shithub: sdbm

ref: 64e312636599ea2c86f21dc1176dca7da77bd74a
dir: /dba.c/

/*
 * dba	dbm analysis/recovery
 */

#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "sdbm.h"

char *progname;
extern void oops(char *, char *);
extern int okpage(char *);

void sdump(int);
int pagestat(char *);

void
main(int argc, char **argv)
{
	int n;
	char *p;
	char *name;
	int pagf;

	progname = argv[0];

	if (argc != 2) oops("usage: %s dbname\n", progname); /* keeps compiler quiet */

	if (p = argv[1]) {
		name = (char *) malloc((n = strlen(p)) + 5);
		strcpy(name, p);
		strcpy(name + n, ".pag");

		if ((pagf = open(name, OREAD)) < 0)
			oops("cannot open %s.", name);

		sdump(pagf);
	}
	else
		oops("usage: %s dbname\n", progname);

	exits(0);
}

void
sdump(int pagf)
{
	int b;
	int n = 0;
	int t = 0;
	int o = 0;
	int e;
	char pag[PBLKSIZ];
	char num[16];

	while ((b = read(pagf, pag, PBLKSIZ)) > 0) {
		printf("#%d: ", n);
		if (!okpage(pag))
			printf("bad\n");
		else {
			printf("ok. ");
			if (!(e = pagestat(pag)))
			    o++;
			else
			    t += e;
		}
		n++;
	}

	if (b == 0)
		printf("%d pages (%d holes):  %d entries\n", n, o, t);
	else
	{
		snprintf(num, 15, "%d", n);
		oops("read failed: block %d", num);
	}
}

int
pagestat(char *pag)
{
	register n;
	register free;
	register short *ino = (short *) pag;

	if (!(n = ino[0]))
		printf("no entries.\n");
	else {
		free = ino[n] - (n + 1) * sizeof(short);
		printf("%3d entries %2d%% used free %d.\n",
		       n / 2, ((PBLKSIZ - free) * 100) / PBLKSIZ, free);
	}
	return n / 2;
}