Reduce indexing boilerplate for serializable/transferrable objects. (#36624)

Rather than creating unique types for each pipeline-namespaced index
type (eg. MessagePortId, DomExceptionId, etc.), we can create a generic
common type that uses a marker to prevent type confusion. This change
allows us to reduce the boilerplate code required when implementing
serializable/transferable interfaces, since the structured clone
implementation can rely on the common type.

Testing: Existing WPT tests for serialization and transferring provide
coverage.

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/compositing/webview_manager.rs

@@ -111,11 +111,7 @@ impl<WebView> WebViewManager<WebView> {
 
 #[cfg(test)]
 mod test {
-    use std::num::NonZeroU32;
+    use base::id::{BrowsingContextId, Index, PipelineNamespace, PipelineNamespaceId, WebViewId};
-
-    use base::id::{
-        BrowsingContextId, BrowsingContextIndex, PipelineNamespace, PipelineNamespaceId, WebViewId,
-    };
 
     use crate::webview_manager::WebViewManager;
     use crate::webview_renderer::UnknownWebView;
@@ -123,7 +119,7 @@ mod test {
     fn top_level_id(namespace_id: u32, index: u32) -> WebViewId {
         WebViewId(BrowsingContextId {
             namespace_id: PipelineNamespaceId(namespace_id),
-            index: BrowsingContextIndex(NonZeroU32::new(index).unwrap()),
+            index: Index::new(index).unwrap(),
         })
     }
 

components/constellation/webview_manager.rs

@@ -81,18 +81,14 @@ impl<WebView> WebViewManager<WebView> {
 
 #[cfg(test)]
 mod test {
-    use std::num::NonZeroU32;
+    use base::id::{BrowsingContextId, Index, PipelineNamespace, PipelineNamespaceId, WebViewId};
-
-    use base::id::{
-        BrowsingContextId, BrowsingContextIndex, PipelineNamespace, PipelineNamespaceId, WebViewId,
-    };
 
     use crate::webview_manager::WebViewManager;
 
     fn id(namespace_id: u32, index: u32) -> WebViewId {
         WebViewId(BrowsingContextId {
             namespace_id: PipelineNamespaceId(namespace_id),
-            index: BrowsingContextIndex(NonZeroU32::new(index).expect("Incorrect test case")),
+            index: Index::new(index).expect("Incorrect test case"),
         })
     }
 

components/script/dom/bindings/serializable.rs

@@ -6,9 +6,8 @@
 //! (<https://html.spec.whatwg.org/multipage/#serializable-objects>).
 
 use std::collections::HashMap;
-use std::num::NonZeroU32;
 
-use base::id::PipelineNamespaceId;
+use base::id::{Index, NamespaceIndex, PipelineNamespaceId};
 
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::root::DomRoot;
@@ -25,9 +24,9 @@ pub(crate) struct StorageKey {
 }
 
 impl StorageKey {
-    pub(crate) fn new(name_space: PipelineNamespaceId, index: NonZeroU32) -> StorageKey {
+    pub(crate) fn new<T>(index: NamespaceIndex<T>) -> StorageKey {
-        let name_space = name_space.0.to_ne_bytes();
+        let name_space = index.namespace_id.0.to_ne_bytes();
-        let index = index.get().to_ne_bytes();
+        let index = index.index.0.get().to_ne_bytes();
         StorageKey {
             index: u32::from_ne_bytes(index),
             name_space: u32::from_ne_bytes(name_space),
@@ -35,11 +34,13 @@ impl StorageKey {
     }
 }
 
-pub(crate) trait IntoStorageKey
+impl<T> From<StorageKey> for NamespaceIndex<T> {
-where
+    fn from(key: StorageKey) -> NamespaceIndex<T> {
-    Self: Sized,
+        NamespaceIndex {
-{
+            namespace_id: PipelineNamespaceId(key.name_space),
-    fn into_storage_key(self) -> StorageKey;
+            index: Index::new(key.index).expect("Index must not be zero"),
+        }
+    }
 }
 
 /// Interface for serializable platform objects.
@@ -48,11 +49,11 @@ pub(crate) trait Serializable: DomObject
 where
     Self: Sized,
 {
-    type Id: Copy + Eq + std::hash::Hash + IntoStorageKey + From<StorageKey>;
+    type Index: Copy + Eq + std::hash::Hash;
     type Data;
 
     /// <https://html.spec.whatwg.org/multipage/#serialization-steps>
-    fn serialize(&self) -> Result<(Self::Id, Self::Data), ()>;
+    fn serialize(&self) -> Result<(NamespaceIndex<Self::Index>, Self::Data), ()>;
     /// <https://html.spec.whatwg.org/multipage/#deserialization-steps>
     fn deserialize(
         owner: &GlobalScope,
@@ -64,7 +65,9 @@ where
 
     /// Returns the field of [StructuredDataReader]/[StructuredDataWriter] that
     /// should be used to read/store serialized instances of this type.
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>>;
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<NamespaceIndex<Self::Index>, Self::Data>>;
 
     /// Returns the field of [StructuredDataReader] that should be used to store
     /// deserialized instances of this type.

components/script/dom/bindings/structuredclone.rs

@@ -6,11 +6,12 @@
 
 use std::collections::HashMap;
 use std::ffi::CStr;
-use std::num::NonZeroU32;
 use std::os::raw;
 use std::ptr;
 
-use base::id::{BlobId, DomExceptionId, DomPointId, MessagePortId, PipelineNamespaceId};
+use base::id::{
+    BlobId, DomExceptionId, DomPointId, Index, MessagePortId, NamespaceIndex, PipelineNamespaceId,
+};
 use constellation_traits::{
     BlobImpl, DomException, DomPoint, MessagePortImpl, Serializable as SerializableInterface,
     StructuredSerializedData, Transferrable as TransferrableInterface,
@@ -34,8 +35,8 @@ use strum::IntoEnumIterator;
 use crate::dom::bindings::conversions::{ToJSValConvertible, root_from_object};
 use crate::dom::bindings::error::{Error, Fallible};
 use crate::dom::bindings::root::DomRoot;
-use crate::dom::bindings::serializable::{IntoStorageKey, Serializable, StorageKey};
+use crate::dom::bindings::serializable::{Serializable, StorageKey};
-use crate::dom::bindings::transferable::{ExtractComponents, IdFromComponents, Transferable};
+use crate::dom::bindings::transferable::Transferable;
 use crate::dom::blob::Blob;
 use crate::dom::dompoint::DOMPoint;
 use crate::dom::dompointreadonly::DOMPointReadOnly;
@@ -120,7 +121,7 @@ unsafe fn read_object<T: Serializable>(
 
     // 1. Re-build the key for the storage location
     // of the serialized object.
-    let id = T::Id::from(storage_key);
+    let id: NamespaceIndex<T::Index> = storage_key.into();
 
     // 2. Get the transferred object from its storage, using the key.
     let objects = T::serialized_storage(StructuredData::Reader(sc_reader));
@@ -155,7 +156,7 @@ unsafe fn write_object<T: Serializable>(
         let objects = T::serialized_storage(StructuredData::Writer(sc_writer))
             .get_or_insert_with(HashMap::new);
         objects.insert(new_id, serialized);
-        let storage_key = new_id.into_storage_key();
+        let storage_key = StorageKey::new(new_id);
 
         assert!(JS_WriteUint32Pair(
             w,
@@ -282,13 +283,13 @@ fn receive_object<T: Transferable>(
             .try_into()
             .expect("name_space to be a slice of four."),
     ));
-    let id = <T::Id as IdFromComponents>::from(
+    let id: NamespaceIndex<T::Index> = NamespaceIndex {
         namespace_id,
-        NonZeroU32::new(u32::from_ne_bytes(
+        index: Index::new(u32::from_ne_bytes(
             index.try_into().expect("index to be a slice of four."),
         ))
         .expect("Index to be non-zero"),
-    );
+    };
 
     // 2. Get the transferred object from its storage, using the key.
     let storage = T::serialized_storage(StructuredData::Reader(sc_reader));
@@ -356,11 +357,10 @@ unsafe fn try_transfer<T: Transferable + IDLInterface>(
                 .get_or_insert_with(HashMap::new);
             objects.insert(id, object);
 
-            let (PipelineNamespaceId(name_space), index) = id.components();
+            let index = id.index.0.get();
-            let index = index.get();
 
             let mut big: [u8; 8] = [0; 8];
-            let name_space = name_space.to_ne_bytes();
+            let name_space = id.namespace_id.0.to_ne_bytes();
             let index = index.to_ne_bytes();
 
             let (left, right) = big.split_at_mut(4);

components/script/dom/bindings/transferable.rs

@@ -6,44 +6,34 @@
 //! (<https://html.spec.whatwg.org/multipage/#transferable-objects>).
 
 use std::collections::HashMap;
-use std::num::NonZeroU32;
+use std::hash::Hash;
 
-use base::id::PipelineNamespaceId;
+use base::id::NamespaceIndex;
 
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::bindings::structuredclone::{StructuredData, StructuredDataReader};
 use crate::dom::globalscope::GlobalScope;
-
-pub(crate) trait IdFromComponents
-where
-    Self: Sized,
-{
-    fn from(namespace_id: PipelineNamespaceId, index: NonZeroU32) -> Self;
-}
-
-pub(crate) trait ExtractComponents {
-    fn components(&self) -> (PipelineNamespaceId, NonZeroU32);
-}
-
 pub(crate) trait Transferable: DomObject
 where
     Self: Sized,
 {
-    type Id: Eq + std::hash::Hash + Copy + IdFromComponents + ExtractComponents;
+    type Index: Copy + Eq + Hash;
     type Data;
 
     fn can_transfer(&self) -> bool {
         true
     }
 
-    fn transfer(&self) -> Result<(Self::Id, Self::Data), ()>;
+    fn transfer(&self) -> Result<(NamespaceIndex<Self::Index>, Self::Data), ()>;
     fn transfer_receive(
         owner: &GlobalScope,
-        id: Self::Id,
+        id: NamespaceIndex<Self::Index>,
         serialized: Self::Data,
     ) -> Result<DomRoot<Self>, ()>;
 
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>>;
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<NamespaceIndex<Self::Index>, Self::Data>>;
     fn deserialized_storage(reader: &mut StructuredDataReader) -> &mut Option<Vec<DomRoot<Self>>>;
 }

components/script/dom/blob.rs

@@ -3,11 +3,10 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use std::collections::HashMap;
-use std::num::NonZeroU32;
 use std::ptr;
 use std::rc::Rc;
 
-use base::id::{BlobId, BlobIndex, PipelineNamespaceId};
+use base::id::{BlobId, BlobIndex};
 use constellation_traits::BlobImpl;
 use dom_struct::dom_struct;
 use encoding_rs::UTF_8;
@@ -25,7 +24,7 @@ use crate::dom::bindings::codegen::UnionTypes::ArrayBufferOrArrayBufferViewOrBlo
 use crate::dom::bindings::error::{Error, Fallible};
 use crate::dom::bindings::reflector::{DomGlobal, Reflector, reflect_dom_object_with_proto};
 use crate::dom::bindings::root::DomRoot;
-use crate::dom::bindings::serializable::{IntoStorageKey, Serializable, StorageKey};
+use crate::dom::bindings::serializable::{Serializable, StorageKey};
 use crate::dom::bindings::str::DOMString;
 use crate::dom::bindings::structuredclone::{StructuredData, StructuredDataReader};
 use crate::dom::globalscope::GlobalScope;
@@ -94,7 +93,7 @@ impl Blob {
 }
 
 impl Serializable for Blob {
-    type Id = BlobId;
+    type Index = BlobIndex;
     type Data = BlobImpl;
 
     /// <https://w3c.github.io/FileAPI/#ref-for-serialization-steps>
@@ -120,9 +119,7 @@ impl Serializable for Blob {
         Ok(deserialized_blob)
     }
 
-    fn serialized_storage(
+    fn serialized_storage(reader: StructuredData<'_>) -> &mut Option<HashMap<BlobId, Self::Data>> {
-        reader: StructuredData<'_>,
-    ) -> &mut Option<HashMap<Self::Id, Self::Data>> {
         match reader {
             StructuredData::Reader(r) => &mut r.blob_impls,
             StructuredData::Writer(w) => &mut w.blobs,
@@ -136,26 +133,6 @@ impl Serializable for Blob {
     }
 }
 
-impl From<StorageKey> for BlobId {
-    fn from(storage_key: StorageKey) -> BlobId {
-        let namespace_id = PipelineNamespaceId(storage_key.name_space);
-        let index =
-            BlobIndex(NonZeroU32::new(storage_key.index).expect("Deserialized blob index is zero"));
-
-        BlobId {
-            namespace_id,
-            index,
-        }
-    }
-}
-
-impl IntoStorageKey for BlobId {
-    fn into_storage_key(self) -> StorageKey {
-        let BlobIndex(index) = self.index;
-        StorageKey::new(self.namespace_id, index)
-    }
-}
-
 /// Extract bytes from BlobParts, used by Blob and File constructor
 /// <https://w3c.github.io/FileAPI/#constructorBlob>
 #[allow(unsafe_code)]

components/script/dom/domexception.rs

@@ -3,9 +3,8 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use std::collections::HashMap;
-use std::num::NonZeroU32;
 
-use base::id::{DomExceptionId, DomExceptionIndex, PipelineNamespaceId};
+use base::id::{DomExceptionId, DomExceptionIndex};
 use constellation_traits::DomException;
 use dom_struct::dom_struct;
 use js::rust::HandleObject;
@@ -18,7 +17,7 @@ use crate::dom::bindings::reflector::{
     Reflector, reflect_dom_object, reflect_dom_object_with_proto,
 };
 use crate::dom::bindings::root::DomRoot;
-use crate::dom::bindings::serializable::{IntoStorageKey, Serializable, StorageKey};
+use crate::dom::bindings::serializable::{Serializable, StorageKey};
 use crate::dom::bindings::str::DOMString;
 use crate::dom::bindings::structuredclone::{StructuredData, StructuredDataReader};
 use crate::dom::globalscope::GlobalScope;
@@ -224,11 +223,11 @@ impl DOMExceptionMethods<crate::DomTypeHolder> for DOMException {
 }
 
 impl Serializable for DOMException {
-    type Id = DomExceptionId;
+    type Index = DomExceptionIndex;
     type Data = DomException;
 
     // https://webidl.spec.whatwg.org/#idl-DOMException
-    fn serialize(&self) -> Result<(Self::Id, Self::Data), ()> {
+    fn serialize(&self) -> Result<(DomExceptionId, Self::Data), ()> {
         let serialized = DomException {
             message: self.message.to_string(),
             name: self.name.to_string(),
@@ -253,7 +252,9 @@ impl Serializable for DOMException {
         ))
     }
 
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>> {
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<DomExceptionId, Self::Data>> {
         match data {
             StructuredData::Reader(reader) => &mut reader.exceptions,
             StructuredData::Writer(writer) => &mut writer.exceptions,
@@ -266,24 +267,3 @@ impl Serializable for DOMException {
         &mut reader.dom_exceptions
     }
 }
-
-impl From<StorageKey> for DomExceptionId {
-    fn from(storage_key: StorageKey) -> DomExceptionId {
-        let namespace_id = PipelineNamespaceId(storage_key.name_space);
-        let index = DomExceptionIndex(
-            NonZeroU32::new(storage_key.index).expect("Deserialized exception index is zero"),
-        );
-
-        DomExceptionId {
-            namespace_id,
-            index,
-        }
-    }
-}
-
-impl IntoStorageKey for DomExceptionId {
-    fn into_storage_key(self) -> StorageKey {
-        let DomExceptionIndex(index) = self.index;
-        StorageKey::new(self.namespace_id, index)
-    }
-}

components/script/dom/dompoint.rs

@@ -4,7 +4,7 @@
 
 use std::collections::HashMap;
 
-use base::id::DomPointId;
+use base::id::{DomPointId, DomPointIndex};
 use constellation_traits::DomPoint;
 use dom_struct::dom_struct;
 use js::rust::HandleObject;
@@ -132,10 +132,10 @@ impl DOMPointMethods<crate::DomTypeHolder> for DOMPoint {
 }
 
 impl Serializable for DOMPoint {
-    type Id = DomPointId;
+    type Index = DomPointIndex;
     type Data = DomPoint;
 
-    fn serialize(&self) -> Result<(Self::Id, Self::Data), ()> {
+    fn serialize(&self) -> Result<(DomPointId, Self::Data), ()> {
         let serialized = DomPoint {
             x: self.X(),
             y: self.Y(),
@@ -163,7 +163,9 @@ impl Serializable for DOMPoint {
         ))
     }
 
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>> {
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<DomPointId, Self::Data>> {
         match data {
             StructuredData::Reader(reader) => &mut reader.points,
             StructuredData::Writer(writer) => &mut writer.points,

components/script/dom/dompointreadonly.rs

@@ -4,9 +4,8 @@
 
 use std::cell::Cell;
 use std::collections::HashMap;
-use std::num::NonZeroU32;
 
-use base::id::{DomPointId, DomPointIndex, PipelineNamespaceId};
+use base::id::{DomPointId, DomPointIndex};
 use constellation_traits::DomPoint;
 use dom_struct::dom_struct;
 use js::rust::HandleObject;
@@ -16,7 +15,7 @@ use crate::dom::bindings::codegen::Bindings::DOMPointReadOnlyBinding::DOMPointRe
 use crate::dom::bindings::error::Fallible;
 use crate::dom::bindings::reflector::{Reflector, reflect_dom_object_with_proto};
 use crate::dom::bindings::root::DomRoot;
-use crate::dom::bindings::serializable::{IntoStorageKey, Serializable, StorageKey};
+use crate::dom::bindings::serializable::{Serializable, StorageKey};
 use crate::dom::bindings::structuredclone::{StructuredData, StructuredDataReader};
 use crate::dom::globalscope::GlobalScope;
 use crate::script_runtime::CanGc;
@@ -142,10 +141,10 @@ impl DOMPointWriteMethods for DOMPointReadOnly {
 }
 
 impl Serializable for DOMPointReadOnly {
-    type Id = DomPointId;
+    type Index = DomPointIndex;
     type Data = DomPoint;
 
-    fn serialize(&self) -> Result<(Self::Id, Self::Data), ()> {
+    fn serialize(&self) -> Result<(DomPointId, Self::Data), ()> {
         let serialized = DomPoint {
             x: self.x.get(),
             y: self.y.get(),
@@ -173,7 +172,9 @@ impl Serializable for DOMPointReadOnly {
         ))
     }
 
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>> {
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<DomPointId, Self::Data>> {
         match data {
             StructuredData::Reader(r) => &mut r.points,
             StructuredData::Writer(w) => &mut w.points,
@@ -186,24 +187,3 @@ impl Serializable for DOMPointReadOnly {
         &mut reader.points_read_only
     }
 }
-
-impl From<StorageKey> for DomPointId {
-    fn from(storage_key: StorageKey) -> DomPointId {
-        let namespace_id = PipelineNamespaceId(storage_key.name_space);
-        let index = DomPointIndex(
-            NonZeroU32::new(storage_key.index).expect("Deserialized point index is zero"),
-        );
-
-        DomPointId {
-            namespace_id,
-            index,
-        }
-    }
-}
-
-impl IntoStorageKey for DomPointId {
-    fn into_storage_key(self) -> StorageKey {
-        let DomPointIndex(index) = self.index;
-        StorageKey::new(self.namespace_id, index)
-    }
-}

components/script/dom/messageport.rs

@@ -4,11 +4,10 @@
 
 use std::cell::{Cell, RefCell};
 use std::collections::HashMap;
-use std::num::NonZeroU32;
 use std::ptr;
 use std::rc::Rc;
 
-use base::id::{MessagePortId, MessagePortIndex, PipelineNamespaceId};
+use base::id::{MessagePortId, MessagePortIndex};
 use constellation_traits::{MessagePortImpl, PortMessageTask};
 use dom_struct::dom_struct;
 use js::jsapi::{Heap, JS_NewObject, JSObject};
@@ -26,7 +25,7 @@ use crate::dom::bindings::reflector::{DomGlobal, reflect_dom_object};
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::bindings::structuredclone::{self, StructuredData, StructuredDataReader};
 use crate::dom::bindings::trace::RootedTraceableBox;
-use crate::dom::bindings::transferable::{ExtractComponents, IdFromComponents, Transferable};
+use crate::dom::bindings::transferable::Transferable;
 use crate::dom::bindings::utils::set_dictionary_property;
 use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
@@ -239,7 +238,7 @@ impl MessagePort {
 }
 
 impl Transferable for MessagePort {
-    type Id = MessagePortId;
+    type Index = MessagePortIndex;
     type Data = MessagePortImpl;
 
     /// <https://html.spec.whatwg.org/multipage/#message-ports:transfer-steps>
@@ -269,7 +268,9 @@ impl Transferable for MessagePort {
         Ok(transferred_port)
     }
 
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>> {
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<MessagePortId, Self::Data>> {
         match data {
             StructuredData::Reader(r) => &mut r.port_impls,
             StructuredData::Writer(w) => &mut w.ports,
@@ -281,21 +282,6 @@ impl Transferable for MessagePort {
     }
 }
 
-impl IdFromComponents for MessagePortId {
-    fn from(namespace_id: PipelineNamespaceId, index: NonZeroU32) -> MessagePortId {
-        MessagePortId {
-            namespace_id,
-            index: MessagePortIndex(index),
-        }
-    }
-}
-
-impl ExtractComponents for MessagePortId {
-    fn components(&self) -> (PipelineNamespaceId, NonZeroU32) {
-        (self.namespace_id, self.index.0)
-    }
-}
-
 impl MessagePortMethods<crate::DomTypeHolder> for MessagePort {
     /// <https://html.spec.whatwg.org/multipage/#dom-messageport-postmessage>
     fn PostMessage(

components/script/dom/readablestream.rs

@@ -8,6 +8,8 @@ use std::ptr::{self};
 use std::rc::Rc;
 use std::collections::HashMap;
 
+use base::id::{MessagePortId, MessagePortIndex};
+use constellation_traits::MessagePortImpl;
 use dom_struct::dom_struct;
 use js::conversions::ToJSValConvertible;
 use js::jsapi::{Heap, JSObject};
@@ -56,8 +58,6 @@ use crate::js::conversions::FromJSValConvertible;
 use crate::realms::{enter_realm, InRealm};
 use crate::script_runtime::{CanGc, JSContext as SafeJSContext};
 use crate::dom::promisenativehandler::{Callback, PromiseNativeHandler};
-use base::id::MessagePortId;
-use constellation_traits::MessagePortImpl;
 use crate::dom::bindings::transferable::Transferable;
 use crate::dom::bindings::structuredclone::{StructuredData, StructuredDataReader};
 
@@ -2179,7 +2179,7 @@ pub(crate) fn get_read_promise_bytes(
 
 /// <https://streams.spec.whatwg.org/#rs-transfer>
 impl Transferable for ReadableStream {
-    type Id = MessagePortId;
+    type Index = MessagePortIndex;
     type Data = MessagePortImpl;
 
     /// <https://streams.spec.whatwg.org/#ref-for-readablestream%E2%91%A1%E2%91%A0>
@@ -2247,7 +2247,9 @@ impl Transferable for ReadableStream {
     }
 
     /// Note: we are relying on the port transfer, so the data returned here are related to the port.
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>> {
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<MessagePortId, Self::Data>> {
         match data {
             StructuredData::Reader(r) => &mut r.port_impls,
             StructuredData::Writer(w) => &mut w.ports,

components/script/dom/writablestream.rs

@@ -8,7 +8,7 @@ use std::mem;
 use std::ptr::{self};
 use std::rc::Rc;
 
-use base::id::MessagePortId;
+use base::id::{MessagePortId, MessagePortIndex};
 use constellation_traits::MessagePortImpl;
 use dom_struct::dom_struct;
 use js::jsapi::{Heap, JSObject};
@@ -1114,7 +1114,7 @@ impl CrossRealmTransformWritable {
 
 /// <https://streams.spec.whatwg.org/#ws-transfer>
 impl Transferable for WritableStream {
-    type Id = MessagePortId;
+    type Index = MessagePortIndex;
     type Data = MessagePortImpl;
 
     /// <https://streams.spec.whatwg.org/#ref-for-writablestream%E2%91%A0%E2%91%A4>
@@ -1182,7 +1182,9 @@ impl Transferable for WritableStream {
     }
 
     /// Note: we are relying on the port transfer, so the data returned here are related to the port.
-    fn serialized_storage(data: StructuredData<'_>) -> &mut Option<HashMap<Self::Id, Self::Data>> {
+    fn serialized_storage(
+        data: StructuredData<'_>,
+    ) -> &mut Option<HashMap<MessagePortId, Self::Data>> {
         match data {
             StructuredData::Reader(r) => &mut r.port_impls,
             StructuredData::Writer(w) => &mut w.ports,

components/shared/base/id.rs

@@ -8,11 +8,12 @@
 
 use std::cell::Cell;
 use std::fmt;
+use std::marker::PhantomData;
 use std::num::NonZeroU32;
 use std::sync::{Arc, LazyLock};
 
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
-use malloc_size_of::malloc_size_of_is_0;
+use malloc_size_of::MallocSizeOfOps;
 use malloc_size_of_derive::MallocSizeOf;
 use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
@@ -26,44 +27,88 @@ macro_rules! size_of_test {
     };
 }
 
-macro_rules! namespace_id_method {
+/// A type that implements this trait is expected to be used as part of
-    ($func_name:ident, $func_return_data_type:ident, $self:ident, $index_name:ident) => {
+/// the [NamespaceIndex] type.
-        fn $func_name(&mut $self) -> $func_return_data_type {
+pub trait Indexable {
-            $func_return_data_type {
+    /// The string prefix to display when debug printing an instance of
-                namespace_id: $self.id,
+    /// this type.
-                index: $index_name($self.next_index()),
+    const DISPLAY_PREFIX: &'static str;
-            }
+}
-        }
+
-    };
+#[derive(Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize)]
+/// A non-zero index, associated with a particular type.
+pub struct Index<T>(pub NonZeroU32, pub PhantomData<T>);
+
+#[derive(Debug)]
+/// An attempt to create a new [Index] value failed because the index value
+/// was zero.
+pub struct ZeroIndex;
+
+impl<T> Index<T> {
+    /// Creates a new instance of [Index] with the given value.
+    /// Returns an error if the value is zero.
+    pub fn new(value: u32) -> Result<Index<T>, ZeroIndex> {
+        Ok(Index(NonZeroU32::new(value).ok_or(ZeroIndex)?, PhantomData))
+    }
+}
+
+impl<T> malloc_size_of::MallocSizeOf for Index<T> {
+    fn size_of(&self, _ops: &mut MallocSizeOfOps) -> usize {
+        0
+    }
+}
+
+#[derive(
+    Clone, Copy, Deserialize, Eq, Hash, MallocSizeOf, Ord, PartialEq, PartialOrd, Serialize,
+)]
+/// A pipeline-namespaced index associated with a particular type.
+pub struct NamespaceIndex<T> {
+    pub namespace_id: PipelineNamespaceId,
+    pub index: Index<T>,
+}
+
+impl<T> fmt::Debug for NamespaceIndex<T> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        let PipelineNamespaceId(namespace_id) = self.namespace_id;
+        let Index(index, _) = self.index;
+        write!(fmt, "({},{})", namespace_id, index.get())
+    }
+}
+
+impl<T: Indexable> fmt::Display for NamespaceIndex<T> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{}{:?}", T::DISPLAY_PREFIX, self)
+    }
 }
 
 macro_rules! namespace_id {
     ($id_name:ident, $index_name:ident, $display_prefix:literal) => {
         #[derive(
-            Clone, Copy, Debug, Deserialize, Eq, Hash, Ord, PartialEq, PartialOrd, Serialize,
+            Clone,
+            Copy,
+            Debug,
+            Deserialize,
+            Eq,
+            Hash,
+            Ord,
+            PartialEq,
+            PartialOrd,
+            Serialize,
+            MallocSizeOf,
         )]
-        pub struct $index_name(pub NonZeroU32);
+        pub struct $index_name;
-        malloc_size_of_is_0!($index_name);
+        impl Indexable for $index_name {
-
+            const DISPLAY_PREFIX: &'static str = $display_prefix;
-        #[derive(
-            Clone, Copy, Deserialize, Eq, Hash, MallocSizeOf, Ord, PartialEq, PartialOrd, Serialize,
-        )]
-        pub struct $id_name {
-            pub namespace_id: PipelineNamespaceId,
-            pub index: $index_name,
         }
-
+        pub type $id_name = NamespaceIndex<$index_name>;
-        impl fmt::Debug for $id_name {
+        impl $id_name {
-            fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+            pub fn new() -> $id_name {
-                let PipelineNamespaceId(namespace_id) = self.namespace_id;
+                PIPELINE_NAMESPACE.with(|tls| {
-                let $index_name(index) = self.index;
+                    let mut namespace = tls.get().expect("No namespace set for this thread!");
-                write!(fmt, "({},{})", namespace_id, index.get())
+                    let next_id = namespace.next_namespace_index();
-            }
+                    tls.set(Some(namespace));
-        }
+                    next_id
-
+                })
-        impl fmt::Display for $id_name {
-            fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-                write!(fmt, "{}{:?}", $display_prefix, self)
             }
         }
     };
@@ -185,18 +230,12 @@ impl PipelineNamespace {
         NonZeroU32::new(self.index).expect("pipeline id index wrapped!")
     }
 
-    namespace_id_method! {next_pipeline_id, PipelineId, self, PipelineIndex}
+    fn next_namespace_index<T>(&mut self) -> NamespaceIndex<T> {
-    namespace_id_method! {next_browsing_context_id, BrowsingContextId, self, BrowsingContextIndex}
+        NamespaceIndex {
-    namespace_id_method! {next_history_state_id, HistoryStateId, self, HistoryStateIndex}
+            namespace_id: self.id,
-    namespace_id_method! {next_message_port_id, MessagePortId, self, MessagePortIndex}
+            index: Index(self.next_index(), PhantomData),
-    namespace_id_method! {next_message_port_router_id, MessagePortRouterId, self, MessagePortRouterIndex}
+        }
-    namespace_id_method! {next_broadcast_channel_router_id, BroadcastChannelRouterId, self, BroadcastChannelRouterIndex}
+    }
-    namespace_id_method! {next_service_worker_id, ServiceWorkerId, self, ServiceWorkerIndex}
-    namespace_id_method! {next_service_worker_registration_id, ServiceWorkerRegistrationId,
-    self, ServiceWorkerRegistrationIndex}
-    namespace_id_method! {next_blob_id, BlobId, self, BlobIndex}
-    namespace_id_method! {next_dom_point_id, DomPointId, self, DomPointIndex}
-    namespace_id_method! {next_dom_exception_id, DomExceptionId, self, DomExceptionIndex}
 }
 
 thread_local!(pub static PIPELINE_NAMESPACE: Cell<Option<PipelineNamespace>> = const { Cell::new(None) });
@@ -212,15 +251,6 @@ size_of_test!(PipelineId, 8);
 size_of_test!(Option<PipelineId>, 8);
 
 impl PipelineId {
-    pub fn new() -> PipelineId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let new_pipeline_id = namespace.next_pipeline_id();
-            tls.set(Some(namespace));
-            new_pipeline_id
-        })
-    }
-
     pub fn root_scroll_id(&self) -> webrender_api::ExternalScrollId {
         ExternalScrollId(0, self.into())
     }
@@ -233,7 +263,7 @@ impl From<WebRenderPipelineId> for PipelineId {
         unsafe {
             PipelineId {
                 namespace_id: PipelineNamespaceId(namespace_id),
-                index: PipelineIndex(NonZeroU32::new_unchecked(index)),
+                index: Index(NonZeroU32::new_unchecked(index), PhantomData),
             }
         }
     }
@@ -242,7 +272,7 @@ impl From<WebRenderPipelineId> for PipelineId {
 impl From<PipelineId> for WebRenderPipelineId {
     fn from(value: PipelineId) -> Self {
         let PipelineNamespaceId(namespace_id) = value.namespace_id;
-        let PipelineIndex(index) = value.index;
+        let Index(index, _) = value.index;
         WebRenderPipelineId(namespace_id, index.get())
     }
 }
@@ -258,17 +288,6 @@ namespace_id! {BrowsingContextId, BrowsingContextIndex, "BrowsingContext"}
 size_of_test!(BrowsingContextId, 8);
 size_of_test!(Option<BrowsingContextId>, 8);
 
-impl BrowsingContextId {
-    pub fn new() -> Self {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let new_browsing_context_id = namespace.next_browsing_context_id();
-            tls.set(Some(namespace));
-            new_browsing_context_id
-        })
-    }
-}
-
 #[derive(Clone, Copy, Debug, Default, Eq, Hash, PartialEq)]
 pub struct BrowsingContextGroupId(pub u32);
 impl fmt::Display for BrowsingContextGroupId {
@@ -336,134 +355,34 @@ impl PartialEq<BrowsingContextId> for WebViewId {
 
 namespace_id! {MessagePortId, MessagePortIndex, "MessagePort"}
 
-impl MessagePortId {
-    pub fn new() -> MessagePortId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_message_port_id = namespace.next_message_port_id();
-            tls.set(Some(namespace));
-            next_message_port_id
-        })
-    }
-}
-
 namespace_id! {MessagePortRouterId, MessagePortRouterIndex, "MessagePortRouter"}
 
-impl MessagePortRouterId {
-    pub fn new() -> MessagePortRouterId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_message_port_router_id = namespace.next_message_port_router_id();
-            tls.set(Some(namespace));
-            next_message_port_router_id
-        })
-    }
-}
-
 namespace_id! {BroadcastChannelRouterId, BroadcastChannelRouterIndex, "BroadcastChannelRouter"}
 
-impl BroadcastChannelRouterId {
-    pub fn new() -> BroadcastChannelRouterId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_broadcast_channel_router_id = namespace.next_broadcast_channel_router_id();
-            tls.set(Some(namespace));
-            next_broadcast_channel_router_id
-        })
-    }
-}
-
 namespace_id! {ServiceWorkerId, ServiceWorkerIndex, "ServiceWorker"}
 
-impl ServiceWorkerId {
-    pub fn new() -> ServiceWorkerId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_service_worker_id = namespace.next_service_worker_id();
-            tls.set(Some(namespace));
-            next_service_worker_id
-        })
-    }
-}
-
 namespace_id! {ServiceWorkerRegistrationId, ServiceWorkerRegistrationIndex, "ServiceWorkerRegistration"}
 
-impl ServiceWorkerRegistrationId {
-    pub fn new() -> ServiceWorkerRegistrationId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_service_worker_registration_id =
-                namespace.next_service_worker_registration_id();
-            tls.set(Some(namespace));
-            next_service_worker_registration_id
-        })
-    }
-}
-
 namespace_id! {BlobId, BlobIndex, "Blob"}
 
-impl BlobId {
-    pub fn new() -> BlobId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_blob_id = namespace.next_blob_id();
-            tls.set(Some(namespace));
-            next_blob_id
-        })
-    }
-}
-
 namespace_id! {DomPointId, DomPointIndex, "DomPoint"}
 
-impl DomPointId {
-    pub fn new() -> DomPointId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_point_id = namespace.next_dom_point_id();
-            tls.set(Some(namespace));
-            next_point_id
-        })
-    }
-}
-
 namespace_id! {DomExceptionId, DomExceptionIndex, "DomException"}
 
-impl DomExceptionId {
-    pub fn new() -> DomExceptionId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_exception_id = namespace.next_dom_exception_id();
-            tls.set(Some(namespace));
-            next_exception_id
-        })
-    }
-}
-
 namespace_id! {HistoryStateId, HistoryStateIndex, "HistoryState"}
 
-impl HistoryStateId {
-    pub fn new() -> HistoryStateId {
-        PIPELINE_NAMESPACE.with(|tls| {
-            let mut namespace = tls.get().expect("No namespace set for this thread!");
-            let next_history_state_id = namespace.next_history_state_id();
-            tls.set(Some(namespace));
-            next_history_state_id
-        })
-    }
-}
-
 // We provide ids just for unit testing.
 pub const TEST_NAMESPACE: PipelineNamespaceId = PipelineNamespaceId(1234);
 #[allow(unsafe_code)]
-pub const TEST_PIPELINE_INDEX: PipelineIndex =
+pub const TEST_PIPELINE_INDEX: Index<PipelineIndex> =
-    unsafe { PipelineIndex(NonZeroU32::new_unchecked(5678)) };
+    unsafe { Index(NonZeroU32::new_unchecked(5678), PhantomData) };
 pub const TEST_PIPELINE_ID: PipelineId = PipelineId {
     namespace_id: TEST_NAMESPACE,
     index: TEST_PIPELINE_INDEX,
 };
 #[allow(unsafe_code)]
-pub const TEST_BROWSING_CONTEXT_INDEX: BrowsingContextIndex =
+pub const TEST_BROWSING_CONTEXT_INDEX: Index<BrowsingContextIndex> =
-    unsafe { BrowsingContextIndex(NonZeroU32::new_unchecked(8765)) };
+    unsafe { Index(NonZeroU32::new_unchecked(8765), PhantomData) };
 pub const TEST_BROWSING_CONTEXT_ID: BrowsingContextId = BrowsingContextId {
     namespace_id: TEST_NAMESPACE,
     index: TEST_BROWSING_CONTEXT_INDEX,