Rework the wire protocol

Send a command stream over the socket.
Implement a new buffer object that holds the data and commands.
Make iterator and builders to parse and construct buffers.
Rework gstreamer elements to use new API for creating and parsing
buffers.
Add _release_buffer to notify a stream when we are done processing the
buffer. This will eventually go all the way to the server and will allow
us to do more complicated buffer management.

src/client/buffer.h

@@ -0,0 +1,132 @@
+/* Pinos
+ * Copyright (C) 2015 Wim Taymans <wim.taymans@gmail.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., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __PINOS_BUFFER_H__
+#define __PINOS_BUFFER_H__
+
+#include <glib-object.h>
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+typedef struct _PinosBuffer PinosBuffer;
+typedef struct _PinosBufferInfo PinosBufferInfo;
+typedef struct _PinosPacketIter PinosPacketIter;
+typedef struct _PinosPacketBuilder PinosPacketBuilder;
+
+#define PINOS_BUFFER_VERSION 0
+
+typedef struct {
+  guint32 flags;
+  guint32 seq;
+  gint64 pts;
+  gint64 dts_offset;
+} PinosBufferHeader;
+
+struct _PinosBuffer {
+  /*< private >*/
+  gsize x[16];
+};
+
+void               pinos_buffer_init_take_data   (PinosBuffer       *buffer,
+                                                  gpointer           data,
+                                                  gsize              size,
+                                                  GSocketControlMessage *message);
+
+void               pinos_buffer_clear            (PinosBuffer       *buffer);
+
+const PinosBufferHeader *
+                   pinos_buffer_get_header       (PinosBuffer       *buffer,
+                                                  guint32           *version);
+int                pinos_buffer_get_fd           (PinosBuffer       *buffer,
+                                                  gint               index,
+                                                  GError           **error);
+GSocketControlMessage *
+                   pinos_buffer_get_socket_control_message  (PinosBuffer *buffer);
+
+gsize              pinos_buffer_get_size         (PinosBuffer       *buffer);
+void               pinos_buffer_store            (PinosBuffer       *buffer,
+                                                  gpointer           data);
+
+
+typedef enum {
+  PINOS_PACKET_TYPE_INVALID           = 0,
+
+  PINOS_PACKET_TYPE_FD_PAYLOAD        = 1,
+  PINOS_PACKET_TYPE_FORMAT_CHANGE     = 2,
+  PINOS_PACKET_TYPE_PROPERTY_CHANGE   = 3,
+} PinosPacketType;
+
+
+/* iterating packets */
+struct _PinosPacketIter {
+  /*< private >*/
+  gsize x[16];
+};
+
+void               pinos_packet_iter_init_full   (PinosPacketIter *iter,
+                                                  PinosBuffer     *buffer,
+                                                  guint32          version);
+#define pinos_packet_iter_init(i,b)   pinos_packet_iter_init_full(i,b, PINOS_BUFFER_VERSION);
+
+gboolean           pinos_packet_iter_next        (PinosPacketIter *iter);
+
+PinosPacketType    pinos_packet_iter_get_type    (PinosPacketIter *iter);
+gpointer           pinos_packet_iter_get_data    (PinosPacketIter *iter, gsize *size);
+
+/**
+ * PinosPacketBuilder:
+ */
+struct _PinosPacketBuilder {
+  /*< private >*/
+  gsize x[16];
+};
+
+void               pinos_packet_builder_init_full (PinosPacketBuilder      *builder,
+                                                   guint32                  version,
+                                                   const PinosBufferHeader *header);
+#define pinos_packet_builder_init(b,h)   pinos_packet_builder_init_full(b, PINOS_BUFFER_VERSION,h);
+
+void               pinos_packet_builder_end       (PinosPacketBuilder *builder,
+                                                   PinosBuffer        *buffer);
+
+/* fd-payload packets */
+/**
+ * PinosPacketFDPayload:
+ * @fd_index: the index of the fd with the data
+ * @offset: the offset of the data
+ * @size: the size of the data
+ *
+ * A Packet that contains data in an fd at @fd_index at @offset and with
+ * @size.
+ */
+typedef struct {
+  gint32 fd_index;
+  gint64 offset;
+  gint64 size;
+} PinosPacketFDPayload;
+
+void               pinos_packet_iter_parse_fd_payload   (PinosPacketIter      *iter,
+                                                         PinosPacketFDPayload *payload);
+gboolean           pinos_packet_builder_add_fd_payload  (PinosPacketBuilder   *builder,
+                                                         gint64 offset, gint64 size, int fd,
+                                                         GError              **error);
+
+#endif /* __PINOS_BUFFER_H__ */
+