diffusion/src/node_modules/protocol/connection-response-deserialiser.js

Diffusion JavaScript client

var BufferInputStream = require('io/buffer-input-stream');
var BEES = require('serialisers/byte-encoded-enum-serialiser');

var SessionId = require('session/session-id');
var SessionTokenDeserialiser = require('session/session-token-deserialiser');

var ResponseCode = require('protocol/response-code');
var consts = require('protocol/consts');

/*
 * Deserialise connection responses according to the V5 protocol.
 */
function deserialise(buffer) {
    var input = new BufferInputStream(buffer);

    var protocol = input.read();
    if (protocol !== consts.PROTOCOL_BYTE) {
        throw new Error('Unrecognised protocol byte: ' + protocol);
    }

    var version = input.read();
    if (version < consts.CURRENT_VERSION) {
        throw new Error('Unrecognised protocol version: ' + version);
    } else if (version > consts.CURRENT_VERSION) {
        throw new Error('Unsupported protocol version: ' + version);
    }

    var responseCode = BEES.read(input, ResponseCode);
    
    if (ResponseCode.isSuccess(responseCode)) {
        // For some reason we serialise session ids as unsigned longs here
        var sessionID = new SessionId(input.readUInt64(), input.readUInt64());
        var sessionToken = SessionTokenDeserialiser(input);
        var systemPingPeriod = input.readInt64();

        var recoverySequence = 0;

        if (responseCode === ResponseCode.RECONNECTED) {
            recoverySequence = input.readInt32();
        }

        return {
            response : responseCode,
            identity : sessionID,
            token : sessionToken,
            systemPingPeriod : systemPingPeriod,
            version : version,
            success : true,
            sequence : recoverySequence
        };
    } else {
        return {
            response : responseCode,
            version : version,
            identity : null,
            token : null,
            systemPingPeriod : null,
            success : false,
            sequence : 0
        };
    }
}

module.exports = deserialise;