vitastor/src/base64.cpp

127 lines
3.4 KiB
C++

// Copyright (c) Vitaliy Filippov, 2019+
// License: VNPL-1.1 (see README.md for details)
#include <assert.h>
#include "base64.h"
std::string base64_encode(const std::string &in)
{
std::string out;
unsigned val = 0;
int valb = -6;
for (unsigned char c: in)
{
val = (val << 8) + c;
valb += 8;
while (valb >= 0)
{
out.push_back("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[(val>>valb) & 0x3F]);
valb -= 6;
}
}
if (valb > -6)
out.push_back("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[((val<<8)>>(valb+8)) & 0x3F]);
while (out.size() % 4)
out.push_back('=');
return out;
}
static char T[256] = { 0 };
std::string base64_decode(const std::string &in)
{
std::string out;
if (T[0] == 0)
{
for (int i = 0; i < 256; i++)
T[i] = -1;
for (int i = 0; i < 64; i++)
T[(unsigned char)("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"[i])] = i;
}
unsigned val = 0;
int valb = -8;
for (unsigned char c: in)
{
if (T[c] == -1)
break;
val = (val<<6) + T[c];
valb += 6;
if (valb >= 0)
{
out.push_back(char((val >> valb) & 0xFF));
valb -= 8;
}
}
return out;
}
uint64_t stoull_full(const std::string & str, int base)
{
if (isspace(str[0]))
{
return 0;
}
char *end = NULL;
uint64_t r = strtoull(str.c_str(), &end, base);
if (end != str.c_str()+str.length())
{
return 0;
}
return r;
}
uint64_t parse_size(std::string size_str)
{
if (!size_str.length())
{
return 0;
}
uint64_t mul = 1;
char type_char = tolower(size_str[size_str.length()-1]);
if (type_char == 'k' || type_char == 'm' || type_char == 'g' || type_char == 't')
{
if (type_char == 'k')
mul = (uint64_t)1<<10;
else if (type_char == 'm')
mul = (uint64_t)1<<20;
else if (type_char == 'g')
mul = (uint64_t)1<<30;
else /*if (type_char == 't')*/
mul = (uint64_t)1<<40;
size_str = size_str.substr(0, size_str.length()-1);
}
uint64_t size = stoull_full(size_str, 0) * mul;
if (size == 0 && size_str != "0" && (size_str != "" || mul != 1))
{
return UINT64_MAX;
}
return size;
}
static uint64_t size_thresh[] = { (uint64_t)1024*1024*1024*1024, (uint64_t)1024*1024*1024, (uint64_t)1024*1024, 1024, 0 };
static uint64_t size_thresh_d[] = { (uint64_t)1000000000000, (uint64_t)1000000000, (uint64_t)1000000, (uint64_t)1000, 0 };
static const int size_thresh_n = sizeof(size_thresh)/sizeof(size_thresh[0]);
static const char *size_unit = "TGMKB";
std::string format_size(uint64_t size, bool nobytes)
{
uint64_t *thr = nobytes ? size_thresh_d : size_thresh;
char buf[256];
for (int i = 0; i < size_thresh_n; i++)
{
if (size >= thr[i] || i >= size_thresh_n-1)
{
double value = thr[i] ? (double)size/thr[i] : size;
int l = snprintf(buf, sizeof(buf), "%.1f", value);
assert(l < sizeof(buf)-2);
if (buf[l-1] == '0')
l -= 2;
buf[l] = i == size_thresh_n-1 && nobytes ? 0 : ' ';
buf[l+1] = i == size_thresh_n-1 && nobytes ? 0 : size_unit[i];
buf[l+2] = 0;
break;
}
}
return std::string(buf);
}