37 lines
816 B
JavaScript
37 lines
816 B
JavaScript
/* global ReadableStream */
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export function transform(readable, transformer) {
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const reader = readable.getReader();
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const tstream = new ReadableStream({
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start(controller) {
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if (transformer.start) {
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return transformer.start(controller);
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}
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},
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async pull(controller) {
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let enqueued = false;
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const c = {
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enqueue(d) {
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enqueued = true;
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controller.enqueue(d);
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}
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};
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while (!enqueued) {
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const x = await reader.read();
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if (x.done) {
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if (transformer.flush) {
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await transformer.flush(controller);
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}
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return controller.close();
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}
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await transformer.transform(x.value, c);
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}
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},
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cancel() {
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readable.cancel();
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}
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});
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return tstream;
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}
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