tools/aapt2/flatten/TableFlattener.cpp - LeafOS-Project/android_frameworks_base - Gitiles

 /*
  * Copyright (C) 2015 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 "ResourceTable.h"
 #include "ResourceValues.h"
 #include "ValueVisitor.h"

 #include "flatten/ChunkWriter.h"
 #include "flatten/ResourceTypeExtensions.h"
 #include "flatten/TableFlattener.h"
 #include "util/BigBuffer.h"

 #include <android-base/macros.h>
 #include <algorithm>
 #include <type_traits>
 #include <numeric>

 using namespace android;

 namespace aapt {

 namespace {

 template <typename T>
 static bool cmpIds(const T* a, const T* b) {
     return a->id.value() < b->id.value();
 }

 static void strcpy16_htod(uint16_t* dst, size_t len, const StringPiece16& src) {
     if (len == 0) {
         return;
     }

     size_t i;
     const char16_t* srcData = src.data();
     for (i = 0; i < len - 1 && i < src.size(); i++) {
         dst[i] = util::hostToDevice16((uint16_t) srcData[i]);
     }
     dst[i] = 0;
 }

 static bool cmpStyleEntries(const Style::Entry& a, const Style::Entry& b) {
    if (a.key.id) {
        if (b.key.id) {
            return a.key.id.value() < b.key.id.value();
        }
        return true;
    } else if (!b.key.id) {
        return a.key.name.value() < b.key.name.value();
    }
    return false;
 }

 struct FlatEntry {
     ResourceEntry* entry;
     Value* value;

     // The entry string pool index to the entry's name.
     uint32_t entryKey;
 };

 class MapFlattenVisitor : public RawValueVisitor {
 public:
     using RawValueVisitor::visit;

     MapFlattenVisitor(ResTable_entry_ext* outEntry, BigBuffer* buffer) :
             mOutEntry(outEntry), mBuffer(buffer) {
     }

     void visit(Attribute* attr) override {
         {
             Reference key = Reference(ResTable_map::ATTR_TYPE);
             BinaryPrimitive val(Res_value::TYPE_INT_DEC, attr->typeMask);
             flattenEntry(&key, &val);
         }

         if (attr->minInt != std::numeric_limits<int32_t>::min()) {
             Reference key = Reference(ResTable_map::ATTR_MIN);
             BinaryPrimitive val(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(attr->minInt));
             flattenEntry(&key, &val);
         }

         if (attr->maxInt != std::numeric_limits<int32_t>::max()) {
             Reference key = Reference(ResTable_map::ATTR_MAX);
             BinaryPrimitive val(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(attr->maxInt));
             flattenEntry(&key, &val);
         }

         for (Attribute::Symbol& s : attr->symbols) {
             BinaryPrimitive val(Res_value::TYPE_INT_DEC, s.value);
             flattenEntry(&s.symbol, &val);
         }
     }

     void visit(Style* style) override {
         if (style->parent) {
             const Reference& parentRef = style->parent.value();
             assert(parentRef.id && "parent has no ID");
             mOutEntry->parent.ident = util::hostToDevice32(parentRef.id.value().id);
         }

         // Sort the style.
         std::sort(style->entries.begin(), style->entries.end(), cmpStyleEntries);

         for (Style::Entry& entry : style->entries) {
             flattenEntry(&entry.key, entry.value.get());
         }
     }

     void visit(Styleable* styleable) override {
         for (auto& attrRef : styleable->entries) {
             BinaryPrimitive val(Res_value{});
             flattenEntry(&attrRef, &val);
         }

     }

     void visit(Array* array) override {
         for (auto& item : array->items) {
             ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
             flattenValue(item.get(), outEntry);
             outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
             mEntryCount++;
         }
     }

     void visit(Plural* plural) override {
         const size_t count = plural->values.size();
         for (size_t i = 0; i < count; i++) {
             if (!plural->values[i]) {
                 continue;
             }

             ResourceId q;
             switch (i) {
             case Plural::Zero:
                 q.id = android::ResTable_map::ATTR_ZERO;
                 break;

             case Plural::One:
                 q.id = android::ResTable_map::ATTR_ONE;
                 break;

             case Plural::Two:
                 q.id = android::ResTable_map::ATTR_TWO;
                 break;

             case Plural::Few:
                 q.id = android::ResTable_map::ATTR_FEW;
                 break;

             case Plural::Many:
                 q.id = android::ResTable_map::ATTR_MANY;
                 break;

             case Plural::Other:
                 q.id = android::ResTable_map::ATTR_OTHER;
                 break;

             default:
                 assert(false);
                 break;
             }

             Reference key(q);
             flattenEntry(&key, plural->values[i].get());
         }
     }

     /**
      * Call this after visiting a Value. This will finish any work that
      * needs to be done to prepare the entry.
      */
     void finish() {
         mOutEntry->count = util::hostToDevice32(mEntryCount);
     }

 private:
     void flattenKey(Reference* key, ResTable_map* outEntry) {
         assert(key->id && "key has no ID");
         outEntry->name.ident = util::hostToDevice32(key->id.value().id);
     }

     void flattenValue(Item* value, ResTable_map* outEntry) {
         bool result = value->flatten(&outEntry->value);
         assert(result && "flatten failed");
     }

     void flattenEntry(Reference* key, Item* value) {
         ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
         flattenKey(key, outEntry);
         flattenValue(value, outEntry);
         outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
         mEntryCount++;
     }

     ResTable_entry_ext* mOutEntry;
     BigBuffer* mBuffer;
     size_t mEntryCount = 0;
 };

 class PackageFlattener {
 public:
     PackageFlattener(IDiagnostics* diag, ResourceTablePackage* package) :
             mDiag(diag), mPackage(package) {
     }

     bool flattenPackage(BigBuffer* buffer) {
         ChunkWriter pkgWriter(buffer);
         ResTable_package* pkgHeader = pkgWriter.startChunk<ResTable_package>(
                 RES_TABLE_PACKAGE_TYPE);
         pkgHeader->id = util::hostToDevice32(mPackage->id.value());

         if (mPackage->name.size() >= arraysize(pkgHeader->name)) {
             mDiag->error(DiagMessage() <<
                          "package name '" << mPackage->name << "' is too long");
             return false;
         }

         // Copy the package name in device endianness.
         strcpy16_htod(pkgHeader->name, arraysize(pkgHeader->name), mPackage->name);

         // Serialize the types. We do this now so that our type and key strings
         // are populated. We write those first.
         BigBuffer typeBuffer(1024);
         flattenTypes(&typeBuffer);

         pkgHeader->typeStrings = util::hostToDevice32(pkgWriter.size());
         StringPool::flattenUtf16(pkgWriter.getBuffer(), mTypePool);

         pkgHeader->keyStrings = util::hostToDevice32(pkgWriter.size());
         StringPool::flattenUtf16(pkgWriter.getBuffer(), mKeyPool);

         // Append the types.
         buffer->appendBuffer(std::move(typeBuffer));

         pkgWriter.finish();
         return true;
     }

 private:
     IDiagnostics* mDiag;
     ResourceTablePackage* mPackage;
     StringPool mTypePool;
     StringPool mKeyPool;

     template <typename T, bool IsItem>
     T* writeEntry(FlatEntry* entry, BigBuffer* buffer) {
         static_assert(std::is_same<ResTable_entry, T>::value ||
                       std::is_same<ResTable_entry_ext, T>::value,
                       "T must be ResTable_entry or ResTable_entry_ext");

         T* result = buffer->nextBlock<T>();
         ResTable_entry* outEntry = (ResTable_entry*)(result);
         if (entry->entry->symbolStatus.state == SymbolState::kPublic) {
             outEntry->flags |= ResTable_entry::FLAG_PUBLIC;
         }

         if (entry->value->isWeak()) {
             outEntry->flags |= ResTable_entry::FLAG_WEAK;
         }

         if (!IsItem) {
             outEntry->flags |= ResTable_entry::FLAG_COMPLEX;
         }

         outEntry->flags = util::hostToDevice16(outEntry->flags);
         outEntry->key.index = util::hostToDevice32(entry->entryKey);
         outEntry->size = util::hostToDevice16(sizeof(T));
         return result;
     }

     bool flattenValue(FlatEntry* entry, BigBuffer* buffer) {
         if (Item* item = valueCast<Item>(entry->value)) {
             writeEntry<ResTable_entry, true>(entry, buffer);
             Res_value* outValue = buffer->nextBlock<Res_value>();
             bool result = item->flatten(outValue);
             assert(result && "flatten failed");
             outValue->size = util::hostToDevice16(sizeof(*outValue));
         } else {
             ResTable_entry_ext* outEntry = writeEntry<ResTable_entry_ext, false>(entry, buffer);
             MapFlattenVisitor visitor(outEntry, buffer);
             entry->value->accept(&visitor);
             visitor.finish();
         }
         return true;
     }

     bool flattenConfig(const ResourceTableType* type, const ConfigDescription& config,
                        std::vector<FlatEntry>* entries, BigBuffer* buffer) {
         ChunkWriter typeWriter(buffer);
         ResTable_type* typeHeader = typeWriter.startChunk<ResTable_type>(RES_TABLE_TYPE_TYPE);
         typeHeader->id = type->id.value();
         typeHeader->config = config;
         typeHeader->config.swapHtoD();

         auto maxAccum = [](uint32_t max, const std::unique_ptr<ResourceEntry>& a) -> uint32_t {
             return std::max(max, (uint32_t) a->id.value());
         };

         // Find the largest entry ID. That is how many entries we will have.
         const uint32_t entryCount =
                 std::accumulate(type->entries.begin(), type->entries.end(), 0, maxAccum) + 1;

         typeHeader->entryCount = util::hostToDevice32(entryCount);
         uint32_t* indices = typeWriter.nextBlock<uint32_t>(entryCount);

         assert((size_t) entryCount <= std::numeric_limits<uint16_t>::max() + 1);
         memset(indices, 0xff, entryCount * sizeof(uint32_t));

         typeHeader->entriesStart = util::hostToDevice32(typeWriter.size());

         const size_t entryStart = typeWriter.getBuffer()->size();
         for (FlatEntry& flatEntry : *entries) {
             assert(flatEntry.entry->id.value() < entryCount);
             indices[flatEntry.entry->id.value()] = util::hostToDevice32(
                     typeWriter.getBuffer()->size() - entryStart);
             if (!flattenValue(&flatEntry, typeWriter.getBuffer())) {
                 mDiag->error(DiagMessage()
                              << "failed to flatten resource '"
                              << ResourceNameRef(mPackage->name, type->type, flatEntry.entry->name)
                              << "' for configuration '" << config << "'");
                 return false;
             }
         }
         typeWriter.finish();
         return true;
     }

     std::vector<ResourceTableType*> collectAndSortTypes() {
         std::vector<ResourceTableType*> sortedTypes;
         for (auto& type : mPackage->types) {
             if (type->type == ResourceType::kStyleable) {
                 // Styleables aren't real Resource Types, they are represented in the R.java
                 // file.
                 continue;
             }

             assert(type->id && "type must have an ID set");

             sortedTypes.push_back(type.get());
         }
         std::sort(sortedTypes.begin(), sortedTypes.end(), cmpIds<ResourceTableType>);
         return sortedTypes;
     }

     std::vector<ResourceEntry*> collectAndSortEntries(ResourceTableType* type) {
         // Sort the entries by entry ID.
         std::vector<ResourceEntry*> sortedEntries;
         for (auto& entry : type->entries) {
             assert(entry->id && "entry must have an ID set");
             sortedEntries.push_back(entry.get());
         }
         std::sort(sortedEntries.begin(), sortedEntries.end(), cmpIds<ResourceEntry>);
         return sortedEntries;
     }

     bool flattenTypeSpec(ResourceTableType* type, std::vector<ResourceEntry*>* sortedEntries,
                          BigBuffer* buffer) {
         ChunkWriter typeSpecWriter(buffer);
         ResTable_typeSpec* specHeader = typeSpecWriter.startChunk<ResTable_typeSpec>(
                 RES_TABLE_TYPE_SPEC_TYPE);
         specHeader->id = type->id.value();

         if (sortedEntries->empty()) {
             typeSpecWriter.finish();
             return true;
         }

         // We can't just take the size of the vector. There may be holes in the entry ID space.
         // Since the entries are sorted by ID, the last one will be the biggest.
         const size_t numEntries = sortedEntries->back()->id.value() + 1;

         specHeader->entryCount = util::hostToDevice32(numEntries);

         // Reserve space for the masks of each resource in this type. These
         // show for which configuration axis the resource changes.
         uint32_t* configMasks = typeSpecWriter.nextBlock<uint32_t>(numEntries);

         const size_t actualNumEntries = sortedEntries->size();
         for (size_t entryIndex = 0; entryIndex < actualNumEntries; entryIndex++) {
             ResourceEntry* entry = sortedEntries->at(entryIndex);

             // Populate the config masks for this entry.

             if (entry->symbolStatus.state == SymbolState::kPublic) {
                 configMasks[entry->id.value()] |=
                         util::hostToDevice32(ResTable_typeSpec::SPEC_PUBLIC);
             }

             const size_t configCount = entry->values.size();
             for (size_t i = 0; i < configCount; i++) {
                 const ConfigDescription& config = entry->values[i]->config;
                 for (size_t j = i + 1; j < configCount; j++) {
                     configMasks[entry->id.value()] |= util::hostToDevice32(
                             config.diff(entry->values[j]->config));
                 }
             }
         }
         typeSpecWriter.finish();
         return true;
     }

     bool flattenTypes(BigBuffer* buffer) {
         // Sort the types by their IDs. They will be inserted into the StringPool in this order.
         std::vector<ResourceTableType*> sortedTypes = collectAndSortTypes();

         size_t expectedTypeId = 1;
         for (ResourceTableType* type : sortedTypes) {
             // If there is a gap in the type IDs, fill in the StringPool
             // with empty values until we reach the ID we expect.
             while (type->id.value() > expectedTypeId) {
                 std::u16string typeName(u"?");
                 typeName += expectedTypeId;
                 mTypePool.makeRef(typeName);
                 expectedTypeId++;
             }
             expectedTypeId++;
             mTypePool.makeRef(toString(type->type));

             std::vector<ResourceEntry*> sortedEntries = collectAndSortEntries(type);

             if (!flattenTypeSpec(type, &sortedEntries, buffer)) {
                 return false;
             }

             // The binary resource table lists resource entries for each configuration.
             // We store them inverted, where a resource entry lists the values for each
             // configuration available. Here we reverse this to match the binary table.
             std::map<ConfigDescription, std::vector<FlatEntry>> configToEntryListMap;
             for (ResourceEntry* entry : sortedEntries) {
                 const uint32_t keyIndex = (uint32_t) mKeyPool.makeRef(entry->name).getIndex();

                 // Group values by configuration.
                 for (auto& configValue : entry->values) {
                     configToEntryListMap[configValue->config].push_back(FlatEntry{
                             entry, configValue->value.get(), keyIndex });
                 }
             }

             // Flatten a configuration value.
             for (auto& entry : configToEntryListMap) {
                 if (!flattenConfig(type, entry.first, &entry.second, buffer)) {
                     return false;
                 }
             }
         }
         return true;
     }
 };

 } // namespace

 bool TableFlattener::consume(IAaptContext* context, ResourceTable* table) {
     // We must do this before writing the resources, since the string pool IDs may change.
     table->stringPool.sort([](const StringPool::Entry& a, const StringPool::Entry& b) -> bool {
         int diff = a.context.priority - b.context.priority;
         if (diff < 0) return true;
         if (diff > 0) return false;
         diff = a.context.config.compare(b.context.config);
         if (diff < 0) return true;
         if (diff > 0) return false;
         return a.value < b.value;
     });
     table->stringPool.prune();

     // Write the ResTable header.
     ChunkWriter tableWriter(mBuffer);
     ResTable_header* tableHeader = tableWriter.startChunk<ResTable_header>(RES_TABLE_TYPE);
     tableHeader->packageCount = util::hostToDevice32(table->packages.size());

     // Flatten the values string pool.
     StringPool::flattenUtf8(tableWriter.getBuffer(), table->stringPool);

     BigBuffer packageBuffer(1024);

     // Flatten each package.
     for (auto& package : table->packages) {
         PackageFlattener flattener(context->getDiagnostics(), package.get());
         if (!flattener.flattenPackage(&packageBuffer)) {
             return false;
         }
     }

     // Finally merge all the packages into the main buffer.
     tableWriter.getBuffer()->appendBuffer(std::move(packageBuffer));
     tableWriter.finish();
     return true;
 }

 } // namespace aapt
	/*
	* Copyright (C) 2015 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 "ResourceTable.h"
	#include "ResourceValues.h"
	#include "ValueVisitor.h"

	#include "flatten/ChunkWriter.h"
	#include "flatten/ResourceTypeExtensions.h"
	#include "flatten/TableFlattener.h"
	#include "util/BigBuffer.h"

	#include <android-base/macros.h>
	#include <algorithm>
	#include <type_traits>
	#include <numeric>

	using namespace android;

	namespace aapt {

	namespace {

	template <typename T>
	static bool cmpIds(const T* a, const T* b) {
	return a->id.value() < b->id.value();
	}

	static void strcpy16_htod(uint16_t* dst, size_t len, const StringPiece16& src) {
	if (len == 0) {
	return;
	}

	size_t i;
	const char16_t* srcData = src.data();
	for (i = 0; i < len - 1 && i < src.size(); i++) {
	dst[i] = util::hostToDevice16((uint16_t) srcData[i]);
	}
	dst[i] = 0;
	}

	static bool cmpStyleEntries(const Style::Entry& a, const Style::Entry& b) {
	if (a.key.id) {
	if (b.key.id) {
	return a.key.id.value() < b.key.id.value();
	}
	return true;
	} else if (!b.key.id) {
	return a.key.name.value() < b.key.name.value();
	}
	return false;
	}

	struct FlatEntry {
	ResourceEntry* entry;
	Value* value;

	// The entry string pool index to the entry's name.
	uint32_t entryKey;
	};

	class MapFlattenVisitor : public RawValueVisitor {
	public:
	using RawValueVisitor::visit;

	MapFlattenVisitor(ResTable_entry_ext* outEntry, BigBuffer* buffer) :
	mOutEntry(outEntry), mBuffer(buffer) {
	}

	void visit(Attribute* attr) override {
	{
	Reference key = Reference(ResTable_map::ATTR_TYPE);
	BinaryPrimitive val(Res_value::TYPE_INT_DEC, attr->typeMask);
	flattenEntry(&key, &val);
	}

	if (attr->minInt != std::numeric_limits<int32_t>::min()) {
	Reference key = Reference(ResTable_map::ATTR_MIN);
	BinaryPrimitive val(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(attr->minInt));
	flattenEntry(&key, &val);
	}

	if (attr->maxInt != std::numeric_limits<int32_t>::max()) {
	Reference key = Reference(ResTable_map::ATTR_MAX);
	BinaryPrimitive val(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(attr->maxInt));
	flattenEntry(&key, &val);
	}

	for (Attribute::Symbol& s : attr->symbols) {
	BinaryPrimitive val(Res_value::TYPE_INT_DEC, s.value);
	flattenEntry(&s.symbol, &val);
	}
	}

	void visit(Style* style) override {
	if (style->parent) {
	const Reference& parentRef = style->parent.value();
	assert(parentRef.id && "parent has no ID");
	mOutEntry->parent.ident = util::hostToDevice32(parentRef.id.value().id);
	}

	// Sort the style.
	std::sort(style->entries.begin(), style->entries.end(), cmpStyleEntries);

	for (Style::Entry& entry : style->entries) {
	flattenEntry(&entry.key, entry.value.get());
	}
	}

	void visit(Styleable* styleable) override {
	for (auto& attrRef : styleable->entries) {
	BinaryPrimitive val(Res_value{});
	flattenEntry(&attrRef, &val);
	}

	}

	void visit(Array* array) override {
	for (auto& item : array->items) {
	ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
	flattenValue(item.get(), outEntry);
	outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
	mEntryCount++;
	}
	}

	void visit(Plural* plural) override {
	const size_t count = plural->values.size();
	for (size_t i = 0; i < count; i++) {
	if (!plural->values[i]) {
	continue;
	}

	ResourceId q;
	switch (i) {
	case Plural::Zero:
	q.id = android::ResTable_map::ATTR_ZERO;
	break;

	case Plural::One:
	q.id = android::ResTable_map::ATTR_ONE;
	break;

	case Plural::Two:
	q.id = android::ResTable_map::ATTR_TWO;
	break;

	case Plural::Few:
	q.id = android::ResTable_map::ATTR_FEW;
	break;

	case Plural::Many:
	q.id = android::ResTable_map::ATTR_MANY;
	break;

	case Plural::Other:
	q.id = android::ResTable_map::ATTR_OTHER;
	break;

	default:
	assert(false);
	break;
	}

	Reference key(q);
	flattenEntry(&key, plural->values[i].get());
	}
	}

	/**
	* Call this after visiting a Value. This will finish any work that
	* needs to be done to prepare the entry.
	*/
	void finish() {
	mOutEntry->count = util::hostToDevice32(mEntryCount);
	}

	private:
	void flattenKey(Reference* key, ResTable_map* outEntry) {
	assert(key->id && "key has no ID");
	outEntry->name.ident = util::hostToDevice32(key->id.value().id);
	}

	void flattenValue(Item* value, ResTable_map* outEntry) {
	bool result = value->flatten(&outEntry->value);
	assert(result && "flatten failed");
	}

	void flattenEntry(Reference* key, Item* value) {
	ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
	flattenKey(key, outEntry);
	flattenValue(value, outEntry);
	outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
	mEntryCount++;
	}

	ResTable_entry_ext* mOutEntry;
	BigBuffer* mBuffer;
	size_t mEntryCount = 0;
	};

	class PackageFlattener {
	public:
	PackageFlattener(IDiagnostics* diag, ResourceTablePackage* package) :
	mDiag(diag), mPackage(package) {
	}

	bool flattenPackage(BigBuffer* buffer) {
	ChunkWriter pkgWriter(buffer);
	ResTable_package* pkgHeader = pkgWriter.startChunk<ResTable_package>(
	RES_TABLE_PACKAGE_TYPE);
	pkgHeader->id = util::hostToDevice32(mPackage->id.value());

	if (mPackage->name.size() >= arraysize(pkgHeader->name)) {
	mDiag->error(DiagMessage() <<
	"package name '" << mPackage->name << "' is too long");
	return false;
	}

	// Copy the package name in device endianness.
	strcpy16_htod(pkgHeader->name, arraysize(pkgHeader->name), mPackage->name);

	// Serialize the types. We do this now so that our type and key strings
	// are populated. We write those first.
	BigBuffer typeBuffer(1024);
	flattenTypes(&typeBuffer);

	pkgHeader->typeStrings = util::hostToDevice32(pkgWriter.size());
	StringPool::flattenUtf16(pkgWriter.getBuffer(), mTypePool);

	pkgHeader->keyStrings = util::hostToDevice32(pkgWriter.size());
	StringPool::flattenUtf16(pkgWriter.getBuffer(), mKeyPool);

	// Append the types.
	buffer->appendBuffer(std::move(typeBuffer));

	pkgWriter.finish();
	return true;
	}

	private:
	IDiagnostics* mDiag;
	ResourceTablePackage* mPackage;
	StringPool mTypePool;
	StringPool mKeyPool;

	template <typename T, bool IsItem>
	T* writeEntry(FlatEntry* entry, BigBuffer* buffer) {
	static_assert(std::is_same<ResTable_entry, T>::value \|\|
	std::is_same<ResTable_entry_ext, T>::value,
	"T must be ResTable_entry or ResTable_entry_ext");

	T* result = buffer->nextBlock<T>();
	ResTable_entry* outEntry = (ResTable_entry*)(result);
	if (entry->entry->symbolStatus.state == SymbolState::kPublic) {
	outEntry->flags \|= ResTable_entry::FLAG_PUBLIC;
	}

	if (entry->value->isWeak()) {
	outEntry->flags \|= ResTable_entry::FLAG_WEAK;
	}

	if (!IsItem) {
	outEntry->flags \|= ResTable_entry::FLAG_COMPLEX;
	}

	outEntry->flags = util::hostToDevice16(outEntry->flags);
	outEntry->key.index = util::hostToDevice32(entry->entryKey);
	outEntry->size = util::hostToDevice16(sizeof(T));
	return result;
	}

	bool flattenValue(FlatEntry* entry, BigBuffer* buffer) {
	if (Item* item = valueCast<Item>(entry->value)) {
	writeEntry<ResTable_entry, true>(entry, buffer);
	Res_value* outValue = buffer->nextBlock<Res_value>();
	bool result = item->flatten(outValue);
	assert(result && "flatten failed");
	outValue->size = util::hostToDevice16(sizeof(*outValue));
	} else {
	ResTable_entry_ext* outEntry = writeEntry<ResTable_entry_ext, false>(entry, buffer);
	MapFlattenVisitor visitor(outEntry, buffer);
	entry->value->accept(&visitor);
	visitor.finish();
	}
	return true;
	}

	bool flattenConfig(const ResourceTableType* type, const ConfigDescription& config,
	std::vector<FlatEntry>* entries, BigBuffer* buffer) {
	ChunkWriter typeWriter(buffer);
	ResTable_type* typeHeader = typeWriter.startChunk<ResTable_type>(RES_TABLE_TYPE_TYPE);
	typeHeader->id = type->id.value();
	typeHeader->config = config;
	typeHeader->config.swapHtoD();

	auto maxAccum = [](uint32_t max, const std::unique_ptr<ResourceEntry>& a) -> uint32_t {
	return std::max(max, (uint32_t) a->id.value());
	};

	// Find the largest entry ID. That is how many entries we will have.
	const uint32_t entryCount =
	std::accumulate(type->entries.begin(), type->entries.end(), 0, maxAccum) + 1;

	typeHeader->entryCount = util::hostToDevice32(entryCount);
	uint32_t* indices = typeWriter.nextBlock<uint32_t>(entryCount);

	assert((size_t) entryCount <= std::numeric_limits<uint16_t>::max() + 1);
	memset(indices, 0xff, entryCount * sizeof(uint32_t));

	typeHeader->entriesStart = util::hostToDevice32(typeWriter.size());

	const size_t entryStart = typeWriter.getBuffer()->size();
	for (FlatEntry& flatEntry : *entries) {
	assert(flatEntry.entry->id.value() < entryCount);
	indices[flatEntry.entry->id.value()] = util::hostToDevice32(
	typeWriter.getBuffer()->size() - entryStart);
	if (!flattenValue(&flatEntry, typeWriter.getBuffer())) {
	mDiag->error(DiagMessage()
	<< "failed to flatten resource '"
	<< ResourceNameRef(mPackage->name, type->type, flatEntry.entry->name)
	<< "' for configuration '" << config << "'");
	return false;
	}
	}
	typeWriter.finish();
	return true;
	}

	std::vector<ResourceTableType*> collectAndSortTypes() {
	std::vector<ResourceTableType*> sortedTypes;
	for (auto& type : mPackage->types) {
	if (type->type == ResourceType::kStyleable) {
	// Styleables aren't real Resource Types, they are represented in the R.java
	// file.
	continue;
	}

	assert(type->id && "type must have an ID set");

	sortedTypes.push_back(type.get());
	}
	std::sort(sortedTypes.begin(), sortedTypes.end(), cmpIds<ResourceTableType>);
	return sortedTypes;
	}

	std::vector<ResourceEntry> collectAndSortEntries(ResourceTableType type) {
	// Sort the entries by entry ID.
	std::vector<ResourceEntry*> sortedEntries;
	for (auto& entry : type->entries) {
	assert(entry->id && "entry must have an ID set");
	sortedEntries.push_back(entry.get());
	}
	std::sort(sortedEntries.begin(), sortedEntries.end(), cmpIds<ResourceEntry>);
	return sortedEntries;
	}

	bool flattenTypeSpec(ResourceTableType* type, std::vector<ResourceEntry> sortedEntries,
	BigBuffer* buffer) {
	ChunkWriter typeSpecWriter(buffer);
	ResTable_typeSpec* specHeader = typeSpecWriter.startChunk<ResTable_typeSpec>(
	RES_TABLE_TYPE_SPEC_TYPE);
	specHeader->id = type->id.value();

	if (sortedEntries->empty()) {
	typeSpecWriter.finish();
	return true;
	}

	// We can't just take the size of the vector. There may be holes in the entry ID space.
	// Since the entries are sorted by ID, the last one will be the biggest.
	const size_t numEntries = sortedEntries->back()->id.value() + 1;

	specHeader->entryCount = util::hostToDevice32(numEntries);

	// Reserve space for the masks of each resource in this type. These
	// show for which configuration axis the resource changes.
	uint32_t* configMasks = typeSpecWriter.nextBlock<uint32_t>(numEntries);

	const size_t actualNumEntries = sortedEntries->size();
	for (size_t entryIndex = 0; entryIndex < actualNumEntries; entryIndex++) {
	ResourceEntry* entry = sortedEntries->at(entryIndex);

	// Populate the config masks for this entry.

	if (entry->symbolStatus.state == SymbolState::kPublic) {
	configMasks[entry->id.value()] \|=
	util::hostToDevice32(ResTable_typeSpec::SPEC_PUBLIC);
	}

	const size_t configCount = entry->values.size();
	for (size_t i = 0; i < configCount; i++) {
	const ConfigDescription& config = entry->values[i]->config;
	for (size_t j = i + 1; j < configCount; j++) {
	configMasks[entry->id.value()] \|= util::hostToDevice32(
	config.diff(entry->values[j]->config));
	}
	}
	}
	typeSpecWriter.finish();
	return true;
	}

	bool flattenTypes(BigBuffer* buffer) {
	// Sort the types by their IDs. They will be inserted into the StringPool in this order.
	std::vector<ResourceTableType*> sortedTypes = collectAndSortTypes();

	size_t expectedTypeId = 1;
	for (ResourceTableType* type : sortedTypes) {
	// If there is a gap in the type IDs, fill in the StringPool
	// with empty values until we reach the ID we expect.
	while (type->id.value() > expectedTypeId) {
	std::u16string typeName(u"?");
	typeName += expectedTypeId;
	mTypePool.makeRef(typeName);
	expectedTypeId++;
	}
	expectedTypeId++;
	mTypePool.makeRef(toString(type->type));

	std::vector<ResourceEntry*> sortedEntries = collectAndSortEntries(type);

	if (!flattenTypeSpec(type, &sortedEntries, buffer)) {
	return false;
	}

	// The binary resource table lists resource entries for each configuration.
	// We store them inverted, where a resource entry lists the values for each
	// configuration available. Here we reverse this to match the binary table.
	std::map<ConfigDescription, std::vector<FlatEntry>> configToEntryListMap;
	for (ResourceEntry* entry : sortedEntries) {
	const uint32_t keyIndex = (uint32_t) mKeyPool.makeRef(entry->name).getIndex();

	// Group values by configuration.
	for (auto& configValue : entry->values) {
	configToEntryListMap[configValue->config].push_back(FlatEntry{
	entry, configValue->value.get(), keyIndex });
	}
	}

	// Flatten a configuration value.
	for (auto& entry : configToEntryListMap) {
	if (!flattenConfig(type, entry.first, &entry.second, buffer)) {
	return false;
	}
	}
	}
	return true;
	}
	};

	} // namespace

	bool TableFlattener::consume(IAaptContext* context, ResourceTable* table) {
	// We must do this before writing the resources, since the string pool IDs may change.
	table->stringPool.sort([](const StringPool::Entry& a, const StringPool::Entry& b) -> bool {
	int diff = a.context.priority - b.context.priority;
	if (diff < 0) return true;
	if (diff > 0) return false;
	diff = a.context.config.compare(b.context.config);
	if (diff < 0) return true;
	if (diff > 0) return false;
	return a.value < b.value;
	});
	table->stringPool.prune();

	// Write the ResTable header.
	ChunkWriter tableWriter(mBuffer);
	ResTable_header* tableHeader = tableWriter.startChunk<ResTable_header>(RES_TABLE_TYPE);
	tableHeader->packageCount = util::hostToDevice32(table->packages.size());

	// Flatten the values string pool.
	StringPool::flattenUtf8(tableWriter.getBuffer(), table->stringPool);

	BigBuffer packageBuffer(1024);

	// Flatten each package.
	for (auto& package : table->packages) {
	PackageFlattener flattener(context->getDiagnostics(), package.get());
	if (!flattener.flattenPackage(&packageBuffer)) {
	return false;
	}
	}

	// Finally merge all the packages into the main buffer.
	tableWriter.getBuffer()->appendBuffer(std::move(packageBuffer));
	tableWriter.finish();
	return true;
	}

	} // namespace aapt