/*
   Attribute handling gear. Shit simple.

   Andrew Molitor, amolitor@eagle.wesleyan.edu

   1991

   */

#include "autoconf.h"
#include "copyright.h"
#ifndef	lint
static char *RCSid = "$Id: udb_attr.c,v 1.7 1995/03/21 00:01:21 ambar Exp $";
USE(RCSid);
#endif

#include	"config.h"
#include	"udb.h"
#include	"udb_defs.h"

/*
   Hash function for the cache code. Stolen from mjr.
   */
/*
   WARNING  - overflows ignored. no big deal
   */
unsigned int
attr_hash(key, width)
    Aname *key;			/* Pointer to the key. */
    int width;			/* Width of the hash table.   */
{
    return ((key->object + key->attrnum) % width);
}

/*
   Free an attribute.
   */

int 
attrfree(a)
    Attr *a;
{

    if (!a)
	return 0;

    free((char *) a);
    return 0;
}

/*
   Routines for dealing with reading/writing attributes to disk.

   We stow attributes on disk as an int containing the size,
   followed by the data proper. This means two disk hits per operation,
   but there seems to be no easy way around this.

   */


Attr *
attrfromFILE(f, size)
    FILE *f;
    int size;
{
    Attr *atr;

    /* Get a new attribute struct */

    /* Get a buffer big enough. */
    if ((atr = (Attr *) XMALLOC(size + 1, "attrfromFILE")) == NULL) {
	free(atr);
	return (ANULL);
    }
    /* Now go get the data */

    if (fread(atr, size, 1, f) != 1) {
	free(atr);
	return (ANULL);
    }
    atr[size] = '\0';
    return (atr);
}


int 
attrtoFILE(a, f, size)
    Attr *a;
    FILE *f;
    int size;
{
    /* Write out the data */

    fwrite(a, size, 1, f);
    return 0;
}

int 
attr_siz(a)
    Attr *a;
{
    return (strlen(a));
}