From 52a598915f780b503efe0e4e35aba85edf02b6aa Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Wed, 10 Mar 2021 12:31:45 +0100
Subject: [PATCH] Re-factor the `PDFScriptingManager._destroyScripting` method
(PR 13042 follow-up)
*Please note:* Given the pre-existing issues raised in PR 13056, which seem to block immediate progress there, this patch extracts some *overall* improvements of the scripting/sandbox destruction in `PDFScriptingManager`.
As can be seen in `BaseViewer.setDocument`, it's currently necessary to *manually* delay the `PDFScriptingManager`-destruction in order for things to work correctly. This is, in hindsight, obviously an *extremely poor* design choice on my part; sorry about the churn here!
In order to improve things overall, the `PDFScriptingManager._destroyScripting`-method is re-factored to wait for the relevant events to be dispatched *before* sandbox-destruction occurs.
To avoid the scripting/sandbox-destruction hanging indefinitely, we utilize a timeout to force-destroy the sandbox after a short time (currently set to 1 second).
---
web/base_viewer.js | 5 +----
web/pdf_scripting_manager.js | 29 ++++++++++++++++++++++++-----
2 files changed, 25 insertions(+), 9 deletions(-)
diff --git a/web/base_viewer.js b/web/base_viewer.js
index bd8816740..c6d5cb557 100644
--- a/web/base_viewer.js
+++ b/web/base_viewer.js
@@ -470,10 +470,7 @@ class BaseViewer {
this.findController.setDocument(null);
}
if (this._scriptingManager) {
- // Defer this slightly, to allow the "PageClose" event to be handled.
- Promise.resolve().then(() => {
- this._scriptingManager.setDocument(null);
- });
+ this._scriptingManager.setDocument(null);
}
}
diff --git a/web/pdf_scripting_manager.js b/web/pdf_scripting_manager.js
index ac5b45935..32c9d0e2b 100644
--- a/web/pdf_scripting_manager.js
+++ b/web/pdf_scripting_manager.js
@@ -31,7 +31,7 @@ import { RenderingStates } from "./pdf_rendering_queue.js";
class PDFScriptingManager {
/**
- * @param {PDFScriptingManager} options
+ * @param {PDFScriptingManagerOptions} options
*/
constructor({
eventBus,
@@ -41,6 +41,7 @@ class PDFScriptingManager {
}) {
this._pdfDocument = null;
this._pdfViewer = null;
+ this._closeCapability = null;
this._destroyCapability = null;
this._scripting = null;
@@ -124,8 +125,10 @@ class PDFScriptingManager {
}
this._dispatchPageOpen(pageNumber);
});
- this._internalEvents.set("pagesdestroy", event => {
- this._dispatchPageClose(this._pdfViewer.currentPageNumber);
+ this._internalEvents.set("pagesdestroy", async event => {
+ await this._dispatchPageClose(this._pdfViewer.currentPageNumber);
+
+ this._closeCapability?.resolve();
});
this._domEvents.set("mousedown", event => {
@@ -307,6 +310,8 @@ class PDFScriptingManager {
visitedPages = this._visitedPages;
if (initialize) {
+ this._closeCapability = createPromiseCapability();
+
this._pageEventsReady = true;
}
if (!this._pageEventsReady) {
@@ -417,12 +422,26 @@ class PDFScriptingManager {
* @private
*/
async _destroyScripting() {
- this._pdfDocument = null; // Ensure that it's *always* reset synchronously.
-
if (!this._scripting) {
+ this._pdfDocument = null;
+
this._destroyCapability?.resolve();
return;
}
+ if (this._closeCapability) {
+ await Promise.race([
+ this._closeCapability.promise,
+ new Promise(resolve => {
+ // Avoid the scripting/sandbox-destruction hanging indefinitely.
+ setTimeout(resolve, 1000);
+ }),
+ ]).catch(reason => {
+ // Ignore any errors, to ensure that the sandbox is always destroyed.
+ });
+ this._closeCapability = null;
+ }
+ this._pdfDocument = null;
+
try {
await this._scripting.destroySandbox();
} catch (ex) {}