tursodatabase/libsql

Make the WebAssembly runtime configurable

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#120 opened on Jan 26, 2023

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 (3 comments) (0 reactions) (1 assignee)C (16,744 stars) (490 forks)batch import
good first issuehelp wanted

Description

Right now the WebAssembly runtime is initialized with default settings only: https://github.com/libsql/libsql/blob/bd68c17adf23c038fcfc44813ea2a943b423ca63/src/rust/wasmtime-bindings/src/lib.rs#L80-L90

It would be nice to have a way of modifying the defaults, e.g. the WebAssembly stack size, various time limits, profiling, preemptions, etc. Here's how Wasmtime can be configured: https://docs.wasmtime.dev/api/wasmtime/struct.Config.html

libsql_wasm_engine_new function does not take parameters now, but we could extend it with a configuration struct, that can be used to pass custom options, e.g. passed as preprocessor macros or a custom PRAGMA statement.

Contributor guide

Tech stack
rustwasm
Domain
backenddatabase
Issue type
feature
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.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Basic Rust knowledgeFamiliarity with wasmtime API
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40
Research direction
The main change is in the `libsql wasm engine new` function in `src/rust/wasmtime bindings/src/lib.rs` (lines 80-90). The task is to design a configuration struct that can be passed to this function to override default Wasmtime settings like stack size, time limits, etc. Review the Wasmtime Config API (https://docs.wasmtime.dev/api/wasmtime/struct.Config.html) to understand available options. Then extend the function signature and implement the parsing of configuration options, possibly via preprocessor macros or a custom PRAGMA statement. Consider how the configuration will be exposed to users of libsql.