a-b-street/abstreet

Web client performance

Open

#377 opened on Nov 3, 2020

View on GitHub
 (11 comments) (0 reactions) (0 assignees)Rust (6,779 stars) (256 forks)batch import
good first issue

Description

Some different ideas for smoothing out the web client:

  • The .wasm binary is around 50MB, which makes initial startup time quite sad. Gzipped is around 20MB. I can't find any option to enable this in wasm-pack, because I think people generally just configure their web servers to do compression on-the-fly if the HTTP client sends Accept-Encoding headers. S3 doesn't support this, but I think it's possible to upload a .wasm.gz, point to it from the .html, and set the Content-Encoding header properly. Just need to test this and make sure browsers understand it.
  • Keep the Scenario for the current map in memory after loading it from a file. Otherwise, everytime the player resets to midnight in many gameplay modes, they have to download the file again!
  • In wasm_loader::FileLoader, display a progress bar with bytes downloaded / total length. I found set_onprogresss for XmlHttpRequest, but actually, we're currently using web_sys::Request, which is different. Can we switch?

Contributor guide

Tech stack
rustwasmhtmlcss
Domain
frontendperformance
Issue type
performance
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 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.
clear
Prerequisites
basic Rustweb assembly knowledgeweb development basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55
Research direction
Investigate wasm pack options for gzip compression of .wasm files, and test serving .wasm.gz with Content Encoding header. For caching, modify the Scenario loading logic to persist the loaded scenario in memory after initial file load. For progress bar, explore switching from web sys::Request to XmlHttpRequest (or use fetch with progress events) in wasm loader::FileLoader, and consult MDN for progress event implementation.