added first pass at the GstTimeCache

Original commit message from CVS:
added first pass at the GstTimeCache

gst/gsttimecache.c

@@ -0,0 +1,242 @@
+/* GStreamer
+ * Copyright (C) 2001 RidgeRun (http://www.ridgerun.com/)
+ * Written by Erik Walthinsen <omega@ridgerun.com>
+ *
+ * gsttimecache.c: Cache for location<>time mapping
+ *
+ * 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_private.h"
+
+#include "gsttimecache.h"
+
+
+static void		gst_timecache_class_init	(GstTimeCacheClass *klass);
+static void		gst_timecache_init		(GstTimeCache *tc);
+
+static GstObject *timecache_parent_class = NULL;
+
+GType
+gst_timecache_get_type(void) {
+  static GType tc_type = 0;
+
+  if (!tc_type) {
+    static const GTypeInfo tc_info = {
+      sizeof(GstTimeCacheClass),
+      NULL,
+      NULL,
+      (GClassInitFunc)gst_timecache_class_init,
+      NULL,
+      NULL,
+      sizeof(GstTimeCache),
+      1,
+      (GInstanceInitFunc)gst_timecache_init,
+    };
+    tc_type = g_type_register_static(GST_TYPE_OBJECT, "GstTimeCache", &tc_info, 0);
+  }
+  return tc_type;
+}
+
+static void
+gst_timecache_class_init (GstTimeCacheClass *klass)
+{
+  timecache_parent_class = g_type_class_ref(GST_TYPE_OBJECT);
+}
+
+static GstTimeCacheGroup *
+gst_timecache_group_new(guint groupnum)
+{
+  GstTimeCacheGroup *tcgroup = g_new(GstTimeCacheGroup,1);
+
+  tcgroup->groupnum = groupnum;
+  tcgroup->entries = NULL;
+  tcgroup->certainty = GST_TIMECACHE_UNKNOWN;
+  tcgroup->peergroup = -1;
+  tcgroup->mintimestamp = 0LL;
+  tcgroup->maxtimestamp = 0LL;
+  tcgroup->minlocation = 0LL;
+  tcgroup->maxlocation = 0LL;
+
+  GST_DEBUG(0, "created new timecache group %d\n",groupnum);
+
+  return tcgroup;
+}
+
+static void
+gst_timecache_init (GstTimeCache *tc)
+{
+  tc->curgroup = gst_timecache_group_new(0);
+  tc->maxgroup = 0;
+  tc->groups = g_list_prepend(NULL, tc->curgroup);
+  GST_DEBUG(0, "created new timecache\n");
+}
+
+GstTimeCache *
+gst_timecache_new()
+{
+  GstTimeCache *tc;
+
+  tc = g_object_new (gst_timecache_get_type (), NULL);
+
+  return tc;
+}
+
+gint
+gst_timecache_get_group(GstTimeCache *tc)
+{
+  return tc->curgroup->groupnum;
+}
+
+gint
+gst_timecache_new_group(GstTimeCache *tc)
+{
+  tc->curgroup = gst_timecache_group_new(++tc->maxgroup);
+  tc->groups = g_list_append(tc->groups,tc->curgroup);
+  GST_DEBUG(0, "created new group %d in timecache\n",tc->maxgroup);
+  return tc->maxgroup;
+}
+
+gboolean
+gst_timecache_set_group(GstTimeCache *tc, gint groupnum)
+{
+  GList *list;
+  GstTimeCacheGroup *tcgroup;
+
+  // first check for null change
+  if (groupnum == tc->curgroup->groupnum)
+    return TRUE;
+
+  // else search for the proper group
+  list = tc->groups;
+  while (list) {
+    tcgroup = (GstTimeCacheGroup *)(list->data);
+    list = g_list_next(list);
+    if (tcgroup->groupnum == groupnum) {
+      tc->curgroup = tcgroup;
+      GST_DEBUG(0, "switched to timecache group %d\n", tcgroup->groupnum);
+      return TRUE;
+    }
+  }
+
+  // couldn't find the group in question
+  GST_DEBUG(0, "couldn't find timecache group %d\n",groupnum);
+  return FALSE;
+}
+
+void
+gst_timecache_set_certainty(GstTimeCache *tc, GstTimeCacheCertainty certainty)
+{
+  tc->curgroup->certainty = certainty;
+}
+
+GstTimeCacheCertainty
+gst_timecache_get_certainty(GstTimeCache *tc)
+{
+  return tc->curgroup->certainty;
+}
+
+void
+gst_timecache_add_entry (GstTimeCache *tc, guint64 location, gint64 timestamp)
+{
+  GstTimeCacheEntry *entry = g_new(GstTimeCacheEntry,1);
+
+  entry->location = location;
+  entry->timestamp = timestamp;
+
+  // add the entry to the list
+  tc->curgroup->entries = g_list_prepend(tc->curgroup->entries,entry);
+
+  // update the bounds
+  if (tc->curgroup->mintimestamp > timestamp) tc->curgroup->mintimestamp = timestamp;
+  if (tc->curgroup->maxtimestamp < timestamp) tc->curgroup->maxtimestamp = timestamp;
+  if (tc->curgroup->minlocation > location) tc->curgroup->minlocation = location;
+  if (tc->curgroup->maxlocation < location) tc->curgroup->maxlocation = location;
+
+  GST_DEBUG(0, "added entry to timecache group %d\n",tc->curgroup->groupnum);
+}
+
+gint _gst_timecache_find_location (const GstTimeCacheEntry *entry, const guint64 *location) {
+  if (*location < entry->location) return -1;
+  else if (*location > entry->location) return 1;
+  else return 0;
+}
+
+gboolean
+gst_timecache_find_location (GstTimeCache *tc, guint64 location, gint64 *timestamp)
+{
+  GList *list;
+  GstTimeCacheEntry *entry = NULL;
+
+  // first check to see if it's in the current group
+  if ((tc->curgroup->minlocation <= location) && (location <= tc->curgroup->maxlocation)) {
+    GST_DEBUG(0, "location %Ld is in group %d\n",location,tc->curgroup->groupnum);
+    list = g_list_find_custom(tc->curgroup->entries,&location,(GCompareFunc)_gst_timecache_find_location);
+    if (list) entry = (GstTimeCacheEntry *)(list->data);
+    if (entry) *timestamp = entry->timestamp;
+    return TRUE;
+  }
+
+  // TODO: search other groups
+
+  // failure
+  return FALSE;
+}
+
+gint _gst_timecache_find_timestamp (const GstTimeCacheEntry *entry, const gint64 *timestamp) {
+  if (*timestamp < entry->timestamp) return -1;
+  else if (*timestamp > entry->timestamp) return 1;
+  else return 0;
+}
+
+gboolean
+gst_timecache_find_timestamp (GstTimeCache *tc, gint64 timestamp, guint64 *location)
+{
+  GList *entries, *groups;
+  GstTimeCacheEntry *entry = NULL;
+  GstTimeCacheGroup *group;
+
+  // first check to see if it's in the current group
+  if ((tc->curgroup->mintimestamp <= timestamp) && (timestamp <= tc->curgroup->maxtimestamp)) {
+    GST_DEBUG(0, "timestamp %Ld may be in group %d\n",timestamp,tc->curgroup->groupnum);
+    entries = g_list_find_custom(tc->curgroup->entries,&timestamp,(GCompareFunc)_gst_timecache_find_timestamp);
+    if (entries) entry = (GstTimeCacheEntry *)(entries->data);
+    if (entry) {
+      *location = entry->location;
+      return TRUE;
+    }
+  }
+
+  groups = tc->groups;
+  while (groups) {
+    group = (GstTimeCacheGroup *)(groups->data);
+    groups = g_list_next(groups);
+
+    if ((group->mintimestamp <= timestamp) && (timestamp <= group->maxtimestamp)) {
+      GST_DEBUG(0, "timestamp %Ld may be in group %d\n",timestamp,group->groupnum);
+      entries = g_list_find_custom(group->entries,&timestamp,(GCompareFunc)_gst_timecache_find_timestamp);
+      if (entries) entry = (GstTimeCacheEntry *)(entries->data);
+      if (entry) {
+        *location = entry->location;
+        return TRUE;
+      }
+    }
+  }
+
+  // failure
+  return FALSE;
+}
+

gst/gsttimecache.h

@@ -0,0 +1,108 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ *                    2000 Wim Taymans <wim.taymans@chello.be>
+ *
+ * gsttimecache.h: Header for GstTimeCache
+ *
+ * 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.
+ */
+
+#ifndef __GST_TIMECACHE_H__
+#define __GST_TIMECACHE_H__
+
+#include <gst/gstobject.h>
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+
+#define GST_TYPE_TIMECACHE		(gst_timecache_get_type ())
+#define GST_TIMECACHE(obj)		(G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_TIMECACHE, GstTimeCache))
+#define GST_TIMECACHE_CLASS(klass)	(G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_TIMECACHE, GstTimeCacheClass))
+#define GST_IS_TIMECACHE(obj)		(G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_TIMECACHE))
+#define GST_IS_TIMECACHE_CLASS(obj)	(GST_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_TIMECACHE))
+
+typedef struct _GstTimeCacheEntry GstTimeCacheEntry;
+typedef struct _GstTimeCacheGroup GstTimeCacheGroup;
+typedef struct _GstTimeCache GstTimeCache;
+typedef struct _GstTimeCacheClass GstTimeCacheClass;
+
+typedef enum {
+  GST_TIMECACHE_UNKNOWN,
+  GST_TIMECACHE_CERTAIN,
+  GST_TIMECACHE_FUZZY_LOCATION,
+  GST_TIMECACHE_FUZZY_TIMESTAMP,
+  GST_TIMECACHE_FUZZY,
+} GstTimeCacheCertainty;
+
+struct _GstTimeCacheEntry {
+  guint64 location;
+  gint64 timestamp;
+};
+
+struct _GstTimeCacheGroup {
+  // unique ID of group in cache
+  gint groupnum;
+
+  // list of entries
+  GList *entries;
+
+  // the certainty level of the group
+  GstTimeCacheCertainty certainty;
+
+  // peer group that contains more certain entries
+  gint peergroup;
+
+  // range variables
+  gint64 mintimestamp,maxtimestamp;
+  guint64 minlocation,maxlocation;
+};
+
+struct _GstTimeCacheClass {
+  GstObjectClass parent_class;
+};
+
+struct _GstTimeCache {
+  GstObject		object;
+
+  GList			*groups;
+  GstTimeCacheGroup	*curgroup;
+  gint			maxgroup;
+};
+
+GType			gst_timecache_get_type		(void);
+GstTimeCache*		gst_timecache_new		();
+
+gint			gst_timecache_get_group		(GstTimeCache *tc);
+gint			gst_timecache_new_group		(GstTimeCache *tc);
+gboolean		gst_timecache_set_group		(GstTimeCache *tc, gint groupnum);
+
+void			gst_timecache_set_certainty	(GstTimeCache *tc, GstTimeCacheCertainty certainty);
+GstTimeCacheCertainty	gst_timecache_get_certainty	(GstTimeCache *tc);
+
+void			gst_timecache_add_entry		(GstTimeCache *tc, guint64 location, gint64 timestamp);
+
+gboolean		gst_timecache_find_location	(GstTimeCache *tc, guint64 location, gint64 *timestamp);
+gboolean		gst_timecache_find_timestamp	(GstTimeCache *tc, gint64 timestamp, guint64 *location);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+
+#endif /* __GST_TIMECACHE_H__ */