publisher.hpp

00001 /*
00002  * Copyright (C) 2014 Pavel Kirienko <pavel.kirienko@gmail.com>
00003  */
00004 
00005 #ifndef UAVCAN_NODE_PUBLISHER_HPP_INCLUDED
00006 #define UAVCAN_NODE_PUBLISHER_HPP_INCLUDED
00007 
00008 #include <uavcan/node/generic_publisher.hpp>
00009 
00010 namespace uavcan
00011 {
00012 /**
00013  * Use this class to publish messages to the bus (broadcast, unicast, or both).
00014  *
00015  * @tparam DataType_    Message data type
00016  */
00017 template <typename DataType_>
00018 class UAVCAN_EXPORT Publisher : protected GenericPublisher<DataType_, DataType_>
00019 {
00020     typedef GenericPublisher<DataType_, DataType_>  BaseType;
00021 
00022 public:
00023     typedef DataType_ DataType; ///< Message data type
00024 
00025     /**
00026      * @param node          Node instance this publisher will be registered with.
00027      *
00028      * @param tx_timeout    If CAN frames of this message are not delivered to the bus
00029      *                      in this amount of time, they will be discarded. Default value
00030      *                      is good enough for rather high-frequency, high-priority messages.
00031      *
00032      * @param max_transfer_interval     Maximum expected transfer interval. It's absolutely safe
00033      *                                  to leave default value here. It just defines how soon the
00034      *                                  Transfer ID  tracking objects associated with this message type
00035      *                                  will be garbage collected by the library if it's no longer
00036      *                                  being published.
00037      */
00038     explicit Publisher(INode& node, MonotonicDuration tx_timeout = getDefaultTxTimeout(),
00039                        MonotonicDuration max_transfer_interval = TransferSender::getDefaultMaxTransferInterval())
00040         : BaseType (node, tx_timeout, max_transfer_interval)
00041     {
00042 #if UAVCAN_DEBUG
00043         UAVCAN_ASSERT(getTxTimeout() == tx_timeout);  // Making sure default values are OK
00044 #endif
00045         StaticAssert<DataTypeKind(DataType::DataTypeKind) == DataTypeKindMessage>::check();
00046     }
00047 
00048     /**
00049      * Broadcast the message.
00050      * Returns negative error code.
00051      */
00052     int broadcast(const DataType& message)
00053     {
00054         return BaseType::publish(message, TransferTypeMessageBroadcast, NodeID::Broadcast);
00055     }
00056 
00057     /**
00058      * Warning: You probably don't want to use this method; it's for advanced use cases like
00059      * e.g. network time synchronization. Use the overloaded method with fewer arguments instead.
00060      * This overload allows to explicitly specify Transfer ID.
00061      * Returns negative error code.
00062      */
00063     int broadcast(const DataType& message, TransferID tid)
00064     {
00065         return BaseType::publish(message, TransferTypeMessageBroadcast, NodeID::Broadcast, tid);
00066     }
00067 
00068     static MonotonicDuration getDefaultTxTimeout() { return MonotonicDuration::fromMSec(100); }
00069 
00070     /**
00071      * Init method can be called prior first publication, but it's not necessary
00072      * because the publisher can be automatically initialized ad-hoc.
00073      */
00074     using BaseType::init;
00075 
00076     using BaseType::allowAnonymousTransfers;
00077     using BaseType::getTransferSender;
00078     using BaseType::getMinTxTimeout;
00079     using BaseType::getMaxTxTimeout;
00080     using BaseType::getTxTimeout;
00081     using BaseType::setTxTimeout;
00082     using BaseType::getPriority;
00083     using BaseType::setPriority;
00084     using BaseType::getNode;
00085 };
00086 
00087 }
00088 
00089 #endif // UAVCAN_NODE_PUBLISHER_HPP_INCLUDED