Commit d741d3e7 authored by Matthias Clasen's avatar Matthias Clasen Committed by Matthias Clasen

Add hash table iterators. (#500507, Jean-Yves Lefort)

2007-12-14  Matthias Clasen  <mclasen@redhat.com>

        * glib/glib.symbols:
        * glib/ghash.[hc]: Add hash table iterators.  (#500507,
        Jean-Yves Lefort)

        * tests/hash-test.c: Test iterators.



svn path=/trunk/; revision=6130
parent f5063650
2007-12-14 Matthias Clasen <mclasen@redhat.com>
* glib/glib.symbols:
* glib/ghash.[hc]: Add hash table iterators. (#500507,
Jean-Yves Lefort)
* tests/hash-test.c: Test iterators.
2007-12-13 Mathias Hasselmann <mathias@openismus.com>
Give exmples in error message unsupported case-changing escape
......
2007-12-14 Matthias Clasen <mclasen@redhat.com>
* glib/tmpl/hash_tables.sgml:
* glib/glib-sections.txt: Add hash iterator functions
2007-12-10 Matthias Clasen <mclasen@redhat.com>
* gio/gio-sections.txt:
......
......@@ -2015,6 +2015,12 @@ g_hash_table_thaw
g_hash_table_destroy
g_hash_table_ref
g_hash_table_unref
GHashTableIter
g_hash_table_iter_init
g_hash_table_iter_next
g_hash_table_iter_get_hash_table
g_hash_table_iter_remove
g_hash_table_iter_steal
<SUBSECTION>
g_direct_equal
......
......@@ -40,7 +40,9 @@ and g_hash_table_lookup_extended().
To remove a key and value, use g_hash_table_remove().
</para>
<para>
To call a function for each key and value pair use g_hash_table_foreach().
To call a function for each key and value pair use g_hash_table_foreach()
or use a iterator to iterate over the key/value pairs in the hash table, see
#GHashTableIter.
</para>
<para>
To destroy a #GHashTable use g_hash_table_destroy().
......@@ -96,7 +98,7 @@ hash functions which can be used when the key is a #gpointer, #gint, and
#gchar* respectively.
</para>
<para>
FIXME: Need more here.
<!-- FIXME: Need more here. -->
The hash values should be evenly distributed over a fairly large range?
The modulus is taken with the hash table size (a prime number)
to find the 'bucket' to place each key into.
......@@ -338,6 +340,51 @@ This function is deprecated and will be removed in the next major
@hash_table:
<!-- ##### FUNCTION g_hash_table_iter_init ##### -->
<para>
</para>
@iter:
@hash_table:
<!-- ##### FUNCTION g_hash_table_iter_next ##### -->
<para>
</para>
@iter:
@key:
@value:
@Returns:
<!-- ##### FUNCTION g_hash_table_iter_get_hash_table ##### -->
<para>
</para>
@iter:
@Returns:
<!-- ##### FUNCTION g_hash_table_iter_remove ##### -->
<para>
</para>
@iter:
<!-- ##### FUNCTION g_hash_table_iter_steal ##### -->
<para>
</para>
@iter:
<!-- ##### FUNCTION g_direct_equal ##### -->
<para>
......
......@@ -56,10 +56,28 @@ struct _GHashTable
GHashFunc hash_func;
GEqualFunc key_equal_func;
volatile gint ref_count;
#ifndef G_DISABLE_ASSERT
/*
* Tracks the structure of the hash table, not its contents: is only
* incremented when a node is added or removed (is not incremented
* when the key or data of a node is modified).
*/
int version;
#endif
GDestroyNotify key_destroy_func;
GDestroyNotify value_destroy_func;
};
typedef struct
{
GHashTable *hash_table;
GHashNode *prev_node;
GHashNode *node;
int position;
gboolean pre_advanced;
int version;
} RealIter;
/*
* g_hash_table_lookup_node:
* @hash_table: our #GHashTable
......@@ -332,6 +350,9 @@ g_hash_table_new_full (GHashFunc hash_func,
hash_table->hash_func = hash_func ? hash_func : g_direct_hash;
hash_table->key_equal_func = key_equal_func;
hash_table->ref_count = 1;
#ifndef G_DISABLE_ASSERT
hash_table->version = 0;
#endif
hash_table->key_destroy_func = key_destroy_func;
hash_table->value_destroy_func = value_destroy_func;
hash_table->nodes = g_new0 (GHashNode*, hash_table->size);
......@@ -339,6 +360,214 @@ g_hash_table_new_full (GHashFunc hash_func,
return hash_table;
}
/**
* g_hash_table_iter_init:
* @iter: an uninitialized #GHashTableIter.
* @hash_table: a #GHashTable.
*
* Initializes a key/value pair iterator and associates it with
* @hash_table. Modifying the hash table after calling this function
* invalidates the returned iterator.
*
* <informalexample><programlisting>
* GHashTableIter iter;
* gpointer key, value;
*
* g_hash_table_iter_init(&iter, hash_table);
* while (g_hash_table_iter_next(&iter, &key, &value)) {
* /&ast; do something with key and value &ast;/
* }
* </programlisting></informalexample>
*
* Since: 2.16
**/
void
g_hash_table_iter_init (GHashTableIter *iter,
GHashTable *hash_table)
{
RealIter *ri = (RealIter *) iter;
g_return_if_fail (iter != NULL);
g_return_if_fail (hash_table != NULL);
ri->hash_table = hash_table;
ri->prev_node = NULL;
ri->node = NULL;
ri->position = -1;
ri->pre_advanced = FALSE;
#ifndef G_DISABLE_ASSERT
ri->version = hash_table->version;
#endif
}
/**
* g_hash_table_iter_next:
* @iter: an initialized #GHashTableIter.
* @key: a location to store the key, or %NULL.
* @value: a location to store the value, or %NULL.
*
* Advances @iter and retrieves the key and/or value that are now
* pointed to as a result of this advancement. If %FALSE is returned,
* @key and @value are not set, and the iterator becomes invalid.
*
* Return value: %FALSE if the end of the #GHashTable has been reached.
*
* Since: 2.16
**/
gboolean
g_hash_table_iter_next (GHashTableIter *iter,
gpointer *key,
gpointer *value)
{
RealIter *ri = (RealIter *) iter;
g_return_val_if_fail (iter != NULL, FALSE);
g_return_val_if_fail (ri->version == ri->hash_table->version, FALSE);
if (ri->pre_advanced)
{
ri->pre_advanced = FALSE;
if (ri->node == NULL)
return FALSE;
}
else
{
if (ri->node != NULL)
{
ri->prev_node = ri->node;
ri->node = ri->node->next;
}
while (ri->node == NULL)
{
ri->position++;
if (ri->position >= ri->hash_table->size)
return FALSE;
ri->prev_node = NULL;
ri->node = ri->hash_table->nodes[ri->position];
}
}
if (key != NULL)
*key = ri->node->key;
if (value != NULL)
*value = ri->node->value;
return TRUE;
}
/**
* g_hash_table_iter_get_hash_table:
* @iter: an initialized #GHashTableIter.
*
* Returns the #GHashTable associated with @iter.
*
* Return value: the #GHashTable associated with @iter.
*
* Since: 2.16
**/
GHashTable *
g_hash_table_iter_get_hash_table (GHashTableIter *iter)
{
g_return_val_if_fail (iter != NULL, NULL);
return ((RealIter *) iter)->hash_table;
}
static void
iter_remove_or_steal (RealIter *ri, gboolean notify)
{
GHashNode *prev;
GHashNode *node;
int position;
g_return_if_fail (ri != NULL);
g_return_if_fail (ri->version == ri->hash_table->version);
g_return_if_fail (ri->node != NULL);
prev = ri->prev_node;
node = ri->node;
position = ri->position;
/* pre-advance the iterator since we will remove the node */
ri->node = ri->node->next;
/* ri->prev_node is still the correct previous node */
while (ri->node == NULL)
{
ri->position++;
if (ri->position >= ri->hash_table->size)
break;
ri->prev_node = NULL;
ri->node = ri->hash_table->nodes[ri->position];
}
ri->pre_advanced = TRUE;
/* remove the node */
if (prev != NULL)
prev->next = node->next;
else
ri->hash_table->nodes[position] = node->next;
if (notify)
{
if (ri->hash_table->key_destroy_func)
ri->hash_table->key_destroy_func(node->key);
if (ri->hash_table->value_destroy_func)
ri->hash_table->value_destroy_func(node->value);
}
g_slice_free (GHashNode, node);
ri->hash_table->nnodes--;
}
/**
* g_hash_table_iter_remove():
* @iter: an initialized #GHashTableIter.
*
* Removes the key/value pair currently pointed to by the iterator
* from its associated #GHashTable. Can only be called after
* g_hash_table_iter_next() returned %TRUE, and cannot be called more
* than once for the same key/value pair.
*
* If the #GHashTable was created using g_hash_table_new_full(), the
* key and value are freed using the supplied destroy functions, otherwise
* you have to make sure that any dynamically allocated values are freed
* yourself.
*
* Since: 2.16
**/
void
g_hash_table_iter_remove (GHashTableIter *iter)
{
iter_remove_or_steal ((RealIter *) iter, TRUE);
}
/**
* g_hash_table_iter_steal():
* @iter: an initialized #GHashTableIter.
*
* Removes the key/value pair currently pointed to by the iterator
* from its associated #GHashTable, without calling the key and value
* destroy functions. Can only be called after
* g_hash_table_iter_next() returned %TRUE, and cannot be called more
* than once for the same key/value pair.
*
* Since: 2.16
**/
void
g_hash_table_iter_steal (GHashTableIter *iter)
{
iter_remove_or_steal ((RealIter *) iter, FALSE);
}
/**
* g_hash_table_ref:
......@@ -531,6 +760,10 @@ g_hash_table_insert_internal (GHashTable *hash_table,
*node_ptr = node;
hash_table->nnodes++;
g_hash_table_maybe_resize (hash_table);
#ifndef G_DISABLE_ASSERT
hash_table->version++;
#endif
}
}
......@@ -606,6 +839,10 @@ g_hash_table_remove_internal (GHashTable *hash_table,
g_hash_table_remove_node (hash_table, &node_ptr, notify);
g_hash_table_maybe_resize (hash_table);
#ifndef G_DISABLE_ASSERT
hash_table->version++;
#endif
return TRUE;
}
......@@ -665,6 +902,11 @@ g_hash_table_remove_all (GHashTable *hash_table)
{
g_return_if_fail (hash_table != NULL);
#ifndef G_DISABLE_ASSERT
if (hash_table->nnodes != 0)
hash_table->version++;
#endif
g_hash_table_remove_all_nodes (hash_table, TRUE);
g_hash_table_maybe_resize (hash_table);
}
......@@ -683,6 +925,11 @@ g_hash_table_steal_all (GHashTable *hash_table)
{
g_return_if_fail (hash_table != NULL);
#ifndef G_DISABLE_ASSERT
if (hash_table->nnodes != 0)
hash_table->version++;
#endif
g_hash_table_remove_all_nodes (hash_table, FALSE);
g_hash_table_maybe_resize (hash_table);
}
......@@ -726,6 +973,11 @@ g_hash_table_foreach_remove_or_steal (GHashTable *hash_table,
g_hash_table_maybe_resize (hash_table);
#ifndef G_DISABLE_ASSERT
if (deleted > 0)
hash_table->version++;
#endif
return deleted;
}
......@@ -741,6 +993,9 @@ g_hash_table_foreach_remove_or_steal (GHashTable *hash_table,
* the #GHashTable, they are used to free the memory allocated for the removed
* keys and values.
*
* See #GHashTableIterator for an alternative way to loop over the
* key/value pairs in the hash table.
*
* Return value: the number of key/value pairs removed.
**/
guint
......@@ -764,6 +1019,9 @@ g_hash_table_foreach_remove (GHashTable *hash_table,
* If the function returns %TRUE, then the key/value pair is removed from the
* #GHashTable, but no key or value destroy functions are called.
*
* See #GHashTableIterator for an alternative way to loop over the
* key/value pairs in the hash table.
*
* Return value: the number of key/value pairs removed.
**/
guint
......
......@@ -38,6 +38,19 @@ typedef gboolean (*GHRFunc) (gpointer key,
gpointer value,
gpointer user_data);
typedef struct _GHashTableIter GHashTableIter;
struct _GHashTableIter
{
/*< private >*/
gpointer dummy1;
gpointer dummy2;
gpointer dummy3;
int dummy4;
gboolean dummy5;
gpointer dummy6;
};
/* Hash tables
*/
GHashTable* g_hash_table_new (GHashFunc hash_func,
......@@ -81,6 +94,15 @@ guint g_hash_table_size (GHashTable *hash_table);
GList * g_hash_table_get_keys (GHashTable *hash_table);
GList * g_hash_table_get_values (GHashTable *hash_table);
void g_hash_table_iter_init (GHashTableIter *iter,
GHashTable *hash_table);
gboolean g_hash_table_iter_next (GHashTableIter *iter,
gpointer *key,
gpointer *value);
GHashTable* g_hash_table_iter_get_hash_table (GHashTableIter *iter);
void g_hash_table_iter_remove (GHashTableIter *iter);
void g_hash_table_iter_steal (GHashTableIter *iter);
/* keeping hash tables alive */
GHashTable* g_hash_table_ref (GHashTable *hash_table);
void g_hash_table_unref (GHashTable *hash_table);
......
......@@ -385,6 +385,11 @@ g_hash_table_replace
g_hash_table_size
g_hash_table_steal
g_hash_table_steal_all
g_hash_table_iter_init
g_hash_table_iter_next
g_hash_table_iter_get_hash_table
g_hash_table_iter_remove
g_hash_table_iter_steal
#endif
#endif
......
......@@ -44,7 +44,50 @@
int array[10000];
static void
fill_hash_table_and_array (GHashTable *hash_table)
{
int i;
for (i = 0; i < 10000; i++)
{
array[i] = i;
g_hash_table_insert (hash_table, &array[i], &array[i]);
}
}
static void
init_result_array (int result_array[10000])
{
int i;
for (i = 0; i < 10000; i++)
result_array[i] = -1;
}
static void
verify_result_array (int array[10000])
{
int i;
for (i = 0; i < 10000; i++)
g_assert (array[i] == i);
}
static void
handle_pair (gpointer key, gpointer value, int result_array[10000])
{
int n;
g_assert (key == value);
n = *((int *) value);
g_assert (n >= 0 && n < 10000);
g_assert (result_array[n] == -1);
result_array[n] = n;
}
static gboolean
my_hash_callback_remove (gpointer key,
......@@ -75,8 +118,7 @@ my_hash_callback (gpointer key,
gpointer value,
gpointer user_data)
{
int *d = value;
*d = 1;
handle_pair (key, value, user_data);
}
static guint
......@@ -347,13 +389,12 @@ main (int argc,
gint *pvalue;
GList *keys, *values;
gint keys_len, values_len;
GHashTableIter iter;
gpointer ikey, ivalue;
int result_array[10000];
hash_table = g_hash_table_new (my_hash, my_hash_equal);
for (i = 0; i < 10000; i++)
{
array[i] = i;
g_hash_table_insert (hash_table, &array[i], &array[i]);
}
fill_hash_table_and_array (hash_table);
pvalue = g_hash_table_find (hash_table, find_first, &value);
if (!pvalue || *pvalue != value)
g_assert_not_reached();
......@@ -373,21 +414,32 @@ main (int argc,
g_list_free (keys);
g_list_free (values);
g_hash_table_foreach (hash_table, my_hash_callback, NULL);
init_result_array (result_array);
g_hash_table_iter_init (&iter, hash_table);
for (i = 0; i < 10000; i++)
if (array[i] == 0)
g_assert_not_reached();
{
g_assert (g_hash_table_iter_next (&iter, &ikey, &ivalue));
handle_pair (ikey, ivalue, result_array);
if (i % 2)
g_hash_table_iter_remove (&iter);
}
g_assert (! g_hash_table_iter_next (&iter, &ikey, &ivalue));
g_assert (g_hash_table_size (hash_table) == 5000);
verify_result_array (result_array);
fill_hash_table_and_array (hash_table);
init_result_array (result_array);
g_hash_table_foreach (hash_table, my_hash_callback, result_array);
verify_result_array (result_array);
for (i = 0; i < 10000; i++)
g_hash_table_remove (hash_table, &array[i]);
for (i = 0; i < 10000; i++)
{
array[i] = i;
g_hash_table_insert (hash_table, &array[i], &array[i]);
}
fill_hash_table_and_array (hash_table);
if (g_hash_table_foreach_remove (hash_table, my_hash_callback_remove, NULL) != 5000 ||
g_hash_table_size (hash_table) != 5000)
......
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