From a1b989c8421e5b1fa6b2954364b4acc4e80db855 Mon Sep 17 00:00:00 2001
From: Divy Srivastava <dj.srivastava23@gmail.com>
Date: Wed, 27 Jul 2022 19:32:21 +0530
Subject: [PATCH] perf(ext/ffi): support Uint8Array in fast calls (#15319)

---
 ext/ffi/jit_trampoline.rs | 26 ++++++++++++++++++++++----
 ext/ffi/lib.rs            |  5 ++---
 ext/ffi/prelude.h         |  6 ++++++
 test_ffi/src/lib.rs       | 10 ++++++++++
 test_ffi/tests/bench.js   |  8 ++++++++
 5 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/ext/ffi/jit_trampoline.rs b/ext/ffi/jit_trampoline.rs
index 6a3efa8764..92e63348d2 100644
--- a/ext/ffi/jit_trampoline.rs
+++ b/ext/ffi/jit_trampoline.rs
@@ -32,7 +32,8 @@ fn native_arg_to_c(ty: &NativeType) -> &'static str {
     NativeType::I64 => "int64_t",
     NativeType::ISize => "intptr_t",
     NativeType::USize => "uintptr_t",
-    NativeType::Pointer | NativeType::Function => "void*",
+    NativeType::Pointer => "struct FastApiTypedArray*",
+    NativeType::Function => "void*",
   }
 }
 
@@ -85,11 +86,15 @@ pub(crate) fn codegen(sym: &crate::Symbol) -> String {
   c += ") {\n";
   // return func(p0, p1, ...);
   c += "  return func(";
-  for (i, _) in sym.parameter_types.iter().enumerate() {
+  for (i, ty) in sym.parameter_types.iter().enumerate() {
     if i > 0 {
       c += ", ";
     }
-    let _ = write!(c, "p{i}");
+    if matches!(ty, NativeType::Pointer) {
+      let _ = write!(c, "p{i}->data");
+    } else {
+      let _ = write!(c, "p{i}");
+    }
   }
   c += ");\n}\n\n";
   c
@@ -103,7 +108,6 @@ pub(crate) fn gen_trampoline(
   // SAFETY: symbol satisfies ABI requirement.
   unsafe { ctx.add_symbol(cstr!("func"), sym.ptr.0 as *const c_void) };
   let c = codegen(&sym);
-
   ctx.compile_string(cstr!(c))?;
   let alloc = Allocation {
     addr: ctx.relocate_and_get_symbol(cstr!("func_trampoline"))?,
@@ -172,6 +176,20 @@ mod tests {
         \n  return func(p0, p1);\n\
       }\n\n",
     );
+    assert_codegen(
+      codegen(vec![NativeType::Pointer, NativeType::U32], NativeType::U32),
+      "extern uint32_t func(void* p0, uint32_t p1);\n\n\
+      uint32_t func_trampoline(void* recv, struct FastApiTypedArray* p0, uint32_t p1) {\
+        \n  return func(p0->data, p1);\n\
+      }\n\n",
+    );
+    assert_codegen(
+      codegen(vec![NativeType::Pointer, NativeType::Pointer], NativeType::U32),
+      "extern uint32_t func(void* p0, void* p1);\n\n\
+      uint32_t func_trampoline(void* recv, struct FastApiTypedArray* p0, struct FastApiTypedArray* p1) {\
+        \n  return func(p0->data, p1->data);\n\
+      }\n\n",
+    );
   }
 
   #[test]
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index 4746a52035..05015a45a7 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -746,9 +746,8 @@ impl From<&NativeType> for fast_api::Type {
       NativeType::I64 => fast_api::Type::Int64,
       NativeType::U64 => fast_api::Type::Uint64,
       NativeType::ISize => fast_api::Type::Int64,
-      NativeType::USize | NativeType::Function | NativeType::Pointer => {
-        fast_api::Type::Uint64
-      }
+      NativeType::USize | NativeType::Function => fast_api::Type::Uint64,
+      NativeType::Pointer => fast_api::Type::TypedArray(fast_api::CType::Uint8),
     }
   }
 }
diff --git a/ext/ffi/prelude.h b/ext/ffi/prelude.h
index ed3d14e1a0..89ae162c1d 100644
--- a/ext/ffi/prelude.h
+++ b/ext/ffi/prelude.h
@@ -17,3 +17,9 @@ typedef unsigned long int uint64_t;
 /* Types for `void *' pointers.  */
 typedef long int intptr_t;
 typedef unsigned long int uintptr_t;
+
+// https://source.chromium.org/chromium/chromium/src/+/main:v8/include/v8-fast-api-calls.h;l=336
+struct FastApiTypedArray {
+  uintptr_t length_;
+  void* data;
+};
diff --git a/test_ffi/src/lib.rs b/test_ffi/src/lib.rs
index 95b7d900ca..bc89bd66c6 100644
--- a/test_ffi/src/lib.rs
+++ b/test_ffi/src/lib.rs
@@ -94,6 +94,16 @@ pub extern "C" fn add_f64(a: f64, b: f64) -> f64 {
   a + b
 }
 
+#[no_mangle]
+unsafe extern "C" fn hash(ptr: *const u8, length: u32) -> u32 {
+  let buf = std::slice::from_raw_parts(ptr, length as usize);
+  let mut hash: u32 = 0;
+  for byte in buf {
+    hash = hash.wrapping_mul(0x10001000).wrapping_add(*byte as u32);
+  }
+  hash
+}
+
 #[no_mangle]
 pub extern "C" fn sleep_blocking(ms: u64) {
   let duration = Duration::from_millis(ms);
diff --git a/test_ffi/tests/bench.js b/test_ffi/tests/bench.js
index 8885c7d7e1..da29f482fa 100644
--- a/test_ffi/tests/bench.js
+++ b/test_ffi/tests/bench.js
@@ -12,6 +12,7 @@ const libPath = `${targetDir}/${libPrefix}test_ffi.${libSuffix}`;
 const dylib = Deno.dlopen(libPath, {
   "nop": { parameters: [], result: "void" },
   "add_u32": { parameters: ["u32", "u32"], result: "u32" },
+  "hash": { parameters: ["pointer", "u32"], result: "u32" },
   "nop_u8": { parameters: ["u8"], result: "void" },
   "nop_i8": { parameters: ["i8"], result: "void" },
   "nop_u16": { parameters: ["u16"], result: "void" },
@@ -231,6 +232,13 @@ Deno.bench("add_u32()", () => {
   add_u32(1, 2);
 });
 
+const bytes = new Uint8Array(64);
+
+const { hash } = dylib.symbols;
+Deno.bench("hash()", () => {
+  hash(bytes, bytes.byteLength);
+});
+
 const { nop_u8 } = dylib.symbols;
 Deno.bench("nop_u8()", () => {
   nop_u8(100);