decodeProperties() — netty Function Reference

Source Code

codec-mqtt/src/main/java/io/netty/handler/codec/mqtt/MqttDecoder.java lines 761–836

    private static Result<MqttProperties> decodeProperties(ByteBuf buffer) {
        final long propertiesLength = decodeVariableByteInteger(buffer);
        int totalPropertiesLength = unpackA(propertiesLength);
        int numberOfBytesConsumed = unpackB(propertiesLength);

        MqttProperties decodedProperties = new MqttProperties();
        while (numberOfBytesConsumed < totalPropertiesLength) {
            long propertyId = decodeVariableByteInteger(buffer);
            final int propertyIdValue = unpackA(propertyId);
            numberOfBytesConsumed += unpackB(propertyId);
            switch (propertyIdValue) {
                case PAYLOAD_FORMAT_INDICATOR:
                case REQUEST_PROBLEM_INFORMATION:
                case REQUEST_RESPONSE_INFORMATION:
                case MAXIMUM_QOS:
                case RETAIN_AVAILABLE:
                case WILDCARD_SUBSCRIPTION_AVAILABLE:
                case SUBSCRIPTION_IDENTIFIER_AVAILABLE:
                case SHARED_SUBSCRIPTION_AVAILABLE:
                    final int b1 = buffer.readUnsignedByte();
                    numberOfBytesConsumed++;
                    decodedProperties.add(new IntegerProperty(propertyIdValue, b1));
                    break;
                case SERVER_KEEP_ALIVE:
                case RECEIVE_MAXIMUM:
                case TOPIC_ALIAS_MAXIMUM:
                case TOPIC_ALIAS:
                    final int int2BytesResult = decodeMsbLsb(buffer);
                    numberOfBytesConsumed += 2;
                    decodedProperties.add(new IntegerProperty(propertyIdValue, int2BytesResult));
                    break;
                case PUBLICATION_EXPIRY_INTERVAL:
                case SESSION_EXPIRY_INTERVAL:
                case WILL_DELAY_INTERVAL:
                case MAXIMUM_PACKET_SIZE:
                    final int maxPacketSize = buffer.readInt();
                    numberOfBytesConsumed += 4;
                    decodedProperties.add(new IntegerProperty(propertyIdValue, maxPacketSize));
                    break;
                case SUBSCRIPTION_IDENTIFIER:
                    long vbIntegerResult = decodeVariableByteInteger(buffer);
                    numberOfBytesConsumed += unpackB(vbIntegerResult);
                    decodedProperties.add(new IntegerProperty(propertyIdValue, unpackA(vbIntegerResult)));
                    break;
                case CONTENT_TYPE:
                case RESPONSE_TOPIC:
                case ASSIGNED_CLIENT_IDENTIFIER:
                case AUTHENTICATION_METHOD:
                case RESPONSE_INFORMATION:
                case SERVER_REFERENCE:
                case REASON_STRING:
                    final Result<String> stringResult = decodeString(buffer);
                    numberOfBytesConsumed += stringResult.numberOfBytesConsumed;
                    decodedProperties.add(new MqttProperties.StringProperty(propertyIdValue, stringResult.value));
                    break;
                case USER_PROPERTY:
                    final Result<String> keyResult = decodeString(buffer);
                    final Result<String> valueResult = decodeString(buffer);
                    numberOfBytesConsumed += keyResult.numberOfBytesConsumed;
                    numberOfBytesConsumed += valueResult.numberOfBytesConsumed;
                    decodedProperties.add(new MqttProperties.UserProperty(keyResult.value, valueResult.value));
                    break;
                case CORRELATION_DATA:
                case AUTHENTICATION_DATA:
                    final byte[] binaryDataResult = decodeByteArray(buffer);
                    numberOfBytesConsumed += binaryDataResult.length + 2;
                    decodedProperties.add(new MqttProperties.BinaryProperty(propertyIdValue, binaryDataResult));
                    break;
                default:
                    //shouldn't reach here
                    throw new DecoderException("Unknown property type: " + propertyIdValue);
            }
        }

        return new Result<MqttProperties>(decodedProperties, numberOfBytesConsumed);
    }