[gnoduino: 94/237] Created an abstract base class UDP to match the Client and Server classes, and reworked the Ethernet

[Lucian Langa <lucilanga src gnome org>]

commit 615dd9163effc81fe034e170704f7e92d1cf2be2
Author: amcewen <amcewen bcs org uk>
Date:   Tue Aug 30 21:27:31 2011 +0100

    Created an abstract base class UDP to match the Client and Server classes, and reworked the Ethernet library to use it and derive EthernetUDP.

 arduino/cores/arduino/Udp.h |   90 +++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 90 insertions(+), 0 deletions(-)
---
diff --git a/arduino/cores/arduino/Udp.h b/arduino/cores/arduino/Udp.h
new file mode 100644
index 0000000..1fb9cd3
--- /dev/null
+++ b/arduino/cores/arduino/Udp.h
@@ -0,0 +1,90 @@
+/*
+ *  Udp.cpp: Library to send/receive UDP packets.
+ *
+ * NOTE: UDP is fast, but has some important limitations (thanks to Warren Gray for mentioning these)
+ * 1) UDP does not guarantee the order in which assembled UDP packets are received. This
+ * might not happen often in practice, but in larger network topologies, a UDP
+ * packet can be received out of sequence. 
+ * 2) UDP does not guard against lost packets - so packets *can* disappear without the sender being
+ * aware of it. Again, this may not be a concern in practice on small local networks.
+ * For more information, see http://www.cafeaulait.org/course/week12/35.html
+ *
+ * MIT License:
+ * Copyright (c) 2008 Bjoern Hartmann
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * bjoern cs stanford edu 12/30/2008
+ */
+
+#ifndef udp_h
+#define udp_h
+
+#include <Stream.h>
+#include <IPAddress.h>
+
+class UDP : public Stream {
+
+public:
+  virtual uint8_t begin(uint16_t) =0;	// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
+  virtual void stop() =0;  // Finish with the UDP socket
+
+  // Sending UDP packets
+  
+  // Start building up a packet to send to the remote host specific in ip and port
+  // Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
+  virtual int beginPacket(IPAddress ip, uint16_t port) =0;
+  // Start building up a packet to send to the remote host specific in host and port
+  // Returns 1 if successful, 0 if there was a problem resolving the hostname or port
+  virtual int beginPacket(const char *host, uint16_t port) =0;
+  // Finish off this packet and send it
+  // Returns 1 if the packet was sent successfully, 0 if there was an error
+  virtual int endPacket() =0;
+  // Write a single byte into the packet
+  virtual size_t write(uint8_t) =0;
+  // Write a string of characters into the packet
+  virtual size_t write(const char *str) =0;
+  // Write size bytes from buffer into the packet
+  virtual size_t write(const uint8_t *buffer, size_t size) =0;
+
+  // Start processing the next available incoming packet
+  // Returns the size of the packet in bytes, or 0 if no packets are available
+  virtual int parsePacket() =0;
+  // Number of bytes remaining in the current packet
+  virtual int available() =0;
+  // Read a single byte from the current packet
+  virtual int read() =0;
+  // Read up to len bytes from the current packet and place them into buffer
+  // Returns the number of bytes read, or 0 if none are available
+  virtual int read(unsigned char* buffer, size_t len) =0;
+  // Read up to len characters from the current packet and place them into buffer
+  // Returns the number of characters read, or 0 if none are available
+  virtual int read(char* buffer, size_t len) =0;
+  // Return the next byte from the current packet without moving on to the next byte
+  virtual int peek() =0;
+  virtual void flush() =0;	// Finish reading the current packet
+
+  // Return the IP address of the host who sent the current incoming packet
+  virtual IPAddress remoteIP() =0;
+  // Return the port of the host who sent the current incoming packet
+  virtual uint16_t remotePort() =0;
+protected:
+  uint8_t* rawIPAddress(IPAddress& addr) { return addr.raw_address(); };
+};
+
+#endif