From 7f2d524df58934a42d1b87c9a13860db8c068c30 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sun, 8 Aug 2021 08:14:51 +0200
Subject: [PATCH] Improve caching of Annotations-data, by using a `Map`, in the
 API

Rather than caching only the *last* `PDFPageProxy.getAnnotations` call, and having to handle the intent separately, we can instead implement the caching in exactly the same way as done in the `PDFPageProxy.{render, getOperatorList}` methods.
---
 src/display/api.js | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/display/api.js b/src/display/api.js
index cee9cf640..978b05802 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -1234,6 +1234,7 @@ class PDFPageProxy {
     this.cleanupAfterRender = false;
     this.pendingCleanup = false;
     this._intentStates = new Map();
+    this._annotationPromises = new Map();
     this.destroyed = false;
   }
 
@@ -1303,17 +1304,15 @@ class PDFPageProxy {
   getAnnotations({ intent = "display" } = {}) {
     const renderingIntent = getRenderingIntent(intent, {});
 
-    if (
-      !this._annotationsPromise ||
-      this._annotationsIntent !== renderingIntent
-    ) {
-      this._annotationsPromise = this._transport.getAnnotations(
+    let promise = this._annotationPromises.get(renderingIntent);
+    if (!promise) {
+      promise = this._transport.getAnnotations(
         this._pageIndex,
         renderingIntent
       );
-      this._annotationsIntent = renderingIntent;
+      this._annotationPromises.set(renderingIntent, promise);
     }
-    return this._annotationsPromise;
+    return promise;
   }
 
   /**
@@ -1623,7 +1622,7 @@ class PDFPageProxy {
       }
     }
     this.objs.clear();
-    this._annotationsPromise = null;
+    this._annotationPromises.clear();
     this._jsActionsPromise = null;
     this._structTreePromise = null;
     this.pendingCleanup = false;
@@ -1658,7 +1657,7 @@ class PDFPageProxy {
 
     this._intentStates.clear();
     this.objs.clear();
-    this._annotationsPromise = null;
+    this._annotationPromises.clear();
     this._jsActionsPromise = null;
     this._structTreePromise = null;
     if (resetStats && this._stats) {