C++字符数字的编码(Encode)与解码(Decode)

  1 #include <iostream>
  3 #include <memory.h>
  4 #include <string.h>
  5 using namespace std;
  6 
  7 #define ENCODE(buf, size, offset, data)  8     if ((NULL == buf) || (0 == size))  9     { 10     return -1; 11     } 12     if (offset + sizeof(data) > size) 13     { 14     return -1; 15     } 16     { 17     uint8_t *p = (uint8_t*)buf; 18     p=p+offset;  19     memcpy(p,&data,sizeof(data));  20     offset = offset + sizeof(data);  21     }
 22 
 23 #define DECODE(buf, size, offset, data) 24     if ((NULL == buf) || (0 == size)) 25     { 26     return -1; 27     } 28     if (offset + sizeof(data) > size) 29     { 30     return -1; 31     } 32     { 33     uint8_t *p = (uint8_t*)buf; 34     p=p+offset;  35     memcpy(&data,p,sizeof(data));  36     offset = offset + sizeof(data);  37     }
 38 
 39 #define ENCODE_STR(buf, size, offset, data, length) 40     if ((NULL == buf) || (0 == size) || (0 >= length) ) 41     { 42     return -1; 43     } 44     if (offset + length > size) 45     { 46     return -1; 47     } 48     { 49     uint8_t *p = (uint8_t*)buf; 50     p=p+offset;  51     memcpy(p,data,length);  52     offset = offset+ length;  53     }
 54 
 55 #define DECODE_STR(buf, size, offset, data, length) 56     if ((NULL == buf) || (0 == size) || (0 >= length) ) 57     { 58     return -1; 59     } 60     if (offset + length > size) 61     { 62     return -1; 63     } 64     { 65     uint8_t *p = (uint8_t*)buf; 66     p=p+offset;  67     memcpy(data,p,length);  68     offset = offset+ length;  69     }
 70 
 71 enum{
 72     enmMaxMsgLength = 1024,
 73     enmMaxNameLength = 20
 74 };
 75 
 76 class Msg{
 77     int iAge;
 78     char szName[enmMaxNameLength];
 79     double dScore;
 80 public:
 81     Msg()
 82     {
 83 
 84     }
 85     Msg(int age,const char* name,double score):iAge(age),dScore(score)
 86     {
 87         strcpy(szName,name);
 88     }
 89     virtual ~Msg(){}
 90     virtual int encode(char *buf)
 91     {
 92         size_t offset = 0;
 93         memset(buf,‘0‘,enmMaxMsgLength);
 94         ENCODE(buf,enmMaxMsgLength,offset,iAge);
 95         ENCODE_STR(buf,enmMaxMsgLength,offset,szName,enmMaxNameLength);
 96         ENCODE(buf,enmMaxMsgLength,offset,dScore);
 97         return offset;
 98     };
 99     virtual int decode(char *buf,size_t bufSize)
100     {
101         size_t offset = 0;
102         DECODE(buf,bufSize,offset,iAge);
103         DECODE_STR(buf,bufSize,offset,szName,enmMaxNameLength);
104         DECODE(buf,bufSize,offset,dScore);
105         return offset;
106     }
107     void display()
108     {
109         cout<<iAge<<" "<<szName<<" "<<dScore<<endl;
110     }
111 };
112 
113 int main(int argc, char* argv[])
114 {
115     size_t offset = 0;
116     char buf[enmMaxMsgLength],*recv = NULL;
117     Msg msg(23,"hwllo world",23.69),msg1;
118     msg.display();
119     offset = msg.encode(buf);
120     cout<<offset<<endl;
121     cout<<sizeof(Msg)<<endl;
122     recv = new char[offset];
123     memcpy(recv,buf,offset);
124     msg1.decode(recv,offset);
125     msg1.display();
126     return 0;
127 }