Function GMT_Open_VirtualFile

src/gmt_api.c:9253–9363

! . */

 /*! . */
int GMT_Open_VirtualFile (void *V_API, unsigned int family, unsigned int geometry, unsigned int direction, void *data, char *name) {
	/* Associate a virtual file with a data object for either reading or writing.
	 * Family and geometry specifies the nature of the data to be read or written.
	 * Direction is either GMT_IN or GMT_OUT and determines if we read or write.
	 * Reading: data must point to a data container we wish to read from via a module.
	 * Writing: data is either an existing output data container that the user created
	 *  beforehand or it is NULL and we create an expanding output resource.
	 * name is the name given to the virtual file and is returned. */
	int object_ID = GMT_NOTSET, item_s = 0;
	unsigned int item, orig_family, actual_family = 0, via_type = 0, messenger = 0, module_input, the_mode = GMT_IS_DUPLICATE;
	struct GMTAPI_DATA_OBJECT *S_obj = NULL;
	struct GMTAPI_CTRL *API = NULL;
	if (V_API == NULL) return_error (V_API, GMT_NOT_A_SESSION);
	module_input = (family & GMT_VIA_MODULE_INPUT);	/* Are we registering a resource that is a module input? */
	family -= module_input;
	if (direction & GMT_IS_REFERENCE) {	/* Treat this memory as read-only */
		direction -= GMT_IS_REFERENCE;
		the_mode = GMT_IS_REFERENCE;
	}
	else if (direction & GMT_IS_DUPLICATE)	/* This is the default - just remove the mode flag */
		direction -= GMT_IS_DUPLICATE;
	if (!(direction == GMT_IN || direction == GMT_OUT)) return GMT_NOT_A_VALID_DIRECTION;
	if (direction == GMT_IN && data == NULL) return GMT_PTR_IS_NULL;
	if (name == NULL) return_error (V_API, GMT_PTR_IS_NULL);
	orig_family = family;	/* In case we will call GMT_Create_Data later */
	actual_family = gmtapi_separate_families (&family);	/* In case via have a VIA situation */
	if (geometry >= GMT_VIA_CHAR) {
		via_type = (geometry / 100);	/* via_type is 1 higher than GMT_CHAR */
		geometry %= 100;
	}
	if (direction == GMT_IN  && !gmtapi_valid_input_family (family))  return GMT_NOT_A_VALID_FAMILY;
	if (direction == GMT_OUT && !gmtapi_valid_output_family (family)) return GMT_NOT_A_VALID_FAMILY;
	if (via_type && data && !gmtapi_valid_type (via_type-1)) return GMT_NOT_A_VALID_TYPE;	/* via type only valid if not passing any data but want vector or matrix */
	if (actual_family != family && !gmtapi_valid_via_family (actual_family)) return GMT_NOT_A_VALID_FAMILY;
	API = gmtapi_get_api_ptr (V_API);

	if (data) {	/* Data container provided, see if registered */
		for (item = 0; object_ID == GMT_NOTSET && item < API->n_objects; item++) {	/* Loop over all objects */
			if (!API->object[item]) continue;	/* Skip freed objects */
			if (API->object[item]->resource == data) object_ID = API->object[item]->ID;	/* Found a matching data pointer */
		}
		if (object_ID != GMT_NOTSET && (item_s = gmtapi_get_item (API, family, data)) == GMT_NOTSET) {	/* Not found in list */
			return_error (API, GMT_OBJECT_NOT_FOUND);	/* Could not find that item in the array despite finding its ID? */
		}
		S_obj = API->object[item_s];	/* Short-hand for later */
		if (!(S_obj->family == family && S_obj->actual_family == actual_family))
			 return GMT_NOT_A_VALID_FAMILY;
	}
	if (direction == GMT_IN) {	/* Set things up for reading */
		/* See if this one is known to us already */
		if (object_ID == GMT_NOTSET) {	/* Register data as a new object for reading [GMT_IN] and reset its status to unread */
			if ((object_ID = GMT_Register_IO (API, family, the_mode|GMT_IO_RESET, geometry, GMT_IN, NULL, data)) == GMT_NOTSET)
				return (API->error);
			if ((item_s = gmtapi_get_item (API, family, data)) == GMT_NOTSET) {	/* Not found in list */
				return_error (API, GMT_OBJECT_NOT_FOUND);	/* Could not find that item in the array despite finding its ID? */
			}
			S_obj = API->object[item_s];	/* Short-hand for later */
		}