dbf_rec.c

/*
 * Copyright (c) 1993 Brad Eacker,
 *              (Music, Intuition, Software, and Computers)
 * All Rights Reserved
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"

#include "ext/standard/flock_compat.h" 

#include <stdio.h>
#include <fcntl.h>

#include "dbf.h"
 
int get_piece(dbhead_t *dbh, long offset, char *cp, int len);
int put_piece(dbhead_t *dbh, long offset, char *cp, int len);

/*
 * get a record off the database
 */
char *get_dbf_record(dbhead_t *dbh, long rec_num)
{
	long	offset;
	char	*cp;

	if (rec_num > dbh->db_records) {
		return NULL;
	}
	cp = (char *)emalloc(dbh->db_rlen);

	/* go to the correct spot on the file */
	offset = dbh->db_hlen + (rec_num - 1) * dbh->db_rlen;
	if (get_piece(dbh, offset, cp, dbh->db_rlen) != dbh->db_rlen) {
		efree(cp);
		cp = NULL;
	}
	if (cp)
		dbh->db_cur_rec = rec_num;
	return cp;
}

int
get_piece(dbhead_t *dbh, long offset, char *cp, int len)
{
	/* go to the correct spot on the file */
	if ( lseek(dbh->db_fd, offset, 0) < 0 ) {
		return -1;
	}

	/* read the record into the allocated space */
	return read(dbh->db_fd, cp, len);
}

/*
 * put a record to the database
 */
long put_dbf_record(dbhead_t *dbh, long rec_num, char *cp)
{
	long	offset;

	if (rec_num == 0) {
		rec_num = dbh->db_records;
	}
	if (rec_num > dbh->db_records) {
		return 0L;
	}
	/* go to the correct spot on the file */
	offset = dbh->db_hlen + (rec_num - 1) * dbh->db_rlen;
	if (put_piece(dbh, offset, cp, dbh->db_rlen) != dbh->db_rlen) {
		rec_num = -1;
	}
	return rec_num;
}

int put_piece(dbhead_t *dbh, long offset, char *cp, int len)
{
	/* go to the correct spot on the file */
	if ( lseek(dbh->db_fd, offset, 0) < 0 ) {
		return -1;
	}

	/* write the record into the file */
	return write(dbh->db_fd, cp, len);
}

int put_dbf_eof_marker(dbhead_t *dbh)
{
	char eof = 0x1A;

	if (put_piece(dbh, dbh->db_hlen + dbh->db_records * dbh->db_rlen, &eof, sizeof(eof)) != sizeof(eof)) {
		php_error_docref(NULL, E_WARNING, "unable to write end-of-file marker");
		return -1;
	}
	return 0;
}

int del_dbf_record(dbhead_t *dbh, long rec_num)
{
	int ret = 0;
	char *cp;

	if (rec_num > dbh->db_records)
		return -1;
	if ((cp = get_dbf_record(dbh, rec_num))) {
		*cp = DELETED_RECORD;
		ret = put_dbf_record(dbh, rec_num, cp);
		efree(cp);
	}
	return ret;
}

int pack_dbf(dbhead_t *dbh)
{
	long	out_off, in_off;
	int	rec_cnt, new_cnt;
	char	*cp;

	cp = (char *)emalloc(dbh->db_rlen);
	in_off = out_off = dbh->db_hlen;

	new_cnt = 0;
	rec_cnt = dbh->db_records;
	while (rec_cnt > 0) {
		if (get_piece(dbh, in_off, cp, dbh->db_rlen) != dbh->db_rlen) {
			php_error_docref(NULL, E_WARNING, "unable to read from the file");
			efree(cp);
			return -1;
		}

		if (*cp != DELETED_RECORD) {
			/* write the record into the file */
			if (put_piece(dbh, out_off, cp, dbh->db_rlen) != dbh->db_rlen) {
				php_error_docref(NULL, E_WARNING, "unable to write to the file");
				efree(cp);
				return -1;
			}
			out_off += dbh->db_rlen;
			new_cnt++;
		}
		in_off += dbh->db_rlen;
		rec_cnt--;
	}
	efree(cp);

	/* Try to truncate the file to the right size. */
	if (ftruncate(dbh->db_fd, out_off) != 0) {
	    php_error_docref(NULL, E_WARNING, "dbase_pack() couldn't truncate the file to the right size. Some deleted records may still be left in there");
		return -1;
	}

	dbh->db_records = new_cnt;

	return 0;
}

/* routine to get a field from a record */
char *get_field_val(char *rp, dbfield_t *fldp, char *cp)
{
	int flen = fldp->db_flen;

	if ( !cp )
		cp = (char *)emalloc(flen + 1);
	strncpy(cp, &rp[fldp->db_foffset], flen);
	cp[flen] = '\0';
	return cp;
}

char *get_binary_field_val(char *rp, dbfield_t *fldp, char *cp)
{
	int flen = fldp->db_flen;

	if ( !cp )
		cp = (char *)emalloc(flen);
	memcpy(cp, &rp[fldp->db_foffset], flen);
	return cp;
}

void put_field_val(char *rp, dbfield_t *fldp, char *cp)
{
	strncpy(&rp[fldp->db_foffset], cp, fldp->db_flen);
}

/* check for record validity */
int is_valid_rec(char *cp)
{
	if (cp && (*cp == VALID_RECORD))
		return 1;
	else
		return 0;
}

/* get the next record */
char *dbf_get_next(dbhead_t *dbh)
{
	return get_dbf_record(dbh, dbh->db_cur_rec + 1);
}

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: sw=4 ts=4 fdm=marker
 * vim<600: sw=4 ts=4
 */