1 // Copyright (C) 2019 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "icing/result/projector.h"
16
17 #include <algorithm>
18
19 namespace icing {
20 namespace lib {
21
22 namespace projector {
23
Project(const std::vector<ProjectionTree::Node> & projection_tree,DocumentProto * document)24 void Project(const std::vector<ProjectionTree::Node>& projection_tree,
25 DocumentProto* document) {
26 int num_kept = 0;
27 for (int cur_pos = 0; cur_pos < document->properties_size(); ++cur_pos) {
28 PropertyProto* prop = document->mutable_properties(cur_pos);
29 auto itr = std::find_if(projection_tree.begin(), projection_tree.end(),
30 [&prop](const ProjectionTree::Node& node) {
31 return node.name == prop->name();
32 });
33 if (itr == projection_tree.end()) {
34 // Property is not present in the projection tree. Just skip it.
35 continue;
36 }
37 // This property should be kept.
38 document->mutable_properties()->SwapElements(num_kept, cur_pos);
39 ++num_kept;
40 if (itr->children.empty()) {
41 // A field mask does refer to this property, but it has no children. So
42 // we should take the entire property, with all of its
43 // subproperties/values
44 continue;
45 }
46 // The field mask refers to children of this property. Recurse through the
47 // document values that this property holds and project the children
48 // requested by this field mask.
49 for (DocumentProto& subproperty : *(prop->mutable_document_values())) {
50 Project(itr->children, &subproperty);
51 }
52 }
53 document->mutable_properties()->DeleteSubrange(
54 num_kept, document->properties_size() - num_kept);
55 }
56
57 } // namespace projector
58
59 } // namespace lib
60 } // namespace icing
61