Add some logging to debug race condition with fetch

code/bitjs/archive/common.js

@@ -36,6 +36,7 @@ export async function getConnectedPort(implFilename) {
   const messageChannel = new MessageChannel();
   const hostPort = messageChannel.port1;
   const implPort = messageChannel.port2;
+  console.log(`debugFetch: Connected host to implementation with ports`);
 
   if (typeof Worker === 'undefined') {
     const implModule = await import(`${implFilename}`);
@@ -49,6 +50,9 @@ export async function getConnectedPort(implFilename) {
   return new Promise((resolve, reject) => {
     const workerScriptPath = new URL(`./webworker-wrapper.js`, import.meta.url).href;
     const worker = new Worker(workerScriptPath, { type: 'module' });
+    worker.addEventListener('connected', () => {
+      console.log(`debugFetch: Got the connected event from the worker`);
+    });
     worker.postMessage({ implSrc: implFilename }, [implPort]);
     resolve({
       hostPort,

code/bitjs/archive/unzip.js

@@ -789,6 +789,7 @@ export function connect(port) {
 
   hostPort = port;
   port.onmessage = onmessage;
+  console.log(`debugFetch: Connected host to unzip implementation`);
 }
 
 export function disconnect() {
@@ -811,3 +812,17 @@ export function disconnect() {
   totalUncompressedBytesInArchive = 0;
   totalFilesInArchive = 0;  
 }
+
+/*
+book-binder.js:172   unarchiving done in 0.292s
+comic-book-binder.js:105   number of pages = 0
+book-viewer.js:263 updateLayout() before current page is loaded
+unzip.js:773 Found an error while unzipping
+onmessage @ unzip.js:773Understand this error
+unzip.js:774 TypeError: Cannot read properties of null (reading 'postMessage')
+    at archiveUnzip (https://codedread.github.io/kthoom/code/bitjs/archive/unzip.js:634:18)
+    at async MessagePort.onmessage (https://codedread.github.io/kthoom/code/bitjs/archive/unzip.js:767:7)
+unzip.js:634 Uncaught (in promise) TypeError: Cannot read properties of null (reading 'postMessage')
+    at archiveUnzip (unzip.js:634:18)
+    at async MessagePort.onmessage (unzip.js:767:7)Understand this error
+*/

code/bitjs/archive/webworker-wrapper.js

@@ -18,9 +18,11 @@ let implPort;
 let module;
 
 onmessage = async (evt) => {
+  console.log(`debugFetch: Got a message inside webworker-wrapper with implSrc: ${evt.data.implSrc}`);
   if (evt.data.implSrc) {
     module = await import(evt.data.implSrc);
     module.connect(evt.ports[0]);
+    postMessage({type: 'connected'});
   } else if (evt.data.disconnect) {
     module.disconnect();
   }

code/book.js

@@ -329,6 +329,12 @@ export class Book extends EventTarget {
       const reader = response.body.getReader();
       const readAndProcessNextChunk = () => {
         reader.read().then(({ done, value }) => {
+          if (Params['debugFetch']) {
+            let str = `debugFetch: readAndProcessNextChunk(), `;
+            if (done) { str += 'done'; }
+            else { str += `buffer.byteLength=${value.buffer.byteLength}`; }
+            console.log(str);
+          }
           if (!done) {
             // value is a chunk of the file as a Uint8Array.
             if (!this.#bookBinder) {
@@ -489,6 +495,9 @@ export class Book extends EventTarget {
   #startBookBinding(fileNameOrUri, ab, totalExpectedSize) {
     this.#arrayBuffer = ab;
     return createBookBinderAsync(fileNameOrUri, ab, totalExpectedSize).then(bookBinder => {
+      if (Params['debugFetch']) {
+        console.log(`debugFetch: Book Binder created`);
+      }
       this.#bookBinder = bookBinder;
       this.#bookMetadata = createEmptyMetadata(bookBinder.getBookType());
 
@@ -506,6 +515,9 @@ export class Book extends EventTarget {
       });
 
       this.#bookBinder.addEventListener(BookEventType.PAGE_EXTRACTED, evt => {
+        if (Params['debugFetch']) {
+          console.log(`debugFetch: Page #${this.#pages.length+1} extracted`);
+        }
         this.#pages.push(evt.page);
         this.dispatchEvent(new BookPageExtractedEvent(this, evt.page, evt.pageNum));
       });