script: Impl cloning of JSPrincipals (#32706)

* Impl cloning of JSPrincipals

* bincode as workspace dependency

* Update mozjs and cc

1 files changed, 59 insertions, 2 deletions

diff --git a/components/script/dom/bindings/principals.rs b/components/script/dom/bindings/principals.rs
index f408f92cbc7..14a3a826f3a 100644
--- a/components/script/dom/bindings/principals.rs
+++ b/components/script/dom/bindings/principals.rs
@@ -11,10 +11,15 @@ use js::glue::{
     CreateRustJSPrincipals, DestroyRustJSPrincipals, GetRustJSPrincipalsPrivate,
     JSPrincipalsCallbacks,
 };
-use js::jsapi::{JSPrincipals, JS_DropPrincipals, JS_HoldPrincipals};
+use js::jsapi::{
+    JSContext, JSPrincipals, JSStructuredCloneReader, JSStructuredCloneWriter, JS_DropPrincipals,
+    JS_HoldPrincipals, JS_ReadUint32Pair,
+};
 use js::rust::Runtime;
 use servo_url::MutableOrigin;
 
+use super::structuredclone::StructuredCloneTags;
+
 /// An owned reference to Servo's `JSPrincipals` instance.
 #[repr(transparent)]
 pub struct ServoJSPrincipals(NonNull<JSPrincipals>);
@@ -123,8 +128,60 @@ pub unsafe extern "C" fn destroy_servo_jsprincipal(principals: *mut JSPrincipals
     DestroyRustJSPrincipals(principals);
 }
 
+pub unsafe extern "C" fn write_jsprincipal(
+    principal: *mut JSPrincipals,
+    _cx: *mut JSContext,
+    writer: *mut JSStructuredCloneWriter,
+) -> bool {
+    let Some(principal) = NonNull::new(principal) else {
+        return false;
+    };
+    let obj = ServoJSPrincipalsRef::from_raw_nonnull(principal);
+    let origin = obj.origin();
+    let Ok(bytes_of_origin) = bincode::serialize(&origin) else {
+        return false;
+    };
+    let Ok(len) = bytes_of_origin.len().try_into() else {
+        return false;
+    };
+    if !js::jsapi::JS_WriteUint32Pair(writer, StructuredCloneTags::Principals as u32, len) {
+        return false;
+    }
+    if !js::jsapi::JS_WriteBytes(writer, bytes_of_origin.as_ptr() as _, len as usize) {
+        return false;
+    }
+    true
+}
+
+pub unsafe extern "C" fn read_jsprincipal(
+    _cx: *mut JSContext,
+    reader: *mut JSStructuredCloneReader,
+    principals: *mut *mut JSPrincipals,
+) -> bool {
+    let mut tag: u32 = 0;
+    let mut len: u32 = 0;
+    if !JS_ReadUint32Pair(reader, &mut tag as *mut u32, &mut len as *mut u32) {
+        return false;
+    }
+    if tag != StructuredCloneTags::Principals as u32 {
+        return false;
+    }
+    let mut bytes = vec![0u8; len as usize];
+    if !js::jsapi::JS_ReadBytes(reader, bytes.as_mut_ptr() as _, len as usize) {
+        return false;
+    }
+    let Ok(origin) = bincode::deserialize(&bytes[..]) else {
+        return false;
+    };
+    let principal = ServoJSPrincipals::new(&origin);
+    *principals = principal.as_raw();
+    // we transferred ownership of principal to the caller
+    std::mem::forget(principal);
+    true
+}
+
 const PRINCIPALS_CALLBACKS: JSPrincipalsCallbacks = JSPrincipalsCallbacks {
-    write: None,
+    write: Some(write_jsprincipal),
     isSystemOrAddonPrincipal: Some(principals_is_system_or_addon_principal),
 };