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[api-minor] Replace the PromiseCapability with Promise.withResolvers()

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This replaces our custom `PromiseCapability`-class with the new native `Promise.withResolvers()` functionality, which does *almost* the same thing[1]; please see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers

The only difference is that `PromiseCapability` also had a `settled`-getter, which was however not widely used and the call-sites can either be removed or re-factored to avoid it. In particular:
 - In `src/display/api.js` we can tweak the `PDFObjects`-class to use a "special" initial data-value and just compare against that, in order to replace the `settled`-state.
 - In `web/app.js` we change the only case to manually track the `settled`-state, which should hopefully be OK given how this is being used.
 - In `web/pdf_outline_viewer.js` we can remove the `settled`-checks, since the code should work just fine without it. The only thing that could potentially happen is that we try to `resolve` a Promise multiple times, which is however *not* a problem since the value of a Promise cannot be changed once fulfilled or rejected.
 - In `web/pdf_viewer.js` we can remove the `settled`-checks, since the code should work fine without them:
     - For the `_onePageRenderedCapability` case the `settled`-check is used in a `EventBus`-listener which is *removed* on its first (valid) invocation.
     - For the `_pagesCapability` case the `settled`-check is used in a print-related helper that works just fine with "only" the other checks.
 - In `test/unit/api_spec.js` we can change the few relevant cases to manually track the `settled`-state, since this is both simple and *test-only* code.

---
[1] In browsers/environments that lack native support, note [the compatibility data](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers#browser_compatibility), it'll be polyfilled via the `core-js` library (but only in `legacy` builds).
This commit is contained in:
Jonas Jenwald 2024-03-28 16:42:37 +01:00
parent 55db43966e
commit e4d0e84802
28 changed files with 159 additions and 252 deletions
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15
src/core/evaluator.js
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@ -25,7 +25,6 @@ import {
isArrayEqual,
normalizeUnicode,
OPS,
PromiseCapability,
shadow,
stringToPDFString,
TextRenderingMode,
@ -1270,7 +1269,7 @@ class PartialEvaluator {
return this.fontCache.get(font.cacheKey);
}
const fontCapability = new PromiseCapability();
const { promise, resolve } = Promise.withResolvers();
let preEvaluatedFont;
try {
@ -1328,10 +1327,10 @@ class PartialEvaluator {
// keys. Also, since `fontRef` is used when getting cached fonts,
// we'll not accidentally match fonts cached with the `fontID`.
if (fontRefIsRef) {
this.fontCache.put(fontRef, fontCapability.promise);
this.fontCache.put(fontRef, promise);
} else {
font.cacheKey = `cacheKey_${fontID}`;
this.fontCache.put(font.cacheKey, fontCapability.promise);
this.fontCache.put(font.cacheKey, promise);
}
// Keep track of each font we translated so the caller can
@ -1340,7 +1339,7 @@ class PartialEvaluator {
this.translateFont(preEvaluatedFont)
.then(translatedFont => {
fontCapability.resolve(
resolve(
new TranslatedFont({
loadedName: font.loadedName,
font: translatedFont,
@ -1350,10 +1349,10 @@ class PartialEvaluator {
);
})
.catch(reason => {
// TODO fontCapability.reject?
// TODO reject?
warn(`loadFont - translateFont failed: "${reason}".`);
fontCapability.resolve(
resolve(
new TranslatedFont({
loadedName: font.loadedName,
font: new ErrorFont(
@ -1364,7 +1363,7 @@ class PartialEvaluator {
})
);
});
return fontCapability.promise;
return promise;
}
buildPath(operatorList, fn, args, parsingText = false) {