mirror of https://github.com/denoland/deno.git synced 2024-11-28 16:20:57 -05:00

History

Divy Srivastava 9b2b8df927 feat(ops): Fast zero copy string arguments (#16777 ) Uses SeqOneByteString optimization to do zero-copy `&str` arguments in fast calls. - [x] Depends on https://github.com/denoland/rusty_v8/pull/1129 - [x] Depends on https://chromium-review.googlesource.com/c/v8/v8/+/4036884 - [x] Disable in async ops - [x] Make it work with owned `String` with an extra alloc in fast path. - [x] Support `Cow<'_, str>`. Owned for slow case, Borrowed for fast case ```rust #[op] fn op_string_len(s: &str) -> u32 { str.len() as u32 } ```		2022-12-02 05:29:15 +00:00
..
optimizer_tests	feat(ops): Fast zero copy string arguments (#16777 )	2022-12-02 05:29:15 +00:00
attrs.rs
Cargo.toml	chore: forward v1.28.3 release commit to main (#16884 )	2022-12-01 22:46:27 +09:00
deno.rs
fast_call.rs	feat(ops): Fast zero copy string arguments (#16777 )	2022-12-02 05:29:15 +00:00
lib.rs	feat(ops): Fast zero copy string arguments (#16777 )	2022-12-02 05:29:15 +00:00
optimizer.rs	feat(ops): Fast zero copy string arguments (#16777 )	2022-12-02 05:29:15 +00:00
README.md

README.md

deno_ops

proc_macro for generating highly optimized V8 functions from Deno ops.

// Declare an op.
#[op(fast)]
pub fn op_add(_: &mut OpState, a: i32, b: i32) -> i32 {
  a + b
}

// Register with an extension.
Extension::builder()
  .ops(vec![op_add::decl()])
  .build();

Performance

The macro can optimize away code, short circuit fast paths and generate a Fast API impl.

Cases where code is optimized away:

-> () skips serde_v8 and rv.set calls.
-> Result<(), E> skips serde_v8 and rv.set calls for Ok() branch.
-> ResourceId or -> [int] types will use specialized method like v8::ReturnValue::set_uint32. A fast path for SMI.
-> Result<ResourceId, E> or -> Result<[int], E> types will be optimized like above for the Ok() branch.

Fast calls

The macro will infer and try to auto generate V8 fast API call trait impl for sync ops with:

arguments: integers, bool, &mut OpState, &[u8], &mut [u8], &[u32], &mut [u32]
return_type: integers, bool

The #[op(fast)] attribute should be used to enforce fast call generation at compile time.

Trait gen for async ops & a ZeroCopyBuf equivalent type is planned and will be added soon.

Wasm calls

The #[op(wasm)] attribute should be used for calls expected to be called from Wasm. This enables the fast call generation and allows seamless WasmMemory integration for generic and fast calls.

#[op(wasm)]
pub fn op_args_get(
  offset: i32,
  buffer_offset: i32,
  memory: Option<&[u8]>, // Must be last parameter. Some(..) when entered from Wasm.
) {
  // ...
}