(test case) GHash bug?

[Jeff Garzik <jgarzik pobox com>]

The following test (attached) inserts 20 values into a hash table.  The
key is a number (0-19) stored as a string, hashed w/ a custom CRC hash
function.  The value is a g_strdup'd copy of that same number, stored as
a string formatted from "%d value".

The current ghash code seems to be failing miserably on this easy test.

	Jeff




create table

table insert 0, key="0", val="0 value"
the_hash = 113246208

table insert 1, key="1", val="1 value"
the_hash = 1321205760

table insert 2, key="2", val="2 value"
the_hash = 583008256
comparing "2" and "2", returning 1

[...]

table insert 18, key="18", val="18 value"
the_hash = 257785856
comparing "18" and "18", returning 1

table insert 19, key="19", val="19 value"
the_hash = 1197309952
comparing "19" and "19", returning 1

table lookup 0
the_hash = 113246208
comparing "0" and "0", returning 1
table lookup("0") returned "18 value"

** ERROR **: file hash-test.c: line 123 (second_hash_test): assertion
failed: (atoi (v) == i)
aborting...
Aborted (core dumped)

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
#undef G_LOG_DOMAIN

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <glib.h>



#define POLY 0x48000000L	/* 31-bit polynomial (avoids sign problems) */

static guint CrcTable[128];

static void crcinit(void)
{
	int i, j;
	guint sum;

	for (i = 0; i < 128; ++i) {
		sum = 0L;
		for (j = 7 - 1; j >= 0; --j)
			if (i & (1 << j))
				sum ^= POLY >> j;
		CrcTable[i] = sum;
	}
}

static guint hash(const char *name, int size)
{
	guint sum = 0;

	while (size--) {
		sum = (sum >> 7) ^ CrcTable[(sum ^ (*name++)) & 0x7f];
	}

	return(sum);
}


static guint second_hash (gconstpointer key)
{
  guint the_hash = hash ((const char *) key, strlen((const char *) key));

  g_print("the_hash = %u\n", the_hash);

  return the_hash;
}



static gint second_hash_cmp (gconstpointer a, gconstpointer b)
{
  gint rc = (strcmp (a, b) == 0);

  g_print("comparing \"%s\" and \"%s\", returning %d\n",
  	   a ? (char*)a : "", b ? (char*)b : "", rc);

  return rc;
}



static void second_hash_test (void)
{
     int       i;
     char      new_key[20] = "", new_val[20]="", *v, *new_val_copy;
     GHashTable     *h;

     crcinit ();

     g_print("create table\n");
     h = g_hash_table_new (second_hash, second_hash_cmp);
     for (i=0; i<20; i++)
          {
          sprintf (new_key, "%d", i);
	  g_assert (atoi (new_key) == i);
	  sprintf (new_val, "%d value", i);
	  g_assert (atoi (new_val) == i);
	  new_val_copy = g_strdup (new_val);
	  g_assert (new_val_copy != NULL);
	  g_assert (*new_val_copy != 0);

          g_print("table insert %d, key=\"%s\", val=\"%s\"\n",
	  	i, new_key, new_val_copy);
          g_hash_table_insert (h, new_key, new_val_copy);
          }

     for (i=0; i<20; i++)
          {
          sprintf (new_key, "%d", i);
	  g_assert (atoi(new_key) == i);
          g_print("table lookup %d\n", i);
          v = (char *) g_hash_table_lookup (h, new_key);

	  g_print("table lookup(\"%s\") returned \"%s\"\n", 
	  	  new_key, v ? v : "");

	  g_assert (v != NULL);
	  g_assert (*v != 0);
	  g_assert (atoi (v) == i);
          }
}


int main (int   argc, char *argv[])
{
  second_hash_test ();
  return 0;

}