MQTTSocket.h

00001 #if !defined(MQTTSOCKET_H)
00002 #define MQTTSOCKET_H
00003 
00004 #include "MQTTmbed.h"
00005 #include <Timer.h>
00006 
00007 class MQTTSocket
00008 {
00009 public:
00010     MQTTSocket(NetworkInterface *anet) : net(anet)
00011     {
00012         open = false;
00013     }
00014     
00015     int connect(char* hostname, int port, int timeout=1000)
00016     {
00017         if (open)
00018             disconnect();
00019         nsapi_error_t rc = mysock.open(net);
00020         open = true;
00021         mysock.set_blocking(true);
00022         mysock.set_timeout((unsigned int)timeout);  
00023         rc = mysock.connect(hostname, port);
00024         mysock.set_blocking(false);  // blocking timeouts seem not to work
00025         return rc;
00026     }
00027 
00028     // common read/write routine, avoiding blocking timeouts
00029     int common(unsigned char* buffer, int len, int timeout, bool read)
00030     {
00031         timer.start();
00032         mysock.set_blocking(false); // blocking timeouts seem not to work
00033         int bytes = 0;
00034         bool first = true;
00035         do 
00036         {
00037             if (first)
00038                 first = false;
00039             else
00040                 wait_ms(timeout < 100 ? timeout : 100);
00041             int rc;
00042             if (read)
00043                 rc = mysock.recv((char*)buffer, len);
00044             else
00045                 rc = mysock.send((char*)buffer, len);
00046             if (rc < 0)
00047             {
00048                 if (rc != NSAPI_ERROR_WOULD_BLOCK)
00049                 {
00050                     bytes = -1;
00051                     break;
00052                 }
00053             } 
00054             else
00055                 bytes += rc;
00056         }
00057         while (bytes < len && timer.read_ms() < timeout);
00058         timer.stop();
00059         return bytes;
00060     }
00061 
00062     /* returns the number of bytes read, which could be 0.
00063        -1 if there was an error on the socket
00064     */
00065     int read(unsigned char* buffer, int len, int timeout)
00066     {
00067         return common(buffer, len, timeout, true);
00068     }
00069 
00070     int write(unsigned char* buffer, int len, int timeout)
00071     {
00072         return common(buffer, len, timeout, false);
00073     }
00074 
00075     int disconnect()
00076     {
00077         open = false;
00078         return mysock.close();
00079     }
00080 
00081     /*bool is_connected()
00082     {
00083         return mysock.is_connected();
00084     }*/
00085 
00086 private:
00087 
00088     bool open;
00089     TCPSocket mysock;
00090     NetworkInterface *net;
00091     Timer timer;
00092 
00093 };
00094 
00095 #endif