// Copyright (C) 1992-1998 by Michael K. Johnson, johnsonm@redhat.com
// Note: most likely none of his code remains
//
// Copyright 2002, Albert Cahalan
//
// This file is placed under the conditions of the GNU Library
// General Public License, version 2, or any later version.
// See file COPYING for information on distribution conditions.

#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <pwd.h>
#include "alloc.h"
#include "pwcache.h"
#include <grp.h>

// might as well fill cache lines... else we waste memory anyway

#define	HASHSIZE	64	/* power of 2 */
#define	HASH(x)		((x) & (HASHSIZE - 1))

#define NAMESIZE	20
#define NAMELENGTH	"19"

static struct pwbuf {
	struct pwbuf *next;
	uid_t uid;
	char name[NAMESIZE];
} *pwhash[HASHSIZE];

char *user_from_uid(uid_t uid)
{
	struct pwbuf **p;
	struct passwd *pw;

	p = &pwhash[HASH(uid)];
	while (*p) {
		if ((*p)->uid == uid)
			return ((*p)->name);
		p = &(*p)->next;
	}
	*p = (struct pwbuf *)xmalloc(sizeof(struct pwbuf));
	(*p)->uid = uid;
	if ((pw = getpwuid(uid)) == NULL)
		sprintf((*p)->name, "#%d", uid);
	else
		sprintf((*p)->name, "%-." NAMELENGTH "s", pw->pw_name);
	(*p)->next = NULL;
	return ((*p)->name);
}

static struct grpbuf {
	struct grpbuf *next;
	gid_t gid;
	char name[NAMESIZE];
} *grphash[HASHSIZE];

char *group_from_gid(gid_t gid)
{
	struct grpbuf **g;
	struct group *gr;

	g = &grphash[HASH(gid)];
	while (*g) {
		if ((*g)->gid == gid)
			return ((*g)->name);
		g = &(*g)->next;
	}
	*g = (struct grpbuf *)malloc(sizeof(struct grpbuf));
	(*g)->gid = gid;
	if ((gr = getgrgid(gid)) == NULL)
		sprintf((*g)->name, "#%d", gid);
	else
		sprintf((*g)->name, "%-." NAMELENGTH "s", gr->gr_name);
	(*g)->next = NULL;
	return ((*g)->name);
}
