/**
* librdf_node_new_static_node_iterator:
* @world: world object
* @nodes: static array of #librdf_node objects
* @size: size of array
*
* Create an iterator over an array of nodes.
*
* This creates an iterator for an existing static array of librdf_node
* objects. It is mostly intended for testing iterator code.
*
* Return value: a #librdf_iterator serialization of the nodes or NULL on failure
**/
librdf_iterator*
librdf_node_new_static_node_iterator(librdf_world* world, librdf_node** nodes,
int size)
{
librdf_node_static_iterator_context* context;
librdf_iterator* iterator;
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(nodes, librdf_node**, NULL);
context = (librdf_node_static_iterator_context*)LIBRDF_CALLOC(librdf_node_static_iterator_context, 1, sizeof(*context));
if(!context)
return NULL;
context->nodes = nodes;
context->size = size;
context->current = 0;
iterator = librdf_new_iterator(world,
(void*)context,
librdf_node_static_iterator_is_end,
librdf_node_static_iterator_next_method,
librdf_node_static_iterator_get_method,
librdf_node_static_iterator_finished);
if(!iterator)
librdf_node_static_iterator_finished(context);
return iterator;
}
/**
* librdf_list_get_iterator:
* @list: #librdf_list object
*
* Get an iterator for the list.
*
* Return value: a new #librdf_iterator object or NULL on failure
**/
librdf_iterator*
librdf_list_get_iterator(librdf_list* list)
{
librdf_list_iterator_context* context;
librdf_iterator* iterator;
context = LIBRDF_CALLOC(librdf_list_iterator_context*, 1, sizeof(*context));
if(!context)
return NULL;
context->list=list;
context->current=list->first;
context->next=context->current != NULL ? context->current->next : NULL;
/* librdf_list_iterator_finished() calls librdf_list_remove_iterator_context(),
* librdf_list_iterator_finished() is called if librdf_new_iterator() fails */
librdf_list_add_iterator_context(list, context);
iterator=librdf_new_iterator(list->world,
(void*)context,
librdf_list_iterator_is_end,
librdf_list_iterator_next_method,
librdf_list_iterator_get_method,
librdf_list_iterator_finished);
if(!iterator)
librdf_list_iterator_finished(context);
else
context->iterator=iterator;
return iterator;
}
/**
* librdf_avltree_get_iterator_start:
* @list: #librdf_avltree object
*
* Get an (in-order) iterator for the start of a range, or the entire tree
* (if range is NULL). If range specifies a range (i.e. the tree comparison
* function will 'match' (return 0 for) range and /several/ nodes), the
* iterator will be placed at the leftmost child matching range, and
* librdf_avltree_iterator_next will iterate over all nodes
* (and only nodes) that match range.
*
* Return value: a new #librdf_iterator object or NULL on failure
**/
librdf_iterator*
librdf_avltree_get_iterator_start(librdf_world* world, librdf_avltree* tree,
void* range,
librdf_avltree_data_free_function range_free_fn)
{
librdf_avltree_iterator_context* context;
librdf_iterator* iterator;
context = (librdf_avltree_iterator_context*)LIBRDF_CALLOC(librdf_avltree_iterator_context, 1, sizeof(*context));
if(!context)
return NULL;
context->tree = tree;
context->range = range;
context->range_free_fn = range_free_fn;
if(range != NULL) {
/* find the topmost match (range is contained entirely in tree rooted here) */
context->current = librdf_avltree_search_internal(tree, tree->root, range);
} else {
context->current=tree->root;
}
context->root = context->current;
/* go down to find start of range (or tree) */
if(context->current) {
while(1) {
librdf_avltree_node* pred;
context->current = librdf_avltree_node_leftmost(tree, context->current,
range);
/* right until we find a match */
pred = librdf_avltree_node_search_right(tree, context->current->left,
range);
if(pred && tree->compare_fn(range, pred->data) == 0)
context->current = pred;
else
break;
}
}
iterator=librdf_new_iterator(world,
(void*)context,
librdf_avltree_iterator_is_end,
librdf_avltree_iterator_next_method,
librdf_avltree_iterator_get_method,
librdf_avltree_iterator_finished);
if(!iterator) {
librdf_avltree_iterator_finished(context);
}
return iterator;
}
/**
* librdf_list_get_iterator - get an iterator for the list
* @list: &librdf_list object
*
* Return value: a new &librdf_iterator object or NULL on failure
**/
librdf_iterator*
librdf_list_get_iterator(librdf_list* list)
{
librdf_list_iterator_context* context;
context=(librdf_list_iterator_context*)LIBRDF_CALLOC(librdf_list_iterator_context, 1, sizeof(librdf_list_iterator_context));
if(!context)
return NULL;
context->list=list;
context->current=list->first;
return librdf_new_iterator(list->world,
(void*)context,
librdf_list_iterator_is_end,
librdf_list_iterator_next_method,
librdf_list_iterator_get_method,
librdf_list_iterator_finished);
}
/*
* librdf_storage_node_stream_to_node_create - Create a stream for get sources, targets or arcs methods using find_statements method
* @storage: the storage object to use
* @node1: the first node to encode in the key
* @node2: the second node to encode in the key
* @want: the field required from the statement
*
* Return value: a new &librdf_iterator or NULL on failure
**/
static librdf_iterator*
librdf_storage_node_stream_to_node_create(librdf_storage* storage,
librdf_node *node1,
librdf_node *node2,
librdf_statement_part want)
{
librdf_statement *partial_statement;
librdf_stream *stream;
librdf_storage_stream_to_node_iterator_context* context;
librdf_iterator *iterator;
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(storage, librdf_storage, NULL);
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(node1, librdf_node, NULL);
LIBRDF_ASSERT_OBJECT_POINTER_RETURN_VALUE(node2, librdf_node, NULL);
partial_statement=librdf_new_statement(storage->world);
if(!partial_statement)
return NULL;
context=(librdf_storage_stream_to_node_iterator_context*)LIBRDF_CALLOC(librdf_storage_stream_to_node_iterator_context, 1, sizeof(librdf_storage_stream_to_node_iterator_context));
if(!context) {
librdf_free_statement(partial_statement);
return NULL;
}
switch(want) {
case LIBRDF_STATEMENT_SUBJECT:
librdf_statement_set_predicate(partial_statement, node1);
librdf_statement_set_object(partial_statement, node2);
break;
case LIBRDF_STATEMENT_PREDICATE:
librdf_statement_set_subject(partial_statement, node1);
librdf_statement_set_object(partial_statement, node2);
break;
case LIBRDF_STATEMENT_OBJECT:
librdf_statement_set_subject(partial_statement, node1);
librdf_statement_set_predicate(partial_statement, node2);
break;
default:
librdf_free_statement(partial_statement);
LIBRDF_ERROR2(storage->world, "Illegal statement part %d seen\n", want);
return NULL;
}
stream=storage->factory->find_statements(storage, partial_statement);
if(!stream) {
librdf_storage_stream_to_node_iterator_finished(context);
return NULL;
}
/* initialise context */
context->partial_statement=partial_statement;
context->stream=stream;
context->want=want;
context->storage=storage;
librdf_storage_add_reference(context->storage);
iterator=librdf_new_iterator(storage->world,
(void*)context,
librdf_storage_stream_to_node_iterator_is_end,
librdf_storage_stream_to_node_iterator_next_method,
librdf_storage_stream_to_node_iterator_get_method,
librdf_storage_stream_to_node_iterator_finished);
if(!iterator)
librdf_storage_stream_to_node_iterator_finished(context);
return iterator;
}