|
|
| export const streamChunk = function* (chunk, chunkSize) { |
| let len = chunk.byteLength; |
|
|
| if (!chunkSize || len < chunkSize) { |
| yield chunk; |
| return; |
| } |
|
|
| let pos = 0; |
| let end; |
|
|
| while (pos < len) { |
| end = pos + chunkSize; |
| yield chunk.slice(pos, end); |
| pos = end; |
| } |
| } |
|
|
| export const readBytes = async function* (iterable, chunkSize) { |
| for await (const chunk of readStream(iterable)) { |
| yield* streamChunk(chunk, chunkSize); |
| } |
| } |
|
|
| const readStream = async function* (stream) { |
| if (stream[Symbol.asyncIterator]) { |
| yield* stream; |
| return; |
| } |
|
|
| const reader = stream.getReader(); |
| try { |
| for (;;) { |
| const {done, value} = await reader.read(); |
| if (done) { |
| break; |
| } |
| yield value; |
| } |
| } finally { |
| await reader.cancel(); |
| } |
| } |
|
|
| export const trackStream = (stream, chunkSize, onProgress, onFinish) => { |
| const iterator = readBytes(stream, chunkSize); |
|
|
| let bytes = 0; |
| let done; |
| let _onFinish = (e) => { |
| if (!done) { |
| done = true; |
| onFinish && onFinish(e); |
| } |
| } |
|
|
| return new ReadableStream({ |
| async pull(controller) { |
| try { |
| const {done, value} = await iterator.next(); |
|
|
| if (done) { |
| _onFinish(); |
| controller.close(); |
| return; |
| } |
|
|
| let len = value.byteLength; |
| if (onProgress) { |
| let loadedBytes = bytes += len; |
| onProgress(loadedBytes); |
| } |
| controller.enqueue(new Uint8Array(value)); |
| } catch (err) { |
| _onFinish(err); |
| throw err; |
| } |
| }, |
| cancel(reason) { |
| _onFinish(reason); |
| return iterator.return(); |
| } |
| }, { |
| highWaterMark: 2 |
| }) |
| } |
|
|