ManchesterMsg.h

00001 /*
00002  ******************************************************************************
00003  * @file    ManchesterMsg.h
00004  * @author  Zoltan Hudak
00005  * @version
00006  * @date    2017-May-16
00007  * @brief   Message container
00008  ******************************************************************************
00009  * @attention
00010  *
00011  * <h2><center>&copy; COPYRIGHT(c) 2017 Zoltan Hudak <hudakz@outlook.com>
00012  *
00013  * All rights reserved.
00014 
00015  This program is free software: you can redistribute it and/or modify
00016  it under the terms of the GNU General Public License as published by
00017  the Free Software Foundation, either version 3 of the License, or
00018  (at your option) any later version.
00019 
00020  This program is distributed in the hope that it will be useful,
00021  but WITHOUT ANY WARRANTY; without even the implied warranty of
00022  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00023  GNU General Public License for more details.
00024 
00025  You should have received a copy of the GNU General Public License
00026  along with this program.  If not, see <http://www.gnu.org/licenses/>.
00027  */
00028 #ifndef MANCHESTERMSG_H
00029 #define MANCHESTERMSG_H
00030 
00031 //#define DEBUG 1
00032 
00033 /** ManchesterMsg class
00034  */
00035 class   ManchesterMsg
00036 {
00037     size_t  _max;   // Max length (capacity) of data field in bytes
00038 
00039 public:
00040     char*   data;   // Data field
00041     size_t  len;    // Length of data in bytes
00042 
00043     /** Creates empty message of specified capacity.
00044      */
00045     ManchesterMsg(size_t max) : _max(max), data(new char[max]) { len = 0; }
00046 
00047     ~ ManchesterMsg(void)   { delete[] data; }
00048 
00049     /** Copy constructor.
00050      */
00051     ManchesterMsg(const ManchesterMsg& msg) { len = msg.len; memcpy(data, msg.data, msg.len); }
00052 
00053     /** Returns message maximum length (capacity)
00054      */
00055     size_t  maxLen(void)    { return _max; }
00056 
00057     /** Clears message content
00058      */
00059     void    clear(void)     { len = 0; memset(data, 0, _max); }
00060 
00061     /** Inserter operator: Appends data (value) to message
00062      */
00063     template<class T>
00064     ManchesterMsg &operator<<(const T val) {
00065         if(len + sizeof(T) <= _max) {
00066             memcpy(&data[len], &val, sizeof(T));
00067             len += sizeof(T);
00068         }
00069 
00070 #if DEBUG
00071         else {
00072             printf("Error: Cannot append data. Exceeding max data length!\r\n");
00073         }
00074 #endif
00075         return *this;
00076     }
00077 
00078     /** Inserter operator: Appends array of char to message
00079      */
00080     ManchesterMsg &operator<<(const char* str) {
00081         size_t  strLen = strlen(str);
00082         if(len + strLen + 1 <= _max) {
00083             memcpy(data + len, (char*)str, strLen);
00084             len += strLen;
00085             data[len++] = '\0';
00086         }
00087 
00088 #if DEBUG
00089         else {
00090             printf("Error: Cannot append data. Exceeding max data length!\r\n");
00091         }
00092 #endif
00093         return *this;
00094     }
00095 
00096     /** Extractor operator: Extracts data (value) from message
00097      */
00098     template<class T>
00099     ManchesterMsg &operator>>(T& val) {
00100         if(sizeof(T) <= len) {
00101             val = *reinterpret_cast < T * > (&data[0]);
00102             len -= sizeof(T);
00103             memcpy(data, data + sizeof(T), len);
00104         }
00105 
00106 #if DEBUG
00107         else {
00108             printf("Error: Cannot extract data. Exceeding data length!\r\n");
00109         }
00110 #endif
00111         return *this;
00112     }
00113 
00114     /** Extractor operator: Extracts array of char from message
00115      */
00116     ManchesterMsg &operator>>(char* str) {
00117         size_t  strLen = strlen(data);
00118         if(strLen <= len) {
00119             memcpy(str, data, strLen + 1);
00120             len -= (strLen + 1);
00121             memcpy(data, data + strLen + 1, len);
00122         }
00123 
00124 #if DEBUG
00125         else {
00126             printf("Error: Cannot extract data. Exceeding data length!\r\n");
00127         }
00128 #endif
00129         return *this;
00130     }
00131 };
00132 #endif // MANCHESTERMSG_H
00133