Fixed issue with getParam size check.

quad/src/quad_app/callbacks.c

@@ -179,7 +179,7 @@ int cb_setparam(modular_structs_t *structs, metadata_t *meta, u8 *data, u16 leng
 int cb_getparam(modular_structs_t* structs, metadata_t *meta,  u8 *data, u16 length)
 {
 	// Check if the data length is correct
-	if (length != 8) {return -1;}
+	if (length != 4) {return -1;}
 	u16 msg_id = meta->msg_id;
 
 	// Get the controller ID, parameter ID
@@ -306,18 +306,86 @@ int cb_getoutput(modular_structs_t* structs, metadata_t *meta,  u8 *data, u16 le
 /*
  * Handles a request for the list of nodes in the graph
  * For N total nodes, returns data in the following format:
- * |---------------------------------------------------------------------------|
- * |  data index ||     0 - 2*N    |     2 - 3     |    4 - 5    |     6 - 7     |
- * |---------------------------------------------------------------------------|
- * |   parameter || Array of node  | dest input ID | src node ID | src output ID |
- * |---------------------------------------------------------------------------|
- * |       bytes ||       2      |       2       |      2      |       2       |
- * |---------------------------------------------------------------------------|
+ * The node IDs and type IDs are consecutive shorts
+ * The node names are null-separated
+ * |---------------------------------------------------------------|
+ * |  data index ||   0 - 2*N-1  |  2*N - 4*N-1  | 4*N - (< 4096)  |
+ * |---------------------------------------------------------------|
+ * |   parameter ||  Node IDs   | Node type IDs  |    Node names   |
+ * |---------------------------------------------------------------|
+ * |       bytes ||     2*N     |      2*N       |      < 4096     |
+ * |---------------------------------------------------------------|
  */
 int cb_getnodes(modular_structs_t* structs, metadata_t *meta,  u8 *data, u16 length) {
+	const struct computation_graph* graph = structs->parameter_struct.graph;
+	if (graph->n_nodes >= 150) {
+		static char* error_msg = "Over 150 nodes. Not responding to cb_getnodes for fear of buffer overflow.";
+		send_data(&structs->hardware_struct.uart, DEBUG_ID, 0,
+				error_msg, sizeof(error_msg));
+		return -1;
+	}
+	
+	// Number of bytes in node ID being sent. Currently short (16 bits)
+	size_t id_len = 2;
+
+	char resp_buf[4096];
+	int i;
+	// Currently ID is always index in array.
+	// computation_graph provides no method of accessing ID, since it is implicit
+	for (i = 0; i < graph->n_nodes; i++) {
+		pack_short(i, resp_buf + (id_len * i));
+	}
+
+	// Construct type IDs
+	size_t offset = id_len * graph->n_nodes;
+	for (i = 0; i < graph->n_nodes; i++) {
+		int type_id = graph->nodes[i].type->type_id;
+		pack_short(type_id, resp_buf + offset + (id_len * i));
+	}
+
+	// Construct list of node names
+	offset += id_len * graph->n_nodes;
+	for (i = 0; i < graph->n_nodes; i++) {
+		size_t remaining_size = sizeof(resp_buf) - offset;
+		const char* name = graph->nodes[i].name;
+		size_t name_len = strlen(name);
+		if (name_len + 1 <= remaining_size) {
+			memcpy(resp_buf + offset, name, name_len);
+			offset += name_len;
+			// Add null-terminator separator
+			resp_buf[offset] = 0;
+			offset += 1;
+		}
+	}
+
+	send_data(&structs->hardware_struct.uart, RESPNODES_ID, meta->msg_id, resp_buf, offset);
 	return 0;
 }
 
+/*
+ * Handles adding a new node with a particular type and name
+ * Expects the uart buff to have data in the following format:
+ * |---------------------------------------------|
+ * |  data index ||    0 - 1     |     2 - ?     |
+ * |---------------------------------------------|
+ * |   parameter ||    type ID   | New node name |
+ * |---------------------------------------------|
+ * |       bytes ||       2      |       ?       |
+ * |---------------------------------------------|
+ *
+ * Returns the new node ID in the following format:
+ * |-----------------------------|
+ * |  data index ||    0 - 1     | 
+ * |-----------------------------|
+ * |   parameter ||    node ID   |
+ * |------------------------------
+ * |       bytes ||       2      |
+ * |-----------------------------|
+ */
 int cb_addnode(modular_structs_t* structs, metadata_t *meta,  u8 *data, u16 length) {
+	if (length < 2) {return -1;}
+	// Size of name
+	size_t name_len = length - 2;
+
 	return 0;
 }
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