about the class Writer 简化

[nenge123]

不如增加一个流ReadableStream?
await entry.getData(new zip.Uint8ArrayWriter(),opt) => await entry.getData('json|Uint8Array',opt) ?
Uint8ArrayWriter|BlobWriter 简化~

	class Writer extends Stream {

		constructor(returntype) {
			super();
			const writer = this;
			if(returntype)writer.returntype = returntype;
			writer.dataReader = new Response(new ReadableStream({
				start(controller){
					return writer.saveChunk(controller);
				}
			}));
			const writable = new WritableStream({
				write(chunk) {
					writer.enqueue(chunk);
					//return writer.writeUint8Array(chunk);
				},
				close(){
					writer.closeChunk();
				}
			});
			Object.defineProperty(writer, PROPERTY_NAME_WRITABLE, {
				get() {
					return writable;
				}
			});
		}
		enqueue(chunk){
			this.controller.enqueue(chunk);
		}
		saveChunk(controller){
			this.controller = controller;
			return new Promise(complete=>this.complete=complete);
		}
		closeChunk(){
			this.controller.close();
			this.complete();
			//console.log(this.dataReader.arrayBuffer());
			//console.log(this.dataReader.blob());
			console.log(this.dataReader);
		}
		async getData(){
			let type = this.returntype||'Uint8Array';
			if(type=='Uint8Array') return new Uint8Array(await this.dataReader.arrayBuffer())
			return await this.dataReader[type]();
		}
		writeUint8Array() {
			// abstract
		}
	}

[gildas-lormeau]

Multiple classes inherit from Writer (see Hierarchy). For example, your changes introduces some issues in Data64URIWriter like breaking the constructor code. Also, writeUint8Array() does nothing in your implementation and this method is used by classes inheriting from Writer. Actually, it's hard for me to understand what is the point of your suggestion in the case of Data64URIWriter, for example.

On the other hand, I'm not a fan of APIs relying on strings, e.g. entry.getData("Uint8Array"), entry.getData("json"), or entry.getData("blob") (I guess TypeScript developers agree). The purpose of the Entry class (and ZipReader, ZipWriter classes) is to be as low-level as possible. The high-level API in zip.js is fs.FS. This is where I would place such code. However, I prefer using explicit APIs like ZipFileEntry#getBlob, ZipFileEntry#getData64URI, ZipFileEntry#getUint8Array etc., see https://gildas-lormeau.github.io/zip.js/api/classes/ZipFileEntry.html.

[nenge123]

@gildas-lormeau I see the "BlobWriter" ,
why the "Uint8ArrayWriter " not be like this?
then can remove the for()

class Uint8ArrayWriter extends BlobWriter {
  async getData(){
	  const blob = await super.getData();
	  console.log(blob);
	  return new Uint8Array(await blob.arrayBuffer());
  }
}
	class TextWriter extends BlobWriter{
		constructor(encoding){
			super(encoding);
		}
		async getData(){
			const blob = await super.getData();
			return await blob.text();

		}
	}
	class Data64URIWriter extends Uint8ArrayWriter{
		constructor(contentType){
			super();
			this.contentType = contentType;
		}
		async getData(){
			return "data:" + (this.contentType || "") + ";base64,"+btoa(await super.getData());

		}
	}

[gildas-lormeau]

Because it will consume at least twice as much RAM when calling blob.arrayBuffer or btoa for a short period of time (i.e. until the GC will destroy unused objects). The purpose of the implementation of Uint8ArrayWriter and Data64URIWriter in zip.js is to avoid this.

[gildas-lormeau]

Note however that nothing prevents you to use your own custom implementation of Writer classes. Actually, zip.js was designed for this, see https://github.com/gildas-lormeau/zip.js/blob/master/tests/all/test-custom-io.js for example.