Use sqlite.interrupt() instead of sqlite_timelimit() - refs #1270

datasette/database.py

@@ -143,7 +143,7 @@ class Database:
                     result = e
             task.reply_queue.sync_q.put(result)
 
-    async def execute_fn(self, fn):
+    async def execute_fn(self, fn, time_limit=None):
         def in_thread():
             conn = getattr(connections, self.name, None)
             if not conn:
@@ -152,9 +152,17 @@ class Database:
                 setattr(connections, self.name, conn)
             return fn(conn)
 
-        return await asyncio.get_event_loop().run_in_executor(
-            self.ds.executor, in_thread
-        )
+        executor = asyncio.get_event_loop().run_in_executor(self.ds.executor, in_thread)
+        try:
+            return await asyncio.wait_for(
+                executor,
+                timeout=(time_limit / 1000.0) if time_limit is not None else None,
+            )
+        except asyncio.TimeoutError:
+            conn = getattr(connections, self.name, None)
+            if conn:
+                conn.interrupt()
+            raise QueryInterrupted()
 
     async def execute(
         self,
@@ -168,36 +176,37 @@ class Database:
         """Executes sql against db_name in a thread"""
         page_size = page_size or self.ds.page_size
 
-        def sql_operation_in_thread(conn):
-            time_limit_ms = self.ds.sql_time_limit_ms
-            if custom_time_limit and custom_time_limit < time_limit_ms:
-                time_limit_ms = custom_time_limit
+        time_limit_ms = self.ds.sql_time_limit_ms
+        if custom_time_limit and custom_time_limit < time_limit_ms:
+            time_limit_ms = custom_time_limit
 
-            with sqlite_timelimit(conn, time_limit_ms):
-                try:
-                    cursor = conn.cursor()
-                    cursor.execute(sql, params if params is not None else {})
-                    max_returned_rows = self.ds.max_returned_rows
-                    if max_returned_rows == page_size:
-                        max_returned_rows += 1
-                    if max_returned_rows and truncate:
-                        rows = cursor.fetchmany(max_returned_rows + 1)
-                        truncated = len(rows) > max_returned_rows
-                        rows = rows[:max_returned_rows]
-                    else:
-                        rows = cursor.fetchall()
-                        truncated = False
-                except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
-                    if e.args == ("interrupted",):
-                        raise QueryInterrupted(e, sql, params)
-                    if log_sql_errors:
-                        sys.stderr.write(
-                            "ERROR: conn={}, sql = {}, params = {}: {}\n".format(
-                                conn, repr(sql), params, e
-                            )
+        def sql_operation_in_thread(conn):
+            try:
+                cursor = conn.cursor()
+                with open("/tmp/sql.log", "ab", buffering=0) as fp:
+                    fp.write(("{}: {}\n".format(sql, params)).encode("utf-8"))
+                cursor.execute(sql, params if params is not None else {})
+                max_returned_rows = self.ds.max_returned_rows
+                if max_returned_rows == page_size:
+                    max_returned_rows += 1
+                if max_returned_rows and truncate:
+                    rows = cursor.fetchmany(max_returned_rows + 1)
+                    truncated = len(rows) > max_returned_rows
+                    rows = rows[:max_returned_rows]
+                else:
+                    rows = cursor.fetchall()
+                    truncated = False
+            except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
+                if e.args == ("interrupted",):
+                    raise QueryInterrupted(e, sql, params)
+                if log_sql_errors:
+                    sys.stderr.write(
+                        "ERROR: conn={}, sql = {}, params = {}: {}\n".format(
+                            conn, repr(sql), params, e
                         )
-                        sys.stderr.flush()
-                    raise
+                    )
+                    sys.stderr.flush()
+                raise
 
             if truncate:
                 return Results(rows, truncated, cursor.description)
@@ -206,7 +215,9 @@ class Database:
                 return Results(rows, False, cursor.description)
 
         with trace("sql", database=self.name, sql=sql.strip(), params=params):
-            results = await self.execute_fn(sql_operation_in_thread)
+            results = await self.execute_fn(
+                sql_operation_in_thread, time_limit=time_limit_ms
+            )
         return results
 
     @property