Documented URStream and TCPSocket

include/ur_rtde_driver/comm/stream.h

@@ -32,13 +32,77 @@ namespace ur_driver
 {
 namespace comm
 {
+/*!
+ * \brief The stream is an abstraction of the TCPSocket that offers reading a full UR data package
+ * out of the socket. This means, it has to have some knowledge about the package structure to
+ * peek at the field defining the package length. This is why it is templated with the package
+ * header type.
+ */
 template <typename HeaderT>
 class URStream : public TCPSocket
 {
-private:
-  std::string host_;
-  int port_;
-  std::mutex write_mutex_, read_mutex_;
+public:
+  /*!
+   * \brief Creates a new URStream object. Note, that this does not immediately open the socket,
+   * that has to be done separately by calling the connect() function.
+   *
+   * \param host IP address of the remote host
+   * \param port Port on which the socket shall be connected
+   */
+  URStream(std::string& host, int port) : host_(host), port_(port)
+  {
+  }
+
+  /*!
+   * \brief Connects to the configured socket.
+   *
+   * \returns True on success, false if connection could not be established.
+   */
+  bool connect()
+  {
+    return TCPSocket::setup(host_, port_);
+  }
+
+  /*!
+   * \brief Disconnects from the configured socket.
+   */
+  void disconnect()
+  {
+    LOG_INFO("Disconnecting from %s:%d", host_.c_str(), port_);
+    TCPSocket::close();
+  }
+
+  /*!
+   * \brief Returns whether the underlying socket is currently closed
+   */
+  bool closed()
+  {
+    return getState() == SocketState::Closed;
+  }
+
+  /*!
+   * \brief Reads a full UR package out of a socket. For this, it looks into the package and reads
+   * the byte length from the socket directly. It returns as soon as all bytes for the package are
+   * read from the socket.
+   *
+   * \param[out] buf The byte buffer where the content shall be stored
+   * \param[in] buf_len Number of bytes allocated for the buffer
+   * \param[out] read Number of bytes actually read from the socket
+   *
+   * \returns True on success, false on error, e.g. the buffer is smaller than the package size.
+   */
+  bool read(uint8_t* buf, const size_t buf_len, size_t& read);
+
+  /*!
+   * \brief Writes directly to the underlying socket (with a mutex guard)
+   *
+   * \param[in] buf Byte stream that should be sent
+   * \param[in] buf_len Number of bytes in buffer
+   * \param[out] written Number of bytes actually written to the socket.
+   *
+   * \returns false if sending went wrong
+   */
+  bool write(const uint8_t* buf, const size_t buf_len, size_t& written);
 
 protected:
   virtual bool open(int socket_fd, struct sockaddr* address, size_t address_len)
@@ -46,39 +110,21 @@ protected:
     return ::connect(socket_fd, address, address_len) == 0;
   }
 
-public:
-  URStream(std::string& host, int port) : host_(host), port_(port)
-  {
-  }
-
-  bool connect()
-  {
-    return TCPSocket::setup(host_, port_);
-  }
-  void disconnect()
-  {
-    LOG_INFO("Disconnecting from %s:%d", host_.c_str(), port_);
-    TCPSocket::close();
-  }
-
-  bool closed()
-  {
-    return getState() == SocketState::Closed;
-  }
-
-  bool read(uint8_t* buf, size_t buf_len, size_t& read);
-  bool write(const uint8_t* buf, size_t buf_len, size_t& written);
+private:
+  std::string host_;
+  int port_;
+  std::mutex write_mutex_, read_mutex_;
 };
 
 template <typename HeaderT>
-bool URStream<HeaderT>::write(const uint8_t* buf, size_t buf_len, size_t& written)
+bool URStream<HeaderT>::write(const uint8_t* buf, const size_t buf_len, size_t& written)
 {
   std::lock_guard<std::mutex> lock(write_mutex_);
   return TCPSocket::write(buf, buf_len, written);
 }
 
 template <typename HeaderT>
-bool URStream<HeaderT>::read(uint8_t* buf, size_t buf_len, size_t& total)
+bool URStream<HeaderT>::read(uint8_t* buf, const size_t buf_len, size_t& total)
 {
   std::lock_guard<std::mutex> lock(read_mutex_);
 

include/ur_rtde_driver/comm/tcp_socket.h

@@ -36,6 +36,9 @@ enum class SocketState
   Closed
 };
 
+/*!
+ * \brief Class for TCP socket abstraction
+ */
 class TCPSocket
 {
 private:
@@ -66,12 +69,47 @@ public:
   }
   bool setSocketFD(int socket_fd);
 
+  /*!
+   * \brief Determines the IP address of the local machine
+   *
+   * \returns The IP address of the local machine.
+   */
   std::string getIP();
 
+  /*!
+   * \brief Reads one byte from the socket
+   *
+   * \param character[out] Target buffer
+   *
+   * \returns True on success, false otherwise
+   */
   bool read(char* character);
-  bool read(uint8_t* buf, size_t buf_len, size_t& read);
-  bool write(const uint8_t* buf, size_t buf_len, size_t& written);
 
+  /*!
+   * \brief Reads data from the socket
+   *
+   * \param[out] buf Buffer where the data shall be stored
+   * \param[in] buf_len Number of bytes allocated for the buffer
+   * \param[out] read Number of bytes actually read
+   *
+   * \returns True on success, false otherwise
+   */
+  bool read(uint8_t* buf, const size_t buf_len, size_t& read);
+
+  /*!
+   * \brief Writes to the socket
+   *
+   * \param[in] buf Buffer of bytes to write
+   * \param[in] buf_len Number of bytes in the buffer
+   * \param[out] written Number of bytes actually written
+   *
+   * \returns True on success, false otherwise
+   */
+  bool write(const uint8_t* buf, const size_t buf_len, size_t& written);
+
+  /*!
+   * \brief Closes the connection to the socket.
+   */
   void close();
 };
 }  // namespace comm

src/comm/tcp_socket.cpp

@@ -144,7 +144,7 @@ bool TCPSocket::read(char* character)
   return read((uint8_t*)character, 1, read_chars);
 }
 
-bool TCPSocket::read(uint8_t* buf, size_t buf_len, size_t& read)
+bool TCPSocket::read(uint8_t* buf, const size_t buf_len, size_t& read)
 {
   read = 0;
 
@@ -165,7 +165,7 @@ bool TCPSocket::read(uint8_t* buf, size_t buf_len, size_t& read)
   return true;
 }
 
-bool TCPSocket::write(const uint8_t* buf, size_t buf_len, size_t& written)
+bool TCPSocket::write(const uint8_t* buf, const size_t buf_len, size_t& written)
 {
   written = 0;