our current experimental Neutrino branch

git-svn-id: file:///home/bas/coolstream_public_svn/THIRDPARTY/applications/neutrino-experimental@27 e54a6e83-5905-42d5-8d5c-058d10e6a962

src/driver/slotbuffer.c

@@ -0,0 +1,107 @@
+/*
+ * $Header: /cvs/tuxbox/apps/tuxbox/neutrino/src/driver/slotbuffer.c,v 1.1 2004/06/03 09:51:54 thegoodguy Exp $
+ *
+ * (C) 2004 by thegoodguy <thegoodguy@berlios.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+/* Note: this slotbuffer "wastes" one slot */
+
+#include "slotbuffer.h"
+#include <stdlib.h>
+
+slotbuffer_t * slotbuffer_construct(const size_t size)
+{
+	slotbuffer_t * slotbuffer;
+
+	slotbuffer = malloc(sizeof(slotbuffer_t));
+
+	slotbuffer->buffer        = malloc(size);
+	slotbuffer->size          = size;
+	slotbuffer->read_pointer  = 0;
+	slotbuffer->write_pointer = 0;
+	
+	return slotbuffer;
+}
+
+void slotbuffer_destruct(slotbuffer_t * const slotbuffer)
+{
+	free(slotbuffer->buffer);
+	free(slotbuffer);
+}
+
+size_t slotbuffer_remaining_read_space(slotbuffer_t * const slotbuffer)
+{
+	ssize_t delta;
+
+	delta = slotbuffer->write_pointer;
+	delta -= slotbuffer->read_pointer;
+
+	return (delta >= 0) ? delta : (delta + slotbuffer->size);
+}
+
+size_t slotbuffer_remaining_write_space(slotbuffer_t * const slotbuffer)
+{
+	ssize_t delta;
+
+	delta = slotbuffer->read_pointer;
+	delta -= slotbuffer->write_pointer;
+
+	return ((delta > 0) ? delta : (delta + slotbuffer->size)) - 1;
+}
+
+size_t slotbuffer_remaining_continuous_read_space(slotbuffer_t * const slotbuffer)
+{
+	ssize_t delta;
+	size_t  read_pointer;
+
+	delta         = slotbuffer->write_pointer;
+	read_pointer  = slotbuffer->read_pointer;
+	delta        -= read_pointer;
+
+	return (delta >= 0) ? delta : (slotbuffer->size - read_pointer);
+}
+
+size_t slotbuffer_remaining_continuous_write_space(slotbuffer_t * const slotbuffer)
+{
+	ssize_t delta;
+	size_t  write_pointer;
+
+	delta          = slotbuffer->read_pointer;
+
+	if (delta == 0)
+		return (slotbuffer->size - slotbuffer->write_pointer - 1);
+
+	write_pointer  = slotbuffer->write_pointer;
+	delta         -= write_pointer;
+
+	return (delta > 0) ? (delta - 1) : (slotbuffer->size - write_pointer);
+}
+
+void slotbuffer_advance_read_pointer(slotbuffer_t * const slotbuffer, const size_t delta)
+{
+	slotbuffer->read_pointer += delta;
+	if (slotbuffer->read_pointer >= slotbuffer->size)
+		slotbuffer->read_pointer = 0;
+}
+
+void slotbuffer_advance_write_pointer(slotbuffer_t * const slotbuffer, const size_t delta)
+{
+	slotbuffer->write_pointer += delta;
+	if (slotbuffer->write_pointer >= slotbuffer->size)
+		slotbuffer->write_pointer = 0;
+}