Implement BMediaRoster::GetNodeAttributesFor

headers/private/media/ServerInterface.h

@@ -93,6 +93,7 @@ enum {
 	NODE_SYNC_TO,
 	NODE_SET_TIMESOURCE,
 	NODE_GET_TIMESOURCE,
+	NODE_GET_ATTRIBUTES_FOR,
 	NODE_REQUEST_COMPLETED,
 	NODE_FINAL_RELEASE,
 	NODE_MESSAGE_END,
@@ -946,6 +947,15 @@ struct node_get_timesource_reply : reply_data {
 	media_node_id			timesource_id;
 };
 
+struct node_get_attributes_for_request : request_data {
+	size_t					count;
+	area_id					area;
+};
+
+struct node_get_attributes_for_reply : reply_data {
+	size_t					filled_count;
+};
+
 struct node_final_release_command : command_data {
 };
 

src/kits/media/MediaNode.cpp

@@ -35,6 +35,7 @@
 #include <FileInterface.h>
 #include <MediaRoster.h>
 #include <MediaNode.h>
+#include <SupportDefs.h>
 #include <TimeSource.h>
 
 #include <string.h>
@@ -707,6 +708,42 @@ BMediaNode::HandleMessage(int32 message, const void* data, size_t size)
 			return B_OK;
 		}
 
+		case NODE_GET_ATTRIBUTES_FOR:
+		{
+			const node_get_attributes_for_request *request =
+				(const node_get_attributes_for_request*) data;
+
+			TRACE("BMediaNode::HandleMessage NODE_GET_ATTRIBUTES_FOR,"
+				"node %ld\n", fNodeID);
+
+			node_get_attributes_for_reply reply;
+
+			media_node_attribute* addr;
+			area_id dataArea = clone_area("client attributes area",
+				(void**)&addr, B_ANY_ADDRESS, B_WRITE_AREA,
+				request->area);
+
+			if (dataArea < 0) {
+				ERROR("NODE_GET_ATTRIBUTES_FOR can't clone area\n");
+				return B_NO_MEMORY;
+			}
+
+			status_t status = GetNodeAttributes(addr, request->count);
+			if (status == B_OK) {
+				// NOTE: we do it because there's not an easy way
+				// to guess the number of attributes filled.
+				size_t i;
+				for (i = 0; i < request->count; i++) {
+					if (addr[i].what <= 0)
+						break;
+				}
+				reply.filled_count = i;
+			}
+			request->SendReply(status, &reply, sizeof(reply));
+			delete_area(dataArea);
+			return B_OK;
+		}
+
 		case NODE_REQUEST_COMPLETED:
 		{
 			const node_request_completed_command* command
@@ -831,7 +868,7 @@ BMediaNode::GetNodeAttributes(media_node_attribute* outAttributes,
 {
 	CALLED();
 	// This is implemented by derived classes that fills
-	// it's own attributes to a max of inMaxCount size.
+	// it's own attributes to a max of inMaxCount elements.
 	return B_ERROR;
 }
 

src/kits/media/MediaRoster.cpp

@@ -3123,8 +3123,41 @@ ssize_t
 BMediaRoster::GetNodeAttributesFor(const media_node& node,
 	media_node_attribute* _array, size_t maxCount)
 {
-	UNIMPLEMENTED();
-	return B_ERROR;
+	CALLED();
+
+	if (IS_INVALID_NODE(node))
+		return B_MEDIA_BAD_NODE;
+
+	node_get_attributes_for_request request;
+	node_get_attributes_for_reply reply;
+	status_t status;
+
+	media_node_attribute* addr = NULL;
+	size_t totalSize = maxCount*sizeof(media_node_attribute);
+	size_t size = (totalSize + (B_PAGE_SIZE - 1)) & ~(B_PAGE_SIZE - 1);
+
+	area_id dataArea = create_area("attributes area", (void**)&addr,
+		B_ANY_ADDRESS, size, B_NO_LOCK,
+		B_READ_AREA | B_WRITE_AREA);
+	// No need to memset the padding
+	memset(addr, 0, totalSize);
+
+	if (dataArea < 0)
+		return B_NO_MEMORY;
+
+	request.count = maxCount;
+	request.area = dataArea;
+
+	status = QueryPort(node.port, NODE_GET_ATTRIBUTES_FOR, &request,
+		sizeof(request), &reply, sizeof(reply));
+	if (status != B_OK)
+		return status;
+
+	memcpy(_array, addr, reply.filled_count
+		* sizeof(media_node_attribute));
+
+	delete_area(dataArea);
+	return reply.filled_count;
 }