perf(core): preserve ops between snapshots (#18080)

This commit changes the build process in a way that preserves already
registered ops in the snapshot. This allows us to skip creating hundreds of
"v8::String" on each startup, but sadly there is still some op registration
going on startup (however we're registering 49 ops instead of >200 ops). 

This situation could be further improved, by moving some of the ops 
from "runtime/" to a separate extension crates.

---------

Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/core/ops.rs b/core/ops.rs
index ca465c821..3a276082f 100644
--- a/core/ops.rs
+++ b/core/ops.rs
@@ -19,10 +19,13 @@ use std::cell::RefCell;
 use std::ops::Deref;
 use std::ops::DerefMut;
 use std::pin::Pin;
+use std::ptr::NonNull;
 use std::rc::Rc;
 use std::rc::Weak;
 use std::task::Context;
 use std::task::Poll;
+use v8::fast_api::CFunctionInfo;
+use v8::fast_api::CTypeInfo;
 
 /// Wrapper around a Future, which causes that Future to be polled immediately.
 ///
@@ -155,11 +158,45 @@ pub struct OpCtx {
   pub id: OpId,
   pub state: Rc<RefCell<OpState>>,
   pub decl: Rc<OpDecl>,
+  pub fast_fn_c_info: Option<NonNull<v8::fast_api::CFunctionInfo>>,
   pub runtime_state: Weak<RefCell<JsRuntimeState>>,
   // Index of the current realm into `JsRuntimeState::known_realms`.
   pub realm_idx: RealmIdx,
 }
 
+impl OpCtx {
+  pub fn new(
+    id: OpId,
+    realm_idx: RealmIdx,
+    decl: Rc<OpDecl>,
+    state: Rc<RefCell<OpState>>,
+    runtime_state: Weak<RefCell<JsRuntimeState>>,
+  ) -> Self {
+    let mut fast_fn_c_info = None;
+
+    if let Some(fast_fn) = &decl.fast_fn {
+      let args = CTypeInfo::new_from_slice(fast_fn.args());
+      let ret = CTypeInfo::new(fast_fn.return_type());
+
+      // SAFETY: all arguments are coming from the trait and they have
+      // static lifetime
+      let c_fn = unsafe {
+        CFunctionInfo::new(args.as_ptr(), fast_fn.args().len(), ret.as_ptr())
+      };
+      fast_fn_c_info = Some(c_fn);
+    }
+
+    OpCtx {
+      id,
+      state,
+      runtime_state,
+      decl,
+      realm_idx,
+      fast_fn_c_info,
+    }
+  }
+}
+
 /// Maintains the resources and ops inside a JS runtime.
 pub struct OpState {
   pub resource_table: ResourceTable,