diffusion/src/internal/util/message-encoding.js

Diffusion JavaScript client

"use strict";
/**
 * @module Util.MessageEncoding
 *
 * @brief Utility functions for encoding messages
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.EncodingType = exports.MessageEncoding = void 0;
/**
 * Bitmask for the message type
 */
var MESSAGE_TYPE_MASK = 0xA7D8C0;
/**
 * A flag indicating a zlib compressed message
 */
var ZLIB_TYPE_FLAGS = 0x80;
/**
 * The _message type flags_ allow a subset of MessageEncodings to be encoded
 * in the upper two bits of the message type byte. Only NO_ENCODING and
 * ZLIB are supported.
 */
var MessageEncoding = /** @class */ (function () {
    /**
     * Create a new message encoding object
     *
     * @param encodingByte     the encoding byte
     * @param messageTypeFlags bit flags
     */
    function MessageEncoding(encodingByte, messageTypeFlags) {
        this.encodingByte = encodingByte;
        this.messageTypeFlags = messageTypeFlags;
    }
    /**
     * Decode the message type from a byte combining the message type and flags.
     *
     * @param typeAndEncoding the encoding byte and message type flags
     * @return                the message type flags
     */
    MessageEncoding.extractMessageType = function (typeAndEncoding) {
        /* eslint-disable-next-line no-bitwise */
        return typeAndEncoding & ~MESSAGE_TYPE_MASK;
    };
    /**
     * Decode the message encoding from a byte combining the message type and flags.
     *
     * @param typeAndEncoding the encoding byte and message type flags
     * @return                the message encoding
     */
    MessageEncoding.extractMessageEncoding = function (typeAndEncoding) {
        /* eslint-disable-next-line no-bitwise */
        var encoding = typeAndEncoding & MESSAGE_TYPE_MASK;
        /* tslint:disable-next-line:no-use-before-declare */
        return (encoding === ZLIB_TYPE_FLAGS) ? exports.EncodingType.ZLIB : exports.EncodingType.NO_ENCODING;
    };
    return MessageEncoding;
}());
exports.MessageEncoding = MessageEncoding;
/* eslint-disable-next-line @typescript-eslint/naming-convention */
exports.EncodingType = {
    NO_ENCODING: new MessageEncoding(0x00, 0x00),
    ZLIB: new MessageEncoding(0x12, 0x01)
};