Benchmark for Oxc, Swc and Rome parser

The purpose of this benchmark is for people who wants to evaluate and compare the performance characteristics of these parsers.

Results

Mac M2 8 cores

	`oxc`	`swc`	`rome`
`single-thread`	`55.86 ms` (1.00x)	`108.68 ms` (1.95x slower)	`168.88 ms` (3.02x slower)
`no-drop`	`56.17 ms` (1.00x)	`101.47 ms` (1.81x slower)	`159.46 ms` (2.84x slower)
`parallel`	`90.12 ms` (1.00x)	`180.26 ms` (2.00x slower)	`315.39 ms` (3.50x slower)

single-thread

This is the standard benchmark run in a single thread.

group.bench_with_input(id, &source, |b, source| {
    b.iter(|| Self::parse(source))
});

no-drop

This uses the iter_with_large_drop function, which does not take AST drop time into account. Notice there is only a 0.3ms difference for oxc, but 7ms difference for swc.

AST drop time can become a bottleneck in applications such as as bundler, where there are a few thousands of files need to be parsed.

group.bench_with_input(id, &source, |b, source| {
    b.iter_with_large_drop(|| Self::parse(source))
});

parallel

This benchmark uses the total number of physical cores as the total number of files to parse per bench iteration. For example it parses 6 files in parallel on my Mac i7 6 cores.

This can indicate the existence of resource contention. For example swc uses string_cache crate, which uses a global concurrent hashmap.

let cpus = num_cpus::get_physical();
group.bench_with_input(id, &source, |b, source| {
    b.iter(|| {
        (0..cpus).into_par_iter().for_each(|_| {
            Self::parse(source);
        });
    })
});

Run

Run the following command on your machine for replication.

cargo bench

To generate the table

cargo install cargo-criterion
cargo install criterion-table
cargo criterion --message-format=json | criterion-table > BENCHMARKS.md

Input

File: https://cdn.jsdelivr.net/npm/typescript@5.1.6/lib/typescript.js
File Size: 7.8M
Uses mimalloc as the global allocator
Uses the following release profile

[profile.release]
opt-level     = 3
lto           = "fat"
codegen-units = 1
strip         = "symbols"
debug         = false
panic         = "abort"

Boshen / bench-javascript-parser-written-in-rust