feat(ops): V8 Fast Calls (#15291)

5 files changed, 103 insertions, 21 deletions

diff --git a/core/bindings.rs b/core/bindings.rs
index f3c16acbf..f75f6c7f3 100644
--- a/core/bindings.rs
+++ b/core/bindings.rs
@@ -9,17 +9,39 @@ use crate::modules::ModuleMap;
 use crate::ops::OpCtx;
 use crate::JsRuntime;
 use log::debug;
-use once_cell::sync::Lazy;
 use std::option::Option;
 use std::os::raw::c_void;
+use v8::fast_api::FastFunction;
 use v8::MapFnTo;
 
-pub static EXTERNAL_REFERENCES: Lazy<v8::ExternalReferences> =
-  Lazy::new(|| {
-    v8::ExternalReferences::new(&[v8::ExternalReference {
-      function: call_console.map_fn_to(),
-    }])
-  });
+pub fn external_references(
+  ops: &[OpCtx],
+  snapshot_loaded: bool,
+) -> v8::ExternalReferences {
+  let mut references = vec![v8::ExternalReference {
+    function: call_console.map_fn_to(),
+  }];
+
+  for ctx in ops {
+    let ctx_ptr = ctx as *const OpCtx as _;
+    references.push(v8::ExternalReference { pointer: ctx_ptr });
+    references.push(v8::ExternalReference {
+      function: ctx.decl.v8_fn_ptr,
+    });
+    if snapshot_loaded {
+      if let Some(fast_fn) = &ctx.decl.fast_fn {
+        references.push(v8::ExternalReference {
+          pointer: fast_fn.function() as _,
+        });
+      }
+    }
+  }
+
+  let refs = v8::ExternalReferences::new(&references);
+  // Leak, V8 takes ownership of the references.
+  std::mem::forget(references);
+  refs
+}
 
 // TODO(nayeemrmn): Move to runtime and/or make `pub(crate)`.
 pub fn script_origin<'a>(
@@ -82,7 +104,8 @@ pub fn initialize_context<'s>(
     // Grab the Deno.core.ops object & init it
     let ops_obj = JsRuntime::grab_global::<v8::Object>(scope, "Deno.core.ops")
       .expect("Deno.core.ops to exist");
-    initialize_ops(scope, ops_obj, op_ctxs);
+    initialize_ops(scope, ops_obj, op_ctxs, snapshot_loaded);
+
     return scope.escape(context);
   }
 
@@ -94,7 +117,8 @@ pub fn initialize_context<'s>(
 
   // Bind functions to Deno.core.ops.*
   let ops_obj = JsRuntime::ensure_objs(scope, global, "Deno.core.ops").unwrap();
-  initialize_ops(scope, ops_obj, op_ctxs);
+
+  initialize_ops(scope, ops_obj, op_ctxs, snapshot_loaded);
   scope.escape(context)
 }
 
@@ -102,10 +126,46 @@ fn initialize_ops(
   scope: &mut v8::HandleScope,
   ops_obj: v8::Local<v8::Object>,
   op_ctxs: &[OpCtx],
+  snapshot_loaded: bool,
 ) {
   for ctx in op_ctxs {
     let ctx_ptr = ctx as *const OpCtx as *const c_void;
-    set_func_raw(scope, ops_obj, ctx.decl.name, ctx.decl.v8_fn_ptr, ctx_ptr);
+
+    // If this is a fast op, we don't want it to be in the snapshot.
+    // Only initialize once snapshot is loaded.
+    if ctx.decl.fast_fn.is_some() && snapshot_loaded {
+      let object_template = v8::ObjectTemplate::new(scope);
+      assert!(object_template.set_internal_field_count(
+        (crate::runtime::V8_WRAPPER_OBJECT_INDEX + 1) as usize
+      ));
+
+      let method_obj = object_template.new_instance(scope).unwrap();
+      method_obj.set_aligned_pointer_in_internal_field(
+        crate::runtime::V8_WRAPPER_OBJECT_INDEX,
+        ctx_ptr,
+      );
+      set_func_raw(
+        scope,
+        method_obj,
+        "fast",
+        ctx.decl.v8_fn_ptr,
+        ctx_ptr,
+        &ctx.decl.fast_fn,
+        snapshot_loaded,
+      );
+      let method_key = v8::String::new(scope, ctx.decl.name).unwrap();
+      ops_obj.set(scope, method_key.into(), method_obj.into());
+    } else {
+      set_func_raw(
+        scope,
+        ops_obj,
+        ctx.decl.name,
+        ctx.decl.v8_fn_ptr,
+        ctx_ptr,
+        &None,
+        snapshot_loaded,
+      );
+    }
   }
 }
 
@@ -129,13 +189,25 @@ pub fn set_func_raw(
   name: &'static str,
   callback: v8::FunctionCallback,
   external_data: *const c_void,
+  fast_function: &Option<Box<dyn FastFunction>>,
+  snapshot_loaded: bool,
 ) {
   let key = v8::String::new(scope, name).unwrap();
   let external = v8::External::new(scope, external_data as *mut c_void);
-  let val = v8::Function::builder_raw(callback)
-    .data(external.into())
-    .build(scope)
-    .unwrap();
+  let builder =
+    v8::FunctionTemplate::builder_raw(callback).data(external.into());
+  let templ = if let Some(fast_function) = fast_function {
+    // Don't initialize fast ops when snapshotting, the external references count mismatch.
+    if !snapshot_loaded {
+      builder.build(scope)
+    } else {
+      // TODO(@littledivy): Support fast api overloads in ops.
+      builder.build_fast(scope, &**fast_function, None)
+    }
+  } else {
+    builder.build(scope)
+  };
+  let val = templ.get_function(scope).unwrap();
   val.set_name(key);
   obj.set(scope, key.into(), val.into());
 }
diff --git a/core/extensions.rs b/core/extensions.rs
index ce6957875..846770d1f 100644
--- a/core/extensions.rs
+++ b/core/extensions.rs
@@ -2,6 +2,7 @@
 use crate::OpState;
 use anyhow::Error;
 use std::{cell::RefCell, rc::Rc, task::Context};
+use v8::fast_api::FastFunction;
 
 pub type SourcePair = (&'static str, &'static str);
 pub type OpFnRef = v8::FunctionCallback;
@@ -9,14 +10,14 @@ pub type OpMiddlewareFn = dyn Fn(OpDecl) -> OpDecl;
 pub type OpStateFn = dyn Fn(&mut OpState) -> Result<(), Error>;
 pub type OpEventLoopFn = dyn Fn(Rc<RefCell<OpState>>, &mut Context) -> bool;
 
-#[derive(Clone, Copy)]
 pub struct OpDecl {
   pub name: &'static str,
   pub v8_fn_ptr: OpFnRef,
   pub enabled: bool,
-  pub is_async: bool, // TODO(@AaronO): enum sync/async/fast ?
+  pub is_async: bool,
   pub is_unstable: bool,
   pub is_v8: bool,
+  pub fast_fn: Option<Box<dyn FastFunction>>,
 }
 
 impl OpDecl {
diff --git a/core/lib.rs b/core/lib.rs
index 57e81ee7a..8043b5e95 100644
--- a/core/lib.rs
+++ b/core/lib.rs
@@ -118,6 +118,8 @@ pub mod _ops {
   pub use super::ops::to_op_result;
   pub use super::ops::OpCtx;
   pub use super::runtime::queue_async_op;
+  pub use super::runtime::V8_WRAPPER_OBJECT_INDEX;
+  pub use super::runtime::V8_WRAPPER_TYPE_INDEX;
 }
 
 /// A helper macro that will return a call site in Rust code. Should be
diff --git a/core/ops_builtin.rs b/core/ops_builtin.rs
index a42c0bae8..2e911e415 100644
--- a/core/ops_builtin.rs
+++ b/core/ops_builtin.rs
@@ -31,6 +31,7 @@ pub(crate) fn init_builtins() -> Extension {
       op_wasm_streaming_set_url::decl(),
       op_void_sync::decl(),
       op_void_async::decl(),
+      op_add::decl(),
       // // TODO(@AaronO): track IO metrics for builtin streams
       op_read::decl(),
       op_write::decl(),
@@ -54,7 +55,12 @@ pub fn op_resources(state: &mut OpState) -> Vec<(ResourceId, String)> {
     .collect()
 }
 
-#[op]
+#[op(fast)]
+fn op_add(a: i32, b: i32) -> i32 {
+  a + b
+}
+
+#[op(fast)]
 pub fn op_void_sync() {}
 
 #[op]
diff --git a/core/runtime.rs b/core/runtime.rs
index 68c3ab002..06c777687 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -328,7 +328,6 @@ impl JsRuntime {
     if let Some(get_error_class_fn) = options.get_error_class_fn {
       op_state.get_error_class_fn = get_error_class_fn;
     }
-
     let op_state = Rc::new(RefCell::new(op_state));
     let op_ctxs = ops
       .into_iter()
@@ -341,12 +340,14 @@ impl JsRuntime {
       .collect::<Vec<_>>()
       .into_boxed_slice();
 
+    let refs = bindings::external_references(&op_ctxs, !options.will_snapshot);
+    // V8 takes ownership of external_references.
+    let refs: &'static v8::ExternalReferences = Box::leak(Box::new(refs));
     let global_context;
     let (mut isolate, maybe_snapshot_creator) = if options.will_snapshot {
       // TODO(ry) Support loading snapshots before snapshotting.
       assert!(options.startup_snapshot.is_none());
-      let mut creator =
-        v8::SnapshotCreator::new(Some(&bindings::EXTERNAL_REFERENCES));
+      let mut creator = v8::SnapshotCreator::new(Some(refs));
       // SAFETY: `get_owned_isolate` is unsafe because it may only be called
       // once. This is the only place we call this function, so this call is
       // safe.
@@ -369,7 +370,7 @@ impl JsRuntime {
             V8_WRAPPER_OBJECT_INDEX,
           )
         })
-        .external_references(&**bindings::EXTERNAL_REFERENCES);
+        .external_references(&**refs);
       let snapshot_loaded = if let Some(snapshot) = options.startup_snapshot {
         params = match snapshot {
           Snapshot::Static(data) => params.snapshot_blob(data),