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 #include "icing/proto/document.pb.h"
20
21 namespace icing {
22 namespace lib {
23
24 namespace projector {
25
Project(const std::vector<ProjectionTree::Node> & projection_tree,DocumentProto * document)26 void Project(const std::vector<ProjectionTree::Node>& projection_tree,
27 DocumentProto* document) {
28 int num_kept = 0;
29 for (int cur_pos = 0; cur_pos < document->properties_size(); ++cur_pos) {
30 PropertyProto* prop = document->mutable_properties(cur_pos);
31 auto itr = std::find_if(projection_tree.begin(), projection_tree.end(),
32 [&prop](const ProjectionTree::Node& node) {
33 return node.name == prop->name();
34 });
35 if (itr == projection_tree.end()) {
36 // Property is not present in the projection tree. Just skip it.
37 continue;
38 }
39 // This property should be kept.
40 document->mutable_properties()->SwapElements(num_kept, cur_pos);
41 ++num_kept;
42 if (itr->children.empty()) {
43 // A field mask does refer to this property, but it has no children. So
44 // we should take the entire property, with all of its
45 // subproperties/values
46 continue;
47 }
48 // The field mask refers to children of this property. Recurse through the
49 // document values that this property holds and project the children
50 // requested by this field mask.
51 for (DocumentProto& subproperty : *(prop->mutable_document_values())) {
52 Project(itr->children, &subproperty);
53 }
54 }
55 document->mutable_properties()->DeleteSubrange(
56 num_kept, document->properties_size() - num_kept);
57 }
58
59 } // namespace projector
60
61 } // namespace lib
62 } // namespace icing
63