1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "DominatorTree.h"
18
19 #include <algorithm>
20
21 #include "android-base/logging.h"
22
23 #include "ConfigDescription.h"
24
25 namespace aapt {
26
DominatorTree(const std::vector<std::unique_ptr<ResourceConfigValue>> & configs)27 DominatorTree::DominatorTree(
28 const std::vector<std::unique_ptr<ResourceConfigValue>>& configs) {
29 for (const auto& config : configs) {
30 product_roots_[config->product].TryAddChild(
31 util::make_unique<Node>(config.get(), nullptr));
32 }
33 }
34
Accept(Visitor * visitor)35 void DominatorTree::Accept(Visitor* visitor) {
36 for (auto& entry : product_roots_) {
37 visitor->VisitTree(entry.first, &entry.second);
38 }
39 }
40
TryAddChild(std::unique_ptr<Node> new_child)41 bool DominatorTree::Node::TryAddChild(std::unique_ptr<Node> new_child) {
42 CHECK(new_child->value_) << "cannot add a root or empty node as a child";
43 if (value_ && !Dominates(new_child.get())) {
44 // This is not the root and the child dominates us.
45 return false;
46 }
47 return AddChild(std::move(new_child));
48 }
49
AddChild(std::unique_ptr<Node> new_child)50 bool DominatorTree::Node::AddChild(std::unique_ptr<Node> new_child) {
51 bool has_dominated_children = false;
52 // Demote children dominated by the new config.
53 for (auto& child : children_) {
54 if (new_child->Dominates(child.get())) {
55 child->parent_ = new_child.get();
56 new_child->children_.push_back(std::move(child));
57 child = {};
58 has_dominated_children = true;
59 }
60 }
61 // Remove dominated children.
62 if (has_dominated_children) {
63 children_.erase(
64 std::remove_if(children_.begin(), children_.end(),
65 [](const std::unique_ptr<Node>& child) -> bool {
66 return child == nullptr;
67 }),
68 children_.end());
69 }
70 // Add the new config to a child if a child dominates the new config.
71 for (auto& child : children_) {
72 if (child->Dominates(new_child.get())) {
73 child->AddChild(std::move(new_child));
74 return true;
75 }
76 }
77 // The new config is not dominated by a child, so add it here.
78 new_child->parent_ = this;
79 children_.push_back(std::move(new_child));
80 return true;
81 }
82
Dominates(const Node * other) const83 bool DominatorTree::Node::Dominates(const Node* other) const {
84 // Check root node dominations.
85 if (other->is_root_node()) {
86 return is_root_node();
87 } else if (is_root_node()) {
88 return true;
89 }
90 // Neither node is a root node; compare the configurations.
91 return value_->config.Dominates(other->value_->config);
92 }
93
94 } // namespace aapt
95