virtual bool next()
{
bool next_res = false;
if (!rs_)
{
// Ensure connection is valid
if (conn_ && conn_->isOK())
{
rs_ = conn_->getAsyncResult();
}
else
{
throw mapnik::datasource_exception("invalid connection in AsyncResultSet::next");
}
}
next_res = rs_->next();
if (!next_res)
{
rs_.reset();
rs_ = conn_->getNextAsyncResult();
if (rs_ && rs_->next())
{
return true;
}
close();
prepare_next();
}
return next_res;
}
/* move record foreward to next entry.
*
* In case of an error the value of *r is undefined !
*/
int record_next(record* r)
{
btree* tree = r->tree;
UInt16 index = r->keyind +1;
UInt32 parent;
node_buf* buf = prepare_next(tree, r->node_index, &index);
if (!buf)
return ENOENT; // No (more) such file or directory
parent = r->key.parent_cnid;
if (record_init(r, tree, buf, index))
return -1;
if (r->key.parent_cnid != parent || // end of current directory
index != r->keyind) // internal error ?
return ENOENT; // No (more) such file or directory
return 0;
}
/* move record foreward to next extent record.
*
* In case of an error the value of *r is undefined !
*/
int record_next_extent(extent_record* r)
{
btree* tree = r->tree;
UInt16 index = r->keyind +1;
UInt32 file_id;
UInt8 fork_type;
node_buf* buf = prepare_next(tree, r->node_index, &index);
if (!buf)
return ENOENT; // No (more) such file or directory
file_id = r->key.file_id;
fork_type = r->key.fork_type;
if (record_init_extent(r, tree, buf, index))
return -1;
if (r->key.file_id != file_id || // end of current file
r->key.fork_type != fork_type || // end of current fork
index != r->keyind) // internal error ?
return ENOENT; // No (more) such file or directory
return 0;
}