Dandandan commented on code in PR #15591: URL: https://github.com/apache/datafusion/pull/15591#discussion_r3080550313
########## datafusion/functions-aggregate-common/src/aggregate/groups_accumulator/blocks.rs: ########## @@ -0,0 +1,308 @@ +// 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. + +//! Aggregation intermediate results blocks in blocked approach + +use std::{ + collections::VecDeque, + fmt::Debug, + iter, + ops::{Index, IndexMut}, +}; + +use datafusion_expr_common::groups_accumulator::EmitTo; + +/// Structure used to store aggregation intermediate results in `blocked approach` +/// +/// Aggregation intermediate results will be stored as multiple [`Block`]s +/// (simply you can think a [`Block`] as a `Vec`). And `Blocks` is the structure +/// to represent such multiple [`Block`]s. +/// +/// More details about `blocked approach` can see in: [`GroupsAccumulator::supports_blocked_groups`]. +/// +/// [`GroupsAccumulator::supports_blocked_groups`]: datafusion_expr_common::groups_accumulator::GroupsAccumulator::supports_blocked_groups +/// +#[derive(Debug)] +pub struct Blocks<B: Block> { + inner: VecDeque<B>, Review Comment: I think it would be nice to avoid the `VecDeque` as I believe it is relatively slow to index (because of the `%`). I think we can use a start offset instead during pop (and increase it), replace the block with an empty one to "pop" it and reclaim the memory. -- 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]
