From a80f10ff1af47f89c2af7bcf2f1b8fef9b3ad743 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 30 Jan 2026 07:56:22 +0100
Subject: [PATCH] Remove the `onProgress` callback from the
 `IPDFStreamRangeReader` interface

Note how there's *nowhere* in the code-base where the `IPDFStreamRangeReader.prototype.onProgress` callback is actually being set and used, however the loadingBar (in the viewer) still works just fine since loading progress is already reported via:
 - The `ChunkedStreamManager` instance respectively the `getPdfManager` function, through the use of a "DocProgress" message, on the worker-thread.
 - A `IPDFStreamReader.prototype.onProgress` callback, on the main-thread.

Furthermore, it would definitely *not* be a good idea to add any `IPDFStreamRangeReader.prototype.onProgress` callbacks since they only include the `loaded`-property which would trigger the "indeterminate" loadingBar (in the viewer).

Looking briefly at the history of this code it's not clear, at least to me, when this became unused however it's probably close to a decade ago.
---
 src/core/worker_stream.js       |  1 -
 src/display/fetch_stream.js     |  6 ------
 src/display/network.js          |  8 +-------
 src/display/node_stream.js      |  6 ------
 src/display/transport_stream.js |  7 +------
 src/interfaces.js               | 10 ----------
 6 files changed, 2 insertions(+), 36 deletions(-)

diff --git a/src/core/worker_stream.js b/src/core/worker_stream.js
index eb8f97f3c..6dfc3962a 100644
--- a/src/core/worker_stream.js
+++ b/src/core/worker_stream.js
@@ -105,7 +105,6 @@ class PDFWorkerStreamReader {
 class PDFWorkerStreamRangeReader {
   constructor(begin, end, msgHandler) {
     this._msgHandler = msgHandler;
-    this.onProgress = null;
 
     const readableStream = this._msgHandler.sendWithStream("GetRangeReader", {
       begin,
diff --git a/src/display/fetch_stream.js b/src/display/fetch_stream.js
index dc08637cc..4f603f9b6 100644
--- a/src/display/fetch_stream.js
+++ b/src/display/fetch_stream.js
@@ -205,7 +205,6 @@ class PDFFetchStreamRangeReader {
   constructor(stream, begin, end) {
     this._stream = stream;
     this._reader = null;
-    this._loaded = 0;
     const source = stream.source;
     this._withCredentials = source.withCredentials || false;
     this._readCapability = Promise.withResolvers();
@@ -235,8 +234,6 @@ class PDFFetchStreamRangeReader {
         this._reader = response.body.getReader();
       })
       .catch(this._readCapability.reject);
-
-    this.onProgress = null;
   }
 
   async read() {
@@ -245,9 +242,6 @@ class PDFFetchStreamRangeReader {
     if (done) {
       return { value, done };
     }
-    this._loaded += value.byteLength;
-    this.onProgress?.({ loaded: this._loaded });
-
     return { value: getArrayBuffer(value), done: false };
   }
 
diff --git a/src/display/network.js b/src/display/network.js
index 48bf60e2a..6f8a1f356 100644
--- a/src/display/network.js
+++ b/src/display/network.js
@@ -367,14 +367,12 @@ class PDFNetworkStreamRangeRequestReader {
       onHeadersReceived: this._onHeadersReceived.bind(this),
       onDone: this._onDone.bind(this),
       onError: this._onError.bind(this),
-      onProgress: this._onProgress.bind(this),
+      onProgress: null,
     });
     this._requests = [];
     this._queuedChunk = null;
     this._done = false;
     this._storedError = undefined;
-
-    this.onProgress = null;
   }
 
   _onHeadersReceived() {
@@ -412,10 +410,6 @@ class PDFNetworkStreamRangeRequestReader {
     this._queuedChunk = null;
   }
 
-  _onProgress(evt) {
-    this.onProgress?.({ loaded: evt.loaded });
-  }
-
   async read() {
     if (this._storedError) {
       throw this._storedError;
diff --git a/src/display/node_stream.js b/src/display/node_stream.js
index 4c6276505..03266b0fe 100644
--- a/src/display/node_stream.js
+++ b/src/display/node_stream.js
@@ -206,9 +206,6 @@ class PDFNodeStreamFsRangeReader {
   _reader = null;
 
   constructor(stream, begin, end) {
-    this.onProgress = null;
-    this._loaded = 0;
-
     const url = stream.url;
     const fs = process.getBuiltinModule("fs");
     try {
@@ -232,9 +229,6 @@ class PDFNodeStreamFsRangeReader {
     if (done) {
       return { value, done };
     }
-    this._loaded += value.length;
-    this.onProgress?.({ loaded: this._loaded });
-
     return { value: getArrayBuffer(value), done: false };
   }
 
diff --git a/src/display/transport_stream.js b/src/display/transport_stream.js
index 8c1a21f16..1fb74f521 100644
--- a/src/display/transport_stream.js
+++ b/src/display/transport_stream.js
@@ -111,10 +111,7 @@ class PDFDataTransportStream {
   }
 
   _onProgress(evt) {
-    if (evt.total === undefined) {
-      // Reporting to first range reader, if it exists.
-      this._rangeReaders[0]?.onProgress?.({ loaded: evt.loaded });
-    } else {
+    if (evt.total !== undefined) {
       this._fullRequestReader?.onProgress?.({
         loaded: evt.loaded,
         total: evt.total,
@@ -265,8 +262,6 @@ class PDFDataTransportStreamRangeReader {
     this._queuedChunk = null;
     this._requests = [];
     this._done = false;
-
-    this.onProgress = null;
   }
 
   _enqueue(chunk) {
diff --git a/src/interfaces.js b/src/interfaces.js
index 587727327..34c5f95bf 100644
--- a/src/interfaces.js
+++ b/src/interfaces.js
@@ -135,16 +135,6 @@ class IPDFStreamReader {
  * @interface
  */
 class IPDFStreamRangeReader {
-  constructor() {
-    /**
-     * Sets or gets the progress callback. The callback can be useful when the
-     * isStreamingSupported property of the object is defined as false.
-     * The callback is called with one parameter: an object with the loaded
-     * property.
-     */
-    this.onProgress = null;
-  }
-
   /**
    * Requests a chunk of the binary data. The method returns the promise, which
    * is resolved into object with properties "value" and "done". If the done