44 lines
1.5 KiB
JavaScript
44 lines
1.5 KiB
JavaScript
import { toBase64 } from "@smithy/util-base64";
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import { Duplex } from "stream";
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export class ChecksumStream extends Duplex {
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constructor({ expectedChecksum, checksum, source, checksumSourceLocation, base64Encoder, }) {
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super();
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if (typeof source.pipe === "function") {
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this.source = source;
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}
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else {
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throw new Error(`@smithy/util-stream: unsupported source type ${source?.constructor?.name ?? source} in ChecksumStream.`);
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}
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this.base64Encoder = base64Encoder ?? toBase64;
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this.expectedChecksum = expectedChecksum;
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this.checksum = checksum;
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this.checksumSourceLocation = checksumSourceLocation;
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this.source.pipe(this);
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}
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_read(size) { }
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_write(chunk, encoding, callback) {
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try {
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this.checksum.update(chunk);
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this.push(chunk);
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}
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catch (e) {
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return callback(e);
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}
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return callback();
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}
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async _final(callback) {
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try {
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const digest = await this.checksum.digest();
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const received = this.base64Encoder(digest);
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if (this.expectedChecksum !== received) {
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return callback(new Error(`Checksum mismatch: expected "${this.expectedChecksum}" but received "${received}"` +
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` in response header "${this.checksumSourceLocation}".`));
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}
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}
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catch (e) {
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return callback(e);
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}
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this.push(null);
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return callback();
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}
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}
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