akka/akka-core

Use AsynchronousFileChannel for FileSource

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#30,031 opened on Feb 14, 2021

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 (4 comments) (0 reactions) (0 assignees)Scala (13,277 stars) (3,547 forks)batch import
1 - triagedhelp wantednice-to-have (low-prio)t:stream

Description

I was a bit surprised reading the Streaming File IO docs to read

Please note that these operators are backed by Actors and by default are configured to run on a pre-configured threadpool-backed dispatcher dedicated for File IO. This is very important as it isolates the blocking file IO operations from the rest of the ActorSystem allowing each dispatcher to be utilised in the most efficient way.

Looking around I found that AsyncFileChannel was implemented differently on different Operating Systems. So on Windows apparently it does use underlying asynchronous IO.

It would be interesting to find out on which other platforms this makes a difference.

Contributor guide

Tech stack
javascala
Domain
backendperformance
Issue type
performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Java NIOAkka StreamsFile I/O
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
Investigate the current implementation of FileSource in akka stream/src/main/scala/akka/stream/impl/io/FileSource.scala. Review how AsynchronousFileChannel can be integrated. Consider platform specific behavior, especially on Windows vs Linux. Look at existing tests for file I/O performance and any related discussions in the comments.