Change signature of FunctionTemplate::build_fast (#1197)

Changes signature of "FunctionTemplate::build_fast" to allow
to pass "CFunctionInfo" explicitly. If it's not passed explicitly,
it's still autogenerated.

benches/function.rs

@@ -87,7 +87,7 @@ fn main() {
         rv.set(v8::Integer::new(scope, 42).into());
       },
     )
-    .build_fast(scope, &FastCall, None);
+    .build_fast(scope, &FastCall, None, None, None);
     let name = v8::String::new(scope, "new_fast").unwrap();
     let value = template.get_function(scope).unwrap();
 

src/fast_api.rs

@@ -30,7 +30,7 @@ pub struct CFunction(Opaque);
 
 impl CFunctionInfo {
   #[inline(always)]
-  pub(crate) unsafe fn new(
+  pub unsafe fn new(
     args: *const CTypeInfo,
     args_len: usize,
     return_type: *const CTypeInfo,
@@ -45,11 +45,11 @@ pub struct CTypeInfo(Opaque);
 
 impl CTypeInfo {
   #[inline(always)]
-  pub(crate) fn new(ty: CType) -> NonNull<CTypeInfo> {
+  pub fn new(ty: CType) -> NonNull<CTypeInfo> {
     unsafe { NonNull::new_unchecked(v8__CTypeInfo__New(ty)) }
   }
 
-  pub(crate) fn new_from_slice(types: &[Type]) -> NonNull<CTypeInfo> {
+  pub fn new_from_slice(types: &[Type]) -> NonNull<CTypeInfo> {
     let mut structs = vec![];
 
     for type_ in types.iter() {

src/template.rs

@@ -372,27 +372,50 @@ impl<'s> FunctionBuilder<'s, FunctionTemplate> {
     .unwrap()
   }
 
+  /// It's not required to provide `CFunctionInfo` for the overloads - if they
+  /// are omitted, then they will be automatically created. In some cases it is
+  /// useful to pass them explicitly - eg. when you are snapshotting you'd provide
+  /// the overloads and `CFunctionInfo` that would be placed in the external
+  /// references array.
   pub fn build_fast(
     self,
     scope: &mut HandleScope<'s, ()>,
     overload1: &dyn FastFunction,
+    c_fn_info1: Option<*const CFunctionInfo>,
     overload2: Option<&dyn FastFunction>,
+    c_fn_info2: Option<*const CFunctionInfo>,
   ) -> Local<'s, FunctionTemplate> {
-    unsafe {
+    let c_fn1 = if let Some(fn_info) = c_fn_info1 {
+      fn_info
+    } else {
       let args = CTypeInfo::new_from_slice(overload1.args());
       let ret = CTypeInfo::new(overload1.return_type());
-      let c_fn1 =
+      let fn_info = unsafe {
-        CFunctionInfo::new(args.as_ptr(), overload1.args().len(), ret.as_ptr());
+        CFunctionInfo::new(args.as_ptr(), overload1.args().len(), ret.as_ptr())
-
-      let c_fn2 = match overload2 {
-        Some(overload) => {
-          let args = CTypeInfo::new_from_slice(overload.args());
-          let ret = CTypeInfo::new(overload.return_type());
-          CFunctionInfo::new(args.as_ptr(), overload.args().len(), ret.as_ptr())
-            .as_ptr()
-        }
-        None => null(),
       };
+      fn_info.as_ptr()
+    };
+
+    let c_fn2 = if let Some(overload2) = overload2 {
+      if let Some(fn_info) = c_fn_info2 {
+        fn_info
+      } else {
+        let args = CTypeInfo::new_from_slice(overload2.args());
+        let ret = CTypeInfo::new(overload2.return_type());
+        let fn_info = unsafe {
+          CFunctionInfo::new(
+            args.as_ptr(),
+            overload2.args().len(),
+            ret.as_ptr(),
+          )
+        };
+        fn_info.as_ptr()
+      }
+    } else {
+      null()
+    };
+
+    unsafe {
       scope.cast_local(|sd| {
         v8__FunctionTemplate__New(
           sd.get_isolate_ptr(),
@@ -403,7 +426,7 @@ impl<'s> FunctionBuilder<'s, FunctionTemplate> {
           ConstructorBehavior::Throw,
           self.side_effect_type,
           overload1.function(),
-          c_fn1.as_ptr(),
+          c_fn1,
           overload2.map_or(null(), |f| f.function()),
           c_fn2,
         )

tests/test_api.rs

@@ -8268,8 +8268,8 @@ fn test_fast_calls() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8341,8 +8341,8 @@ fn test_fast_calls_sequence() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8414,8 +8414,8 @@ fn test_fast_calls_arraybuffer() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8490,8 +8490,8 @@ fn test_fast_calls_typedarray() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8580,8 +8580,8 @@ fn test_fast_calls_reciever() {
     embedder_obj as _,
   );
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "method").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8674,7 +8674,9 @@ fn test_fast_calls_overload() {
   let template = v8::FunctionTemplate::builder(slow_fn).build_fast(
     scope,
     &FastTest,
+    None,
     Some(&FastTest2),
+    None,
   );
 
   let name = v8::String::new(scope, "func").unwrap();
@@ -8748,8 +8750,8 @@ fn test_fast_calls_callback_options_fallback() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8824,7 +8826,7 @@ fn test_fast_calls_callback_options_data() {
 
   let template = v8::FunctionTemplate::builder(slow_fn)
     .data(external.into())
-    .build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -8936,8 +8938,8 @@ fn test_fast_calls_onebytestring() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();
@@ -9076,8 +9078,8 @@ fn test_fast_calls_pointer() {
 
   let global = context.global(scope);
 
-  let template =
+  let template = v8::FunctionTemplate::builder(slow_fn)
-    v8::FunctionTemplate::builder(slow_fn).build_fast(scope, &FastTest, None);
+    .build_fast(scope, &FastTest, None, None, None);
 
   let name = v8::String::new(scope, "func").unwrap();
   let value = template.get_function(scope).unwrap();