himesh512 / pdf-blob-cache Goto Github PK

async downloadChunk(url: string, name: string) {
  if (this.verifyDocCachedOrNot(name)) {
    this.rangeObj = this.docCaching.get(name);
    return;
  }

  console.log(`=========  Chunk ${this.rangeObj.chunkCounter}/${this.rangeObj.totalChunks} Download Started  =========`);

  try {
    const response = await fetch(url, {
      cache: 'no-cache',
      headers: {
        'Range': this.createRangeToDownload()
      }
    });

    if (!this.rangeObj.fileTotalSize) {
      this.rangeObj.fileTotalSize = this.setTotalFileSize(response);
      this.setTotalChunks();
    }

    const reader = response.body?.getReader();
    if (!reader) throw new Error("Failed to get reader from response body");

    const stream = new ReadableStream({
      async start(controller) {
        while (true) {
          const { done, value } = await reader.read();

          if (done) {
            console.log(`=========  Chunk ${this.rangeObj.chunkCounter}/${this.rangeObj.totalChunks} Download Ended  =========`);

            if (this.rangeObj.end === this.rangeObj.fileTotalSize) {
              console.log(`#########      Full File is Downloaded      #########`);
              this.fileDownloaded(name);
              break;
            }

            setTimeout(() => {
              this.rangeObj.chunkCounter++;
              this.updateRange();
              this.downloadChunk(url, name);
            }, 150);
            break;
          }

          this.workOnChunk(value);
          controller.enqueue(value);
        }

        controller.close();
        reader.releaseLock();
      }
    });

    const blob = await new Response(stream).blob();
    return blob;

  } catch (error) {
    console.error("Error :: =>", error);
  }
}