AAPT2: Rename strip phase to optimize
- Allow resource deduping, version collapsing, and sparse resource
encoding.
Test: manual
Change-Id: Ia4aa892ab5b06ba1d5ea4a6efb51b00bc3a980c4
diff --git a/tools/aapt2/optimize/ResourceDeduper.cpp b/tools/aapt2/optimize/ResourceDeduper.cpp
new file mode 100644
index 0000000..3aab2e3
--- /dev/null
+++ b/tools/aapt2/optimize/ResourceDeduper.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "optimize/ResourceDeduper.h"
+
+#include <algorithm>
+
+#include "DominatorTree.h"
+#include "ResourceTable.h"
+
+namespace aapt {
+
+namespace {
+
+/**
+ * Remove duplicated key-value entries from dominated resources.
+ *
+ * Based on the dominator tree, we can remove a value of an entry if:
+ *
+ * 1. The configuration for the entry's value is dominated by a configuration
+ * with an equivalent entry value.
+ * 2. All compatible configurations for the entry (those not in conflict and
+ * unrelated by domination with the configuration for the entry's value) have
+ * an equivalent entry value.
+ */
+class DominatedKeyValueRemover : public DominatorTree::BottomUpVisitor {
+ public:
+ using Node = DominatorTree::Node;
+
+ explicit DominatedKeyValueRemover(IAaptContext* context, ResourceEntry* entry)
+ : context_(context), entry_(entry) {}
+
+ void VisitConfig(Node* node) {
+ Node* parent = node->parent();
+ if (!parent) {
+ return;
+ }
+ ResourceConfigValue* node_value = node->value();
+ ResourceConfigValue* parent_value = parent->value();
+ if (!node_value || !parent_value) {
+ return;
+ }
+ if (!node_value->value->Equals(parent_value->value.get())) {
+ return;
+ }
+
+ // Compare compatible configs for this entry and ensure the values are
+ // equivalent.
+ const ConfigDescription& node_configuration = node_value->config;
+ for (const auto& sibling : entry_->values) {
+ if (!sibling->value) {
+ // Sibling was already removed.
+ continue;
+ }
+ if (node_configuration.IsCompatibleWith(sibling->config) &&
+ !node_value->value->Equals(sibling->value.get())) {
+ // The configurations are compatible, but the value is
+ // different, so we can't remove this value.
+ return;
+ }
+ }
+ if (context_->IsVerbose()) {
+ context_->GetDiagnostics()->Note(
+ DiagMessage(node_value->value->GetSource())
+ << "removing dominated duplicate resource with name \""
+ << entry_->name << "\"");
+ }
+ node_value->value = {};
+ }
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(DominatedKeyValueRemover);
+
+ IAaptContext* context_;
+ ResourceEntry* entry_;
+};
+
+static void DedupeEntry(IAaptContext* context, ResourceEntry* entry) {
+ DominatorTree tree(entry->values);
+ DominatedKeyValueRemover remover(context, entry);
+ tree.Accept(&remover);
+
+ // Erase the values that were removed.
+ entry->values.erase(
+ std::remove_if(
+ entry->values.begin(), entry->values.end(),
+ [](const std::unique_ptr<ResourceConfigValue>& val) -> bool {
+ return val == nullptr || val->value == nullptr;
+ }),
+ entry->values.end());
+}
+
+} // namespace
+
+bool ResourceDeduper::Consume(IAaptContext* context, ResourceTable* table) {
+ for (auto& package : table->packages) {
+ for (auto& type : package->types) {
+ for (auto& entry : type->entries) {
+ DedupeEntry(context, entry.get());
+ }
+ }
+ }
+ return true;
+}
+
+} // namespace aapt