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Ensure that onProgress is always called when the entire PDF file has been loaded, regardless of how it was fetched (issue 10160)

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*Please note:* I'm totally fine with this patch being rejected, and the issue closed as WONTFIX; however these changes should address the issue if that's desired.

From a conceptual point of view, reporting loading progress doesn't really make a lot of sense for PDF files opened by passing raw binary data directly to `getDocument` (since obviously *all* data was loaded).
This is compared to PDF files loaded via e.g. `XMLHttpRequest` or the Fetch API, where the entire PDF file isn't available from the start and knowing the loading progress makes total sense.

However I can certainly see why the current API could be considered inconsistent, which isn't great, since a registered `onProgress` callback will never be called for certain `getDocument` calls.
The simplest solution to this inconsistency thus seem to be to ensure that `onProgress` is always called when handling the `DataLoaded` message, since that will *always* be dispatched[1] from the worker-thread.

---
[1] Note that this isn't guaranteed to happen, since setting `disableAutoFetch = true` often prevents the *entire* file from ever loading. However, this isn't relevant for the issue at hand, and is a well-known consequence of using `disableAutoFetch = true`; note how the default viewer even has a specialized code-path for hiding the loadingBar.
This commit is contained in:
Jonas Jenwald 2018-10-16 13:24:02 +02:00
parent ecbdc508f7
commit 327f2eb588
2 changed files with 25 additions and 9 deletions
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17
src/display/api.js
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@ -1763,12 +1763,9 @@ class WorkerTransport {
fullReader.headersReady.then(() => {
// If stream or range are disabled, it's our only way to report
// loading progress.
if (!fullReader.isStreamingSupported ||
!fullReader.isRangeSupported) {
if (this._lastProgress) {
if (loadingTask.onProgress) {
loadingTask.onProgress(this._lastProgress);
}
if (!fullReader.isStreamingSupported || !fullReader.isRangeSupported) {
if (this._lastProgress && loadingTask.onProgress) {
loadingTask.onProgress(this._lastProgress);
}
fullReader.onProgress = (evt) => {
if (loadingTask.onProgress) {
@ -1866,6 +1863,14 @@ class WorkerTransport {
}, this);
messageHandler.on('DataLoaded', function(data) {
// For consistency: Ensure that progress is always reported when the
// entire PDF file has been loaded, regardless of how it was fetched.
if (loadingTask.onProgress) {
loadingTask.onProgress({
loaded: data.length,
total: data.length,
});
}
this.downloadInfoCapability.resolve(data);
}, this);

17
test/unit/api_spec.js
View File

@ -142,9 +142,20 @@ describe('api', function() {
// Sanity check to make sure that we fetched the entire PDF file.
expect(typedArrayPdf.length).toEqual(basicApiFileLength);
var loadingTask = getDocument(typedArrayPdf);
loadingTask.promise.then(function(data) {
expect(data instanceof PDFDocumentProxy).toEqual(true);
const loadingTask = getDocument(typedArrayPdf);
const progressReportedCapability = createPromiseCapability();
loadingTask.onProgress = function(data) {
progressReportedCapability.resolve(data);
};
Promise.all([
loadingTask.promise,
progressReportedCapability.promise,
]).then(function(data) {
expect(data[0] instanceof PDFDocumentProxy).toEqual(true);
expect(data[1].loaded / data[1].total).toEqual(1);
loadingTask.destroy().then(done);
}).catch(done.fail);
});