NOTE: This is a test project, not suitable to be used for anything except testing.
The main use case of this project is to see whether we can speed up generating ISO-8601 timestamp strings using a native library and how efficient different FFI interface declarations will be (essentially, where are the bottlenecks).
This project includes a set of benchmarks with comparison to the basic JavaScript forms of:
// 1. generate an ISO-8601 string from given (static) milliseconds
new Date(millis).toISOString()
// 2. generate an ISO-8601 string for the current time
new Date().toISOString()While the first merely tests the performance of the FFI interface overhead as well as the performance of the underlying Rust library iso8601-timestamp for generating a string for a given timestamp, the second includes the time for retrieving the current time, which is quite significant.
Absolute results are mostly irrelevant, but the comparison shows where bottlenecks exist:
$ make bench
cargo build --release
Finished `release` profile [optimized] target(s) in 0.04s
deno bench --allow-ffi --allow-env bench.ts
CPU | AMD Ryzen 7 5700G with Radeon Graphics
Runtime | Deno 1.46.3 (x86_64-unknown-linux-gnu)
file:///home/ancoron/dev/ancoron/deno-iso8601-rs/bench.ts
benchmark time/iter (avg) iter/s (min … max) p75 p99 p995
---------------------------------------- ----------------------------- --------------------- --------------------------
group From Milliseconds
standard JavaScript (new Date(millis)) 606.2 ns 1,650,000 (537.9 ns … 1.2 µs) 555.2 ns 1.2 µs 1.2 µs
FFI (bindgen; return String) 1.5 µs 675,000 ( 1.3 µs … 2.0 µs) 1.6 µs 2.0 µs 2.0 µs
FFI (bindgen; pass a buffer) 769.0 ns 1,300,000 (473.6 ns … 1.3 µs) 868.0 ns 1.3 µs 1.3 µs
FFI (manual; return CString + free) 228.8 ns 4,370,000 (209.6 ns … 354.7 ns) 225.4 ns 342.7 ns 352.8 ns
FFI (manual; fill buffer with CString) 1.6 µs 641,600 (843.7 ns … 3.4 µs) 2.0 µs 3.4 µs 3.4 µs
summary
standard JavaScript (new Date(millis))
2.65x slower than FFI (manual; return CString + free)
1.27x faster than FFI (bindgen; pass a buffer)
2.44x faster than FFI (bindgen; return String)
2.57x faster than FFI (manual; fill buffer with CString)
group Current Timestamp
standard JavaScript (new Date()) 2.1 µs 485,200 ( 1.8 µs … 2.8 µs) 2.1 µs 2.8 µs 2.8 µs
FFI (bindgen; return String) 2.8 µs 357,700 ( 2.4 µs … 3.2 µs) 2.9 µs 3.2 µs 3.2 µs
FFI (bindgen; pass a buffer) 3.3 µs 307,500 ( 1.8 µs … 941.3 µs) 3.4 µs 4.7 µs 5.3 µs
FFI (manual; return CString + free) 1.5 µs 660,700 ( 1.4 µs … 3.6 µs) 1.5 µs 3.6 µs 3.6 µs
FFI (manual; fill buffer with CString) 3.1 µs 326,700 ( 2.3 µs … 5.2 µs) 3.6 µs 5.2 µs 5.2 µs
summary
standard JavaScript (new Date())
1.36x slower than FFI (manual; return CString + free)
1.36x faster than FFI (bindgen; return String)
1.49x faster than FFI (manual; fill buffer with CString)
1.58x faster than FFI (bindgen; pass a buffer)
Contributions are welcome on any area (within the scope/use-case of this project).