Implement serialize and deserialize for primitive types

boa_engine/src/builtins/iterable/mod.rs

@@ -74,6 +74,29 @@ pub struct IteratorPrototypes {
     segment: JsObject,
 }
 
+impl crate::snapshot::Serialize for IteratorPrototypes {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.iterator.serialize(s)?;
+        self.async_iterator.serialize(s)?;
+        self.async_from_sync_iterator.serialize(s)?;
+        self.array.serialize(s)?;
+        self.set.serialize(s)?;
+        self.string.serialize(s)?;
+        self.regexp_string.serialize(s)?;
+        self.map.serialize(s)?;
+        self.for_in.serialize(s)?;
+        #[cfg(feature = "intl")]
+        {
+            self.segment.serialize(s)?;
+        }
+
+        Ok(())
+    }
+}
+
 impl IteratorPrototypes {
     /// Returns the `ArrayIteratorPrototype` object.
     #[inline]

boa_engine/src/builtins/uri/mod.rs

@@ -47,6 +47,27 @@ pub struct UriFunctions {
     encode_uri_component: JsFunction,
 }
 
+impl crate::snapshot::Serialize for UriFunctions {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.decode_uri.serialize(s)?;
+        self.decode_uri_component.serialize(s)?;
+        self.encode_uri.serialize(s)?;
+        self.encode_uri_component.serialize(s)?;
+        Ok(())
+    }
+}
+
+impl crate::snapshot::Deserialize for UriFunctions {
+    fn deserialize(
+        _d: &mut crate::snapshot::SnapshotDeserializer<'_>,
+    ) -> crate::snapshot::SnapshotResult<Self> {
+        todo!()
+    }
+}
+
 impl Default for UriFunctions {
     fn default() -> Self {
         Self {

boa_engine/src/context/intrinsics.rs

@@ -32,6 +32,8 @@ impl crate::snapshot::Serialize for Intrinsics {
         s: &mut crate::snapshot::SnapshotSerializer,
     ) -> Result<(), crate::snapshot::SnapshotError> {
         self.constructors.serialize(s)?;
+        self.objects.serialize(s)?;
+        self.templates.serialize(s)?;
         Ok(())
     }
 }
@@ -896,6 +898,40 @@ pub struct IntrinsicObjects {
     segments_prototype: JsObject,
 }
 
+impl crate::snapshot::Serialize for IntrinsicObjects {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.reflect.serialize(s)?;
+        self.math.serialize(s)?;
+        self.json.serialize(s)?;
+        self.throw_type_error.serialize(s)?;
+        self.array_prototype_values.serialize(s)?;
+        self.iterator_prototypes.serialize(s)?;
+        self.generator.serialize(s)?;
+        self.async_generator.serialize(s)?;
+        self.eval.serialize(s)?;
+        self.uri_functions.serialize(s)?;
+        self.is_finite.serialize(s)?;
+        self.is_nan.serialize(s)?;
+        self.parse_float.serialize(s)?;
+        self.parse_int.serialize(s)?;
+        #[cfg(feature = "annex-b")]
+        {
+            self.escape.serialize(s)?;
+            self.unescape.serialize(s)?;
+        }
+        #[cfg(feature = "intl")]
+        {
+            self.intl.serialize(s)?;
+            self.segments_prototype.serialize(s)?;
+        }
+
+        Ok(())
+    }
+}
+
 impl Default for IntrinsicObjects {
     fn default() -> Self {
         Self {
@@ -1085,6 +1121,33 @@ pub(crate) struct ObjectTemplates {
     namespace: ObjectTemplate,
 }
 
+impl crate::snapshot::Serialize for ObjectTemplates {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.iterator_result.serialize(s)?;
+        self.ordinary_object.serialize(s)?;
+        self.array.serialize(s)?;
+        self.number.serialize(s)?;
+        self.string.serialize(s)?;
+        self.symbol.serialize(s)?;
+        self.bigint.serialize(s)?;
+        self.boolean.serialize(s)?;
+
+        self.unmapped_arguments.serialize(s)?;
+        self.mapped_arguments.serialize(s)?;
+        self.function_with_prototype.serialize(s)?;
+        self.function_prototype.serialize(s)?;
+        self.function.serialize(s)?;
+        self.async_function.serialize(s)?;
+        self.function_without_proto.serialize(s)?;
+        self.function_with_prototype_without_proto.serialize(s)?;
+        self.namespace.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl ObjectTemplates {
     pub(crate) fn new(root_shape: &RootShape, constructors: &StandardConstructors) -> Self {
         let root_shape = root_shape.shape();

boa_engine/src/context/mod.rs

@@ -1004,6 +1004,7 @@ impl crate::snapshot::Deserialize for Context<'_> {
     ) -> Result<Self, crate::snapshot::SnapshotError> {
         let strict = d.read_bool()?;
         let optimizer_options = OptimizerOptions::deserialize(d)?;
+        // let realm = Realm::deserialize(d)?;
         let mut context = Context::default();
 
         context.strict(strict);

boa_engine/src/environments/compile.rs

@@ -19,6 +19,19 @@ struct CompileTimeBinding {
     strict: bool,
 }
 
+impl crate::snapshot::Serialize for CompileTimeBinding {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.index.serialize(s)?;
+        self.mutable.serialize(s)?;
+        self.lex.serialize(s)?;
+        self.strict.serialize(s)?;
+        Ok(())
+    }
+}
+
 /// A compile time environment maps bound identifiers to their binding positions.
 ///
 /// A compile time environment also indicates, if it is a function environment.
@@ -30,6 +43,29 @@ pub(crate) struct CompileTimeEnvironment {
     function_scope: bool,
 }
 
+impl crate::snapshot::Serialize for Identifier {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.sym().get().serialize(s)?;
+        Ok(())
+    }
+}
+
+impl crate::snapshot::Serialize for CompileTimeEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.outer.serialize(s)?;
+        self.environment_index.serialize(s)?;
+        self.bindings.serialize(s)?;
+        self.function_scope.serialize(s)?;
+        Ok(())
+    }
+}
+
 // Safety: Nothing in this struct needs tracing, so this is safe.
 unsafe impl Trace for CompileTimeEnvironment {
     empty_trace!();

boa_engine/src/environments/runtime/declarative/function.rs

@@ -10,6 +10,17 @@ pub(crate) struct FunctionEnvironment {
     slots: FunctionSlots,
 }
 
+impl crate::snapshot::Serialize for FunctionEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.inner.serialize(s)?;
+        self.slots.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl FunctionEnvironment {
     /// Creates a new `FunctionEnvironment`.
     pub(crate) fn new(bindings: u32, poisoned: bool, with: bool, slots: FunctionSlots) -> Self {
@@ -160,6 +171,22 @@ pub(crate) enum ThisBindingStatus {
     Initialized(JsValue),
 }
 
+impl crate::snapshot::Serialize for ThisBindingStatus {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            ThisBindingStatus::Lexical => b'L'.serialize(s),
+            ThisBindingStatus::Uninitialized => b'U'.serialize(s),
+            ThisBindingStatus::Initialized(v) => {
+                b'I'.serialize(s)?;
+                v.serialize(s)
+            }
+        }
+    }
+}
+
 unsafe impl Trace for ThisBindingStatus {
     custom_trace!(this, {
         match this {
@@ -182,6 +209,18 @@ pub(crate) struct FunctionSlots {
     new_target: Option<JsObject>,
 }
 
+impl crate::snapshot::Serialize for FunctionSlots {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.this.borrow().serialize(s)?;
+        self.function_object.serialize(s)?;
+        self.new_target.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl FunctionSlots {
     /// Creates a new `FunctionSluts`.
     pub(crate) fn new(

boa_engine/src/environments/runtime/declarative/global.rs

@@ -10,6 +10,17 @@ pub(crate) struct GlobalEnvironment {
     global_this: JsObject,
 }
 
+impl crate::snapshot::Serialize for GlobalEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.inner.serialize(s)?;
+        self.global_this.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl GlobalEnvironment {
     /// Creates a new `GlobalEnvironment`.
     pub(crate) fn new(global_this: JsObject) -> Self {

boa_engine/src/environments/runtime/declarative/lexical.rs

@@ -9,6 +9,15 @@ pub(crate) struct LexicalEnvironment {
     inner: PoisonableEnvironment,
 }
 
+impl crate::snapshot::Serialize for LexicalEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.inner.serialize(s)
+    }
+}
+
 impl LexicalEnvironment {
     /// Creates a new `LexicalEnvironment`.
     pub(crate) fn new(bindings: u32, poisoned: bool, with: bool) -> Self {

boa_engine/src/environments/runtime/declarative/mod.rs

@@ -45,6 +45,17 @@ pub(crate) struct DeclarativeEnvironment {
     compile: Rc<RefCell<CompileTimeEnvironment>>,
 }
 
+impl crate::snapshot::Serialize for DeclarativeEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.kind.serialize(s)?;
+        self.compile.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl DeclarativeEnvironment {
     /// Creates a new global `DeclarativeEnvironment`.
     pub(crate) fn global(global_this: JsObject) -> Self {
@@ -145,6 +156,34 @@ pub(crate) enum DeclarativeEnvironmentKind {
     Module(ModuleEnvironment),
 }
 
+impl crate::snapshot::Serialize for DeclarativeEnvironmentKind {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            DeclarativeEnvironmentKind::Lexical(env) => {
+                s.write_u8(b'L')?;
+                env.serialize(s)?;
+            }
+            DeclarativeEnvironmentKind::Global(env) => {
+                s.write_u8(b'G')?;
+                env.serialize(s)?;
+            }
+            DeclarativeEnvironmentKind::Function(env) => {
+                s.write_u8(b'F')?;
+                env.serialize(s)?;
+            }
+            DeclarativeEnvironmentKind::Module(env) => {
+                s.write_u8(b'M')?;
+                env.serialize(s)?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
 impl DeclarativeEnvironmentKind {
     /// Unwraps the inner function environment if possible. Returns `None` otherwise.
     pub(crate) const fn as_function(&self) -> Option<&FunctionEnvironment> {
@@ -278,6 +317,18 @@ pub(crate) struct PoisonableEnvironment {
     with: Cell<bool>,
 }
 
+impl crate::snapshot::Serialize for PoisonableEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.bindings.borrow().serialize(s)?;
+        self.poisoned.serialize(s)?;
+        self.with.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl PoisonableEnvironment {
     /// Creates a new `PoisonableEnvironment`.
     pub(crate) fn new(bindings_count: u32, poisoned: bool, with: bool) -> Self {

boa_engine/src/environments/runtime/declarative/module.rs

@@ -12,6 +12,25 @@ enum BindingAccessor {
     Index(u32),
 }
 
+impl crate::snapshot::Serialize for BindingAccessor {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            BindingAccessor::Identifier(i) => {
+                s.write_u8(b'I')?;
+                i.serialize(s)?;
+            }
+            BindingAccessor::Index(i) => {
+                s.write_u8(b'X')?;
+                i.serialize(s)?;
+            }
+        }
+        Ok(())
+    }
+}
+
 /// An indirect reference to a binding inside an environment.
 #[derive(Clone, Debug, Trace, Finalize)]
 struct IndirectBinding {
@@ -20,6 +39,17 @@ struct IndirectBinding {
     accessor: Cell<BindingAccessor>,
 }
 
+impl crate::snapshot::Serialize for IndirectBinding {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.module.serialize(s)?;
+        self.accessor.serialize(s)?;
+        Ok(())
+    }
+}
+
 /// The type of binding a [`ModuleEnvironment`] can contain.
 #[derive(Clone, Debug, Trace, Finalize)]
 enum BindingType {
@@ -27,6 +57,25 @@ enum BindingType {
     Indirect(IndirectBinding),
 }
 
+impl crate::snapshot::Serialize for BindingType {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            BindingType::Direct(v) => {
+                s.write_u8(b'D')?;
+                v.serialize(s)?;
+            }
+            BindingType::Indirect(i) => {
+                s.write_u8(b'I')?;
+                i.serialize(s)?;
+            }
+        }
+        Ok(())
+    }
+}
+
 /// A [**Module Environment Record**][spec].
 ///
 /// Module environments allow referencing bindings inside other environments, in addition
@@ -39,6 +88,16 @@ pub(crate) struct ModuleEnvironment {
     bindings: GcRefCell<Vec<BindingType>>,
 }
 
+impl crate::snapshot::Serialize for ModuleEnvironment {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.bindings.borrow().serialize(s)?;
+        Ok(())
+    }
+}
+
 impl ModuleEnvironment {
     /// Creates a new `LexicalEnvironment`.
     pub(crate) fn new(bindings: u32) -> Self {

boa_engine/src/error.rs

@@ -49,6 +49,15 @@ pub struct JsError {
     inner: Repr,
 }
 
+impl crate::snapshot::Serialize for JsError {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.inner.serialize(s)
+    }
+}
+
 /// Internal representation of a [`JsError`].
 ///
 /// `JsError` is represented by an opaque enum because it restricts
@@ -65,6 +74,24 @@ enum Repr {
     Opaque(JsValue),
 }
 
+impl crate::snapshot::Serialize for Repr {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            Repr::Native(v) => {
+                b'N'.serialize(s)?;
+                v.serialize(s)?;
+            }
+            Repr::Opaque(v) => {
+                v.serialize(s)?;
+            }
+        }
+        Ok(())
+    }
+}
+
 /// The error type returned by the [`JsError::try_native`] method.
 #[derive(Debug, Clone, Error)]
 pub enum TryNativeError {
@@ -428,6 +455,19 @@ pub struct JsNativeError {
     realm: Option<Realm>,
 }
 
+impl crate::snapshot::Serialize for JsNativeError {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.kind.serialize(s)?;
+        self.message.serialize(s)?;
+        self.cause.serialize(s)?;
+        self.realm.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl std::fmt::Debug for JsNativeError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("JsNativeError")
@@ -953,6 +993,49 @@ pub enum JsNativeErrorKind {
     RuntimeLimit,
 }
 
+impl crate::snapshot::Serialize for JsNativeErrorKind {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            JsNativeErrorKind::Aggregate(errors) => {
+                b'0'.serialize(s)?;
+                errors.serialize(s)?;
+            }
+            JsNativeErrorKind::Error => {
+                b'1'.serialize(s)?;
+            }
+            JsNativeErrorKind::Eval => {
+                b'2'.serialize(s)?;
+            }
+            JsNativeErrorKind::Range => {
+                b'3'.serialize(s)?;
+            }
+            JsNativeErrorKind::Reference => {
+                b'4'.serialize(s)?;
+            }
+            JsNativeErrorKind::Syntax => {
+                b'5'.serialize(s)?;
+            }
+            JsNativeErrorKind::Type => {
+                b'6'.serialize(s)?;
+            }
+            JsNativeErrorKind::Uri => {
+                b'7'.serialize(s)?;
+            }
+            JsNativeErrorKind::RuntimeLimit => {
+                b'8'.serialize(s)?;
+            }
+            #[cfg(feature = "fuzz")]
+            JsNativeErrorKind::NoInstructionsRemain => {
+                b'9'.serialize(s)?;
+            }
+        }
+        Ok(())
+    }
+}
+
 impl PartialEq<ErrorKind> for JsNativeErrorKind {
     fn eq(&self, other: &ErrorKind) -> bool {
         matches!(

boa_engine/src/module/mod.rs

@@ -269,6 +269,16 @@ pub struct Module {
     inner: Gc<Inner>,
 }
 
+impl crate::snapshot::Serialize for Module {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.inner.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl std::fmt::Debug for Module {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("Module")
@@ -290,6 +300,20 @@ struct Inner {
     host_defined: (),
 }
 
+impl crate::snapshot::Serialize for Inner {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.realm.serialize(s)?;
+        self.environment.borrow().serialize(s)?;
+        self.namespace.borrow().serialize(s)?;
+        self.kind.serialize(s)?;
+        self.host_defined.serialize(s)?;
+        Ok(())
+    }
+}
+
 /// The kind of a [`Module`].
 #[derive(Debug, Trace, Finalize)]
 pub(crate) enum ModuleKind {
@@ -300,6 +324,24 @@ pub(crate) enum ModuleKind {
     Synthetic,
 }
 
+impl crate::snapshot::Serialize for ModuleKind {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        match self {
+            ModuleKind::SourceText(v) => {
+                s.write_u8(b'S')?;
+                v.serialize(s)?;
+            }
+            ModuleKind::Synthetic => {
+                s.write_u8(b'C')?;
+            }
+        }
+        Ok(())
+    }
+}
+
 /// Return value of the [`Module::resolve_export`] operation.
 ///
 /// Indicates how to access a specific export in a module.

boa_engine/src/module/source.rs

@@ -93,6 +93,15 @@ enum Status {
     },
 }
 
+impl crate::snapshot::Serialize for Status {
+    fn serialize(
+        &self,
+        _s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        todo!()
+    }
+}
+
 // SAFETY: This must be synced with `Status` to mark any new data added that needs to be traced.
 // `Status` doesn't implement `Drop`, making this manual implementation safe.
 //
@@ -251,6 +260,15 @@ pub(crate) struct SourceTextModule {
     inner: Gc<Inner>,
 }
 
+impl crate::snapshot::Serialize for SourceTextModule {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        self.inner.serialize(s)
+    }
+}
+
 impl std::fmt::Debug for SourceTextModule {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let limiter = RecursionLimiter::new(&*self.inner);
@@ -279,6 +297,15 @@ struct Inner {
     code: ModuleCode,
 }
 
+impl crate::snapshot::Serialize for Inner {
+    fn serialize(
+        &self,
+        _s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        todo!()
+    }
+}
+
 #[derive(Debug)]
 struct ModuleCode {
     has_tla: bool,

boa_engine/src/object/property_map.rs

@@ -231,6 +231,8 @@ impl crate::snapshot::Serialize for PropertyMap {
         &self,
         s: &mut crate::snapshot::SnapshotSerializer,
     ) -> Result<(), crate::snapshot::SnapshotError> {
+        // FIXME: indexed properties.
+        self.shape.serialize(s)?;
         self.storage.serialize(s)?;
         Ok(())
     }

boa_engine/src/object/shape/mod.rs

@@ -58,12 +58,41 @@ enum Inner {
     Shared(SharedShape),
 }
 
+impl crate::snapshot::Serialize for Inner {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        match self {
+            Inner::Unique(shape) => {
+                b'U'.serialize(s)?;
+                shape.serialize(s)?;
+            }
+            Inner::Shared(shape) => {
+                b'S'.serialize(s)?;
+                shape.serialize(s)?;
+            }
+        }
+        Ok(())
+    }
+}
+
 /// Represents the shape of an object.
 #[derive(Debug, Trace, Finalize, Clone)]
 pub struct Shape {
     inner: Inner,
 }
 
+impl crate::snapshot::Serialize for Shape {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.inner.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Default for Shape {
     #[inline]
     fn default() -> Self {

boa_engine/src/object/shape/property_table.rs

@@ -14,6 +14,17 @@ pub(crate) struct PropertyTableInner {
     pub(crate) keys: Vec<(PropertyKey, Slot)>,
 }
 
+impl crate::snapshot::Serialize for PropertyTableInner {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.map.serialize(s)?;
+        self.keys.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl PropertyTableInner {
     /// Returns all the keys, in insertion order.
     pub(crate) fn keys(&self) -> Vec<PropertyKey> {
@@ -73,6 +84,19 @@ pub(crate) struct PropertyTable {
     pub(super) inner: Rc<RefCell<PropertyTableInner>>,
 }
 
+impl crate::snapshot::Serialize for PropertyTable {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        let ptr = self.inner.as_ptr() as usize;
+        s.reference_or(ptr, |s| {
+            self.inner.borrow().serialize(s)?;
+            Ok(())
+        })
+    }
+}
+
 impl PropertyTable {
     /// Returns the inner representation of a [`PropertyTable`].
     pub(super) fn inner(&self) -> &RefCell<PropertyTableInner> {

boa_engine/src/object/shape/shared_shape/mod.rs

@@ -49,6 +49,16 @@ bitflags! {
     }
 }
 
+impl crate::snapshot::Serialize for ShapeFlags {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.bits().serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Default for ShapeFlags {
     fn default() -> Self {
         Self::empty()
@@ -113,12 +123,36 @@ struct Inner {
     flags: ShapeFlags,
 }
 
+impl crate::snapshot::Serialize for Inner {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.property_count.serialize(s)?;
+        self.prototype.serialize(s)?;
+        self.property_table.serialize(s)?;
+        self.previous.serialize(s)?;
+        self.transition_count.serialize(s)?;
+        self.flags.serialize(s)?;
+        Ok(())
+    }
+}
+
 /// Represents a shared object shape.
 #[derive(Debug, Trace, Finalize, Clone)]
 pub struct SharedShape {
     inner: Gc<Inner>,
 }
 
+impl crate::snapshot::Serialize for SharedShape {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.inner.serialize(s)
+    }
+}
+
 impl SharedShape {
     fn property_table(&self) -> &PropertyTable {
         &self.inner.property_table

boa_engine/src/object/shape/shared_shape/template.rs

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

boa_engine/src/object/shape/slot.rs

@@ -13,6 +13,16 @@ bitflags! {
     }
 }
 
+impl crate::snapshot::Serialize for SlotAttributes {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.bits().serialize(s)?;
+        Ok(())
+    }
+}
+
 impl SlotAttributes {
     pub(crate) const fn is_accessor_descriptor(self) -> bool {
         self.contains(Self::GET) || self.contains(Self::SET)
@@ -48,6 +58,17 @@ pub(crate) struct Slot {
     pub(crate) attributes: SlotAttributes,
 }
 
+impl crate::snapshot::Serialize for Slot {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.index.serialize(s)?;
+        self.attributes.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl Slot {
     /// Get the width of the slot.
     pub(crate) fn width(self) -> u32 {

boa_engine/src/object/shape/unique_shape.rs

@@ -22,6 +22,17 @@ struct Inner {
     prototype: GcRefCell<JsPrototype>,
 }
 
+impl crate::snapshot::Serialize for Inner {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.property_table.borrow().serialize(s)?;
+        self.prototype.borrow().serialize(s)?;
+        Ok(())
+    }
+}
+
 /// Represents a [`Shape`] that is not shared with any other object.
 ///
 /// This is useful for objects that are inherently unique like,
@@ -33,6 +44,16 @@ pub(crate) struct UniqueShape {
     inner: Gc<Inner>,
 }
 
+impl crate::snapshot::Serialize for UniqueShape {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        self.inner.serialize(s)?;
+        Ok(())
+    }
+}
+
 impl UniqueShape {
     /// Create a new [`UniqueShape`].
     pub(crate) fn new(prototype: JsPrototype, property_table: PropertyTableInner) -> Self {

boa_engine/src/property/mod.rs

@@ -582,6 +582,46 @@ pub enum PropertyKey {
     Index(u32),
 }
 
+impl crate::snapshot::Serialize for PropertyKey {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> Result<(), crate::snapshot::SnapshotError> {
+        match self {
+            PropertyKey::String(v) => {
+                s.write_u8(0)?;
+                v.serialize(s)?
+            }
+            PropertyKey::Symbol(v) => {
+                s.write_u8(1)?;
+                v.serialize(s)?
+            }
+            PropertyKey::Index(v) => {
+                s.write_u8(2)?;
+                v.serialize(s)?
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl crate::snapshot::Deserialize for PropertyKey {
+    fn deserialize(
+        d: &mut crate::snapshot::SnapshotDeserializer<'_>,
+    ) -> crate::snapshot::SnapshotResult<Self> {
+        let typ = u8::deserialize(d)?;
+        let result = match typ {
+            0 => Self::String(JsString::deserialize(d)?),
+            1 => Self::Symbol(JsSymbol::deserialize(d)?),
+            2 => Self::Index(u32::deserialize(d)?),
+            _ => unreachable!("corrupted snapshot!"),
+        };
+
+        Ok(result)
+    }
+}
+
 /// Utility function for parsing [`PropertyKey`].
 fn parse_u32_index<I, T>(mut input: I) -> Option<u32>
 where

boa_engine/src/realm.rs

@@ -35,6 +35,17 @@ impl crate::snapshot::Serialize for Realm {
     }
 }
 
+impl crate::snapshot::Deserialize for Realm {
+    fn deserialize(
+        d: &mut crate::snapshot::SnapshotDeserializer<'_>,
+    ) -> Result<Self, crate::snapshot::SnapshotError> {
+        let inner = Inner::deserialize(d)?;
+        Ok(Realm {
+            inner: Gc::new(inner),
+        })
+    }
+}
+
 impl Eq for Realm {}
 
 impl PartialEq for Realm {
@@ -70,10 +81,24 @@ impl crate::snapshot::Serialize for Inner {
         s: &mut crate::snapshot::SnapshotSerializer,
     ) -> Result<(), crate::snapshot::SnapshotError> {
         self.intrinsics.serialize(s)?;
+        self.global_object.serialize(s)?;
+        self.global_this.serialize(s)?;
+        self.template_map.borrow().serialize(s)?;
         Ok(())
     }
 }
 
+impl crate::snapshot::Deserialize for Inner {
+    fn deserialize(
+        _d: &mut crate::snapshot::SnapshotDeserializer<'_>,
+    ) -> Result<Self, crate::snapshot::SnapshotError> {
+        // let intrinsics = Intrinsics::deserialize(d)?;
+
+        // Ok(Inner::)
+        todo!()
+    }
+}
+
 impl Realm {
     /// Create a new Realm.
     #[inline]

boa_engine/src/snapshot/deserializer.rs

@@ -1,11 +1,15 @@
+use std::hash::Hash;
+
 use indexmap::IndexSet;
+use rustc_hash::FxHashMap;
+use thin_vec::ThinVec;
 
-use super::SnapshotError;
+use super::{SnapshotError, SnapshotResult};
 
 /// TODO: doc
 pub trait Deserialize: Sized {
     /// TODO: doc
-    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> Result<Self, SnapshotError>;
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self>;
 }
 
 /// TODO: doc
@@ -111,3 +115,201 @@ impl SnapshotDeserializer<'_> {
         Ok(bytes)
     }
 }
+
+impl Deserialize for bool {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_bool()
+    }
+}
+
+impl Deserialize for u8 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_u8()
+    }
+}
+
+impl Deserialize for i8 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_i8()
+    }
+}
+
+impl Deserialize for u16 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_u16()
+    }
+}
+
+impl Deserialize for i16 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_i16()
+    }
+}
+
+impl Deserialize for u32 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_u32()
+    }
+}
+
+impl Deserialize for i32 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_i32()
+    }
+}
+
+impl Deserialize for u64 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_u64()
+    }
+}
+
+impl Deserialize for i64 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_i64()
+    }
+}
+
+impl Deserialize for usize {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_usize()
+    }
+}
+
+impl Deserialize for isize {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_isize()
+    }
+}
+
+impl Deserialize for f32 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_f32()
+    }
+}
+
+impl Deserialize for f64 {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        d.read_f64()
+    }
+}
+
+impl<T: Deserialize> Deserialize for Option<T> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let is_some = bool::deserialize(d)?;
+        if is_some {
+            return Ok(Some(T::deserialize(d)?));
+        }
+
+        Ok(None)
+    }
+}
+
+impl<T: Deserialize, E: Deserialize> Deserialize for Result<T, E> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let is_ok = bool::deserialize(d)?;
+        Ok(if is_ok {
+            Ok(T::deserialize(d)?)
+        } else {
+            Err(E::deserialize(d)?)
+        })
+    }
+}
+
+impl<T: Deserialize> Deserialize for Vec<T> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let len = usize::deserialize(d)?;
+        let mut values = Vec::with_capacity(len);
+        for _ in 0..len {
+            let value = T::deserialize(d)?;
+            values.push(value);
+        }
+        Ok(values)
+    }
+}
+
+impl<T: Deserialize> Deserialize for ThinVec<T> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let len = usize::deserialize(d)?;
+        let mut values = ThinVec::with_capacity(len);
+        for _ in 0..len {
+            let value = T::deserialize(d)?;
+            values.push(value);
+        }
+        Ok(values)
+    }
+}
+
+impl<T: Deserialize> Deserialize for Box<T> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let value = T::deserialize(d)?;
+        Ok(Box::new(value))
+    }
+}
+
+impl Deserialize for Box<str> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let len = usize::deserialize(d)?;
+        let bytes = d.read_bytes(len)?;
+        Ok(String::from_utf8(bytes.into()).unwrap().into_boxed_str())
+    }
+}
+
+impl Deserialize for () {
+    fn deserialize(_d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        // Deserialize nothing, zero size type.
+        Ok(())
+    }
+}
+
+impl<T1: Deserialize> Deserialize for (T1,) {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let v1 = T1::deserialize(d)?;
+        Ok((v1,))
+    }
+}
+
+impl<T1: Deserialize, T2: Deserialize> Deserialize for (T1, T2) {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let v1 = T1::deserialize(d)?;
+        let v2 = T2::deserialize(d)?;
+        Ok((v1, v2))
+    }
+}
+
+impl<T1: Deserialize, T2: Deserialize, T3: Deserialize> Deserialize for (T1, T2, T3) {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let v1 = T1::deserialize(d)?;
+        let v2 = T2::deserialize(d)?;
+        let v3 = T3::deserialize(d)?;
+        Ok((v1, v2, v3))
+    }
+}
+
+impl<T1: Deserialize, T2: Deserialize, T3: Deserialize, T4: Deserialize> Deserialize
+    for (T1, T2, T3, T4)
+{
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let v1 = T1::deserialize(d)?;
+        let v2 = T2::deserialize(d)?;
+        let v3 = T3::deserialize(d)?;
+        let v4 = T4::deserialize(d)?;
+        Ok((v1, v2, v3, v4))
+    }
+}
+
+impl<K: Deserialize + PartialEq + Eq + Hash, V: Deserialize> Deserialize for FxHashMap<K, V> {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let len = usize::deserialize(d)?;
+
+        let mut result = Self::default();
+        for _ in 0..len {
+            let key = K::deserialize(d)?;
+            let value = V::deserialize(d)?;
+            let ret = result.insert(key, value);
+
+            assert!(ret.is_none());
+        }
+        Ok(result)
+    }
+}

boa_engine/src/snapshot/error.rs

@@ -23,3 +23,6 @@ impl From<std::io::Error> for SnapshotError {
         Self::Io(value)
     }
 }
+
+/// Type alias for [`Result`] return type snapshot operations.
+pub type SnapshotResult<T> = Result<T, SnapshotError>;

boa_engine/src/snapshot/header.rs

@@ -0,0 +1,28 @@
+use super::{Deserialize, Serialize, SnapshotDeserializer, SnapshotResult, SnapshotSerializer};
+
+/// TODO: doc
+#[derive(Debug, Clone, Copy)]
+pub struct Header {
+    pub(crate) signature: [u8; 4],
+    pub(crate) version: u32,
+    // checksum: u64,
+}
+
+impl Serialize for Header {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_bytes(&self.signature)?;
+        s.write_u32(self.version)?;
+        Ok(())
+    }
+}
+
+impl Deserialize for Header {
+    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> SnapshotResult<Self> {
+        let signature = d.read_bytes(4)?;
+        let signature = [signature[0], signature[1], signature[2], signature[3]];
+
+        let version = d.read_u32()?;
+
+        Ok(Self { signature, version })
+    }
+}

boa_engine/src/snapshot/mod.rs

@@ -5,34 +5,16 @@
 
 mod deserializer;
 mod error;
+mod header;
 mod serializer;
 
 pub use deserializer::*;
 pub use error::*;
+pub use header::*;
 pub use serializer::*;
 
 use crate::Context;
 use indexmap::IndexSet;
-use std::fmt::Debug;
-
-/// TODO: doc
-#[derive(Debug, Clone, Copy)]
-pub struct Header {
-    signature: [u8; 4],
-    version: u32,
-    // checksum: u64,
-}
-
-impl Deserialize for Header {
-    fn deserialize(d: &mut SnapshotDeserializer<'_>) -> Result<Self, SnapshotError> {
-        let signature = d.read_bytes(4)?;
-        let signature = [signature[0], signature[1], signature[2], signature[3]];
-
-        let version = d.read_u32()?;
-
-        Ok(Self { signature, version })
-    }
-}
 
 /// TODO: doc
 pub struct Snapshot {

boa_engine/src/snapshot/serializer.rs

@@ -1,19 +1,44 @@
+use std::{
+    cell::{Cell, RefCell},
+    hash::Hash,
+    mem::size_of,
+    rc::Rc,
+};
+
+use boa_gc::{Gc, Trace};
 use indexmap::{IndexMap, IndexSet};
+use rustc_hash::FxHashMap;
+use thin_vec::ThinVec;
 
-use crate::{Context, JsBigInt, JsObject, JsString, JsSymbol};
+use crate::{object::shape::SharedShape, Context, JsBigInt, JsObject, JsString, JsSymbol};
 
-use super::{Header, Snapshot, SnapshotError};
+use super::{Header, Snapshot, SnapshotError, SnapshotResult};
 
 /// TODO: doc
 pub trait Serialize {
     /// Serialize type
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError>;
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()>;
+}
+
+/// TODO: doc
+struct Reference {
+    is_inlined: u8,
+    index: u32,
+}
+
+impl Reference {
+    fn new(is_inlined: bool, index: u32) -> Self {
+        Self {
+            is_inlined: if is_inlined { b'I' } else { b'R' },
+            index,
+        }
+    }
 }
 
-impl Serialize for Header {
+impl Serialize for Reference {
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
-        s.write_bytes(&self.signature)?;
+        self.is_inlined.serialize(s)?;
-        s.write_u32(self.version)?;
+        self.index.serialize(s)?;
         Ok(())
     }
 }
@@ -25,6 +50,9 @@ pub struct SnapshotSerializer {
     strings: IndexMap<usize, JsString>,
     symbols: IndexMap<u64, JsSymbol>,
     bigints: IndexSet<JsBigInt>,
+    shared_shapes: IndexMap<usize, SharedShape>,
+
+    pub(crate) internal_reference: IndexMap<usize, u32>,
     external_references: IndexSet<usize>,
 }
 
@@ -37,6 +65,8 @@ impl SnapshotSerializer {
             strings: IndexMap::default(),
             symbols: IndexMap::default(),
             bigints: IndexSet::default(),
+            shared_shapes: IndexMap::default(),
+            internal_reference: IndexMap::default(),
             external_references: IndexSet::default(),
         }
     }
@@ -45,6 +75,8 @@ impl SnapshotSerializer {
     pub fn serialize(mut self, context: &mut Context<'_>) -> Result<Snapshot, SnapshotError> {
         // Remove any garbage objects before serialization.
         boa_gc::force_collect();
+        boa_gc::force_collect();
+        boa_gc::force_collect();
 
         // boa_gc::walk_gc_alloc_pointers(|address| {
         // });
@@ -82,23 +114,6 @@ impl SnapshotSerializer {
             }
         }
 
-        for i in 0..self.strings.len() {
-            let string = self
-                .strings
-                .get_index(i)
-                .expect("There should be an string")
-                .1
-                .clone();
-            // string.
-            string.serialize(&mut self)?;
-
-            self.write_bool(string.is_static())?;
-            self.write_usize(string.len())?;
-            for elem in string.as_slice() {
-                self.write_u16(*elem)?;
-            }
-        }
-
         Ok(Snapshot {
             bytes: self.bytes,
             external_references: self.external_references,
@@ -106,85 +121,222 @@ impl SnapshotSerializer {
     }
 
     /// TODO: doc
-    pub fn write_bool(&mut self, v: bool) -> Result<(), SnapshotError> {
+    pub fn write_bool(&mut self, v: bool) -> SnapshotResult<()> {
         Ok(self.write_u8(if v { 1 } else { 0 })?)
     }
     /// TODO: doc
-    pub fn write_u8(&mut self, v: u8) -> Result<(), SnapshotError> {
+    pub fn write_u8(&mut self, v: u8) -> SnapshotResult<()> {
         Ok(self.write_bytes(&[v])?)
     }
     /// TODO: doc
-    pub fn write_i8(&mut self, v: i8) -> Result<(), SnapshotError> {
+    pub fn write_i8(&mut self, v: i8) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
 
     /// TODO: doc
-    pub fn write_u16(&mut self, v: u16) -> Result<(), SnapshotError> {
+    pub fn write_u16(&mut self, v: u16) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_i16(&mut self, v: i16) -> Result<(), SnapshotError> {
+    pub fn write_i16(&mut self, v: i16) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
 
     /// TODO: doc
-    pub fn write_u32(&mut self, v: u32) -> Result<(), SnapshotError> {
+    pub fn write_u32(&mut self, v: u32) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_i32(&mut self, v: i32) -> Result<(), SnapshotError> {
+    pub fn write_i32(&mut self, v: i32) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
 
     /// TODO: doc
-    pub fn write_f32(&mut self, v: f32) -> Result<(), SnapshotError> {
+    pub fn write_f32(&mut self, v: f32) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_f64(&mut self, v: f64) -> Result<(), SnapshotError> {
+    pub fn write_f64(&mut self, v: f64) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
 
     /// TODO: doc
-    pub fn write_u64(&mut self, v: u64) -> Result<(), SnapshotError> {
+    pub fn write_u64(&mut self, v: u64) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_i64(&mut self, v: i64) -> Result<(), SnapshotError> {
+    pub fn write_i64(&mut self, v: i64) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_u128(&mut self, v: u128) -> Result<(), SnapshotError> {
+    pub fn write_u128(&mut self, v: u128) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_i128(&mut self, v: i128) -> Result<(), SnapshotError> {
+    pub fn write_i128(&mut self, v: i128) -> SnapshotResult<()> {
         Ok(self.write_bytes(&v.to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_usize(&mut self, v: usize) -> Result<(), SnapshotError> {
+    pub fn write_usize(&mut self, v: usize) -> SnapshotResult<()> {
         Ok(self.write_bytes(&(v as u64).to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_isize(&mut self, v: isize) -> Result<(), SnapshotError> {
+    pub fn write_isize(&mut self, v: isize) -> SnapshotResult<()> {
         Ok(self.write_bytes(&(v as i64).to_le_bytes())?)
     }
     /// TODO: doc
-    pub fn write_string(&mut self, v: &str) -> Result<(), SnapshotError> {
+    pub fn write_string(&mut self, v: &str) -> SnapshotResult<()> {
         let asb = v.as_bytes();
         self.write_usize(asb.len())?;
         self.bytes.extend_from_slice(asb);
         Ok(())
     }
     /// TODO: doc
-    pub fn write_bytes(&mut self, v: &[u8]) -> Result<(), SnapshotError> {
+    pub fn write_bytes(&mut self, v: &[u8]) -> SnapshotResult<()> {
         self.bytes.extend_from_slice(v);
         Ok(())
     }
+
+    /// TODO: doc
+    pub fn reference_or<F>(&mut self, ptr: usize, f: F) -> SnapshotResult<()>
+    where
+        F: FnOnce(&mut SnapshotSerializer) -> SnapshotResult<()>,
+    {
+        match self.internal_reference.entry(ptr) {
+            indexmap::map::Entry::Occupied(entry) => {
+                let index = *entry.get();
+                Reference::new(false, index).serialize(self)?;
+                return Ok(());
+            }
+            indexmap::map::Entry::Vacant(entry) => {
+                let index =
+                    *entry.insert((self.bytes.len() + size_of::<u8>() + size_of::<u32>()) as u32);
+                Reference::new(true, index).serialize(self)?;
+            }
+        }
+
+        f(self)
+    }
+}
+
+impl Serialize for bool {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_bool(*self)
+    }
+}
+
+impl Serialize for u8 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_u8(*self)
+    }
+}
+
+impl Serialize for i8 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_i8(*self)
+    }
+}
+
+impl Serialize for u16 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_u16(*self)
+    }
+}
+
+impl Serialize for i16 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_i16(*self)
+    }
+}
+
+impl Serialize for u32 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_u32(*self)
+    }
+}
+
+impl Serialize for i32 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_i32(*self)
+    }
+}
+
+impl Serialize for u64 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_u64(*self)
+    }
+}
+
+impl Serialize for i64 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_i64(*self)
+    }
+}
+
+impl Serialize for usize {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_usize(*self)
+    }
+}
+
+impl Serialize for isize {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_isize(*self)
+    }
+}
+
+impl Serialize for f32 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_f32(*self)
+    }
+}
+
+impl Serialize for f64 {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_f64(*self)
+    }
+}
+
+impl<T: Serialize> Serialize for Option<T> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        if let Some(value) = self {
+            s.write_bool(true)?;
+            value.serialize(s)?
+        } else {
+            s.write_bool(false)?;
+        }
+        Ok(())
+    }
+}
+
+impl<T: Serialize, E: Serialize> Serialize for Result<T, E> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        match self {
+            Ok(value) => {
+                s.write_bool(true)?;
+                value.serialize(s)?;
+            }
+            Err(err) => {
+                s.write_bool(false)?;
+                err.serialize(s)?;
+            }
+        }
+        Ok(())
+    }
 }
 
 impl<T: Serialize> Serialize for Vec<T> {
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        s.write_usize(self.len())?;
+        for element in self {
+            element.serialize(s)?;
+        }
+        Ok(())
+    }
+}
+
+impl<T: Serialize> Serialize for ThinVec<T> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
         s.write_usize(self.len())?;
         for element in self {
             element.serialize(s)?;
@@ -193,37 +345,127 @@ impl<T: Serialize> Serialize for Vec<T> {
     }
 }
 
-impl Serialize for JsString {
+impl<T: Serialize> Serialize for Box<T> {
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
-        let index = s.strings.insert_full(self.ptr.addr(), self.clone()).0;
+        T::serialize(&self, s)
+    }
+}
+
+impl Serialize for Box<str> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.len().serialize(s)?;
+        s.write_bytes(self.as_bytes())?;
+        Ok(())
+    }
+}
 
-        s.write_u32(index as u32)?;
+impl Serialize for String {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.len().serialize(s)?;
+        s.write_bytes(self.as_bytes())?;
         Ok(())
     }
 }
 
-impl Serialize for JsSymbol {
+impl Serialize for () {
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError> {
+    fn serialize(&self, _s: &mut SnapshotSerializer) -> SnapshotResult<()> {
-        let index = s.symbols.insert_full(self.hash(), self.clone()).0;
+        // Serialize nothing
+        Ok(())
+    }
+}
 
-        s.write_u32(index as u32)?;
+impl<T1: Serialize> Serialize for (T1,) {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.0.serialize(s)?;
         Ok(())
     }
 }
 
-impl Serialize for JsBigInt {
+impl<T1: Serialize, T2: Serialize> Serialize for (T1, T2) {
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
-        let index = s.bigints.insert_full(self.clone()).0;
+        self.0.serialize(s)?;
-        s.write_u32(index as u32)?;
+        self.1.serialize(s)?;
         Ok(())
     }
 }
 
-impl Serialize for JsObject {
+impl<T1: Serialize, T2: Serialize, T3: Serialize> Serialize for (T1, T2, T3) {
-    fn serialize(&self, s: &mut SnapshotSerializer) -> Result<(), SnapshotError> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
-        let value = s.objects.insert_full(self.clone()).0;
+        self.0.serialize(s)?;
+        self.1.serialize(s)?;
+        self.2.serialize(s)?;
+        Ok(())
+    }
+}
+
+impl<T1: Serialize, T2: Serialize, T3: Serialize, T4: Serialize> Serialize for (T1, T2, T3, T4) {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.0.serialize(s)?;
+        self.1.serialize(s)?;
+        self.2.serialize(s)?;
+        self.3.serialize(s)?;
+        Ok(())
+    }
+}
 
-        s.write_u32(value as u32)?;
+impl<K: Serialize + PartialEq + Eq + Hash, V: Serialize> Serialize for FxHashMap<K, V> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.len().serialize(s)?;
+        for (key, value) in self {
+            key.serialize(s)?;
+            value.serialize(s)?;
+        }
         Ok(())
     }
 }
+
+impl Serialize for JsBigInt {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        let ptr: *const _ = self.as_inner();
+        s.reference_or(ptr as usize, |s| {
+            let (sign, bytes) = self.as_inner().to_bytes_le();
+
+            match sign {
+                num_bigint::Sign::Minus => b'-',
+                num_bigint::Sign::NoSign => b' ',
+                num_bigint::Sign::Plus => b'+',
+            }
+            .serialize(s)?;
+
+            bytes.serialize(s)
+        })
+    }
+}
+
+impl Serialize for JsObject {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        let ptr: *const _ = self.inner();
+        s.reference_or(ptr as usize, |s| self.inner().serialize(s))
+    }
+}
+
+impl<T: Serialize + Trace> Serialize for Gc<T> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        let ptr: *const _ = &*self;
+        s.reference_or(ptr as usize, |s| T::serialize(&*self, s))
+    }
+}
+
+impl<T: Serialize> Serialize for Rc<T> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        let ptr: *const _ = &*self;
+        s.reference_or(ptr as usize, |s| T::serialize(&*self, s))
+    }
+}
+
+impl<T: Serialize> Serialize for RefCell<T> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.borrow().serialize(s)
+    }
+}
+
+impl<T: Serialize + Copy> Serialize for Cell<T> {
+    fn serialize(&self, s: &mut SnapshotSerializer) -> SnapshotResult<()> {
+        self.get().serialize(s)
+    }
+}

boa_engine/src/string/mod.rs

@@ -209,6 +209,36 @@ pub struct JsString {
     pub(crate) ptr: Tagged<RawJsString>,
 }
 
+impl crate::snapshot::Serialize for JsString {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        let addr = self.ptr.addr();
+        s.reference_or(addr, |s| {
+            s.write_bool(self.is_static())?;
+            if !self.is_static() {
+                s.write_usize(self.len())?;
+                for elem in self.as_slice() {
+                    s.write_u16(*elem)?;
+                }
+            } else {
+                s.write_usize(addr)?;
+            }
+
+            Ok(())
+        })
+    }
+}
+
+impl crate::snapshot::Deserialize for JsString {
+    fn deserialize(
+        _d: &mut crate::snapshot::SnapshotDeserializer<'_>,
+    ) -> crate::snapshot::SnapshotResult<Self> {
+        todo!()
+    }
+}
+
 // JsString should always be pointer sized.
 sa::assert_eq_size!(JsString, *const ());
 

boa_engine/src/symbol.rs

@@ -118,7 +118,40 @@ pub(crate) struct Inner {
 
 /// This represents a JavaScript symbol primitive.
 pub struct JsSymbol {
-    pub(crate) repr: Tagged<Inner>,
+    repr: Tagged<Inner>,
+}
+
+impl crate::snapshot::Serialize for JsSymbol {
+    fn serialize(
+        &self,
+        s: &mut crate::snapshot::SnapshotSerializer,
+    ) -> crate::snapshot::SnapshotResult<()> {
+        let addr = self.repr.addr();
+        s.reference_or(addr, |s| {
+            s.write_bool(self.repr.is_tagged())?;
+            if !self.repr.is_tagged() {
+                self.hash().serialize(s)?;
+                if let Some(desc) = self.description() {
+                    s.write_bool(true)?;
+                    desc.serialize(s)?;
+                } else {
+                    s.write_bool(false)?;
+                }
+            } else {
+                s.write_usize(addr)?;
+            }
+
+            Ok(())
+        })
+    }
+}
+
+impl crate::snapshot::Deserialize for JsSymbol {
+    fn deserialize(
+        _d: &mut crate::snapshot::SnapshotDeserializer<'_>,
+    ) -> crate::snapshot::SnapshotResult<Self> {
+        todo!()
+    }
 }
 
 // SAFETY: `JsSymbol` uses `Arc` to do the reference counting, making this type thread-safe.

docs/snapshot.md

@@ -1,6 +1,6 @@
 # Snapshot File format
 
-This docoment describes the binary file format of the boa snapshot files.
+This document describes the binary file format of the boa snapshot files.
 
 ## Header
 
@@ -12,52 +12,8 @@ The header composes the first part of the snapshot.
 | guid                  | Guid generated in compile time and backed into the binary, that is used to check if snapshot is compatibile. |
 | checksum              | Checksum that is used to check that the snapshot is not corrupted.                                           |
 
-## JsString Table
+## Internal Reference Map
 
-After the `Header` the table containing `JsString`s each entry contains
-
-| static? `: u8` | length: `: usize` | `JsString` elements `: [u16]` |
-| -------------- | ----------------- | ----------------------------- |
-| 0              | 5                 | `'H', 'e', 'l', 'l', 'o'`     |
-| 1              | -                 | 3                             |
-| ...            | ...               | ...                           |
-
-If it's a static string then it's elements comprise the index into the `STATIC_STRING`s.
-
-## JsSymbol Table
-
-| `JsSymbol` hash `: u64` | Description (index into `JsString` table) `: usize` |
-| ----------------------- | --------------------------------------------------- |
-| 200                     | 0                                                   |
-| ...                     | ...                                                 |
-
-## JsBigInt Table
-
-| Length in bytes `: u64` | Content |
-| ----------------------- | ------- |
-| 32                      | ...     |
-
-## Shapes (Hidden classes) Table
-
-### Unique Shapes
-
-| `[[prototype]]` `: u32` (index into `JsObject` table) | property count `: u32` | key-value pairs |
-| ----------------------------------------------------- | ---------------------- | --------------- |
-|                                                       | 0                      |                 |
-|                                                       | ...                    |                 |
-
-### Shared Shapes
-
-| previous `: u32` | flags | transition |
-| ---------------- | ----- | ---------- |
-| `MAX` (root)     | ...   | `x`        |
-
-## JsObject Table
-
-| length | Content |
-| ------ | ------- |
-| 200    | ...     |
-| ...    | ...     |
 
 ## JsValue Encoding