Merge pull request #21576 from Snuffleupagus/RefSetCache-getOrPutComputed

Add a `getOrPutComputed` method in the `RefSetCache` class

src/core/editor/pdf_editor.js

@@ -455,12 +455,7 @@ class PDFEditor {
     // Re-entry means a (malformed) cycle back to this stream: allocate its
     // reference now to break the loop, like the generic path's eager alloc.
     if (resourceStreamPath.has(oldRef)) {
-      let ref = oldRefMapping.get(oldRef);
-      if (!ref) {
-        ref = this.newRef;
-        oldRefMapping.put(oldRef, ref);
-      }
-      return ref;
+      return oldRefMapping.getOrPutComputed(oldRef, () => this.newRef);
     }
 
     const key = oldRef.toString();

src/core/glyf.js

@@ -13,6 +13,8 @@
  * limitations under the License.
  */
 
+import { makeSet } from "../shared/util.js";
+
 const ON_CURVE_POINT = 1 << 0;
 const X_SHORT_VECTOR = 1 << 1;
 const Y_SHORT_VECTOR = 1 << 2;
@@ -756,13 +758,7 @@ function pruneCompositeGlyphCycles(glyfTable, locaEntries, numGlyphs) {
         stack.push({ node: next, idx: 0 });
         continue;
       }
-
-      let removeSet = backEdges.get(top.node);
-      if (!removeSet) {
-        removeSet = new Set();
-        backEdges.set(top.node, removeSet);
-      }
-      removeSet.add(compIdx);
+      backEdges.getOrInsertComputed(top.node, makeSet).add(compIdx);
     }
   }
 

src/core/image_utils.js

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { assert, unreachable, warn } from "../shared/util.js";
+import { assert, makeSet, unreachable, warn } from "../shared/util.js";
 import { RefSet, RefSetCache } from "./primitives.js";
 
 class BaseLocalCache {
@@ -228,11 +228,7 @@ class GlobalImageCache {
   }
 
   shouldCache(ref, pageIndex) {
-    let pageIndexSet = this._refCache.get(ref);
-    if (!pageIndexSet) {
-      pageIndexSet = new Set();
-      this._refCache.put(ref, pageIndexSet);
-    }
+    const pageIndexSet = this._refCache.getOrPutComputed(ref, makeSet);
     pageIndexSet.add(pageIndex);
 
     if (pageIndexSet.size < GlobalImageCache.NUM_PAGES_THRESHOLD) {

src/core/primitives.js

@@ -398,6 +398,16 @@ class RefSetCache {
     this._map.set(ref.toString(), this.get(aliasRef));
   }
 
+  getOrPutComputed(ref, callback) {
+    const map = this._map,
+      refStr = ref.toString();
+
+    if (!map.has(refStr)) {
+      map.set(refStr, callback(ref));
+    }
+    return map.get(refStr);
+  }
+
   [Symbol.iterator]() {
     return this._map.values();
   }

src/core/struct_tree.js

@@ -93,12 +93,7 @@ class StructTreeRoot {
       return;
     }
     this.structParentIds ||= new RefSetCache();
-    let ids = this.structParentIds.get(pageRef);
-    if (!ids) {
-      ids = [];
-      this.structParentIds.put(pageRef, ids);
-    }
-    ids.push([id, type]);
+    this.structParentIds.getOrPutComputed(pageRef, makeArr).push([id, type]);
   }
 
   addAnnotationIdToPage(pageRef, id) {
@@ -537,11 +532,9 @@ class StructTreeRoot {
       return;
     }
 
-    let cachedParentDict = cache.get(parentRef);
-    if (!cachedParentDict) {
-      cachedParentDict = parentDict.clone();
-      cache.put(parentRef, cachedParentDict);
-    }
+    const cachedParentDict = cache.getOrPutComputed(parentRef, () =>
+      parentDict.clone()
+    );
     const parentKidsRaw = cachedParentDict.getRaw("K");
     let cachedParentKids =
       parentKidsRaw instanceof Ref ? cache.get(parentKidsRaw) : null;

src/pdf.js

@@ -36,6 +36,7 @@ import {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   normalizeUnicode,
   OPS,
   PasswordException,
@@ -131,6 +132,7 @@ globalThis.pdfjsLib = {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   MathClamp,
   noContextMenu,
   normalizeUnicode,
@@ -195,6 +197,7 @@ export {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   MathClamp,
   noContextMenu,
   normalizeUnicode,

src/shared/util.js

@@ -1135,6 +1135,7 @@ function _isValidExplicitDest(validRef, validName, dest) {
 const makeArr = () => [];
 const makeMap = () => new Map();
 const makeObj = () => Object.create(null);
+const makeSet = () => new Set();
 
 // See https://developer.mozilla.org/en-US/docs/Web/API/Blob/bytes#browser_compatibility
 if (
@@ -1197,6 +1198,7 @@ export {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   MeshFigureType,
   normalizeUnicode,
   objectSize,

test/unit/pdf_spec.js

@@ -27,6 +27,7 @@ import {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   normalizeUnicode,
   OPS,
   PasswordException,
@@ -115,6 +116,7 @@ const expectedAPI = Object.freeze({
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   MathClamp,
   noContextMenu,
   normalizeUnicode,

test/unit/primitives_spec.js

@@ -568,6 +568,12 @@ describe("primitives", function () {
       cache.put(ref2, obj2);
       expect([...cache.keys()]).toEqual([ref1, ref2]);
     });
+
+    it("should handle getOrPutComputed correctly", function () {
+      expect(cache.getOrPutComputed(ref1, () => obj1)).toEqual(obj1);
+      // Trying to set it again should be ignored.
+      expect(cache.getOrPutComputed(ref1, () => obj2)).toEqual(obj1);
+    });
   });
 
   describe("isName", function () {

web/debugger.mjs

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-const { OPS } = globalThis.pdfjsLib || (await import("pdfjs-lib"));
+const { makeSet, OPS } = globalThis.pdfjsLib || (await import("pdfjs-lib"));
 
 const opMap = Object.create(null);
 for (const key in OPS) {
@@ -460,7 +460,7 @@ class Stepper {
     for (const [dependentIdx, { dependencies: ownDependencies }] of metadata) {
       for (const dependencyIdx of ownDependencies) {
         dependents
-          .getOrInsertComputed(dependencyIdx, () => new Set())
+          .getOrInsertComputed(dependencyIdx, makeSet)
           .add(dependentIdx);
       }
     }

web/pdfjs.js

@@ -47,6 +47,7 @@ const {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   MathClamp,
   noContextMenu,
   normalizeUnicode,
@@ -111,6 +112,7 @@ export {
   makeArr,
   makeMap,
   makeObj,
+  makeSet,
   MathClamp,
   noContextMenu,
   normalizeUnicode,