static rasqal_row*
rasqal_distinct_rowsource_read_row(rasqal_rowsource* rowsource, void *user_data)
{
rasqal_distinct_rowsource_context *con;
rasqal_row *row = NULL;
con = (rasqal_distinct_rowsource_context*)user_data;
while(1) {
int result;
row = rasqal_rowsource_read_row(con->rowsource);
if(!row)
break;
result = rasqal_engine_rowsort_map_add_row(con->map, row);
RASQAL_DEBUG2("row is %s\n", result ? "not distinct" : "distinct");
if(!result)
/* row was distinct (not a duplicate) so return it */
break;
}
if(row) {
row = rasqal_new_row_from_row(row);
row->rowsource = rowsource;
row->offset = con->offset++;
}
return row;
}
static void
rasqal_engine_rowsort_map_add_to_sequence(void *key, void *value,
void *user_data)
{
rasqal_row* row;
row = rasqal_new_row_from_row((rasqal_row*)key);
raptor_sequence_push((raptor_sequence*)user_data, row);
}
/**
* rasqal_query_results_get_row_from_saved:
* @query_results: Query results to execute
*
* INTERNAL - Get next result row from a stored query result sequence
*
* Return value: result row or NULL if finished or failed
*/
static rasqal_row*
rasqal_query_results_get_row_from_saved(rasqal_query_results* query_results)
{
rasqal_query* query = query_results->query;
int size;
rasqal_row* row = NULL;
size = raptor_sequence_size(query_results->results_sequence);
while(1) {
int check;
if(query_results->result_count >= size) {
query_results->finished = 1;
break;
}
query_results->result_count++;
check = rasqal_query_check_limit_offset(query, query_results->result_count);
/* finished if beyond result range */
if(check > 0) {
query_results->finished = 1;
query_results->result_count--;
break;
}
/* continue if before start of result range */
if(check < 0)
continue;
/* else got result */
row = (rasqal_row*)raptor_sequence_get_at(query_results->results_sequence,
query_results->result_count - 1);
if(row) {
row = rasqal_new_row_from_row(row);
/* stored results may not be canonicalized yet - do it lazily */
rasqal_row_to_nodes(row);
query_results->row = row;
if(query && query->constructs)
rasqal_query_results_update_bindings(query_results);
}
break;
}
return row;
}
/**
* rasqal_query_results_get_row_by_offset:
* @query_results: query result
* @result_offset: index into result rows
*
* Get stored result row by an offset
*
* The result_offset index is 0-indexed into the subset of results
* constrained by any query limit and offset.
*
* Return value: row or NULL if @result_offset is out of range
*/
rasqal_row*
rasqal_query_results_get_row_by_offset(rasqal_query_results* query_results,
int result_offset)
{
rasqal_query* query;
int check;
rasqal_row* row;
int offset = 0;
RASQAL_ASSERT_OBJECT_POINTER_RETURN_VALUE(query_results, rasqal_query_results, NULL);
if(!query_results->results_sequence)
return NULL;
if(result_offset < 0)
return NULL;
query = query_results->query;
if(query)
offset = rasqal_query_get_offset(query);
/* Adjust 0-indexed to query results 1-indexed + query result offset */
result_offset += 1 + offset;
check = rasqal_query_check_limit_offset(query_results->query,
result_offset);
/* outside limit/offset range in some way */
if(check < 0 || check > 0)
return NULL;
row = (rasqal_row*)raptor_sequence_get_at(query_results->results_sequence,
result_offset - 1);
if(row) {
row = rasqal_new_row_from_row(row);
/* stored results may not be canonicalized yet - do it lazily */
rasqal_row_to_nodes(row);
}
return row;
}
static rasqal_row*
rasqal_rowsequence_rowsource_read_row(rasqal_rowsource* rowsource,
void *user_data)
{
rasqal_rowsequence_rowsource_context* con;
rasqal_row* row = NULL;
con = (rasqal_rowsequence_rowsource_context*)user_data;
if(con->failed || con->offset < 0)
return NULL;
row = (rasqal_row*)raptor_sequence_get_at(con->seq, con->offset);
if(!row) {
/* finished */
con->offset = -1;
} else {
row = rasqal_new_row_from_row(row);
con->offset++;
}
return row;
}
static raptor_sequence*
rasqal_rowsequence_rowsource_read_all_rows(rasqal_rowsource* rowsource,
void *user_data)
{
rasqal_rowsequence_rowsource_context* con;
raptor_sequence* seq;
con = (rasqal_rowsequence_rowsource_context*)user_data;
if(con->offset < 0)
return NULL;
seq = raptor_new_sequence((raptor_data_free_handler)rasqal_free_row,
(raptor_data_print_handler)rasqal_row_print);
if(seq) {
int i;
int size = raptor_sequence_size(con->seq);
for(i = 0; i < size; i++) {
rasqal_row *row = (rasqal_row*)raptor_sequence_get_at(con->seq, i);
raptor_sequence_push(seq, rasqal_new_row_from_row(row));
}
}
return seq;
}
/**
* rasqal_rowsource_read_row:
* @rowsource: rasqal rowsource
*
* Read a query result row from the rowsource.
*
* If a row is returned, it is owned by the caller.
*
* Return value: row or NULL when no more rows are available
**/
rasqal_row*
rasqal_rowsource_read_row(rasqal_rowsource *rowsource)
{
rasqal_row* row = NULL;
if(!rowsource || rowsource->finished)
return NULL;
if(rowsource->flags & RASQAL_ROWSOURCE_FLAGS_SAVED_ROWS) {
/* return row from saved rows sequence at offset */
row = (rasqal_row*)raptor_sequence_get_at(rowsource->rows_sequence,
rowsource->offset++);
#ifdef RASQAL_DEBUG
RASQAL_DEBUG3("%s rowsource %p returned saved row: ",
rowsource->handler->name, rowsource);
if(row)
rasqal_row_print(row, stderr);
else
fputs("NONE", stderr);
fputs("\n", stderr);
#endif
if(row)
row = rasqal_new_row_from_row(row);
/* row is owned by us */
} else {
if(rasqal_rowsource_ensure_variables(rowsource))
return NULL;
if(rowsource->handler->read_row) {
row = rowsource->handler->read_row(rowsource, rowsource->user_data);
/* row is owned by us */
if(row && rowsource->flags & RASQAL_ROWSOURCE_FLAGS_SAVE_ROWS) {
if(!rowsource->rows_sequence) {
rowsource->rows_sequence = raptor_new_sequence((raptor_data_free_handler)rasqal_free_row,
(raptor_data_print_handler)rasqal_row_print);
rowsource->offset = 0;
}
/* copy to save it away */
row = rasqal_new_row_from_row(row);
raptor_sequence_push(rowsource->rows_sequence, row);
}
} else {
if(!rowsource->rows_sequence) {
raptor_sequence* seq;
seq = rasqal_rowsource_read_all_rows(rowsource);
if(rowsource->rows_sequence)
raptor_free_sequence(rowsource->rows_sequence);
/* rows_sequence now owns all rows */
rowsource->rows_sequence = seq;
rowsource->offset = 0;
}
if(rowsource->rows_sequence) {
/* return row from sequence at offset */
row = (rasqal_row*)raptor_sequence_get_at(rowsource->rows_sequence,
rowsource->offset++);
if(row)
row = rasqal_new_row_from_row(row);
/* row is owned by us */
}
}
}
if(!row) {
rowsource->finished = 1;
if(rowsource->flags & RASQAL_ROWSOURCE_FLAGS_SAVE_ROWS)
rowsource->flags |= RASQAL_ROWSOURCE_FLAGS_SAVED_ROWS;
} else {
rowsource->count++;
/* Generate a group around all rows if there are no groups returned */
if(rowsource->generate_group && row->group_id < 0)
row->group_id = 0;
}
#ifdef RASQAL_DEBUG
RASQAL_DEBUG3("%s rowsource %p returned row: ", rowsource->handler->name,
rowsource);
if(row)
rasqal_row_print(row, stderr);
else
fputs("NONE", stderr);
fputs("\n", stderr);
#endif
return row;
}
