Merge pull request #13948 from Snuffleupagus/structuredClone

Use the native `structuredClone` implementation when it's available

src/display/api.js

@@ -1899,83 +1899,94 @@ class PDFPageProxy {
 class LoopbackPort {
   constructor() {
     this._listeners = [];
-    this._deferred = Promise.resolve(undefined);
+    this._deferred = Promise.resolve();
   }
 
   postMessage(obj, transfers) {
-    function cloneValue(value) {
+    function cloneValue(object) {
+      if (
+        (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) ||
+        globalThis.structuredClone
+      ) {
+        return globalThis.structuredClone(object, transfers);
+      }
+
       // Trying to perform a structured clone close to the spec, including
       // transfers.
-      if (
+      function fallbackCloneValue(value) {
-        typeof value === "function" ||
+        if (
-        typeof value === "symbol" ||
+          typeof value === "function" ||
-        value instanceof URL
+          typeof value === "symbol" ||
-      ) {
+          value instanceof URL
-        throw new Error(
+        ) {
-          `LoopbackPort.postMessage - cannot clone: ${value?.toString()}`
+          throw new Error(
-        );
+            `LoopbackPort.postMessage - cannot clone: ${value?.toString()}`
+          );
+        }
+
+        if (typeof value !== "object" || value === null) {
+          return value;
+        }
+        if (cloned.has(value)) {
+          // already cloned the object
+          return cloned.get(value);
+        }
+        let buffer, result;
+        if ((buffer = value.buffer) && isArrayBuffer(buffer)) {
+          // We found object with ArrayBuffer (typed array).
+          if (transfers?.includes(buffer)) {
+            result = new value.constructor(
+              buffer,
+              value.byteOffset,
+              value.byteLength
+            );
+          } else {
+            result = new value.constructor(value);
+          }
+          cloned.set(value, result);
+          return result;
+        }
+        if (value instanceof Map) {
+          result = new Map();
+          cloned.set(value, result); // Adding to cache now for cyclic references.
+          for (const [key, val] of value) {
+            result.set(key, fallbackCloneValue(val));
+          }
+          return result;
+        }
+        if (value instanceof Set) {
+          result = new Set();
+          cloned.set(value, result); // Adding to cache now for cyclic references.
+          for (const val of value) {
+            result.add(fallbackCloneValue(val));
+          }
+          return result;
+        }
+        result = Array.isArray(value) ? [] : Object.create(null);
+        cloned.set(value, result); // Adding to cache now for cyclic references.
+        // Cloning all value and object properties, however ignoring properties
+        // defined via getter.
+        for (const i in value) {
+          let desc,
+            p = value;
+          while (!(desc = Object.getOwnPropertyDescriptor(p, i))) {
+            p = Object.getPrototypeOf(p);
+          }
+          if (typeof desc.value === "undefined") {
+            continue;
+          }
+          if (typeof desc.value === "function" && !value.hasOwnProperty?.(i)) {
+            continue;
+          }
+          result[i] = fallbackCloneValue(desc.value);
+        }
+        return result;
       }
 
-      if (typeof value !== "object" || value === null) {
+      const cloned = new WeakMap();
-        return value;
+      return fallbackCloneValue(object);
-      }
-      if (cloned.has(value)) {
-        // already cloned the object
-        return cloned.get(value);
-      }
-      let buffer, result;
-      if ((buffer = value.buffer) && isArrayBuffer(buffer)) {
-        // We found object with ArrayBuffer (typed array).
-        if (transfers?.includes(buffer)) {
-          result = new value.constructor(
-            buffer,
-            value.byteOffset,
-            value.byteLength
-          );
-        } else {
-          result = new value.constructor(value);
-        }
-        cloned.set(value, result);
-        return result;
-      }
-      if (value instanceof Map) {
-        result = new Map();
-        cloned.set(value, result); // Adding to cache now for cyclic references.
-        for (const [key, val] of value) {
-          result.set(key, cloneValue(val));
-        }
-        return result;
-      }
-      if (value instanceof Set) {
-        result = new Set();
-        cloned.set(value, result); // Adding to cache now for cyclic references.
-        for (const val of value) {
-          result.add(cloneValue(val));
-        }
-        return result;
-      }
-      result = Array.isArray(value) ? [] : Object.create(null);
-      cloned.set(value, result); // Adding to cache now for cyclic references.
-      // Cloning all value and object properties, however ignoring properties
-      // defined via getter.
-      for (const i in value) {
-        let desc,
-          p = value;
-        while (!(desc = Object.getOwnPropertyDescriptor(p, i))) {
-          p = Object.getPrototypeOf(p);
-        }
-        if (typeof desc.value === "undefined") {
-          continue;
-        }
-        if (typeof desc.value === "function" && !value.hasOwnProperty?.(i)) {
-          continue;
-        }
-        result[i] = cloneValue(desc.value);
-      }
-      return result;
     }
 
-    const cloned = new WeakMap();
     const event = { data: cloneValue(obj) };
 
     this._deferred.then(() => {