uri_template_string.c

/*
  +----------------------------------------------------------------------+
  | See LICENSE file for further copyright information                   |
  +----------------------------------------------------------------------+
  | Authors: Ioseb Dzmanashvili <ioseb.dzmanashvili@gmail.com>           |
  +----------------------------------------------------------------------+
*/

#include "php_uri_template.h"

#define MAX_ONE_BYTE_CHAR   0x7f
#define MAX_TWO_BYTE_CHAR   0x7ff
#define MAX_THREE_BYTE_CHAR 0xffff
#define MAX_FOUR_BYTE_CHAR  0x1fffff

static unsigned char hexchars[]       = "0123456789ABCDEF";
static unsigned char badchar[]        = {239, 191, 189};
static unsigned char urlchars[3][128] = {
	{
		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,   0,   0, '-', '.',   0,
		'0', '1', '2', '3', '4', '5', '6', '7',
		'8', '9',   0,   0,   0,   0,   0,   0,
		0,   'A', 'B', 'C', 'D', 'E', 'F', 'G',
		'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
		'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
		'X', 'Y', 'Z',   0,   0,   0,   0, '_',
		0,   'a', 'b', 'c', 'd', 'e', 'f', 'g',
		'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
		'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
		'x', 'y', 'z',   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, '#', '$',   0, '&',   0,
		'(', ')', '*', '+', ',', '-', '.', '/',
		'0', '1', '2', '3', '4', '5', '6', '7',
		'8', '9', ':', ';',   0, '=',   0, '?',
		'@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
		'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
		'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
		'X', 'Y', 'Z', '[',   0, ']',   0, '_',
		0,   'a', 'b', 'c', 'd', 'e', 'f', 'g',
		'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
		'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
		'x', 'y', 'z',   0,   0,   0, '~',  0
	}, {
		0,     0,   0,   0,   0,   0,   0,   0,
		0,     0,   0,   0,   0,   0,   0,   0,
		0,     0,   0,   0,   0,   0,   0,   0,
		0,     0,   0,   0,   0,   0,   0,   0,
		0,   '!',   0, '#', '$',   0, '&','\'',
		'(', ')', '*', '+', ',', '-', '.', '/',
		'0', '1', '2', '3', '4', '5', '6', '7',
		'8', '9', ':', ';',   0, '=',   0, '?',
		'@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
		'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
		'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
		'X', 'Y', 'Z', '[',   0, ']',   0, '_',
		0,   'a', 'b', 'c', 'd', 'e', 'f', 'g',
		'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
		'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
		'x', 'y', 'z',   0,   0,   0, '~',  0
	}
};

inline static void append_encoded(smart_str *dest, const char *source, size_t num)
{
	unsigned char c;
	int i;

	for (i = 0; i < num; i++) {
		c = *source++;  

		smart_str_appendc(dest, '%');
		smart_str_appendc(dest, hexchars[c >> 4]);
		smart_str_appendc(dest, hexchars[c & 15]);
	}
}

inline static void utf8_append_badchar(smart_str *dest)
{
	int i;

	for (i = 0; i < 3; i++) {
		smart_str_appendc(dest, '%');
		smart_str_appendc(dest, hexchars[badchar[i] >> 4]);
		smart_str_appendc(dest, hexchars[badchar[i] & 15]);
	}
}

static char *utf8_copy_char(smart_str *dest, char *source)
{
	unsigned char first = *source;
	unsigned char second = *(source + 1) ^ 0x80;
	unsigned char third;
	unsigned char fourth;

	if (second & 0xC0) {
		utf8_append_badchar(dest);
		return ++source;
	}

	if (first < 0xE0) {
		if (first < 0xC0) {
			utf8_append_badchar(dest);
			return ++source;
		}

		if ((((first << 6) | second) 
				& MAX_TWO_BYTE_CHAR) <= MAX_ONE_BYTE_CHAR) {
			utf8_append_badchar(dest);
			return ++source;
		}

		append_encoded(dest, source, 2);
		return source += 2;
	}

	third = *(source + 2) ^ 0x80;
	if (third & 0xC0) {
		utf8_append_badchar(dest);
		return ++source;
	}

	if (first < 0xF0) {
		if ((((((first << 6) | second) << 6) | third) 
				& MAX_THREE_BYTE_CHAR) <= MAX_TWO_BYTE_CHAR) {
			utf8_append_badchar(dest);
			return ++source;
		}

		append_encoded(dest, source, 3);
		return source += 3;
	}

	fourth = *(source + 3) ^ 0x80;
	if (fourth & 0xC0) {
		utf8_append_badchar(dest);
		return ++source;
	}
	
	if (first < 0xF8) {
		if (((((((first << 6 | second) << 6) | third) << 6) | fourth)
				& MAX_FOUR_BYTE_CHAR) <= MAX_THREE_BYTE_CHAR) {
			utf8_append_badchar(dest);
			return ++source;
		}

		append_encoded(dest, source, 4);
		return source += 4;
	}
	
	return source;
}

void uri_template_substr_copy(smart_str *dest, char *source, size_t num, int allowed_chars)
{
	unsigned char c;
	
	if (num <= 0) {
		return;
	}

	while (*source && num-- > 0) {
		c = *source;
		
		if (c > 127) {
			source = utf8_copy_char(dest, source);
		} else {
			if (urlchars[allowed_chars][c]) {
				smart_str_appendc(dest, *source);
			} else {
				append_encoded(dest, source, 1);
			}

			source++;
		}
	}
}