libs/gst/bytestream/: add GstAdapter, similar to bytestream, but oesn't require ugly event handling or uglier loopbas...

Original commit message from CVS:
* libs/gst/bytestream/Makefile.am:
* libs/gst/bytestream/adapter.c:
* libs/gst/bytestream/adapter.h:
add GstAdapter, similar to bytestream, but oesn't require ugly event
handling or uglier loopbased elements

ChangeLog

@@ -1,3 +1,11 @@
+2004-05-04  Benjamin Otte  <otte@gnome.org>
+
+	* libs/gst/bytestream/Makefile.am:
+	* libs/gst/bytestream/adapter.c: 
+	* libs/gst/bytestream/adapter.h:
+	  add GstAdapter, similar to bytestream, but oesn't require ugly event
+	  handling or uglier loopbased elements
+
 2004-05-03  David Schleef  <ds@schleef.org>
 
 	* testsuite/caps/Makefile.am: Fix spelling of Ηρατοσθενες

libs/gst/bytestream/Makefile.am

@@ -6,9 +6,9 @@ EXTRA_DIST = $(as_libtool_EXTRA_DIST)
 noinst_DATA = $(as_libtool_noinst_DATA_files)
 
 libgstbytestreamincludedir = $(includedir)/gstreamer-@GST_MAJORMINOR@/gst/bytestream
-libgstbytestreaminclude_HEADERS = bytestream.h
+libgstbytestreaminclude_HEADERS = bytestream.h adapter.h
 
-libgstbytestream_la_SOURCES = bytestream.c 
+libgstbytestream_la_SOURCES = bytestream.c adapter.c
 libgstbytestream_la_CFLAGS = $(GST_CFLAGS)
 libgstbytestream_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS) $(as_libtool_LDFLAGS)
 

libs/gst/bytestream/adapter.c

@@ -0,0 +1,253 @@
+/* GStreamer
+ * Copyright (C) 2001 Erik Walthinsen <omega@temple-baptist.com>
+ *
+ * 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 "adapter.h"
+#include <string.h>
+
+/* default size for the assembled data buffer */
+#define DEFAULT_SIZE 16
+
+GST_DEBUG_CATEGORY_STATIC (gst_adapter_debug);
+#define GST_CAT_DEFAULT gst_adapter_debug
+
+#define _do_init(thing) \
+  GST_DEBUG_CATEGORY_INIT (gst_adapter_debug, "GstAdapter", 0, "object to splice and merge buffers to dewsired size")
+GST_BOILERPLATE_FULL (GstAdapter, gst_adapter, GObject, G_TYPE_OBJECT, _do_init)
+
+     static void gst_adapter_dispose (GObject * object);
+     static void gst_adapter_finalize (GObject * object);
+
+     static void gst_adapter_base_init (gpointer g_class)
+{
+}
+
+static void
+gst_adapter_class_init (GstAdapterClass * klass)
+{
+  GObjectClass *object = G_OBJECT_CLASS (klass);
+
+  object->dispose = gst_adapter_dispose;
+  object->finalize = gst_adapter_finalize;
+}
+
+static void
+gst_adapter_init (GstAdapter * adapter)
+{
+  adapter->assembled_data = g_malloc (DEFAULT_SIZE);
+  adapter->assembled_size = DEFAULT_SIZE;
+}
+
+static void
+gst_adapter_dispose (GObject * object)
+{
+  GstAdapter *adapter = GST_ADAPTER (object);
+
+  gst_adapter_clear (adapter);
+
+  GST_CALL_PARENT (G_OBJECT_CLASS, dispose, (object));
+}
+
+static void
+gst_adapter_finalize (GObject * object)
+{
+  GstAdapter *adapter = GST_ADAPTER (object);
+
+  g_free (adapter->assembled_data);
+
+  GST_CALL_PARENT (G_OBJECT_CLASS, finalize, (object));
+}
+
+/**
+ * gst_adapter_new:
+ *
+ * Creates a new #GstAdapter.
+ *
+ * Returns: a new #GstAdapter
+ */
+GstAdapter *
+gst_adapter_new (void)
+{
+  return g_object_new (GST_TYPE_ADAPTER, NULL);
+}
+
+/**
+ * gst_adapter_clear:
+ * @adapter: the #GstAdapter to clear
+ *
+ * Removes all buffers from the @adapter.
+ */
+void
+gst_adapter_clear (GstAdapter * adapter)
+{
+  g_return_if_fail (GST_IS_ADAPTER (adapter));
+
+  g_slist_foreach (adapter->buflist, (GFunc) gst_data_unref, NULL);
+  g_slist_free (adapter->buflist);
+  adapter->buflist = NULL;
+  adapter->size = 0;
+  adapter->skip = 0;
+  adapter->assembled_len = 0;
+}
+
+/**
+ * gst_adapter_push:
+ * @adapter: a #GstAdapter
+ * @buf: the #GstBuffer to queue into the adapter
+ *
+ * Adds the data from @buf to the data stored inside @adapter and takes 
+ * ownership of the buffer.
+ */
+void
+gst_adapter_push (GstAdapter * adapter, GstBuffer * buf)
+{
+  g_return_if_fail (GST_IS_ADAPTER (adapter));
+  g_return_if_fail (GST_IS_BUFFER (buf));
+
+  adapter->size += GST_BUFFER_SIZE (buf);
+  adapter->buflist = g_slist_append (adapter->buflist, buf);
+}
+
+/**
+ * gst_adapter_peek:
+ * @adapter: a #GstAdapter
+ * @size: number of bytes to peek
+ *
+ * Gets the first @size bytes stored in the @adapter. If this many bytes are
+ * not available, it returns NULL. The returned pointer is valid until the next
+ * function is called on the adapter.
+ *
+ * Returns: a pointer to the first @size bytes of data or NULL
+ */
+const guint8 *
+gst_adapter_peek (GstAdapter * adapter, guint size)
+{
+  GstBuffer *cur;
+  GSList *cur_list;
+  guint copied;
+
+  g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
+  g_return_val_if_fail (size > 0, NULL);
+
+  if (size > adapter->size)
+    return NULL;
+
+  if (adapter->assembled_len >= size)
+    return adapter->assembled_data;
+
+  cur = adapter->buflist->data;
+  if (GST_BUFFER_SIZE (cur) >= size + adapter->skip)
+    return GST_BUFFER_DATA (cur) + adapter->skip;
+
+  if (adapter->assembled_size < size) {
+    adapter->assembled_size = (size / DEFAULT_SIZE + 1) * DEFAULT_SIZE;
+    GST_DEBUG_OBJECT (adapter, "setting size of internal buffer to %u\n",
+        adapter->assembled_size);
+    adapter->assembled_data =
+        g_realloc (adapter->assembled_data, adapter->assembled_size);
+  }
+  adapter->assembled_len = size;
+  copied = GST_BUFFER_SIZE (cur) - adapter->skip;
+  memcpy (adapter->assembled_data, GST_BUFFER_DATA (cur) + adapter->skip,
+      copied);
+  cur_list = g_slist_next (adapter->buflist);
+  while (copied < size) {
+    g_assert (cur_list);
+    cur = cur_list->data;
+    cur_list = g_slist_next (cur_list);
+    memcpy (adapter->assembled_data + copied, GST_BUFFER_DATA (cur),
+        MIN (GST_BUFFER_SIZE (cur), size - copied));
+    copied = MIN (size, copied + GST_BUFFER_SIZE (cur));
+  }
+
+  return adapter->assembled_data;
+}
+
+/**
+ * gst_adapter_flush:
+ * @adapter: a #GstAdapter
+ * @flush: number of bytes to flush
+ *
+ * Flushes the first @flush bytes of the @adapter.
+ */
+void
+gst_adapter_flush (GstAdapter * adapter, guint flush)
+{
+  GstBuffer *cur;
+
+  g_return_if_fail (GST_IS_ADAPTER (adapter));
+  g_return_if_fail (flush > 0);
+  g_return_if_fail (flush <= adapter->size);
+
+  GST_LOG_OBJECT (adapter, "flushing %u bytes\n", flush);
+  adapter->size -= flush;
+  adapter->assembled_len = 0;
+  while (flush > 0) {
+    cur = adapter->buflist->data;
+    if (GST_BUFFER_SIZE (cur) <= flush + adapter->skip) {
+      /* can skip whole buffer */
+      flush -= GST_BUFFER_SIZE (cur) - adapter->skip;
+      adapter->skip = 0;
+      adapter->buflist = g_slist_remove (adapter->buflist, cur);
+      gst_data_unref (GST_DATA (cur));
+    } else {
+      adapter->skip += flush;
+      break;
+    }
+  }
+}
+
+/**
+ * gst_adapter_available:
+ * @adapter: a #GstAdapter
+ *
+ * Gets the maximum amount of bytes available, that is it returns the maximum 
+ * value that can be supplied to gst_adapter_peek() without that function 
+ * returning NULL.
+ *
+ * Returns: amount of bytes available in @adapter
+ */
+guint
+gst_adapter_available (GstAdapter * adapter)
+{
+  g_return_val_if_fail (GST_IS_ADAPTER (adapter), 0);
+
+  return adapter->size;
+}
+
+/**
+ * gst_adapter_available_fast:
+ * @adapter: a #GstAdapter
+ *
+ * Gets the maximum amount of bytes available without the need to do expensive
+ * operations (like copying the data into a temporary buffer).
+ *
+ * Returns: amount of bytes available in @adapter without expensive operations
+ */
+guint
+gst_adapter_available_fast (GstAdapter * adapter)
+{
+  g_return_val_if_fail (GST_IS_ADAPTER (adapter), 0);
+
+  if (!adapter->buflist)
+    return 0;
+  if (adapter->assembled_len)
+    return adapter->assembled_len;
+  g_assert (GST_BUFFER_SIZE (adapter->buflist->data) > adapter->skip);
+  return GST_BUFFER_SIZE (adapter->buflist->data) - adapter->skip;
+}

libs/gst/bytestream/adapter.h

@@ -0,0 +1,75 @@
+/* GStreamer
+ * Copyright (C) 2001 Erik Walthinsen <omega@temple-baptist.com>
+ *
+ * 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>
+
+#ifndef __GST_ADAPTER_H__
+#define __GST_ADAPTER_H__
+
+G_BEGIN_DECLS
+
+
+#define GST_TYPE_ADAPTER \
+  (gst_adapter_get_type())
+#define GST_ADAPTER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ADAPTER,GstAdapter))
+#define GST_ADAPTER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ADAPTER,GstAdapterClass))
+#define GST_IS_ADAPTER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ADAPTER))
+#define GST_IS_ADAPTER_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ADAPTER))
+
+typedef struct _GstAdapter GstAdapter;
+typedef struct _GstAdapterClass GstAdapterClass;
+
+struct _GstAdapter {
+  GObject	object;
+
+  GSList *	buflist;
+  guint		size;
+  guint		skip;
+
+  /* we keep state of assembled pieces */
+  guint8 *	assembled_data;
+  guint		assembled_size;
+  guint		assembled_len;
+
+  gpointer _gst_reserved[GST_PADDING];
+};
+
+struct _GstAdapterClass {
+  GObjectClass	parent_class;
+
+  gpointer _gst_reserved[GST_PADDING];
+};
+
+GstAdapter *		gst_adapter_new			(void);
+
+void			gst_adapter_clear		(GstAdapter *adapter);
+void			gst_adapter_push		(GstAdapter *adapter, GstBuffer* buf);
+const guint8 *		gst_adapter_peek      		(GstAdapter *adapter, guint size);
+void			gst_adapter_flush		(GstAdapter *adapter, guint flush);
+guint			gst_adapter_available		(GstAdapter *adapter);
+guint			gst_adapter_available_fast    	(GstAdapter *adapter);
+
+
+G_END_DECLS
+
+#endif /* __GST_ADAPTER_H__ */