Implement snapshot Serializer

.gitignore

@@ -36,3 +36,6 @@ chrome_profiler.json
 # e2e test
 playwright-report
 test-results
+
+# Binary snapshot file
+snapshot.bin

boa_cli/src/debug/mod.rs

@@ -10,6 +10,7 @@ mod object;
 mod optimizer;
 mod realm;
 mod shape;
+mod snapshot;
 
 fn create_boa_object(context: &mut Context<'_>) -> JsObject {
     let function_module = function::create_object(context);
@@ -19,6 +20,7 @@ fn create_boa_object(context: &mut Context<'_>) -> JsObject {
     let gc_module = gc::create_object(context);
     let realm_module = realm::create_object(context);
     let limits_module = limits::create_object(context);
+    let snapshot_module = snapshot::create_object(context);
 
     ObjectInitializer::new(context)
         .property(
@@ -56,6 +58,11 @@ fn create_boa_object(context: &mut Context<'_>) -> JsObject {
             limits_module,
             Attribute::WRITABLE | Attribute::NON_ENUMERABLE | Attribute::CONFIGURABLE,
         )
+        .property(
+            "snapshot",
+            snapshot_module,
+            Attribute::WRITABLE | Attribute::NON_ENUMERABLE | Attribute::CONFIGURABLE,
+        )
         .build()
 }
 

boa_cli/src/debug/snapshot.rs

@@ -0,0 +1,29 @@
+use std::{fs::OpenOptions, io::Write};
+
+use boa_engine::{
+    object::ObjectInitializer, snapshot::SnapshotSerializer, Context, JsNativeError, JsObject,
+    JsResult, JsValue, NativeFunction,
+};
+
+const SNAPSHOT_PATH: &str = "./snapshot.bin";
+
+fn create(_: &JsValue, _: &[JsValue], context: &mut Context<'_>) -> JsResult<JsValue> {
+    let Ok(mut file) = OpenOptions::new().write(true).create(true).open(SNAPSHOT_PATH) else {
+        return Err(JsNativeError::error().with_message("could not create snapshot.bin file").into());
+    };
+
+    let mut serializer = SnapshotSerializer::new();
+
+    serializer.serialize(context).unwrap();
+
+    file.write_all(serializer.bytes()).unwrap();
+    file.flush().unwrap();
+
+    Ok(JsValue::undefined())
+}
+
+pub(super) fn create_object(context: &mut Context<'_>) -> JsObject {
+    ObjectInitializer::new(context)
+        .function(NativeFunction::from_fn_ptr(create), "create", 0)
+        .build()
+}

boa_engine/src/context/intrinsics.rs

@@ -26,6 +26,16 @@ pub struct Intrinsics {
     pub(super) templates: ObjectTemplates,
 }
 
+impl crate::snapshot::Serialize for Intrinsics {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.constructors.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Intrinsics {
     pub(crate) fn new(root_shape: &RootShape) -> Self {
         let constructors = StandardConstructors::default();
@@ -62,6 +72,17 @@ pub struct StandardConstructor {
     prototype: JsObject,
 }
 
+impl crate::snapshot::Serialize for StandardConstructor {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.constructor.serialize(s)?;
+        self.prototype.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Default for StandardConstructor {
     fn default() -> Self {
         Self {
@@ -153,6 +174,67 @@ pub struct StandardConstructors {
     segmenter: StandardConstructor,
 }
 
+impl crate::snapshot::Serialize for StandardConstructors {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.object.serialize(s)?;
+        self.proxy.serialize(s)?;
+        self.date.serialize(s)?;
+        self.function.serialize(s)?;
+        self.async_function.serialize(s)?;
+        self.generator_function.serialize(s)?;
+        self.async_generator_function.serialize(s)?;
+        self.array.serialize(s)?;
+        self.bigint.serialize(s)?;
+        self.number.serialize(s)?;
+        self.boolean.serialize(s)?;
+        self.string.serialize(s)?;
+        self.regexp.serialize(s)?;
+        self.symbol.serialize(s)?;
+        self.error.serialize(s)?;
+        self.type_error.serialize(s)?;
+        self.reference_error.serialize(s)?;
+        self.range_error.serialize(s)?;
+        self.syntax_error.serialize(s)?;
+        self.eval_error.serialize(s)?;
+        self.uri_error.serialize(s)?;
+        self.aggregate_error.serialize(s)?;
+        self.map.serialize(s)?;
+        self.set.serialize(s)?;
+        self.typed_array.serialize(s)?;
+        self.typed_int8_array.serialize(s)?;
+        self.typed_uint8_array.serialize(s)?;
+        self.typed_uint8clamped_array.serialize(s)?;
+        self.typed_int16_array.serialize(s)?;
+        self.typed_uint16_array.serialize(s)?;
+        self.typed_int32_array.serialize(s)?;
+        self.typed_uint32_array.serialize(s)?;
+        self.typed_bigint64_array.serialize(s)?;
+        self.typed_biguint64_array.serialize(s)?;
+        self.typed_float32_array.serialize(s)?;
+        self.typed_float64_array.serialize(s)?;
+        self.array_buffer.serialize(s)?;
+        self.data_view.serialize(s)?;
+        self.date_time_format.serialize(s)?;
+        self.promise.serialize(s)?;
+        self.weak_ref.serialize(s)?;
+        self.weak_map.serialize(s)?;
+        self.weak_set.serialize(s)?;
+        #[cfg(feature = "intl")]
+        self.collator.serialize(s)?;
+        #[cfg(feature = "intl")]
+        self.list_format.serialize(s)?;
+        #[cfg(feature = "intl")]
+        self.locale.serialize(s)?;
+        #[cfg(feature = "intl")]
+        self.segmenter.serialize(s)?;
+
+        Ok(())
+    }
+}
+
 impl Default for StandardConstructors {
     fn default() -> Self {
         Self {

boa_engine/src/context/mod.rs

@@ -985,3 +985,14 @@ where
         }
     }
 }
+
+impl crate::snapshot::Serialize for Context<'_> {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        s.write_bool(self.strict)?;
+        self.realm.serialize(s)?;
+        Ok(())
+    }
+}

boa_engine/src/lib.rs

@@ -147,6 +147,8 @@ mod tests;
 pub mod value;
 pub mod vm;
 
+pub mod snapshot;
+
 /// A convenience module that re-exports the most commonly-used Boa APIs
 pub mod prelude {
     pub use crate::{

boa_engine/src/object/builtins/jsfunction.rs

@@ -16,6 +16,16 @@ pub struct JsFunction {
     inner: JsObject,
 }
 
+impl crate::snapshot::Serialize for JsFunction {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.inner.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl JsFunction {
     /// Creates a new `JsFunction` from an object, without checking if the object is callable.
     pub(crate) fn from_object_unchecked(object: JsObject) -> Self {

boa_engine/src/object/jsobject.rs

@@ -51,6 +51,18 @@ pub struct VTableObject {
     vtable: &'static InternalObjectMethods,
 }
 
+impl crate::snapshot::Serialize for VTableObject {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> StdResult<(), crate::snapshot::SnapshotError> {
+        // TODO: add internal methods to references
+
+        self.object.borrow().serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Default for JsObject {
     fn default() -> Self {
         let data = ObjectData::ordinary();

boa_engine/src/object/mod.rs

@@ -142,6 +142,17 @@ pub struct Object {
     private_elements: ThinVec<(PrivateName, PrivateElement)>,
 }
 
+impl crate::snapshot::Serialize for Object {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        s.write_bool(self.extensible)?;
+        self.properties.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Default for Object {
     fn default() -> Self {
         Self {

boa_engine/src/object/property_map.rs

@@ -226,6 +226,16 @@ pub struct PropertyMap {
     pub(crate) storage: ObjectStorage,
 }
 
+impl crate::snapshot::Serialize for PropertyMap {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.storage.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl PropertyMap {
     /// Create a new [`PropertyMap`].
     #[must_use]

boa_engine/src/realm.rs

@@ -25,6 +25,16 @@ pub struct Realm {
     inner: Gc<Inner>,
 }
 
+impl crate::snapshot::Serialize for Realm {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.inner.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Eq for Realm {}
 
 impl PartialEq for Realm {
@@ -54,6 +64,16 @@ struct Inner {
     loaded_modules: GcRefCell<FxHashMap<JsString, Module>>,
 }
 
+impl crate::snapshot::Serialize for Inner {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.intrinsics.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Realm {
     /// Create a new Realm.
     #[inline]