142 lines
4.3 KiB
JavaScript
142 lines
4.3 KiB
JavaScript
import Dispatcher from "./Dispatcher";
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import { bitsToInt } from "./converters";
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const dispatcher = new Dispatcher('StreamManager', ['change']);
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const BITS = [];
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let BITS_PER_PACKET = 0;
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let SEGMENTS_PER_PACKET = 0;
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let BITS_PER_SEGMENT = 0;
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let STREAM_HEADERS = [];
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let SEGMENT_ENCODING = {
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encode: bits => bits,
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decode: bits => bits
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};
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let PACKET_ENCODING = {
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encode: bits => bits,
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decode: bits => bits
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}
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export const addEventListener = dispatcher.addListener;
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export const removeEventListener = dispatcher.removeListener;
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export const reset = () => {
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if(BITS.length !== 0) {
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BITS.length = 0;
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dispatcher.emit('change');
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}
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}
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export const changeConfiguration = ({
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segmentsPerPacket,
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bitsPerPacket,
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bitsPerSegment,
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streamHeaders
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}) => {
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BITS_PER_PACKET = bitsPerPacket;
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SEGMENTS_PER_PACKET = segmentsPerPacket;
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BITS_PER_SEGMENT = bitsPerSegment;
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STREAM_HEADERS = streamHeaders;
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}
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const noEncoding = bits => bits;
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export const setSegmentEncoding = ({ encode, decode } = {}) => {
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SEGMENT_ENCODING.encode = encode ?? noEncoding;
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SEGMENT_ENCODING.decode = decode ?? noEncoding;
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}
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export const setPacketEncoding = ({ encode, decode } = {}) => {
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PACKET_ENCODING.encode = encode ?? noEncoding;
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PACKET_ENCODING.decode = decode ?? noEncoding;
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}
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export const addBits = (
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packetIndex,
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segmentIndex,
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bits
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) => {
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if(BITS[packetIndex] === undefined) {
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BITS[packetIndex] = [];
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}
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const oldBits = BITS[packetIndex][segmentIndex];
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BITS[packetIndex][segmentIndex] = bits;
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if(hasNewBits(oldBits, bits))
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dispatcher.emit('change');
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}
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const sumSegmentBits = (sum, segment) => sum + segment.length;
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const sumPacketBits = (sum, packet) => sum + packet.reduce(sumSegmentBits, 0);
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export const sumTotalBits = () => BITS.reduce(sumPacketBits, 0);
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const hasNewBits = (oldBits = [], bits = []) => {
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if(oldBits.length === 0 && bits.length === BITS_PER_SEGMENT)
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return true;
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for(let i = 0; i < BITS_PER_SEGMENT; i++) {
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let a = oldBits[i] ?? 0;
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let b = bits[i] ?? 0;
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if(a !== b) return true;
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}
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return false;
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}
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export const getPacketReceivedCount = () => {
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if(BITS.length === 0) return 1;
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return BITS.length;
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}
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export const getStreamBits = () => {
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const bits = [];
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const packetCount = getPacketReceivedCount();
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for(let packetIndex = 0; packetIndex < packetCount; packetIndex++) {
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const packet = BITS[packetIndex] ?? [];
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for(let segmentIndex = 0; segmentIndex < SEGMENTS_PER_PACKET; segmentIndex++) {
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let segment = packet[segmentIndex] ?? [];
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for(let bitIndex = 0; bitIndex < BITS_PER_SEGMENT; bitIndex++) {
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const bit = segment[bitIndex];
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bits.push(bit ?? 0);
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}
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}
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}
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return bits;
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}
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export const getPacketSegmentBits = (packetIndex, segmentIndex) => BITS[packetIndex]?.[segmentIndex];
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export const getAllPacketBits = () => {
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const packetCount = getPacketReceivedCount();
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const bits = [];
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for(let packetIndex = 0; packetIndex < packetCount; packetIndex++) {
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bits.push(...getPacketBits(packetIndex));
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}
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return bits;
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}
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export const getPacketBits = (packetIndex, defaultBit = 0) => {
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const bits = [];
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const packet = BITS[packetIndex] ?? [];
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for(let segmentIndex = 0; segmentIndex < SEGMENTS_PER_PACKET; segmentIndex++) {
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let segment = packet[segmentIndex] ?? [];
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segment = SEGMENT_ENCODING.decode(segment);
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for(let bitIndex = 0; bitIndex < BITS_PER_SEGMENT; bitIndex++) {
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const bit = segment[bitIndex];
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bits.push(bit ?? defaultBit);
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if(bits.length === BITS_PER_PACKET) return bits;
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}
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}
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while(bits.length < BITS_PER_PACKET) bits.push(defaultBit);
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return bits;
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}
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export const getPacketBitsDecoded = (packetIndex, defaultBit = 0) => {
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const bits = getPacketBits(packetIndex, defaultBit);
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return PACKET_ENCODING.decode(bits);
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}
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const getStreamHeaderBits = name => {
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const header = STREAM_HEADERS[name];
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if(!header) return [];
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const { index, length } = header;
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const packetCount = getPacketReceivedCount();
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const bits = [];
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for(let packetIndex = 0; packetIndex < packetCount; packetIndex++) {
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bits.push(...getPacketBitsDecoded(packetIndex, 1));
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if(bits.length >= index + length) break;
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}
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return bits.slice(index, index + length);
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}
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export const getTransferByteCount = () => {
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const name = 'transfer byte count';
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const length = STREAM_HEADERS[name].length;
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const bits = getStreamHeaderBits(name);
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return bitsToInt(bits, length);
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}
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