Add ResTable_sparseTypeEntry support
Benchmarks on bullhead-userdebug show that there is a negligent
performance impact when using sparse entries on a 30% loaded
sparse type of 1000 resources.
Benchmark Time CPU Iterations
-----------------------------------------------------------------------------------
BM_SparseEntryGetResourceSparseLarge 255 ns 254 ns 2751408
BM_SparseEntryGetResourceNotSparseLarge 254 ns 254 ns 2756534
Bug: 27381711
Test: make libandroidfw_tests aapt2_tests
Change-Id: I051ea22f2f6b2bc3696e446adc9e2a34be18009f
diff --git a/tools/aapt2/flatten/TableFlattener.cpp b/tools/aapt2/flatten/TableFlattener.cpp
index 19d030e..697b07f 100644
--- a/tools/aapt2/flatten/TableFlattener.cpp
+++ b/tools/aapt2/flatten/TableFlattener.cpp
@@ -26,6 +26,7 @@
#include "ResourceTable.h"
#include "ResourceValues.h"
+#include "SdkConstants.h"
#include "ValueVisitor.h"
#include "flatten/ChunkWriter.h"
#include "flatten/ResourceTypeExtensions.h"
@@ -216,8 +217,11 @@
class PackageFlattener {
public:
- PackageFlattener(IDiagnostics* diag, ResourceTablePackage* package)
- : diag_(diag), package_(package) {}
+ PackageFlattener(IAaptContext* context, ResourceTablePackage* package, bool use_sparse_entries)
+ : context_(context),
+ diag_(context->GetDiagnostics()),
+ package_(package),
+ use_sparse_entries_(use_sparse_entries) {}
bool FlattenPackage(BigBuffer* buffer) {
ChunkWriter pkg_writer(buffer);
@@ -298,9 +302,12 @@
return true;
}
- bool FlattenConfig(const ResourceTableType* type,
- const ConfigDescription& config,
- std::vector<FlatEntry>* entries, BigBuffer* buffer) {
+ bool FlattenConfig(const ResourceTableType* type, const ConfigDescription& config,
+ const size_t num_total_entries, std::vector<FlatEntry>* entries,
+ BigBuffer* buffer) {
+ CHECK(num_total_entries != 0);
+ CHECK(num_total_entries <= std::numeric_limits<uint16_t>::max());
+
ChunkWriter type_writer(buffer);
ResTable_type* type_header =
type_writer.StartChunk<ResTable_type>(RES_TABLE_TYPE_TYPE);
@@ -308,39 +315,60 @@
type_header->config = config;
type_header->config.swapHtoD();
- auto max_accum = [](uint32_t max,
- const std::unique_ptr<ResourceEntry>& a) -> uint32_t {
- return std::max(max, (uint32_t)a->id.value());
- };
+ std::vector<uint32_t> offsets;
+ offsets.resize(num_total_entries, 0xffffffffu);
- // Find the largest entry ID. That is how many entries we will have.
- const uint32_t entry_count =
- std::accumulate(type->entries.begin(), type->entries.end(), 0,
- max_accum) +
- 1;
-
- type_header->entryCount = util::HostToDevice32(entry_count);
- uint32_t* indices = type_writer.NextBlock<uint32_t>(entry_count);
-
- CHECK((size_t)entry_count <= std::numeric_limits<uint16_t>::max());
- memset(indices, 0xff, entry_count * sizeof(uint32_t));
-
- type_header->entriesStart = util::HostToDevice32(type_writer.size());
-
- const size_t entry_start = type_writer.buffer()->size();
+ BigBuffer values_buffer(512);
for (FlatEntry& flat_entry : *entries) {
- CHECK(flat_entry.entry->id.value() < entry_count);
- indices[flat_entry.entry->id.value()] =
- util::HostToDevice32(type_writer.buffer()->size() - entry_start);
- if (!FlattenValue(&flat_entry, type_writer.buffer())) {
+ CHECK(static_cast<size_t>(flat_entry.entry->id.value()) < num_total_entries);
+ offsets[flat_entry.entry->id.value()] = values_buffer.size();
+ if (!FlattenValue(&flat_entry, &values_buffer)) {
diag_->Error(DiagMessage()
<< "failed to flatten resource '"
- << ResourceNameRef(package_->name, type->type,
- flat_entry.entry->name)
+ << ResourceNameRef(package_->name, type->type, flat_entry.entry->name)
<< "' for configuration '" << config << "'");
return false;
}
}
+
+ bool sparse_encode = use_sparse_entries_;
+
+ // Only sparse encode if the entries will be read on platforms O+.
+ sparse_encode =
+ sparse_encode && (context_->GetMinSdkVersion() >= SDK_O || config.sdkVersion >= SDK_O);
+
+ // Only sparse encode if the offsets are representable in 2 bytes.
+ sparse_encode =
+ sparse_encode && (values_buffer.size() / 4u) <= std::numeric_limits<uint16_t>::max();
+
+ // Only sparse encode if the ratio of populated entries to total entries is below some
+ // threshold.
+ sparse_encode =
+ sparse_encode && ((100 * entries->size()) / num_total_entries) < kSparseEncodingThreshold;
+
+ if (sparse_encode) {
+ type_header->entryCount = util::HostToDevice32(entries->size());
+ type_header->flags |= ResTable_type::FLAG_SPARSE;
+ ResTable_sparseTypeEntry* indices =
+ type_writer.NextBlock<ResTable_sparseTypeEntry>(entries->size());
+ for (size_t i = 0; i < num_total_entries; i++) {
+ if (offsets[i] != ResTable_type::NO_ENTRY) {
+ CHECK((offsets[i] & 0x03) == 0);
+ indices->idx = util::HostToDevice16(i);
+ indices->offset = util::HostToDevice16(offsets[i] / 4u);
+ indices++;
+ }
+ }
+ } else {
+ type_header->entryCount = util::HostToDevice32(num_total_entries);
+ uint32_t* indices = type_writer.NextBlock<uint32_t>(num_total_entries);
+ for (size_t i = 0; i < num_total_entries; i++) {
+ indices[i] = util::HostToDevice32(offsets[i]);
+ }
+ }
+
+ type_header->entriesStart = util::HostToDevice32(type_writer.size());
+ type_writer.buffer()->AppendBuffer(std::move(values_buffer));
type_writer.Finish();
return true;
}
@@ -370,8 +398,7 @@
CHECK(bool(entry->id)) << "entry must have an ID set";
sorted_entries.push_back(entry.get());
}
- std::sort(sorted_entries.begin(), sorted_entries.end(),
- cmp_ids<ResourceEntry>);
+ std::sort(sorted_entries.begin(), sorted_entries.end(), cmp_ids<ResourceEntry>);
return sorted_entries;
}
@@ -443,22 +470,22 @@
type_pool_.MakeRef(ToString(type->type));
std::vector<ResourceEntry*> sorted_entries = CollectAndSortEntries(type);
-
if (!FlattenTypeSpec(type, &sorted_entries, buffer)) {
return false;
}
+ // Since the entries are sorted by ID, the last ID will be the largest.
+ const size_t num_entries = sorted_entries.back()->id.value() + 1;
+
// 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>>
- config_to_entry_list_map;
+ std::map<ConfigDescription, std::vector<FlatEntry>> config_to_entry_list_map;
for (ResourceEntry* entry : sorted_entries) {
- const uint32_t key_index =
- (uint32_t)key_pool_.MakeRef(entry->name).index();
+ const uint32_t key_index = (uint32_t)key_pool_.MakeRef(entry->name).index();
// Group values by configuration.
for (auto& config_value : entry->values) {
@@ -469,7 +496,7 @@
// Flatten a configuration value.
for (auto& entry : config_to_entry_list_map) {
- if (!FlattenConfig(type, entry.first, &entry.second, buffer)) {
+ if (!FlattenConfig(type, entry.first, num_entries, &entry.second, buffer)) {
return false;
}
}
@@ -477,8 +504,10 @@
return true;
}
+ IAaptContext* context_;
IDiagnostics* diag_;
ResourceTablePackage* package_;
+ bool use_sparse_entries_;
StringPool type_pool_;
StringPool key_pool_;
};
@@ -513,7 +542,7 @@
// Flatten each package.
for (auto& package : table->packages) {
- PackageFlattener flattener(context->GetDiagnostics(), package.get());
+ PackageFlattener flattener(context, package.get(), options_.use_sparse_entries);
if (!flattener.FlattenPackage(&package_buffer)) {
return false;
}
diff --git a/tools/aapt2/flatten/TableFlattener.h b/tools/aapt2/flatten/TableFlattener.h
index 53f52c2..223aef8 100644
--- a/tools/aapt2/flatten/TableFlattener.h
+++ b/tools/aapt2/flatten/TableFlattener.h
@@ -25,15 +25,29 @@
namespace aapt {
+// The percentage of used entries for a type for which using a sparse encoding is
+// preferred.
+constexpr const size_t kSparseEncodingThreshold = 60;
+
+struct TableFlattenerOptions {
+ // When true, types for configurations with a sparse set of entries are encoded
+ // as a sparse map of entry ID and offset to actual data.
+ // This is only available on platforms O+ and will only be respected when
+ // minSdk is O+.
+ bool use_sparse_entries = false;
+};
+
class TableFlattener : public IResourceTableConsumer {
public:
- explicit TableFlattener(BigBuffer* buffer) : buffer_(buffer) {}
+ explicit TableFlattener(const TableFlattenerOptions& options, BigBuffer* buffer)
+ : options_(options), buffer_(buffer) {}
bool Consume(IAaptContext* context, ResourceTable* table) override;
private:
DISALLOW_COPY_AND_ASSIGN(TableFlattener);
+ TableFlattenerOptions options_;
BigBuffer* buffer_;
};
diff --git a/tools/aapt2/flatten/TableFlattener_test.cpp b/tools/aapt2/flatten/TableFlattener_test.cpp
index c726240..ff71742 100644
--- a/tools/aapt2/flatten/TableFlattener_test.cpp
+++ b/tools/aapt2/flatten/TableFlattener_test.cpp
@@ -16,7 +16,10 @@
#include "flatten/TableFlattener.h"
+#include "android-base/stringprintf.h"
+
#include "ResourceUtils.h"
+#include "SdkConstants.h"
#include "test/Test.h"
#include "unflatten/BinaryResourceParser.h"
#include "util/Util.h"
@@ -34,32 +37,40 @@
.Build();
}
- ::testing::AssertionResult Flatten(ResourceTable* table,
- ResTable* out_table) {
+ ::testing::AssertionResult Flatten(IAaptContext* context, const TableFlattenerOptions& options,
+ ResourceTable* table, std::string* out_content) {
BigBuffer buffer(1024);
- TableFlattener flattener(&buffer);
- if (!flattener.Consume(context_.get(), table)) {
+ TableFlattener flattener(options, &buffer);
+ if (!flattener.Consume(context, table)) {
return ::testing::AssertionFailure() << "failed to flatten ResourceTable";
}
+ *out_content = buffer.to_string();
+ return ::testing::AssertionSuccess();
+ }
- std::unique_ptr<uint8_t[]> data = util::Copy(buffer);
- if (out_table->add(data.get(), buffer.size(), -1, true) != NO_ERROR) {
+ ::testing::AssertionResult Flatten(IAaptContext* context, const TableFlattenerOptions& options,
+ ResourceTable* table, ResTable* out_table) {
+ std::string content;
+ auto result = Flatten(context, options, table, &content);
+ if (!result) {
+ return result;
+ }
+
+ if (out_table->add(content.data(), content.size(), -1, true) != NO_ERROR) {
return ::testing::AssertionFailure() << "flattened ResTable is corrupt";
}
return ::testing::AssertionSuccess();
}
- ::testing::AssertionResult Flatten(ResourceTable* table,
- ResourceTable* out_table) {
- BigBuffer buffer(1024);
- TableFlattener flattener(&buffer);
- if (!flattener.Consume(context_.get(), table)) {
- return ::testing::AssertionFailure() << "failed to flatten ResourceTable";
+ ::testing::AssertionResult Flatten(IAaptContext* context, const TableFlattenerOptions options,
+ ResourceTable* table, ResourceTable* out_table) {
+ std::string content;
+ auto result = Flatten(context, options, table, &content);
+ if (!result) {
+ return result;
}
- std::unique_ptr<uint8_t[]> data = util::Copy(buffer);
- BinaryResourceParser parser(context_.get(), out_table, {}, data.get(),
- buffer.size());
+ BinaryResourceParser parser(context, out_table, {}, content.data(), content.size());
if (!parser.Parse()) {
return ::testing::AssertionFailure() << "flattened ResTable is corrupt";
}
@@ -127,7 +138,7 @@
return ::testing::AssertionSuccess();
}
- private:
+ protected:
std::unique_ptr<IAaptContext> context_;
};
@@ -153,7 +164,7 @@
.Build();
ResTable res_table;
- ASSERT_TRUE(Flatten(table.get(), &res_table));
+ ASSERT_TRUE(Flatten(context_.get(), {}, table.get(), &res_table));
EXPECT_TRUE(Exists(&res_table, "com.app.test:id/one", ResourceId(0x7f020000),
{}, Res_value::TYPE_INT_BOOLEAN, 0u, 0u));
@@ -200,7 +211,7 @@
.Build();
ResTable res_table;
- ASSERT_TRUE(Flatten(table.get(), &res_table));
+ ASSERT_TRUE(Flatten(context_.get(), {}, table.get(), &res_table));
EXPECT_TRUE(Exists(&res_table, "com.app.test:id/one", ResourceId(0x7f020001),
{}, Res_value::TYPE_INT_BOOLEAN, 0u, 0u));
@@ -222,7 +233,7 @@
.Build();
ResourceTable result;
- ASSERT_TRUE(Flatten(table.get(), &result));
+ ASSERT_TRUE(Flatten(context_.get(), {}, table.get(), &result));
Attribute* actualAttr =
test::GetValue<Attribute>(&result, "android:attr/foo");
@@ -233,4 +244,119 @@
EXPECT_EQ(attr.max_int, actualAttr->max_int);
}
+static std::unique_ptr<ResourceTable> BuildTableWithSparseEntries(
+ IAaptContext* context, const ConfigDescription& sparse_config, float load) {
+ std::unique_ptr<ResourceTable> table =
+ test::ResourceTableBuilder()
+ .SetPackageId(context->GetCompilationPackage(), context->GetPackageId())
+ .Build();
+
+ // Add regular entries.
+ int stride = static_cast<int>(1.0f / load);
+ for (int i = 0; i < 100; i++) {
+ const ResourceName name = test::ParseNameOrDie(
+ base::StringPrintf("%s:string/foo_%d", context->GetCompilationPackage().data(), i));
+ const ResourceId resid(context->GetPackageId(), 0x02, static_cast<uint16_t>(i));
+ const auto value =
+ util::make_unique<BinaryPrimitive>(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(i));
+ CHECK(table->AddResource(name, resid, ConfigDescription::DefaultConfig(), "",
+ std::unique_ptr<Value>(value->Clone(nullptr)),
+ context->GetDiagnostics()));
+
+ // Every few entries, write out a sparse_config value. This will give us the desired load.
+ if (i % stride == 0) {
+ CHECK(table->AddResource(name, resid, sparse_config, "",
+ std::unique_ptr<Value>(value->Clone(nullptr)),
+ context->GetDiagnostics()));
+ }
+ }
+ return table;
+}
+
+TEST_F(TableFlattenerTest, FlattenSparseEntryWithMinSdkO) {
+ std::unique_ptr<IAaptContext> context = test::ContextBuilder()
+ .SetCompilationPackage("android")
+ .SetPackageId(0x01)
+ .SetMinSdkVersion(SDK_O)
+ .Build();
+
+ const ConfigDescription sparse_config = test::ParseConfigOrDie("en-rGB");
+ auto table_in = BuildTableWithSparseEntries(context.get(), sparse_config, 0.25f);
+
+ TableFlattenerOptions options;
+ options.use_sparse_entries = true;
+
+ std::string no_sparse_contents;
+ ASSERT_TRUE(Flatten(context.get(), {}, table_in.get(), &no_sparse_contents));
+
+ std::string sparse_contents;
+ ASSERT_TRUE(Flatten(context.get(), options, table_in.get(), &sparse_contents));
+
+ EXPECT_GT(no_sparse_contents.size(), sparse_contents.size());
+
+ // Attempt to parse the sparse contents.
+
+ ResourceTable sparse_table;
+ BinaryResourceParser parser(context.get(), &sparse_table, Source("test.arsc"),
+ sparse_contents.data(), sparse_contents.size());
+ ASSERT_TRUE(parser.Parse());
+
+ auto value = test::GetValueForConfig<BinaryPrimitive>(&sparse_table, "android:string/foo_0",
+ sparse_config);
+ ASSERT_NE(nullptr, value);
+ EXPECT_EQ(0u, value->value.data);
+
+ ASSERT_EQ(nullptr, test::GetValueForConfig<BinaryPrimitive>(&sparse_table, "android:string/foo_1",
+ sparse_config));
+
+ value = test::GetValueForConfig<BinaryPrimitive>(&sparse_table, "android:string/foo_4",
+ sparse_config);
+ ASSERT_NE(nullptr, value);
+ EXPECT_EQ(4u, value->value.data);
+}
+
+TEST_F(TableFlattenerTest, FlattenSparseEntryWithConfigSdkVersionO) {
+ std::unique_ptr<IAaptContext> context = test::ContextBuilder()
+ .SetCompilationPackage("android")
+ .SetPackageId(0x01)
+ .SetMinSdkVersion(SDK_LOLLIPOP)
+ .Build();
+
+ const ConfigDescription sparse_config = test::ParseConfigOrDie("en-rGB-v26");
+ auto table_in = BuildTableWithSparseEntries(context.get(), sparse_config, 0.25f);
+
+ TableFlattenerOptions options;
+ options.use_sparse_entries = true;
+
+ std::string no_sparse_contents;
+ ASSERT_TRUE(Flatten(context.get(), {}, table_in.get(), &no_sparse_contents));
+
+ std::string sparse_contents;
+ ASSERT_TRUE(Flatten(context.get(), options, table_in.get(), &sparse_contents));
+
+ EXPECT_GT(no_sparse_contents.size(), sparse_contents.size());
+}
+
+TEST_F(TableFlattenerTest, DoNotUseSparseEntryForDenseConfig) {
+ std::unique_ptr<IAaptContext> context = test::ContextBuilder()
+ .SetCompilationPackage("android")
+ .SetPackageId(0x01)
+ .SetMinSdkVersion(SDK_O)
+ .Build();
+
+ const ConfigDescription sparse_config = test::ParseConfigOrDie("en-rGB");
+ auto table_in = BuildTableWithSparseEntries(context.get(), sparse_config, 0.80f);
+
+ TableFlattenerOptions options;
+ options.use_sparse_entries = true;
+
+ std::string no_sparse_contents;
+ ASSERT_TRUE(Flatten(context.get(), {}, table_in.get(), &no_sparse_contents));
+
+ std::string sparse_contents;
+ ASSERT_TRUE(Flatten(context.get(), options, table_in.get(), &sparse_contents));
+
+ EXPECT_EQ(no_sparse_contents.size(), sparse_contents.size());
+}
+
} // namespace aapt