133 lines
5.5 KiB
JavaScript
133 lines
5.5 KiB
JavaScript
'use strict';
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var eventstreamCodec = require('@smithy/eventstream-codec');
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function getChunkedStream(source) {
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let currentMessageTotalLength = 0;
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let currentMessagePendingLength = 0;
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let currentMessage = null;
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let messageLengthBuffer = null;
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const allocateMessage = (size) => {
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if (typeof size !== "number") {
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throw new Error("Attempted to allocate an event message where size was not a number: " + size);
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}
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currentMessageTotalLength = size;
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currentMessagePendingLength = 4;
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currentMessage = new Uint8Array(size);
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const currentMessageView = new DataView(currentMessage.buffer);
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currentMessageView.setUint32(0, size, false);
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};
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const iterator = async function* () {
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const sourceIterator = source[Symbol.asyncIterator]();
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while (true) {
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const { value, done } = await sourceIterator.next();
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if (done) {
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if (!currentMessageTotalLength) {
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return;
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}
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else if (currentMessageTotalLength === currentMessagePendingLength) {
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yield currentMessage;
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}
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else {
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throw new Error("Truncated event message received.");
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}
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return;
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}
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const chunkLength = value.length;
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let currentOffset = 0;
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while (currentOffset < chunkLength) {
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if (!currentMessage) {
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const bytesRemaining = chunkLength - currentOffset;
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if (!messageLengthBuffer) {
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messageLengthBuffer = new Uint8Array(4);
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}
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const numBytesForTotal = Math.min(4 - currentMessagePendingLength, bytesRemaining);
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messageLengthBuffer.set(value.slice(currentOffset, currentOffset + numBytesForTotal), currentMessagePendingLength);
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currentMessagePendingLength += numBytesForTotal;
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currentOffset += numBytesForTotal;
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if (currentMessagePendingLength < 4) {
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break;
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}
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allocateMessage(new DataView(messageLengthBuffer.buffer).getUint32(0, false));
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messageLengthBuffer = null;
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}
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const numBytesToWrite = Math.min(currentMessageTotalLength - currentMessagePendingLength, chunkLength - currentOffset);
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currentMessage.set(value.slice(currentOffset, currentOffset + numBytesToWrite), currentMessagePendingLength);
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currentMessagePendingLength += numBytesToWrite;
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currentOffset += numBytesToWrite;
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if (currentMessageTotalLength && currentMessageTotalLength === currentMessagePendingLength) {
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yield currentMessage;
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currentMessage = null;
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currentMessageTotalLength = 0;
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currentMessagePendingLength = 0;
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}
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}
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}
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};
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return {
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[Symbol.asyncIterator]: iterator,
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};
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}
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function getMessageUnmarshaller(deserializer, toUtf8) {
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return async function (message) {
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const { value: messageType } = message.headers[":message-type"];
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if (messageType === "error") {
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const unmodeledError = new Error(message.headers[":error-message"].value || "UnknownError");
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unmodeledError.name = message.headers[":error-code"].value;
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throw unmodeledError;
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}
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else if (messageType === "exception") {
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const code = message.headers[":exception-type"].value;
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const exception = { [code]: message };
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const deserializedException = await deserializer(exception);
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if (deserializedException.$unknown) {
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const error = new Error(toUtf8(message.body));
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error.name = code;
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throw error;
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}
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throw deserializedException[code];
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}
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else if (messageType === "event") {
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const event = {
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[message.headers[":event-type"].value]: message,
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};
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const deserialized = await deserializer(event);
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if (deserialized.$unknown)
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return;
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return deserialized;
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}
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else {
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throw Error(`Unrecognizable event type: ${message.headers[":event-type"].value}`);
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}
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};
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}
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class EventStreamMarshaller {
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eventStreamCodec;
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utfEncoder;
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constructor({ utf8Encoder, utf8Decoder }) {
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this.eventStreamCodec = new eventstreamCodec.EventStreamCodec(utf8Encoder, utf8Decoder);
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this.utfEncoder = utf8Encoder;
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}
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deserialize(body, deserializer) {
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const inputStream = getChunkedStream(body);
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return new eventstreamCodec.SmithyMessageDecoderStream({
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messageStream: new eventstreamCodec.MessageDecoderStream({ inputStream, decoder: this.eventStreamCodec }),
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deserializer: getMessageUnmarshaller(deserializer, this.utfEncoder),
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});
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}
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serialize(inputStream, serializer) {
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return new eventstreamCodec.MessageEncoderStream({
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messageStream: new eventstreamCodec.SmithyMessageEncoderStream({ inputStream, serializer }),
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encoder: this.eventStreamCodec,
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includeEndFrame: true,
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});
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}
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}
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const eventStreamSerdeProvider = (options) => new EventStreamMarshaller(options);
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exports.EventStreamMarshaller = EventStreamMarshaller;
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exports.eventStreamSerdeProvider = eventStreamSerdeProvider;
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