TakeLast Performance Improvement suggestion · dotnet/runtime#118312

(3 评论) (0 反应) (0 负责人)C# (17,886 star) (5,445 fork)batch import

area-System.Linqhelp wantedtenet-performance

描述

TakeRangeFromEndIterator uses a regular Queue <T>when IsStartIndexFromEnd, but this process can be done without intervening yields, allowing optimization using ArrayPool and Span.

https://github.com/dotnet/runtime/blob/3f25a276772b8d0e54452321e7525b7a176aa4a7/src/libraries/System.Linq/src/System/Linq/Take.cs#L111C13-L154C18

Below is the PR I did on ZLinq. https://github.com/Cysharp/ZLinq/pull/207/files Unlike ZLinq, a ToArray is required at the end of the queueing for Linq, but it will be similar.

贡献者指南

技术栈: csharp
领域: backend
议题类型: performance
难度: 4
预计时间: half day
活动状态: fresh
清晰度: mostly clear
前置要求: C#LINQArrayPoolSpan<T>
新手友好度: 30
研究方向: Examine the current implementation of TakeRangeFromEndIterator in Take.cs (line 111). Review the linked PR in ZLinq (https://github.com/Cysharp/ZLinq/pull/207) for optimization patterns using ArrayPool and Span. Investigate whether ToArray is necessary after queueing and if the same approach can be applied without breaking changes. Consider performance benchmarks and memory allocation trade offs.