gstreamer/gst/indexers/gstmemindex.c

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/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
#include <gst/gst.h>
#define GST_TYPE_MEM_INDEX \
(gst_index_get_type ())
#define GST_MEM_INDEX(obj) \
(G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_MEM_INDEX, GstMemIndex))
#define GST_MEM_INDEX_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_MEM_INDEX, GstMemIndexClass))
#define GST_IS_MEM_INDEX(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_MEM_INDEX))
#define GST_IS_MEM_INDEX_CLASS(obj) \
(GST_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_MEM_INDEX))
/*
* Object model:
*
* All entries are simply added to a GList first. Then we build
* an index to each entry for each id/format
*
*
* memindex
* -----------------------------...
* ! !
* id1 id2
* ------------
* ! !
* format1 format2
* ! !
* GTree GTree
*
*
* The memindex creates a MemIndexId object for each writer id, a
* Hashtable is kept to map the id to the MemIndexId
*
* The MemIndexId keeps a MemIndexFormatIndex for each format the
* specific writer wants indexed.
*
* The MemIndexFormatIndex keeps all the values of the particular
* format in a GTree, The values of the GTree point back to the entry.
*
* Finding a value for an id/format requires locating the correct GTree,
* then do a lookup in the Tree to get the required value.
*/
typedef struct
{
GstFormat format;
gint offset;
GTree *tree;
} GstMemIndexFormatIndex;
typedef struct
{
gint id;
GHashTable *format_index;
} GstMemIndexId;
typedef struct _GstMemIndex GstMemIndex;
typedef struct _GstMemIndexClass GstMemIndexClass;
struct _GstMemIndex
{
GstIndex parent;
GList *associations;
GHashTable *id_index;
};
struct _GstMemIndexClass
{
GstIndexClass parent_class;
};
/* Index signals and args */
enum
{
LAST_SIGNAL
};
enum
{
ARG_0,
/* FILL ME */
};
static void gst_mem_index_class_init (GstMemIndexClass * klass);
static void gst_mem_index_init (GstMemIndex * index);
static void gst_mem_index_dispose (GObject * object);
static void gst_mem_index_add_entry (GstIndex * index, GstIndexEntry * entry);
static GstIndexEntry *gst_mem_index_get_assoc_entry (GstIndex * index, gint id,
GstIndexLookupMethod method, GstAssocFlags flags,
GstFormat format, gint64 value, GCompareDataFunc func, gpointer user_data);
#define CLASS(mem_index) GST_MEM_INDEX_CLASS (G_OBJECT_GET_CLASS (mem_index))
static GstIndex *parent_class = NULL;
/*static guint gst_mem_index_signals[LAST_SIGNAL] = { 0 }; */
GType
gst_mem_index_get_type (void)
{
static GType mem_index_type = 0;
if (!mem_index_type) {
static const GTypeInfo mem_index_info = {
sizeof (GstMemIndexClass),
NULL,
NULL,
(GClassInitFunc) gst_mem_index_class_init,
NULL,
NULL,
sizeof (GstMemIndex),
1,
(GInstanceInitFunc) gst_mem_index_init,
NULL
};
mem_index_type =
g_type_register_static (GST_TYPE_INDEX, "GstMemIndex", &mem_index_info,
0);
}
return mem_index_type;
}
static void
gst_mem_index_class_init (GstMemIndexClass * klass)
{
GObjectClass *gobject_class;
GstIndexClass *gstindex_class;
gobject_class = (GObjectClass *) klass;
gstindex_class = (GstIndexClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_INDEX);
gobject_class->dispose = gst_mem_index_dispose;
gstindex_class->add_entry = gst_mem_index_add_entry;
gstindex_class->get_assoc_entry = gst_mem_index_get_assoc_entry;
}
static void
gst_mem_index_init (GstMemIndex * index)
{
GST_DEBUG ("created new mem index");
index->associations = NULL;
index->id_index = g_hash_table_new (g_int_hash, g_int_equal);
}
static void
gst_mem_index_dispose (GObject * object)
{
//GstMemIndex *memindex = GST_MEM_INDEX (object);
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_mem_index_add_id (GstIndex * index, GstIndexEntry * entry)
{
GstMemIndex *memindex = GST_MEM_INDEX (index);
GstMemIndexId *id_index;
id_index = g_hash_table_lookup (memindex->id_index, &entry->id);
if (!id_index) {
id_index = g_new0 (GstMemIndexId, 1);
id_index->id = entry->id;
id_index->format_index = g_hash_table_new (g_int_hash, g_int_equal);
g_hash_table_insert (memindex->id_index, &id_index->id, id_index);
}
}
static gint
mem_index_compare (gconstpointer a, gconstpointer b, gpointer user_data)
{
GstMemIndexFormatIndex *index = user_data;
gint64 val1, val2;
gint64 diff;
val1 = GST_INDEX_ASSOC_VALUE (((GstIndexEntry *) a), index->offset);
val2 = GST_INDEX_ASSOC_VALUE (((GstIndexEntry *) b), index->offset);
diff = (val2 - val1);
return (diff == 0 ? 0 : (diff > 0 ? 1 : -1));
}
static void
gst_mem_index_index_format (GstMemIndexId * id_index, GstIndexEntry * entry,
gint assoc)
{
GstMemIndexFormatIndex *index;
GstFormat *format;
format = &GST_INDEX_ASSOC_FORMAT (entry, assoc);
index = g_hash_table_lookup (id_index->format_index, format);
if (!index) {
index = g_new0 (GstMemIndexFormatIndex, 1);
index->format = *format;
index->offset = assoc;
index->tree = g_tree_new_with_data (mem_index_compare, index);
g_hash_table_insert (id_index->format_index, &index->format, index);
}
g_tree_insert (index->tree, entry, entry);
}
static void
gst_mem_index_add_association (GstIndex * index, GstIndexEntry * entry)
{
GstMemIndex *memindex = GST_MEM_INDEX (index);
GstMemIndexId *id_index;
memindex->associations = g_list_prepend (memindex->associations, entry);
id_index = g_hash_table_lookup (memindex->id_index, &entry->id);
if (id_index) {
gint i;
for (i = 0; i < GST_INDEX_NASSOCS (entry); i++) {
gst_mem_index_index_format (id_index, entry, i);
}
}
}
static void
gst_mem_index_add_object (GstIndex * index, GstIndexEntry * entry)
{
}
static void
gst_mem_index_add_format (GstIndex * index, GstIndexEntry * entry)
{
}
static void
gst_mem_index_add_entry (GstIndex * index, GstIndexEntry * entry)
{
GST_LOG_OBJECT (index, "added this entry");
switch (entry->type) {
case GST_INDEX_ENTRY_ID:
gst_mem_index_add_id (index, entry);
break;
case GST_INDEX_ENTRY_ASSOCIATION:
gst_mem_index_add_association (index, entry);
break;
case GST_INDEX_ENTRY_OBJECT:
gst_mem_index_add_object (index, entry);
break;
case GST_INDEX_ENTRY_FORMAT:
gst_mem_index_add_format (index, entry);
break;
default:
break;
}
}
typedef struct
{
gint64 value;
GstMemIndexFormatIndex *index;
gboolean exact;
GstIndexEntry *lower;
gint64 low_diff;
GstIndexEntry *higher;
gint64 high_diff;
} GstMemIndexSearchData;
static gint
mem_index_search (gconstpointer a, gconstpointer b)
{
GstMemIndexSearchData *data = (GstMemIndexSearchData *) b;
GstMemIndexFormatIndex *index = data->index;
gint64 val1, val2;
gint64 diff;
val1 = GST_INDEX_ASSOC_VALUE (((GstIndexEntry *) a), index->offset);
val2 = data->value;
diff = (val1 - val2);
if (diff == 0)
return 0;
/* exact matching, don't update low/high */
if (data->exact)
return (diff > 0 ? 1 : -1);
if (diff < 0) {
if (diff > data->low_diff) {
data->low_diff = diff;
data->lower = (GstIndexEntry *) a;
}
diff = -1;
} else {
if (diff < data->high_diff) {
data->high_diff = diff;
data->higher = (GstIndexEntry *) a;
}
diff = 1;
}
return diff;
}
static GstIndexEntry *
gst_mem_index_get_assoc_entry (GstIndex * index, gint id,
GstIndexLookupMethod method,
GstAssocFlags flags,
GstFormat format, gint64 value, GCompareDataFunc func, gpointer user_data)
{
GstMemIndex *memindex = GST_MEM_INDEX (index);
GstMemIndexId *id_index;
GstMemIndexFormatIndex *format_index;
GstIndexEntry *entry;
GstMemIndexSearchData data;
id_index = g_hash_table_lookup (memindex->id_index, &id);
if (!id_index)
return NULL;
format_index = g_hash_table_lookup (id_index->format_index, &format);
if (!format_index)
return NULL;
data.value = value;
data.index = format_index;
data.exact = (method == GST_INDEX_LOOKUP_EXACT);
/* setup data for low/high checks if we are not looking
* for an exact match */
if (!data.exact) {
data.low_diff = G_MININT64;
data.lower = NULL;
data.high_diff = G_MAXINT64;
data.higher = NULL;
}
entry = g_tree_search (format_index->tree, mem_index_search, &data);
/* get the low/high values if we're not exact */
if (entry == NULL && !data.exact) {
if (method == GST_INDEX_LOOKUP_BEFORE)
entry = data.lower;
else if (method == GST_INDEX_LOOKUP_AFTER) {
entry = data.higher;
}
}
if (entry) {
if ((GST_INDEX_ASSOC_FLAGS (entry) & flags) != flags) {
GList *l_entry = g_list_find (memindex->associations, entry);
entry = NULL;
while (l_entry) {
entry = (GstIndexEntry *) l_entry->data;
if (entry->id == id && (GST_INDEX_ASSOC_FLAGS (entry) & flags) == flags)
break;
if (method == GST_INDEX_LOOKUP_BEFORE)
l_entry = g_list_next (l_entry);
else if (method == GST_INDEX_LOOKUP_AFTER) {
l_entry = g_list_previous (l_entry);
}
}
}
}
return entry;
}
gboolean
gst_mem_index_plugin_init (GstPlugin * plugin)
{
GstIndexFactory *factory;
factory = gst_index_factory_new ("memindex",
"A index that stores entries in memory", gst_mem_index_get_type ());
if (factory != NULL) {
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
} else {
g_warning ("could not register memindex");
}
return TRUE;
}