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// Copyright 2017 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
// https://github.com/kostya/benchmarks/blob/master/base64/test.c
#include "stdlib.h"
#include "stdio.h"
#include "time.h"
#include <stdint.h>
typedef unsigned int uint;
const char* chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static char decode_table[256];
int encode_size(int size) {
return (int)(size * 4 / 3.0) + 6;
}
int decode_size(int size) {
return (int)(size * 3 / 4.0) + 6;
}
void init_decode_table() {
for (int i = 0; i < 256; i++) {
char ch = (char)i;
char code = -1;
if (ch >= 'A' && ch <= 'Z') code = ch - 0x41;
if (ch >= 'a' && ch <= 'z') code = ch - 0x47;
if (ch >= '0' && ch <= '9') code = ch + 0x04;
if (ch == '+' || ch == '-') code = 0x3E;
if (ch == '/' || ch == '_') code = 0x3F;
decode_table[i] = code;
}
}
#define next_char(x) char x = decode_table[(unsigned char)*str++]; if (x < 0) return 1;
int decode(int size, const char* str, int* out_size, char** output) {
*output = (char*) malloc( decode_size(size) );
char *out = *output;
while (size > 0 && (str[size - 1] == '\n' || str[size - 1] == '\r' || str[size - 1] == '=')) size--;
const char* ends = str + size - 4;
while (1) {
if (str > ends) break;
while (*str == '\n' || *str == '\r') str++;
if (str > ends) break;
next_char(a); next_char(b); next_char(c); next_char(d);
*out++ = (char)(a << 2 | b >> 4);
*out++ = (char)(b << 4 | c >> 2);
*out++ = (char)(c << 6 | d >> 0);
}
int mod = (str - ends) % 4;
if (mod == 2) {
next_char(a); next_char(b);
*out++ = (char)(a << 2 | b >> 4);
} else if (mod == 3) {
next_char(a); next_char(b); next_char(c);
*out++ = (char)(a << 2 | b >> 4);
*out++ = (char)(b << 4 | c >> 2);
}
*out = '\0';
*out_size = out - *output;
return 0;
}
void encode(int size, const char* str, int* out_size, char** output) {
*output = (char*) malloc( encode_size(size) );
char *out = *output;
const char* ends = str + (size - size % 3);
uint n;
while (str != ends) {
uint32_t n = __builtin_bswap32(*(uint32_t*)str);
*out++ = chars[(n >> 26) & 63];
*out++ = chars[(n >> 20) & 63];
*out++ = chars[(n >> 14) & 63];
*out++ = chars[(n >> 8) & 63];
str += 3;
}
int pd = size % 3;
if (pd == 1) {
n = (uint)*str << 16;
*out++ = chars[(n >> 18) & 63];
*out++ = chars[(n >> 12) & 63];
*out++ = '=';
*out++ = '=';
} else if (pd == 2) {
n = (uint)*str++ << 16;
n |= (uint)*str << 8;
*out++ = chars[(n >> 18) & 63];
*out++ = chars[(n >> 12) & 63];
*out++ = chars[(n >> 6) & 63];
*out++ = '=';
}
*out = '\0';
*out_size = out - *output;
}
int main(int argc, char **argv) {
int TRIES;
int arg = argc > 1 ? argv[1][0] - '0' : 3;
switch(arg) {
case 0: return 0; break;
case 1: TRIES = 3; break;
case 2: TRIES = 15; break;
case 3: TRIES = 25; break;
case 4: TRIES = 50; break;
case 5: TRIES = 100; break;
default: printf("error: %d\\n", arg); return -1;
}
init_decode_table();
const int STR_SIZE = 10000000;
char *str = (char*) malloc(STR_SIZE + 1);
for (int i = 0; i < STR_SIZE; i++) { str[i] = 'a'; }
str[STR_SIZE] = '\0';
int s = 0;
clock_t t = clock();
for (int i = 0; i < TRIES; i++) {
char *str2;
int str2_size;
encode(STR_SIZE, str, &str2_size, &str2);
s += str2_size;
free(str2);
}
printf("encode: %d, %.2f\n", s, (float)(clock() - t)/CLOCKS_PER_SEC);
char *str2;
int str2_size;
encode(STR_SIZE, str, &str2_size, &str2);
s = 0;
t = clock();
for (int i = 0; i < TRIES; i++) {
char *str3;
int str3_size;
if (decode(str2_size, str2, &str3_size, &str3) != 0) {
printf("error when decoding");
}
s += str3_size;
free(str3);
}
printf("decode: %d, %.2f\n", s, (float)(clock() - t)/CLOCKS_PER_SEC);
return 0;
}
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