perf(ext/ffi): Fast UnsafePointerView read functions (#16351)

This PR makes pointer read methods of `Deno.UnsafePointerView` Fast API
compliant, with the exception of `getCString` which cannot be made fast
with current V8 Fast API.

1 files changed, 44 insertions, 20 deletions

diff --git a/ext/ffi/00_ffi.js b/ext/ffi/00_ffi.js
index 3f5c57a9c..f5b0fb4c3 100644
--- a/ext/ffi/00_ffi.js
+++ b/ext/ffi/00_ffi.js
@@ -6,7 +6,6 @@
   const ops = core.ops;
   const __bootstrap = window.__bootstrap;
   const {
-    BigInt,
     ObjectDefineProperty,
     ArrayPrototypeMap,
     Number,
@@ -17,9 +16,13 @@
     Int32Array,
     Uint32Array,
     BigInt64Array,
+    BigUint64Array,
     Function,
   } = window.__bootstrap.primordials;
 
+  const U32_BUFFER = new Uint32Array(2);
+  const U64_BUFFER = new BigUint64Array(U32_BUFFER.buffer);
+  const I64_BUFFER = new BigInt64Array(U32_BUFFER.buffer);
   class UnsafePointerView {
     pointer;
 
@@ -29,99 +32,119 @@
 
     getBool(offset = 0) {
       return ops.op_ffi_read_bool(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getUint8(offset = 0) {
       return ops.op_ffi_read_u8(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getInt8(offset = 0) {
       return ops.op_ffi_read_i8(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getUint16(offset = 0) {
       return ops.op_ffi_read_u16(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getInt16(offset = 0) {
       return ops.op_ffi_read_i16(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getUint32(offset = 0) {
       return ops.op_ffi_read_u32(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getInt32(offset = 0) {
       return ops.op_ffi_read_i32(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getBigUint64(offset = 0) {
-      return ops.op_ffi_read_u64(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+      ops.op_ffi_read_u64(
+        this.pointer,
+        offset,
+        U32_BUFFER,
       );
+      return U64_BUFFER[0];
     }
 
     getBigInt64(offset = 0) {
-      return ops.op_ffi_read_i64(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+      ops.op_ffi_read_i64(
+        this.pointer,
+        offset,
+        U32_BUFFER,
       );
+      return I64_BUFFER[0];
     }
 
     getFloat32(offset = 0) {
       return ops.op_ffi_read_f32(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getFloat64(offset = 0) {
       return ops.op_ffi_read_f64(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     getCString(offset = 0) {
       return ops.op_ffi_cstr_read(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
       );
     }
 
     static getCString(pointer, offset = 0) {
       return ops.op_ffi_cstr_read(
-        offset ? BigInt(pointer) + BigInt(offset) : pointer,
+        pointer,
+        offset,
       );
     }
 
     getArrayBuffer(byteLength, offset = 0) {
       return ops.op_ffi_get_buf(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
         byteLength,
       );
     }
 
     static getArrayBuffer(pointer, byteLength, offset = 0) {
       return ops.op_ffi_get_buf(
-        offset ? BigInt(pointer) + BigInt(offset) : pointer,
+        pointer,
+        offset,
         byteLength,
       );
     }
 
     copyInto(destination, offset = 0) {
       ops.op_ffi_buf_copy_into(
-        offset ? BigInt(this.pointer) + BigInt(offset) : this.pointer,
+        this.pointer,
+        offset,
         destination,
         destination.byteLength,
       );
@@ -129,7 +152,8 @@
 
     static copyInto(pointer, destination, offset = 0) {
       ops.op_ffi_buf_copy_into(
-        offset ? BigInt(pointer) + BigInt(offset) : pointer,
+        pointer,
+        offset,
         destination,
         destination.byteLength,
       );