将昨天的php代码改造成C++
/*base_64.h文件*/
#ifndef BASE_64_H
#define BASE_64_H
/**
* Base64 编码/解码
* @author liruixing
*/
class Base64{
private:
std::string _base64hash;
int _encode_data;
int _decode_data;
int _width;
bool _debug;
std::string _encode_result,_decode_result;
void _encode_func(int bin,int bytes = 3);
void _decode_func(int bin,int bytes = 2);
public:
Base64()
{
_base64hash = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; /*这是Base64编码使用的标准字典*/
_encode_data = 0xfc0000;
_decode_data = 0xff0000;
_width = 0xffffff;
_debug = false;
}
/**
* 这里必须是unsigned类型，否则编码中文的时候出错
*/
std::string Encode(const unsigned char * str,int bytes);
std::string Decode(const char *str,int bytes);
void Debug(bool open = true);
};
#endif
上面定义了一个头文件，定义base64的类
/*base_64.cpp文件*/
#include <iostream>
#include <string>
#include <cstring>
#include "base_64.h"
void Base64::_encode_func(int bin,int bytes) {
int num = 3,matches = 0,bits1=0,bits2=0,result=0;
bits1 = (num - bytes) * 6;
bits2 = bytes * 6;
matches = _encode_data >> bits1;
while( matches ) {
result = bin & matches;
result = result >> bits2;
bytes--;
bits1 = (num - bytes) * 6;
bits2 = bytes * 6;
matches = _encode_data >> bits1;
if(_debug) {
printf("result = %d , hex = %x\n",result,result);
}
_encode_result += _base64hash[result];
}
}
void Base64::_decode_func(int bin,int bytes) {
int num = 2,matches = 0,bits1=0,bits2=0,result=0;
bits1 = (num - bytes) * 8;
bits2 = bytes * 8;
matches = _decode_data >> bits1;
while( matches ) {
result = bin & matches;
result = result >> bits2;
bytes--;
bits1 = (num - bytes) * 8;
bits2 = bytes * 8;
matches = _decode_data >> bits1;
if(_debug) {
printf("result = %d , hex = %x\n",result,result);
}
_decode_result += (char)result;
}
}
std::string Base64::Encode(const unsigned char * str,int bytes) {
int num = 0,bin = 0,i;
if(bytes >= 3) {
for(i=0;i<bytes;i++) {
bin = bin << 8;
if(_debug) {
printf("bin = %d , hex = %x\n",bin,str[i]);
}
bin = bin | (int)str[i];
if((i+1)%3 == 0) {
_encode_func(bin,3);
bin = 0;
}
}
}
if(bytes%3 == 1) {
bin = (int)str[bytes-1];
bin = bin << 4;
_encode_func(bin,1);
_encode_result += "==";
} else if(bytes%3 == 2) {
bin = (int)str[bytes-2];
bin = bin << 8;
bin = bin | (int)str[bytes-1];
bin = bin << 2;
_encode_func(bin,2);
_encode_result += "=";
}
return _encode_result;
}
std::string Base64::Decode(const char *str,int bytes) {
//解码表
const char DecodeTable[] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
62, // ‘+‘
0, 0, 0,
63, // ‘/‘
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // ‘0‘-‘9‘
0, 0, 0, 0, 0, 0, 0,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // ‘A‘-‘Z‘
0, 0, 0, 0, 0, 0,
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // ‘a‘-‘z‘
};
int bin = 0,i,pos=0;
char *_decode_string = new char[bytes];
strcpy(_decode_string,str);
while(_decode_string[bytes-1] == ‘=‘)
{
_decode_string[bytes-1] = ‘\0‘;
bytes--;
}
if(bytes >= 4) {
for(i=0;i<bytes;i++) {
bin = bin << 6;
pos = DecodeTable[(int)_decode_string[i]];
if(_debug) {
printf("bin = %d , binary = %x-----ch = %c\n",bin,pos,_decode_string[i]);
}
bin = bin | pos;
if((i+1)%4 == 0) {
_decode_func(bin);
bin = 0;
}
}
}
if(bytes%4 == 3) {
bin = 0;
if(_debug) {
printf("bin = %x , ch = %c\n",bin, _decode_string[bytes-3]);
}
pos = DecodeTable[(int)_decode_string[bytes-3]];
bin = bin | pos;
bin = bin << 6;
if(_debug) {
printf("bin = %x , ch = %c\n",bin, _decode_string[bytes-2]);
}
pos = DecodeTable[(int)_decode_string[bytes-2]];
bin = bin | pos;
bin = bin << 6;
if(_debug) {
printf("bin = %x , ch = %c\n",bin, _decode_string[bytes-1]);
}
pos = DecodeTable[(int)_decode_string[bytes-1]];
bin = bin | pos;
if(_debug) {
printf("bin = %x\n",bin);
}
bin = bin >> 2;
_decode_func(bin,1);
} else if(bytes%4 == 2) {
bin = 0;
if( _debug ) {
printf("bin = %x , ch = %c\n",bin, _decode_string[bytes-2]);
}
pos = DecodeTable[(int)_decode_string[bytes-2]];
bin = bin | pos;
bin = bin << 6;
if( _debug ) {
printf("bin = %x , ch = %c\n",bin, _decode_string[bytes-1]);
}
pos = DecodeTable[(int)_decode_string[bytes-1]];
bin = bin | pos;
bin = bin >> 4;
_decode_func(bin,0);
}
delete [] _decode_string;
return _decode_result;
}
void Base64::Debug(bool open) {
_debug = open;
}
base64类中方法的定义实际上是在base_64.cpp中进行的。
上面的两个文件用来生成一个静态链接库：libbase_64.a
g++ -c base_64.cpp ar rs libbase_64.a base_64.o
下面来进行实际的测试：
/*main.cppe文件*/
#include <iostream>
#include "base_64.h"
using namespace std;
int main()
{
unsigned char str[] = "这是一条测试数据：http://img.v.cmcm.com/7dd6e6d7-0c2d-5a58-a072-71f828b94cbc_crop_216x150.jpg";
string normal,encoded;
int i,len = sizeof(str)-1;
Base64 *base = new Base64();
encoded = base->Encode(str,len);
cout << "base64 encode : " << encoded << endl;
len = encoded.length();
const char * str2 = encoded.c_str();
normal = base->Decode(str2,len);
cout << "base64 decode : " << normal <<endl;
return 0;
}
编译代码并运行
g++ main.cpp -L. -lbase_64 -Ibase_64 -o main ./main
输出效果：
在改造昨天的php代码过程中，还参考了cnblogs上洞庭散人的代码实现的。
参考：
http://www.cnblogs.com/phinecos/archive/2008/10/10/1308272.html
时间： 2024-10-07 19:14:24