Himi的base64代码

//
// DataHimi.cpp
// Oh!MonsterMR
//
// Created by Himi on 12-3-8.
// Copyright (c) 2012年 Augustimpression. All rights reserved.
// #include "DataBase64Himi.h" static const std::string dataChars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/"; static inline bool baseData(unsigned char c) {
return (isalnum(c) || (c == '+') || (c == '/'));
} std::string himiSaveData(unsigned char const* bytes_to_encode, unsigned int in_len) {
std::string ret;
int i = 0;
int j = 0;
unsigned char char_array_3[3];
unsigned char char_array_4[4]; while (in_len--) {
char_array_3[i++] = *(bytes_to_encode++);
if (i == 3) {
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f; for(i = 0; (i <4) ; i++)
ret += dataChars[char_array_4[i]];
i = 0;
}
} if (i)
{
for(j = i; j < 3; j++)
char_array_3[j] = '\0'; char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f; for (j = 0; (j < i + 1); j++)
ret += dataChars[char_array_4[j]]; while((i++ < 3))
ret += '='; } return ret; } std::string himiParseData(std::string const& encoded_string) {
int in_len = encoded_string.size();
int i = 0;
int j = 0;
int in_ = 0;
unsigned char char_array_4[4], char_array_3[3];
std::string ret; while (in_len-- && ( encoded_string[in_] != '=') && baseData(encoded_string[in_])) {
char_array_4[i++] = encoded_string[in_]; in_++;
if (i ==4) {
for (i = 0; i <4; i++)
char_array_4[i] = dataChars.find(char_array_4[i]); char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; for (i = 0; (i < 3); i++)
ret += char_array_3[i];
i = 0;
}
} if (i) {
for (j = i; j <4; j++)
char_array_4[j] = 0; for (j = 0; j <4; j++)
char_array_4[j] = dataChars.find(char_array_4[j]); char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
} return ret;
}
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