cleanup(core): recursive get & ensure helpers (#13972)

2 files changed, 61 insertions, 47 deletions

diff --git a/core/bindings.rs b/core/bindings.rs
index 2c879c21a..6e85a57d4 100644
--- a/core/bindings.rs
+++ b/core/bindings.rs
@@ -153,9 +153,6 @@ pub fn initialize_context<'s>(
 
   let scope = &mut v8::ContextScope::new(scope, context);
 
-  let deno_key = v8::String::new(scope, "Deno").unwrap();
-  let core_key = v8::String::new(scope, "core").unwrap();
-  let ops_key = v8::String::new(scope, "ops").unwrap();
   // Snapshot already registered `Deno.core.ops` but
   // extensions may provide ops that aren't part of the snapshot.
   //
@@ -164,30 +161,18 @@ pub fn initialize_context<'s>(
   // tsc ops are static at snapshot time.
   if snapshot_loaded {
     // Grab Deno.core.ops object
-    let deno_val = global.get(scope, deno_key.into()).unwrap();
-    let deno_val = v8::Local::<v8::Object>::try_from(deno_val)
-      .expect("`Deno` not in global scope.");
-    let core_val = deno_val.get(scope, core_key.into()).unwrap();
-    let core_val = v8::Local::<v8::Object>::try_from(core_val)
-      .expect("`Deno.core` not in global scope");
-    let ops_val = core_val.get(scope, ops_key.into()).unwrap();
-    let ops_val = v8::Local::<v8::Object>::try_from(ops_val)
-      .expect("`Deno.core.ops` not in global scope");
+    let ops_obj = JsRuntime::grab_global::<v8::Object>(scope, "Deno.core.ops")
+      .expect("Deno.core.ops to exist");
 
     let raw_op_state = Rc::as_ptr(&op_state) as *const c_void;
     for op in ops {
-      set_func_raw(scope, ops_val, op.name, op.v8_fn_ptr, raw_op_state);
+      set_func_raw(scope, ops_obj, op.name, op.v8_fn_ptr, raw_op_state);
     }
     return scope.escape(context);
   }
 
-  // global.Deno = { core: { ops: {} } };
-  let deno_val = v8::Object::new(scope);
-  global.set(scope, deno_key.into(), deno_val.into());
-  let core_val = v8::Object::new(scope);
-  deno_val.set(scope, core_key.into(), core_val.into());
-  let ops_val = v8::Object::new(scope);
-  core_val.set(scope, ops_key.into(), ops_val.into());
+  // global.Deno = { core: { } };
+  let core_val = JsRuntime::ensure_objs(scope, global, "Deno.core").unwrap();
 
   // Bind functions to Deno.core.*
   set_func(scope, core_val, "refOp_", ref_op);
@@ -245,6 +230,7 @@ pub fn initialize_context<'s>(
   set_func(scope, global, "queueMicrotask", queue_microtask);
 
   // Bind functions to Deno.core.ops.*
+  let ops_val = JsRuntime::ensure_objs(scope, global, "Deno.core.ops").unwrap();
   let raw_op_state = Rc::as_ptr(&op_state) as *const c_void;
   for op in ops {
     set_func_raw(scope, ops_val, op.name, op.v8_fn_ptr, raw_op_state);
diff --git a/core/runtime.rs b/core/runtime.rs
index 8ec3dfb08..6ca586997 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -507,36 +507,64 @@ impl JsRuntime {
     Ok(())
   }
 
-  /// Grab a Global handle to a function returned by the given expression
-  fn grab_fn(
-    scope: &mut v8::HandleScope,
-    code: &str,
-  ) -> v8::Global<v8::Function> {
-    let code = v8::String::new(scope, code).unwrap();
-    let script = v8::Script::compile(scope, code, None).unwrap();
-    let v8_value = script.run(scope).unwrap();
-    let cb = v8::Local::<v8::Function>::try_from(v8_value).unwrap();
-    v8::Global::new(scope, cb)
-  }
-
-  fn grab_obj<'s>(
+  /// Grab a Global handle to a v8 value returned by the expression
+  pub(crate) fn grab<'s, T>(
     scope: &mut v8::HandleScope<'s>,
-    code: &str,
-  ) -> v8::Local<'s, v8::Object> {
-    let scope = &mut v8::EscapableHandleScope::new(scope);
-    let code = v8::String::new(scope, code).unwrap();
-    let script = v8::Script::compile(scope, code, None).unwrap();
-    let v8_value = script.run(scope).unwrap();
-    let obj = v8::Local::<v8::Object>::try_from(v8_value).unwrap();
-    scope.escape(obj)
+    root: v8::Local<'s, v8::Value>,
+    path: &str,
+  ) -> Option<v8::Local<'s, T>>
+  where
+    v8::Local<'s, T>: TryFrom<v8::Local<'s, v8::Value>, Error = v8::DataError>,
+  {
+    path
+      .split('.')
+      .fold(Some(root), |p, k| {
+        let p = v8::Local::<v8::Object>::try_from(p?).ok()?;
+        let k = v8::String::new(scope, k)?;
+        p.get(scope, k.into())
+      })?
+      .try_into()
+      .ok()
+  }
+
+  pub(crate) fn grab_global<'s, T>(
+    scope: &mut v8::HandleScope<'s>,
+    path: &str,
+  ) -> Option<v8::Local<'s, T>>
+  where
+    v8::Local<'s, T>: TryFrom<v8::Local<'s, v8::Value>, Error = v8::DataError>,
+  {
+    let context = scope.get_current_context();
+    let global = context.global(scope);
+    Self::grab(scope, global.into(), path)
+  }
+
+  pub(crate) fn ensure_objs<'s>(
+    scope: &mut v8::HandleScope<'s>,
+    root: v8::Local<'s, v8::Object>,
+    path: &str,
+  ) -> Option<v8::Local<'s, v8::Object>> {
+    path.split('.').fold(Some(root), |p, k| {
+      let k = v8::String::new(scope, k)?.into();
+      match p?.get(scope, k) {
+        Some(v) if !v.is_null_or_undefined() => v.try_into().ok(),
+        _ => {
+          let o = v8::Object::new(scope);
+          p?.set(scope, k, o.into());
+          Some(o)
+        }
+      }
+    })
   }
 
   /// Grabs a reference to core.js' opresolve & syncOpsCache()
   fn init_cbs(&mut self) {
-    let mut scope = self.handle_scope();
-    let recv_cb = Self::grab_fn(&mut scope, "Deno.core.opresolve");
+    let scope = &mut self.handle_scope();
+    let recv_cb =
+      Self::grab_global::<v8::Function>(scope, "Deno.core.opresolve").unwrap();
+    let recv_cb = v8::Global::new(scope, recv_cb);
     // Put global handles in state
-    let state_rc = JsRuntime::state(&scope);
+    let state_rc = JsRuntime::state(scope);
     let mut state = state_rc.borrow_mut();
     state.js_recv_cb.replace(recv_cb);
   }
@@ -612,11 +640,11 @@ impl JsRuntime {
     // TODO(@AaronO): make ops stable across snapshots
     {
       let scope = &mut self.handle_scope();
-      let obj = Self::grab_obj(scope, "Deno.core.ops");
-      let names = obj.get_own_property_names(scope).unwrap();
+      let o = Self::grab_global::<v8::Object>(scope, "Deno.core.ops").unwrap();
+      let names = o.get_own_property_names(scope).unwrap();
       for i in 0..names.length() {
         let key = names.get_index(scope, i).unwrap();
-        obj.delete(scope, key);
+        o.delete(scope, key);
       }
     }