alamb commented on code in PR #21882: URL: https://github.com/apache/datafusion/pull/21882#discussion_r3470735459
########## datafusion/execution/src/spill_file.rs: ########## @@ -0,0 +1,54 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use bytes::Bytes; +use datafusion_common::Result; +use futures::Stream; +use std::path::Path; +use std::pin::Pin; +use std::sync::Arc; + +/// Abstraction over a spill file backend. +/// Implementations handle their own quota enforcement and blocking concerns. +pub trait SpillFile: Send + Sync { + /// Returns the OS path if this is a local file, None otherwise. + fn path(&self) -> Option<&Path> { + None + } + + /// Returns current size in bytes if cheaply available. + fn size(&self) -> Option<u64>; + + /// Returns file contents as an async stream of byte chunks. + fn read_stream(&self) -> Result<Pin<Box<dyn Stream<Item = Result<Bytes>> + Send>>>; + + /// Opens a writer for appending data to this file. + fn open_writer(&self) -> Result<Box<dyn SpillWriter>>; +} + +/// Writer for spill file backends. +pub trait SpillWriter: std::io::Write + Send { Review Comment: It was also strange that the SpillWriter is a sync API, but the read stream API is `async` ```rust fn read_stream(&self) -> Result<Pin<Box<dyn Stream<Item = Result<Bytes>> + Send>>>; ``` I found this while working on an example showing how to write to a remote object store - https://github.com/apache/datafusion/pull/23170 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
