adriangb commented on code in PR #18207: URL: https://github.com/apache/datafusion/pull/18207#discussion_r2461395234
########## datafusion/physical-plan/src/spill/spill_pool.rs: ########## @@ -0,0 +1,1099 @@ +// 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. + +//! SpillPool: A reusable abstraction for managing spill files with FIFO semantics. +//! +//! # Overview +//! +//! The `SpillPool` provides a centralized mechanism for spilling record batches to disk +//! when memory is constrained. It manages a collection of spill files, each containing +//! multiple batches, with configurable maximum file sizes. +//! +//! # Design +//! +//! - **FIFO (Queue) semantics**: Batches are read in the order they were spilled +//! - **File handle reuse**: Multiple batches are written to the same file to minimize syscalls +//! - **Automatic file rotation**: When a file exceeds `max_file_size_bytes`, rotate to a new file +//! - **Sequential reading**: Uses IPC Stream format's natural sequential access pattern +//! - **Automatic cleanup**: Files are deleted once fully consumed +//! +//! # Usage Example +//! +//! ```ignore +//! use std::sync::Arc; +//! use parking_lot::Mutex; +//! +//! let pool = SpillPool::new( +//! 100 * 1024 * 1024, // 100MB max per file +//! spill_manager, +//! schema, +//! ); +//! let pool = Arc::new(Mutex::new(pool)); +//! +//! // Spill batches - automatically rotates files when size limit reached +//! { +//! let mut pool = pool.lock(); +//! pool.push_batch(batch1)?; +//! pool.push_batch(batch2)?; +//! pool.flush()?; // Finalize current file +//! pool.finalize(); // Signal no more writes +//! } +//! +//! // Read back in FIFO order using a stream +//! let mut stream = SpillPool::reader(pool, spill_manager); +//! let batch1 = stream.next().await.unwrap()?; // Returns batch1 +//! let batch2 = stream.next().await.unwrap()?; // Returns batch2 +//! // stream.next() returns None after finalize +//! ``` + +use std::collections::VecDeque; +use std::sync::Arc; +use std::task::Waker; + +use parking_lot::Mutex; + +use arrow::datatypes::SchemaRef; +use arrow::record_batch::RecordBatch; +use datafusion_common::Result; +use datafusion_execution::disk_manager::RefCountedTempFile; +use datafusion_execution::{RecordBatchStream, SendableRecordBatchStream}; + +use super::in_progress_spill_file::InProgressSpillFile; +use super::spill_manager::SpillManager; + +/// A pool of spill files that manages batch-level spilling with FIFO semantics. +/// +/// Batches are written sequentially to files, with automatic rotation when the +/// configured size limit is reached. Reading is done via an infinite stream +/// that can read concurrently while writes continue. +/// +/// # Thread Safety +/// +/// `SpillPool` is not thread-safe and should be used from a single thread or +/// protected with appropriate synchronization (e.g., `Arc<Mutex<SpillPool>>`). +pub struct SpillPool { + /// Maximum size in bytes before rotating to a new file + max_file_size_bytes: usize, + /// Queue of spill files (front = oldest, back = newest) + files: VecDeque<RefCountedTempFile>, + /// Current file being written to (if any) + current_write_file: Option<InProgressSpillFile>, + /// Size of current write file in bytes (estimated) + current_write_size: usize, + /// Number of batches written to current file + current_batch_count: usize, Review Comment: done ########## datafusion/physical-plan/src/spill/spill_pool.rs: ########## @@ -0,0 +1,1099 @@ +// 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. + +//! SpillPool: A reusable abstraction for managing spill files with FIFO semantics. +//! +//! # Overview +//! +//! The `SpillPool` provides a centralized mechanism for spilling record batches to disk +//! when memory is constrained. It manages a collection of spill files, each containing +//! multiple batches, with configurable maximum file sizes. +//! +//! # Design +//! +//! - **FIFO (Queue) semantics**: Batches are read in the order they were spilled +//! - **File handle reuse**: Multiple batches are written to the same file to minimize syscalls +//! - **Automatic file rotation**: When a file exceeds `max_file_size_bytes`, rotate to a new file +//! - **Sequential reading**: Uses IPC Stream format's natural sequential access pattern +//! - **Automatic cleanup**: Files are deleted once fully consumed +//! +//! # Usage Example +//! +//! ```ignore +//! use std::sync::Arc; +//! use parking_lot::Mutex; +//! +//! let pool = SpillPool::new( +//! 100 * 1024 * 1024, // 100MB max per file +//! spill_manager, +//! schema, +//! ); +//! let pool = Arc::new(Mutex::new(pool)); +//! +//! // Spill batches - automatically rotates files when size limit reached +//! { +//! let mut pool = pool.lock(); +//! pool.push_batch(batch1)?; +//! pool.push_batch(batch2)?; +//! pool.flush()?; // Finalize current file +//! pool.finalize(); // Signal no more writes +//! } +//! +//! // Read back in FIFO order using a stream +//! let mut stream = SpillPool::reader(pool, spill_manager); +//! let batch1 = stream.next().await.unwrap()?; // Returns batch1 +//! let batch2 = stream.next().await.unwrap()?; // Returns batch2 +//! // stream.next() returns None after finalize +//! ``` + +use std::collections::VecDeque; +use std::sync::Arc; +use std::task::Waker; + +use parking_lot::Mutex; + +use arrow::datatypes::SchemaRef; +use arrow::record_batch::RecordBatch; +use datafusion_common::Result; +use datafusion_execution::disk_manager::RefCountedTempFile; +use datafusion_execution::{RecordBatchStream, SendableRecordBatchStream}; + +use super::in_progress_spill_file::InProgressSpillFile; +use super::spill_manager::SpillManager; + +/// A pool of spill files that manages batch-level spilling with FIFO semantics. +/// +/// Batches are written sequentially to files, with automatic rotation when the +/// configured size limit is reached. Reading is done via an infinite stream +/// that can read concurrently while writes continue. +/// +/// # Thread Safety +/// +/// `SpillPool` is not thread-safe and should be used from a single thread or +/// protected with appropriate synchronization (e.g., `Arc<Mutex<SpillPool>>`). +pub struct SpillPool { + /// Maximum size in bytes before rotating to a new file + max_file_size_bytes: usize, + /// Queue of spill files (front = oldest, back = newest) + files: VecDeque<RefCountedTempFile>, + /// Current file being written to (if any) + current_write_file: Option<InProgressSpillFile>, + /// Size of current write file in bytes (estimated) + current_write_size: usize, + /// Number of batches written to current file + current_batch_count: usize, + /// SpillManager for creating files and tracking metrics + spill_manager: Arc<SpillManager>, + /// Schema for batches (used by SpillPoolStream to implement RecordBatchStream) + schema: SchemaRef, Review Comment: 👍🏻 done -- This is an automated message from the Apache Git Service. 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