Files
test2/intern/ghost/intern/GHOST_PathUtils.cc
2024-02-19 15:59:59 +01:00

105 lines
2.9 KiB
C++

/* SPDX-FileCopyrightText: 2010 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
/** \file
* \ingroup GHOST
*/
#include <cassert>
#include <cctype>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include "GHOST_Debug.hh"
#include "GHOST_PathUtils.hh"
#include "GHOST_Types.h"
/* Based on: https://stackoverflow.com/a/2766963/432509 */
using DecodeState_e = enum DecodeState_e {
/** Searching for an ampersand to convert. */
STATE_SEARCH = 0,
/** Convert the two proceeding characters from hex. */
STATE_CONVERTING
};
void GHOST_URL_decode(char *buf_dst, int buf_dst_size, const char *buf_src, const int buf_src_len)
{
GHOST_ASSERT(strnlen(buf_src, buf_src_len) == buf_src_len, "Incorrect length");
DecodeState_e state = STATE_SEARCH;
uint ascii_character;
memset(buf_dst, 0, buf_dst_size);
for (uint i = 0; i < buf_src_len; i++) {
switch (state) {
case STATE_SEARCH: {
if (buf_src[i] != '%') {
strncat(buf_dst, &buf_src[i], 1);
assert(int(strlen(buf_dst)) < buf_dst_size);
break;
}
/* We are now converting. */
state = STATE_CONVERTING;
break;
}
case STATE_CONVERTING: {
/* Create a buffer to hold the hex. For example, if `%20`,
* this buffer would hold 20 (in ASCII). */
char temp_num_buf[3];
/* Conversion complete (i.e. don't convert again next iteration). */
state = STATE_SEARCH;
/* Ensure both characters are hexadecimal. */
bool both_digits = true;
for (int j = 0; j < 2; j++) {
/* `isxdigit` serves to early null terminate the string too. */
const char hex_char = buf_src[i + j];
if (!isxdigit(hex_char)) {
both_digits = false;
break;
}
temp_num_buf[j] = hex_char;
}
if (!both_digits) {
break;
}
/* Convert two hexadecimal characters into one character. */
temp_num_buf[2] = '\0';
sscanf(temp_num_buf, "%x", &ascii_character);
/* Ensure we aren't going to overflow. */
assert(int(strlen(buf_dst)) < buf_dst_size);
/* Concatenate this character onto the output. */
strncat(buf_dst, (char *)&ascii_character, 1);
/* Skip the next character. */
i++;
break;
}
}
}
}
char *GHOST_URL_decode_alloc(const char *buf_src, const int buf_src_len)
{
/* Assume one character of encoded URL can be expanded to 4 chars max. */
const size_t decoded_size_max = 4 * buf_src_len + 1;
char *buf_dst = (char *)malloc(decoded_size_max);
GHOST_URL_decode(buf_dst, decoded_size_max, buf_src, buf_src_len);
const size_t decoded_size = strlen(buf_dst) + 1;
if (decoded_size != decoded_size_max) {
char *buf_dst_trim = (char *)malloc(decoded_size);
memcpy(buf_dst_trim, buf_dst, decoded_size);
free(buf_dst);
buf_dst = buf_dst_trim;
}
return buf_dst;
}