/* GLIB - Library of useful routines for C programming

 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald

 * Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free

 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

/*

 * Modified by the GLib Team and others 1997-2000.  See the AUTHORS

 * file for a list of people on the GLib Team.  See the ChangeLog

 * files for a list of changes.  These files are distributed with

 * GLib at ftp://ftp.gtk.org/pub/gtk/. 

 */

/* 

 * MT safe

 */

#include "config.h"

#include <stdarg.h>

#include <string.h>

#include "glib.h"

#include "galias.h"

typedef struct _GRealTuples        GRealTuples;

struct _GRelation

{

  gint fields;

  gint current_field;

  GHashTable   *all_tuples;

  GHashTable  **hashed_tuple_tables;

  gint count;

};

struct _GRealTuples

{

  gint      len;

  gint      width;

  gpointer *data;

};

static gboolean

tuple_equal_2 (gconstpointer v_a,

	       gconstpointer v_b)

{

  gpointer* a = (gpointer*) v_a;

  gpointer* b = (gpointer*) v_b;

  return a[0] == b[0] && a[1] == b[1];

}

static guint

tuple_hash_2 (gconstpointer v_a)

{

  gpointer* a = (gpointer*) v_a;

  return (gulong)a[0] ^ (gulong)a[1];

}

static GHashFunc

tuple_hash (gint fields)

{

  switch (fields)

    {

    case 2:

      return tuple_hash_2;

    default:

      g_error ("no tuple hash for %d", fields);

    }

  return NULL;

}

static GEqualFunc

tuple_equal (gint fields)

{

  switch (fields)

    {

    case 2:

      return tuple_equal_2;

    default:

      g_error ("no tuple equal for %d", fields);

    }

  return NULL;

}

EXPORT_C GRelation*

g_relation_new (gint fields)

{

  GRelation* rel = g_new0 (GRelation, 1);

  rel->fields = fields;

  rel->all_tuples = g_hash_table_new (tuple_hash (fields), tuple_equal (fields));

  rel->hashed_tuple_tables = g_new0 (GHashTable*, fields);  

  return rel;

}

static void

relation_delete_value_tuple (gpointer tuple_key,

                             gpointer tuple_value,

                             gpointer user_data)

{

  GRelation *relation = user_data;

  gpointer *tuple = tuple_value;

  g_slice_free1 (relation->fields * sizeof (gpointer), tuple);

}

static void

g_relation_free_array (gpointer key, gpointer value, gpointer user_data)

{

  g_hash_table_destroy ((GHashTable*) value);

}

EXPORT_C void

g_relation_destroy (GRelation *relation)

{

  gint i;

  if (relation)

    {

      for (i = 0; i < relation->fields; i += 1)

	{

	  if (relation->hashed_tuple_tables[i])

	    {

	      g_hash_table_foreach (relation->hashed_tuple_tables[i], g_relation_free_array, NULL);

	      g_hash_table_destroy (relation->hashed_tuple_tables[i]);

	    }

	}

      g_hash_table_foreach (relation->all_tuples, relation_delete_value_tuple, relation);

      g_hash_table_destroy (relation->all_tuples);

      g_free (relation->hashed_tuple_tables);

      g_free (relation);

    }

}

EXPORT_C void

g_relation_index (GRelation   *relation,

		  gint         field,

		  GHashFunc    hash_func,

		  GEqualFunc   key_equal_func)

{

  g_return_if_fail (relation != NULL);

  g_return_if_fail (relation->count == 0 && relation->hashed_tuple_tables[field] == NULL);

  relation->hashed_tuple_tables[field] = g_hash_table_new (hash_func, key_equal_func);

}

EXPORT_C void

g_relation_insert (GRelation   *relation,

		   ...)

{

  gpointer* tuple = g_slice_alloc (relation->fields * sizeof (gpointer));

  va_list args;

  gint i;

  va_start (args, relation);

  for (i = 0; i < relation->fields; i += 1)

    tuple[i] = va_arg (args, gpointer);

  va_end (args);

  g_hash_table_insert (relation->all_tuples, tuple, tuple);

  relation->count += 1;

  for (i = 0; i < relation->fields; i += 1)

    {

      GHashTable *table;

      gpointer    key;

      GHashTable *per_key_table;

      table = relation->hashed_tuple_tables[i];

      if (table == NULL)

	continue;

      key = tuple[i];

      per_key_table = g_hash_table_lookup (table, key);

      if (per_key_table == NULL)

	{

	  per_key_table = g_hash_table_new (tuple_hash (relation->fields), tuple_equal (relation->fields));

	  g_hash_table_insert (table, key, per_key_table);

	}

      g_hash_table_insert (per_key_table, tuple, tuple);

    }

}

static void

g_relation_delete_tuple (gpointer tuple_key,

			 gpointer tuple_value,

			 gpointer user_data)

{

  gpointer      *tuple = (gpointer*) tuple_value;

  GRelation     *relation = (GRelation *) user_data;

  gint           j;

  g_assert (tuple_key == tuple_value);

  for (j = 0; j < relation->fields; j += 1)

    {

      GHashTable *one_table = relation->hashed_tuple_tables[j];

      gpointer    one_key;

      GHashTable *per_key_table;

      if (one_table == NULL)

	continue;

      if (j == relation->current_field)

	/* can't delete from the table we're foreaching in */

	continue;

      one_key = tuple[j];

      per_key_table = g_hash_table_lookup (one_table, one_key);

      g_hash_table_remove (per_key_table, tuple);

    }

  if (g_hash_table_remove (relation->all_tuples, tuple))

    g_slice_free1 (relation->fields * sizeof (gpointer), tuple);

  relation->count -= 1;

}

EXPORT_C gint

g_relation_delete  (GRelation     *relation,

		    gconstpointer  key,

		    gint           field)

{

  GHashTable *table = relation->hashed_tuple_tables[field];

  GHashTable *key_table;

  gint        count = relation->count;

  g_return_val_if_fail (relation != NULL, 0);

  g_return_val_if_fail (table != NULL, 0);

  key_table = g_hash_table_lookup (table, key);

  if (!key_table)

    return 0;

  relation->current_field = field;

  g_hash_table_foreach (key_table, g_relation_delete_tuple, relation);

  g_hash_table_remove (table, key);

  g_hash_table_destroy (key_table);

  /* @@@ FIXME: Remove empty hash tables. */

  return count - relation->count;

}

static void

g_relation_select_tuple (gpointer tuple_key,

			 gpointer tuple_value,

			 gpointer user_data)

{

  gpointer    *tuple = (gpointer*) tuple_value;

  GRealTuples *tuples = (GRealTuples*) user_data;

  gint stride = sizeof (gpointer) * tuples->width;

  g_assert (tuple_key == tuple_value);

  memcpy (tuples->data + (tuples->len * tuples->width),

	  tuple,

	  stride);

  tuples->len += 1;

}

EXPORT_C GTuples*

g_relation_select (GRelation     *relation,

		   gconstpointer  key,

		   gint           field)

{

  GHashTable  *table = relation->hashed_tuple_tables[field];

  GHashTable  *key_table;

  GRealTuples *tuples = g_new0 (GRealTuples, 1);

  gint count;

  g_return_val_if_fail (relation != NULL, NULL);

  g_return_val_if_fail (table != NULL, NULL);

  key_table = g_hash_table_lookup (table, key);

  if (!key_table)

    return (GTuples*)tuples;

  count = g_relation_count (relation, key, field);

  tuples->data = g_malloc (sizeof (gpointer) * relation->fields * count);

  tuples->width = relation->fields;

  g_hash_table_foreach (key_table, g_relation_select_tuple, tuples);

  g_assert (count == tuples->len);

  return (GTuples*)tuples;

}

EXPORT_C gint

g_relation_count (GRelation     *relation,

		  gconstpointer  key,

		  gint           field)

{

  GHashTable  *table = relation->hashed_tuple_tables[field];

  GHashTable  *key_table;

  g_return_val_if_fail (relation != NULL, 0);

  g_return_val_if_fail (table != NULL, 0);

  key_table = g_hash_table_lookup (table, key);

  if (!key_table)

    return 0;

  return g_hash_table_size (key_table);

}

EXPORT_C gboolean

g_relation_exists (GRelation   *relation, ...)

{

  gpointer *tuple = g_slice_alloc (relation->fields * sizeof (gpointer));

  va_list args;

  gint i;

  gboolean result;

  va_start(args, relation);

  for (i = 0; i < relation->fields; i += 1)

    tuple[i] = va_arg(args, gpointer);

  va_end(args);

  result = g_hash_table_lookup (relation->all_tuples, tuple) != NULL;

  g_slice_free1 (relation->fields * sizeof (gpointer), tuple);

  return result;

}

EXPORT_C void

g_tuples_destroy (GTuples *tuples0)

{

  GRealTuples *tuples = (GRealTuples*) tuples0;

  if (tuples)

    {

      g_free (tuples->data);

      g_free (tuples);

    }

}

EXPORT_C gpointer

g_tuples_index (GTuples     *tuples0,

		gint         index,

		gint         field)

{

  GRealTuples *tuples = (GRealTuples*) tuples0;

  g_return_val_if_fail (tuples0 != NULL, NULL);

  g_return_val_if_fail (field < tuples->width, NULL);

  return tuples->data[index * tuples->width + field];

}

/* Print

 */

static void

g_relation_print_one (gpointer tuple_key,

		      gpointer tuple_value,

		      gpointer user_data)

{

  gint i;

  GString *gstring;

  GRelation* rel = (GRelation*) user_data;

  gpointer* tuples = (gpointer*) tuple_value;

  gstring = g_string_new ("[");

  for (i = 0; i < rel->fields; i += 1)

    {

      g_string_append_printf (gstring, "%p", tuples[i]);

      if (i < (rel->fields - 1))

	g_string_append (gstring, ",");

    }

  g_string_append (gstring, "]");

  g_log (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, gstring->str);

  g_string_free (gstring, TRUE);

}

static void

g_relation_print_index (gpointer tuple_key,

			gpointer tuple_value,

			gpointer user_data)

{

  GRelation* rel = (GRelation*) user_data;

  GHashTable* table = (GHashTable*) tuple_value;

  g_log (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "*** key %p", tuple_key);

  g_hash_table_foreach (table,

			g_relation_print_one,

			rel);

}

EXPORT_C void

g_relation_print (GRelation *relation)

{

  gint i;

  g_log (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "*** all tuples (%d)", relation->count);

  g_hash_table_foreach (relation->all_tuples,

			g_relation_print_one,

			relation);

  for (i = 0; i < relation->fields; i += 1)

    {

      if (relation->hashed_tuple_tables[i] == NULL)

	continue;

      g_log (G_LOG_DOMAIN, G_LOG_LEVEL_INFO, "*** index %d", i);

      g_hash_table_foreach (relation->hashed_tuple_tables[i],

			    g_relation_print_index,

			    relation);

    }

}

#define __G_REL_C__

#include "galiasdef.c"