 from datasette.utils import UNSTABLE_API_MESSAGE, sqlite3
 from datasette.utils.asgi import Response
@@ -384,7 +385,7 @@ class ExecuteWriteView(BaseView):
         try:
             execute_write_kwargs = {"request": request}
             cursor = await db.execute_write(sql, params, **execute_write_kwargs)
-        except sqlite3.DatabaseError as ex:
+        except (QueryInterrupted, sqlite3.DatabaseError) as ex:
             message = str(ex)
             if wants_json:
                 return _block_framing(Response.error([message], 400))

docs/internals.rst

@@ -2023,8 +2023,8 @@ Example usage:
 
 .. _database_execute_write:
 
-await db.execute_write(sql, params=None, block=True, request=None, return_all=False, returning_limit=10, transaction=True)
---------------------------------------------------------------------------------------------------------------------------
+await db.execute_write(sql, params=None, block=True, request=None, return_all=False, returning_limit=10, transaction=True, time_limit_ms=2000)
+----------------------------------------------------------------------------------------------------------------------------------------------
 
 SQLite only allows one database connection to write at a time. Datasette handles this for you by maintaining a queue of writes to be executed against a given database. Plugins can submit write operations to this queue and they will be executed in the order in which they are received.
 
@@ -2063,6 +2063,10 @@ Each call to ``execute_write()`` will be executed inside a transaction. Pass
 ``transaction=False`` for statements such as ``VACUUM`` that cannot run inside
 a transaction.
 
+Write statements have a default time limit of 2,000ms. Pass a different value
+using ``time_limit_ms=`` or use ``time_limit_ms=None`` to allow the statement to
+run without a time limit.
+
 .. _database_execute_write_script:
 
 await db.execute_write_script(sql, block=True)