node: Add id to set_io

Make it possible to configure multiple io areas on a port by giving
an id to set_io.
Add some types to enumerate the supported ids
Make an area to exchange buffers and one to specify pull ranges.
The idea is to make more area types for controlable properties.
Implement enumeration of IO areas in volume.

spa/include/spa/node/node.h

@@ -38,32 +38,6 @@ struct spa_node;
 #include <spa/node/event.h>
 #include <spa/node/command.h>
 
-/** A range */
-struct spa_range {
-	uint64_t offset;	/**< offset in range */
-	uint32_t min_size;	/**< minimum size of data */
-	uint32_t max_size;	/**< maximum size of data */
-};
-
-/** Port IO area
- *
- * IO information for a port on a node. This is allocated
- * by the host and configured on all ports for which IO is requested.
- */
-struct spa_port_io {
-#define SPA_STATUS_OK			0
-#define SPA_STATUS_NEED_BUFFER		1
-#define SPA_STATUS_HAVE_BUFFER		2
-#define SPA_STATUS_FORMAT_CHANGED	3
-#define SPA_STATUS_PORTS_CHANGED	4
-#define SPA_STATUS_PARAM_CHANGED	5
-	int32_t status;			/**< the status code */
-	uint32_t buffer_id;		/**< a buffer id */
-	struct spa_range range;		/**< the requested range */
-};
-
-#define SPA_PORT_IO_INIT  (struct spa_port_io) { SPA_STATUS_OK, SPA_ID_INVALID, }
-
 /**
  * Port information structure
  *
@@ -350,6 +324,7 @@ struct spa_node {
 	 * \param node a #struct spa_node
 	 * \param direction a #enum spa_direction
 	 * \param port_id the port to configure
+	 * \param id the parameter id to set
 	 * \param flags optional flags
 	 * \param param a #struct spa_pod with the parameter to set
 	 * \return 0 on success
@@ -372,16 +347,19 @@ struct spa_node {
 	/**
 	 * Tell the port to use the given buffers
 	 *
+	 * The port should also have a spa_io_buffers io area configured to exchange
+	 * the buffers with the port.
+	 *
 	 * For an input port, all the buffers will remain dequeued. Once a buffer
 	 * has been pushed on a port with port_push_input, it should not be reused
 	 * until the reuse_buffer event is notified or when the buffer has been
-	 * returned in the spa_port_io of the port.
+	 * returned in the spa_io_buffers of the port.
 	 *
 	 * For output ports, all buffers will be queued in the port. When process_input
 	 * or process_output return SPA_STATUS_HAVE_BUFFER, buffers are available in
-	 * one or more of the spa_port_io areas.
+	 * one or more of the spa_io_buffers areas.
 	 * When a buffer can be reused, port_reuse_buffer() should be called or the
-	 * buffer_id should be placed in the spa_port_io area before calling
+	 * buffer_id should be placed in the spa_io_buffers area before calling
 	 * process_output.
 	 *
 	 * Passing NULL as \a buffers will remove the reference that the port has
@@ -404,6 +382,9 @@ struct spa_node {
 	/**
 	 * Tell the port to allocate memory for \a buffers.
 	 *
+	 * The port should also have a spa_io_buffers io area configured to exchange
+	 * the buffers with the port.
+	 *
 	 * \a buffers should contain an array of pointers to buffers. The data
 	 * in the buffers should point to an array of at least 1 data entry
 	 * with a 0 type that will be filled by this function.
@@ -439,23 +420,28 @@ struct spa_node {
 				   uint32_t *n_buffers);
 
 	/**
-	 * Configure the given io structure on \a port_id. This
-	 * structure is allocated by the host and is used to query the state
-	 * of the port and exchange buffers with the port.
+	 * Configure the given memory area with \a id on \a port_id. This
+	 * structure is allocated by the host and is used to exchange
+	 * data and parameters with the port.
 	 *
-	 * Setting an \a io of NULL will disable the port.
+	 * Setting an \a io of NULL will disable the port io.
 	 *
 	 * This function must be called from the main thread.
 	 *
 	 * \param direction a spa_direction
 	 * \param port_id a port id
-	 * \param io a spa_port_io
+	 * \param id the id of the io area, the available ids can be
+	 *        enumerated with the port parameters.
+	 * \param io a io area memory
 	 * \return 0 on success
+	 *         -EINVAL when node is NULL the port is not valid
+	 *         -ENOENT when \id is unknown
 	 */
 	int (*port_set_io) (struct spa_node *node,
 			    enum spa_direction direction,
 			    uint32_t port_id,
-			    struct spa_port_io *io);
+			    uint32_t id,
+			    void *io);
 
 	/**
 	 * Tell an output port to reuse a buffer.