diff options
Diffstat (limited to 'src/libtracker-sparql/remote/tracker-json-cursor.vala')
| -rw-r--r-- | src/libtracker-sparql/remote/tracker-json-cursor.vala | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/libtracker-sparql/remote/tracker-json-cursor.vala b/src/libtracker-sparql/remote/tracker-json-cursor.vala new file mode 100644 index 000000000..047d47278 --- /dev/null +++ b/src/libtracker-sparql/remote/tracker-json-cursor.vala @@ -0,0 +1,140 @@ +/* + * Copyright (C) 2016 Carlos Garnacho <carlosg@gnome.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the + * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + * + * Author: Carlos Garnacho <carlosg@gnome.org> + */ + +public class Tracker.Remote.JsonCursor : Tracker.Sparql.Cursor { + internal Json.Parser _parser; + internal Json.Array _vars; + internal Json.Array _results; + internal Json.Object _cur_row; + internal uint _cur_idx = 0; + internal bool _started_iterating = false; + + const string XSD_NS = "http://www.w3.org/2001/XMLSchema#"; + + public JsonCursor (string document, long length) throws GLib.Error { + Object (); + var parser = new Json.Parser (); + parser.load_from_data (document, length); + + var root = parser.get_root ().get_object (); + var head = root.get_object_member ("head"); + var results = root.get_object_member ("results"); + + _parser = parser; + _vars = head.get_array_member ("vars"); + _results = results.get_array_member ("bindings"); + _started_iterating = false; + } + + public override int n_columns { + get { return (int) _vars.get_length (); } + } + + public override Sparql.ValueType get_value_type (int column) requires (_cur_row != null) { + var col_node = _cur_row.get_member (get_variable_name (column)); + + if (col_node == null) + return Sparql.ValueType.UNBOUND; + + var object = col_node.get_object ();//_cur_row.get_object_member (get_variable_name (column)); + unowned string str = object.get_string_member ("type"); + + switch (str) { + case "uri": + return Sparql.ValueType.URI; + case "bnode": + return Sparql.ValueType.BLANK_NODE; + case "literal": { + var node = object.get_member ("datatype"); + + if (node == null) + return Sparql.ValueType.STRING; + + str = node.get_string (); + + switch (str) { + case XSD_NS + "byte": + case XSD_NS + "int": + case XSD_NS + "integer": + case XSD_NS + "long": + return Sparql.ValueType.INTEGER; + case XSD_NS + "decimal": + case XSD_NS + "double": + return Sparql.ValueType.DOUBLE; + case XSD_NS + "dateTime": + return Sparql.ValueType.DATETIME; + default: + return Sparql.ValueType.STRING; + } + } + + default: + return Sparql.ValueType.STRING; + } + } + + public override unowned string? get_variable_name (int column) { + return _vars.get_string_element (column); + } + + public override unowned string? get_string (int column, out long length = null) requires (_cur_row != null) { + var col_node = _cur_row.get_member (get_variable_name (column)); + length = 0; + + if (col_node == null) + return null; + + var object = col_node.get_object (); + + if (object == null) + return null; + + unowned string str = object.get_string_member ("value"); + length = str.length; + return str; + } + + public override bool next (Cancellable? cancellable = null) throws IOError, GLib.Error { + if (_started_iterating) + _cur_idx++; + + if (_cur_idx >= _results.get_length ()) + return false; + + if (cancellable != null && cancellable.is_cancelled ()) + throw new IOError.CANCELLED ("Operation was cancelled"); + + _started_iterating = true; + _cur_row = _results.get_object_element (_cur_idx); + return true; + } + + public async override bool next_async (Cancellable? cancellable = null) throws IOError, GLib.Error { + return next (cancellable); + } + + public override void rewind () { + _started_iterating = false; + } + + public override void close () { + } +} |