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/*
* 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 () {
}
}
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