OSCMatch.c

#define OSC_MATCH_ENABLE_2STARS 1
#define OSC_MATCH_ENABLE_NSTARS 1
/*
 Written by John MacCallum, The Center for New Music and Audio Technologies,
 University of California, Berkeley.  Copyright (c) 2009, The Regents of
 the University of California (Regents).
 Permission to use, copy, modify, distribute, and distribute modified versions
 of this software and its documentation without fee and without a signed
 licensing agreement, is hereby granted, provided that the above copyright
 notice, this paragraph and the following two paragraphs appear in all copies,
 modifications, and distributions.
 
 IN NO EVENT SHALL REGENTS BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
 SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS, ARISING
 OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF REGENTS HAS
 BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 REGENTS SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 PURPOSE. THE SOFTWARE AND ACCOMPANYING DOCUMENTATION, IF ANY, PROVIDED
 HEREUNDER IS PROVIDED "AS IS". REGENTS HAS NO OBLIGATION TO PROVIDE
 MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */
#include <string.h>
#include "OSCMatch.h"

static int osc_match_star(const char *pattern, const char *address);
static int osc_match_star_r(const char *pattern, const char *address);
static int osc_match_single_char(const char *pattern, const char *address);
static int osc_match_bracket(const char *pattern, const char *address);
static int osc_match_curly_brace(const char *pattern, const char *address);

int osc_match(const char *pattern, const char *address, int *pattern_offset, int *address_offset)
{
	if(!strcmp(pattern, address)){
		*pattern_offset = strlen(pattern);
		*address_offset = strlen(address);
		return OSC_MATCH_ADDRESS_COMPLETE | OSC_MATCH_PATTERN_COMPLETE;
	}
	
	const char *pattern_start;
	const char *address_start;
	
	pattern_start = pattern;
	address_start = address;
	
	*pattern_offset = 0;
	*address_offset = 0;
	
	while(*address != '\0' && *pattern != '\0'){
		if(*pattern == '*'){
			if(!osc_match_star(pattern, address)){
				return 0;
			}
			while(*pattern != '/' && *pattern != '\0'){
				pattern++;
			}
			while(*address != '/' && *address != '\0'){
				address++;
			}
		}else if(*address == '*'){
			while(*pattern != '/' && *pattern != '\0'){
				pattern++;
			}
			while(*address != '/' && *address != '\0'){
				address++;
			}
		}else{
			int n = 0;
			if(!(n = osc_match_single_char(pattern, address))){
				return 0;
			}
			if(*pattern == '['){
				while(*pattern != ']'){
					pattern++;
				}
				pattern++;
				address++;
			}else if(*pattern == '{'){
				while(*pattern != '}'){
					pattern++;
				}
				pattern++;
				address += n;
			}else{
				pattern++;
				address++;
			}
		}
	}
	
	*pattern_offset = pattern - pattern_start;
	*address_offset = address - address_start;
	
	int r = 0;
	
	if(*address == '\0') {
		r |= OSC_MATCH_ADDRESS_COMPLETE;
	}
	
	if(*pattern == '\0') {
		r |= OSC_MATCH_PATTERN_COMPLETE;
	}
	
	return r;
}

static int osc_match_star(const char *pattern, const char *address)
{
	const char *address_start = address;
	const char *pattern_start = pattern;
	int num_stars = 0;
	if(*address == '\0') { return 0; }
	while(*address != '/' && *address != '\0'){
		address++;
	}
	while(*pattern != '/' && *pattern != '\0'){
		if(*pattern == '*'){
			num_stars++;
		}
		pattern++;
	}
	pattern--;
	address--;
	switch(num_stars){
		case 1:
		{
			const char *pp = pattern, *aa = address;
			while(*pp != '*'){
				if(!(osc_match_single_char(pp, aa))){
					return 0;
				}
				if(*pp == ']' || *pp == '}'){
					while(*pp != '[' && *pp != '{'){
						pp--;
					}
				}
				pp--;
				aa--;
			}
		}
			break;
		case 2:
#if (OSC_MATCH_ENABLE_2STARS == 1)
		{
			const char *pp = pattern, *aa = address;
			while(*pp != '*'){
				if(!(osc_match_single_char(pp, aa))){
					return 0;
				}
				if(*pp == ']' || *pp == '}'){
					while(*pp != '[' && *pp != '{'){
						pp--;
					}
				}
				pp--;
				aa--;
			}
			aa++; // we want to start one character forward to allow the star to match nothing
			const char *star2 = pp;
			const char *test = aa;
			int i = 0;
			while(test > address_start){
				pp = star2 - 1;
				aa = test - 1;
				i++;
				while(*pp != '*'){
					if(!osc_match_single_char(pp, aa)){
						break;
					}
					if(*pp == ']' || *pp == '}'){
						while(*pp != '[' && *pp != '{'){
							pp--;
						}
					}
					pp--;
					aa--;
				}
				if(pp == pattern_start){
					return 1;
				}
				test--;
			}
			return 0;
		}
			break;
#else
			return 0;
#endif
		default:
#if (OSC_MATCH_ENABLE_NSTARS == 1)
			return osc_match_star_r(pattern_start, address_start);
			break;
#else
			return 0;
#endif
	}
	return 1;
}

#if (OSC_MATCH_ENABLE_NSTARS == 1)
static int osc_match_star_r(const char *pattern, const char *address)
{
	if(*address == '/' || *address == '\0'){
		if(*pattern == '/' || *pattern == '\0' || (*pattern == '*' && ((*(pattern + 1) == '/') || *(pattern + 1) == '\0'))){
			return 1;
		}else{
			return 0;
		}
	}
	if(*pattern == '*'){
		if(osc_match_star_r(pattern + 1, address)){
			return 1;
		}else{
			return osc_match_star_r(pattern, address + 1);
		}
	}else{
		if(!osc_match_single_char(pattern, address)){
			return 0;
		}
		if(*pattern == '[' || *pattern == '{'){
			while(*pattern != ']' && *pattern != '}'){
				pattern++;
			}
		}
		return osc_match_star_r(pattern + 1, address + 1);
	}
}
#endif

static int osc_match_single_char(const char *pattern, const char *address)
{
	switch(*pattern){
		case '[':
			return osc_match_bracket(pattern, address);
		case ']':
			while(*pattern != '['){
				pattern--;
			}
			return osc_match_bracket(pattern, address);
		case '{':
			return osc_match_curly_brace(pattern, address);
		case '}':
			while(*pattern != '{'){
				pattern--;
			}
			return osc_match_curly_brace(pattern, address);
		case '?':
			return 1;
		default:
			if(*pattern == *address){
				return 1;
			}else{
				return 0;
			}
	}
	return 0;
}

static int osc_match_bracket(const char *pattern, const char *address)
{
	pattern++;
	int val = 1;
	if(*pattern == '!'){
		pattern++;
		val = 0;
	}
	int matched = !val;
	while(*pattern != ']' && *pattern != '\0'){
		// the character we're on now is the beginning of a range
		if(*(pattern + 1) == '-'){
			if(*address >= *pattern && *address <= *(pattern + 2)){
				matched = val;
				break;
			}else{
				pattern += 3;
			}
		}else{
			// just test the character
			if(*pattern == *address){
				matched = val;
				break;
			}
			pattern++;
		}
	}
	return matched;
}

static int osc_match_curly_brace(const char *pattern, const char *address)
{
	pattern++;
	const char *ptr = pattern;
	while(*ptr != '}' && *ptr != '\0' && *ptr != '/'){
		while(*ptr != '}' && *ptr != '\0' && *ptr != '/' && *ptr != ','){
			ptr++;
		}
		int n = ptr - pattern;
		if(!strncmp(pattern, address, n)){
			return n;
		}else{
			ptr++;
			pattern = ptr;
		}
	}
	return 0;
}