36 lines
1.5 KiB
JavaScript
36 lines
1.5 KiB
JavaScript
import { toBase64 } from "@smithy/util-base64";
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import { isReadableStream } from "../stream-type-check";
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import { ChecksumStream } from "./ChecksumStream.browser";
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export const createChecksumStream = ({ expectedChecksum, checksum, source, checksumSourceLocation, base64Encoder, }) => {
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if (!isReadableStream(source)) {
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throw new Error(`@smithy/util-stream: unsupported source type ${source?.constructor?.name ?? source} in ChecksumStream.`);
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}
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const encoder = base64Encoder ?? toBase64;
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if (typeof TransformStream !== "function") {
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throw new Error("@smithy/util-stream: unable to instantiate ChecksumStream because API unavailable: ReadableStream/TransformStream.");
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}
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const transform = new TransformStream({
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start() { },
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async transform(chunk, controller) {
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checksum.update(chunk);
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controller.enqueue(chunk);
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},
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async flush(controller) {
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const digest = await checksum.digest();
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const received = encoder(digest);
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if (expectedChecksum !== received) {
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const error = new Error(`Checksum mismatch: expected "${expectedChecksum}" but received "${received}"` +
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` in response header "${checksumSourceLocation}".`);
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controller.error(error);
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}
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else {
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controller.terminate();
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}
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},
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});
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source.pipeThrough(transform);
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const readable = transform.readable;
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Object.setPrototypeOf(readable, ChecksumStream.prototype);
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return readable;
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};
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