deb-mbse/lib/dbdupe.c

/*****************************************************************************
 *
 * File ..................: dbdupe.c
 * Purpose ...............: Dupe checking.
 * Last modification date : 25-May-2001
 *
 *****************************************************************************
 * Copyright (C) 1997-2001
 *   
 * Michiel Broek		FIDO:		2:280/2802
 * Beekmansbos 10
 * 1971 BV IJmuiden
 * the Netherlands
 *
 * This file is part of MBSE BBS.
 *
 * This BBS is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * MBSE BBS is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with MBSE BBS; see the file COPYING.  If not, write to the Free
 * Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *****************************************************************************/

#include "../config.h"
#include "libs.h"
#include "memwatch.h"
#include "structs.h"
#include "clcomm.h"
#include "dbdupe.h"


typedef struct _dupesrec {
	unsigned long	*crcs;
	int		loaded;
	int		changed;
	int		count;
	int		max;
	int		peak;
} dupesrec;


dupesrec	dupes[3];
static char	*files[] = {(char *)"echomail", (char *)"fileecho", (char *)"news"};
void		CloseDdb(int);



void InitDupes()
{
	int	i;

	for (i = 0; i < 3; i++) {
		dupes[i].crcs= NULL;
		dupes[i].loaded = FALSE;
		dupes[i].changed = FALSE;
		dupes[i].count = 0;
		dupes[i].max = 0;
	}
}



int CheckDupe(unsigned long crc, int idx, int max)
{
	char		*dfile;
	FILE		*fil;
	unsigned long	test;
	int		i, size = 0;

	if (!dupes[idx].loaded) {
		dfile = calloc(PATH_MAX, sizeof(char));
		sprintf(dfile, "%s/etc/%s.dupe", getenv("MBSE_ROOT"), files[idx]);
		if ((fil = fopen(dfile, "r+")) == NULL) {
			/*
			 * Dupe database doesn't exist yet.
			 */
			if ((fil = fopen(dfile, "w")) == NULL) {
				WriteError("$PANIC: dbdupe.c, can't create %s", dfile);
				free(dfile);
				exit(1);
			}
			fclose(fil);
			fil = fopen(dfile, "r+");
		} else {
			fseek(fil, 0L, SEEK_END);
			size = ftell(fil) / sizeof(unsigned long);
			fseek(fil, 0L, SEEK_SET);
		}

		/*
		 * Reserve some extra memeory and record howmuch.
		 */
		if (size > max)
			dupes[idx].peak = size + 5000;
		else
			dupes[idx].peak = max + 5000;
		dupes[idx].crcs = (unsigned long *)malloc(dupes[idx].peak * sizeof(unsigned long));

		/*
		 *  Load dupe records
		 */
		while (fread(&test, sizeof(test), 1, fil) == 1) {
			dupes[idx].crcs[dupes[idx].count] = test;
			dupes[idx].count++;
		}
		fclose(fil);
		free(dfile);
		dupes[idx].loaded = TRUE;
		dupes[idx].max = max;
	}

	for (i = 0; i < dupes[idx].count; i++) {
		if (dupes[idx].crcs[i] == crc) {
			return TRUE;
		}
	}
	/*
	 * Not a dupe, append new crc value
	 */
	dupes[idx].crcs[dupes[idx].count] = crc;
	dupes[idx].count++;
	dupes[idx].changed = TRUE;

	/*
	 * If we reach the high limit, flush the current dupelist.
	 */
	if (dupes[idx].count >= dupes[idx].peak)
		CloseDdb(idx);
	return FALSE;
}



void CloseDdb(int idx)
{
	int	j, start;
	char	*dfile;
	FILE	*fil;

	dfile = calloc(PATH_MAX, sizeof(char));
	if (dupes[idx].loaded) {
		if (dupes[idx].changed) {
			if (dupes[idx].count > dupes[idx].max)
				start = dupes[idx].count - dupes[idx].max;
			else
				start = 0;
			sprintf(dfile, "%s/etc/%s.dupe", getenv("MBSE_ROOT"), files[idx]);
			if ((fil = fopen(dfile, "w"))) {
				for (j = start; j < dupes[idx].count; j++)
					fwrite(&dupes[idx].crcs[j], sizeof(unsigned long), 1, fil);
				fclose(fil);
			} else {
				WriteError("$Can't write %s", dfile);
			}
		}

		dupes[idx].changed = FALSE;
		dupes[idx].loaded  = FALSE;
		dupes[idx].count = 0;
		dupes[idx].max   = 0;
		dupes[idx].peak  = 0;
		free(dupes[idx].crcs);
		dupes[idx].crcs = NULL;
	}
	free(dfile);
}



void CloseDupes()
{
	int	i;

	for (i = 0; i < 3; i++)
		CloseDdb(i);
}