rocksdb/table/block_based/data_block_hash_index_test.cc
Andrew Kryczka 69679e7375 Fix range deletion tombstone ingestion with global seqno (#6429)
Summary:
Original author: jeffrey-xiao

If we are writing a global seqno for an ingested file, the range
tombstone metablock gets accessed and put into the cache during
ingestion preparation. At the time, the global seqno of the ingested
file has not yet been determined, so the cached block will not have a
global seqno. When the file is ingested and we read its range tombstone
metablock, it will be returned from the cache with no global seqno. In
that case, we use the actual seqnos stored in the range tombstones,
which are all zero, so the tombstones cover nothing.

This commit removes global_seqno_ variable from Block. When iterating
over a block, the global seqno for the block is determined by the
iterator instead of storing this mutable attribute in Block.
Additionally, this commit adds a regression test to check that keys are
deleted when ingesting a file with a global seqno and range deletion
tombstones.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6429

Differential Revision: D19961563

Pulled By: ajkr

fbshipit-source-id: 5cf777397fa3e452401f0bf0364b0750492487b7
2020-02-25 15:31:48 -08:00

723 lines
24 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include <cstdlib>
#include <string>
#include <unordered_map>
#include "db/table_properties_collector.h"
#include "rocksdb/slice.h"
#include "table/block_based/block.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/block_based/block_builder.h"
#include "table/block_based/data_block_hash_index.h"
#include "table/get_context.h"
#include "table/table_builder.h"
#include "test_util/testharness.h"
#include "test_util/testutil.h"
namespace ROCKSDB_NAMESPACE {
bool SearchForOffset(DataBlockHashIndex& index, const char* data,
uint16_t map_offset, const Slice& key,
uint8_t& restart_point) {
uint8_t entry = index.Lookup(data, map_offset, key);
if (entry == kCollision) {
return true;
}
if (entry == kNoEntry) {
return false;
}
return entry == restart_point;
}
// Random KV generator similer to block_test
static std::string RandomString(Random* rnd, int len) {
std::string r;
test::RandomString(rnd, len, &r);
return r;
}
std::string GenerateKey(int primary_key, int secondary_key, int padding_size,
Random* rnd) {
char buf[50];
char* p = &buf[0];
snprintf(buf, sizeof(buf), "%6d%4d", primary_key, secondary_key);
std::string k(p);
if (padding_size) {
k += RandomString(rnd, padding_size);
}
return k;
}
// Generate random key value pairs.
// The generated key will be sorted. You can tune the parameters to generated
// different kinds of test key/value pairs for different scenario.
void GenerateRandomKVs(std::vector<std::string>* keys,
std::vector<std::string>* values, const int from,
const int len, const int step = 1,
const int padding_size = 0,
const int keys_share_prefix = 1) {
Random rnd(302);
// generate different prefix
for (int i = from; i < from + len; i += step) {
// generating keys that shares the prefix
for (int j = 0; j < keys_share_prefix; ++j) {
keys->emplace_back(GenerateKey(i, j, padding_size, &rnd));
// 100 bytes values
values->emplace_back(RandomString(&rnd, 100));
}
}
}
TEST(DataBlockHashIndex, DataBlockHashTestSmall) {
DataBlockHashIndexBuilder builder;
builder.Initialize(0.75 /*util_ratio*/);
for (int j = 0; j < 5; j++) {
for (uint8_t i = 0; i < 2 + j; i++) {
std::string key("key" + std::to_string(i));
uint8_t restart_point = i;
builder.Add(key, restart_point);
}
size_t estimated_size = builder.EstimateSize();
std::string buffer("fake"), buffer2;
size_t original_size = buffer.size();
estimated_size += original_size;
builder.Finish(buffer);
ASSERT_EQ(buffer.size(), estimated_size);
buffer2 = buffer; // test for the correctness of relative offset
Slice s(buffer2);
DataBlockHashIndex index;
uint16_t map_offset;
index.Initialize(s.data(), static_cast<uint16_t>(s.size()), &map_offset);
// the additional hash map should start at the end of the buffer
ASSERT_EQ(original_size, map_offset);
for (uint8_t i = 0; i < 2; i++) {
std::string key("key" + std::to_string(i));
uint8_t restart_point = i;
ASSERT_TRUE(
SearchForOffset(index, s.data(), map_offset, key, restart_point));
}
builder.Reset();
}
}
TEST(DataBlockHashIndex, DataBlockHashTest) {
// bucket_num = 200, #keys = 100. 50% utilization
DataBlockHashIndexBuilder builder;
builder.Initialize(0.75 /*util_ratio*/);
for (uint8_t i = 0; i < 100; i++) {
std::string key("key" + std::to_string(i));
uint8_t restart_point = i;
builder.Add(key, restart_point);
}
size_t estimated_size = builder.EstimateSize();
std::string buffer("fake content"), buffer2;
size_t original_size = buffer.size();
estimated_size += original_size;
builder.Finish(buffer);
ASSERT_EQ(buffer.size(), estimated_size);
buffer2 = buffer; // test for the correctness of relative offset
Slice s(buffer2);
DataBlockHashIndex index;
uint16_t map_offset;
index.Initialize(s.data(), static_cast<uint16_t>(s.size()), &map_offset);
// the additional hash map should start at the end of the buffer
ASSERT_EQ(original_size, map_offset);
for (uint8_t i = 0; i < 100; i++) {
std::string key("key" + std::to_string(i));
uint8_t restart_point = i;
ASSERT_TRUE(
SearchForOffset(index, s.data(), map_offset, key, restart_point));
}
}
TEST(DataBlockHashIndex, DataBlockHashTestCollision) {
// bucket_num = 2. There will be intense hash collisions
DataBlockHashIndexBuilder builder;
builder.Initialize(0.75 /*util_ratio*/);
for (uint8_t i = 0; i < 100; i++) {
std::string key("key" + std::to_string(i));
uint8_t restart_point = i;
builder.Add(key, restart_point);
}
size_t estimated_size = builder.EstimateSize();
std::string buffer("some other fake content to take up space"), buffer2;
size_t original_size = buffer.size();
estimated_size += original_size;
builder.Finish(buffer);
ASSERT_EQ(buffer.size(), estimated_size);
buffer2 = buffer; // test for the correctness of relative offset
Slice s(buffer2);
DataBlockHashIndex index;
uint16_t map_offset;
index.Initialize(s.data(), static_cast<uint16_t>(s.size()), &map_offset);
// the additional hash map should start at the end of the buffer
ASSERT_EQ(original_size, map_offset);
for (uint8_t i = 0; i < 100; i++) {
std::string key("key" + std::to_string(i));
uint8_t restart_point = i;
ASSERT_TRUE(
SearchForOffset(index, s.data(), map_offset, key, restart_point));
}
}
TEST(DataBlockHashIndex, DataBlockHashTestLarge) {
DataBlockHashIndexBuilder builder;
builder.Initialize(0.75 /*util_ratio*/);
std::unordered_map<std::string, uint8_t> m;
for (uint8_t i = 0; i < 100; i++) {
if (i % 2) {
continue; // leave half of the keys out
}
std::string key = "key" + std::to_string(i);
uint8_t restart_point = i;
builder.Add(key, restart_point);
m[key] = restart_point;
}
size_t estimated_size = builder.EstimateSize();
std::string buffer("filling stuff"), buffer2;
size_t original_size = buffer.size();
estimated_size += original_size;
builder.Finish(buffer);
ASSERT_EQ(buffer.size(), estimated_size);
buffer2 = buffer; // test for the correctness of relative offset
Slice s(buffer2);
DataBlockHashIndex index;
uint16_t map_offset;
index.Initialize(s.data(), static_cast<uint16_t>(s.size()), &map_offset);
// the additional hash map should start at the end of the buffer
ASSERT_EQ(original_size, map_offset);
for (uint8_t i = 0; i < 100; i++) {
std::string key = "key" + std::to_string(i);
uint8_t restart_point = i;
if (m.count(key)) {
ASSERT_TRUE(m[key] == restart_point);
ASSERT_TRUE(
SearchForOffset(index, s.data(), map_offset, key, restart_point));
} else {
// we allow false positve, so don't test the nonexisting keys.
// when false positive happens, the search will continue to the
// restart intervals to see if the key really exist.
}
}
}
TEST(DataBlockHashIndex, RestartIndexExceedMax) {
DataBlockHashIndexBuilder builder;
builder.Initialize(0.75 /*util_ratio*/);
std::unordered_map<std::string, uint8_t> m;
for (uint8_t i = 0; i <= 253; i++) {
std::string key = "key" + std::to_string(i);
uint8_t restart_point = i;
builder.Add(key, restart_point);
}
ASSERT_TRUE(builder.Valid());
builder.Reset();
for (uint8_t i = 0; i <= 254; i++) {
std::string key = "key" + std::to_string(i);
uint8_t restart_point = i;
builder.Add(key, restart_point);
}
ASSERT_FALSE(builder.Valid());
builder.Reset();
ASSERT_TRUE(builder.Valid());
}
TEST(DataBlockHashIndex, BlockRestartIndexExceedMax) {
Options options = Options();
BlockBuilder builder(1 /* block_restart_interval */,
true /* use_delta_encoding */,
false /* use_value_delta_encoding */,
BlockBasedTableOptions::kDataBlockBinaryAndHash);
// #restarts <= 253. HashIndex is valid
for (int i = 0; i <= 253; i++) {
std::string ukey = "key" + std::to_string(i);
InternalKey ikey(ukey, 0, kTypeValue);
builder.Add(ikey.Encode().ToString(), "value");
}
{
// read serialized contents of the block
Slice rawblock = builder.Finish();
// create block reader
BlockContents contents;
contents.data = rawblock;
Block reader(std::move(contents));
ASSERT_EQ(reader.IndexType(),
BlockBasedTableOptions::kDataBlockBinaryAndHash);
}
builder.Reset();
// #restarts > 253. HashIndex is not used
for (int i = 0; i <= 254; i++) {
std::string ukey = "key" + std::to_string(i);
InternalKey ikey(ukey, 0, kTypeValue);
builder.Add(ikey.Encode().ToString(), "value");
}
{
// read serialized contents of the block
Slice rawblock = builder.Finish();
// create block reader
BlockContents contents;
contents.data = rawblock;
Block reader(std::move(contents));
ASSERT_EQ(reader.IndexType(),
BlockBasedTableOptions::kDataBlockBinarySearch);
}
}
TEST(DataBlockHashIndex, BlockSizeExceedMax) {
Options options = Options();
std::string ukey(10, 'k');
InternalKey ikey(ukey, 0, kTypeValue);
BlockBuilder builder(1 /* block_restart_interval */,
false /* use_delta_encoding */,
false /* use_value_delta_encoding */,
BlockBasedTableOptions::kDataBlockBinaryAndHash);
{
// insert a large value. The block size plus HashIndex is 65536.
std::string value(65502, 'v');
builder.Add(ikey.Encode().ToString(), value);
// read serialized contents of the block
Slice rawblock = builder.Finish();
ASSERT_LE(rawblock.size(), kMaxBlockSizeSupportedByHashIndex);
std::cerr << "block size: " << rawblock.size() << std::endl;
// create block reader
BlockContents contents;
contents.data = rawblock;
Block reader(std::move(contents));
ASSERT_EQ(reader.IndexType(),
BlockBasedTableOptions::kDataBlockBinaryAndHash);
}
builder.Reset();
{
// insert a large value. The block size plus HashIndex would be 65537.
// This excceed the max block size supported by HashIndex (65536).
// So when build finishes HashIndex will not be created for the block.
std::string value(65503, 'v');
builder.Add(ikey.Encode().ToString(), value);
// read serialized contents of the block
Slice rawblock = builder.Finish();
ASSERT_LE(rawblock.size(), kMaxBlockSizeSupportedByHashIndex);
std::cerr << "block size: " << rawblock.size() << std::endl;
// create block reader
BlockContents contents;
contents.data = rawblock;
Block reader(std::move(contents));
// the index type have fallen back to binary when build finish.
ASSERT_EQ(reader.IndexType(),
BlockBasedTableOptions::kDataBlockBinarySearch);
}
}
TEST(DataBlockHashIndex, BlockTestSingleKey) {
Options options = Options();
BlockBuilder builder(16 /* block_restart_interval */,
true /* use_delta_encoding */,
false /* use_value_delta_encoding */,
BlockBasedTableOptions::kDataBlockBinaryAndHash);
std::string ukey("gopher");
std::string value("gold");
InternalKey ikey(ukey, 10, kTypeValue);
builder.Add(ikey.Encode().ToString(), value /*value*/);
// read serialized contents of the block
Slice rawblock = builder.Finish();
// create block reader
BlockContents contents;
contents.data = rawblock;
Block reader(std::move(contents));
const InternalKeyComparator icmp(BytewiseComparator());
auto iter = reader.NewDataIterator(&icmp, icmp.user_comparator(),
kDisableGlobalSequenceNumber);
bool may_exist;
// search in block for the key just inserted
{
InternalKey seek_ikey(ukey, 10, kValueTypeForSeek);
may_exist = iter->SeekForGet(seek_ikey.Encode().ToString());
ASSERT_TRUE(may_exist);
ASSERT_TRUE(iter->Valid());
ASSERT_EQ(
options.comparator->Compare(iter->key(), ikey.Encode().ToString()), 0);
ASSERT_EQ(iter->value(), value);
}
// search in block for the existing ukey, but with higher seqno
{
InternalKey seek_ikey(ukey, 20, kValueTypeForSeek);
// HashIndex should be able to set the iter correctly
may_exist = iter->SeekForGet(seek_ikey.Encode().ToString());
ASSERT_TRUE(may_exist);
ASSERT_TRUE(iter->Valid());
// user key should match
ASSERT_EQ(options.comparator->Compare(ExtractUserKey(iter->key()), ukey),
0);
// seek_key seqno number should be greater than that of iter result
ASSERT_GT(GetInternalKeySeqno(seek_ikey.Encode()),
GetInternalKeySeqno(iter->key()));
ASSERT_EQ(iter->value(), value);
}
// Search in block for the existing ukey, but with lower seqno
// in this case, hash can find the only occurrence of the user_key, but
// ParseNextDataKey() will skip it as it does not have a older seqno.
// In this case, GetForSeek() is effective to locate the user_key, and
// iter->Valid() == false indicates that we've reached to the end of
// the block and the caller should continue searching the next block.
{
InternalKey seek_ikey(ukey, 5, kValueTypeForSeek);
may_exist = iter->SeekForGet(seek_ikey.Encode().ToString());
ASSERT_TRUE(may_exist);
ASSERT_FALSE(iter->Valid()); // should have reached to the end of block
}
delete iter;
}
TEST(DataBlockHashIndex, BlockTestLarge) {
Random rnd(1019);
Options options = Options();
std::vector<std::string> keys;
std::vector<std::string> values;
BlockBuilder builder(16 /* block_restart_interval */,
true /* use_delta_encoding */,
false /* use_value_delta_encoding */,
BlockBasedTableOptions::kDataBlockBinaryAndHash);
int num_records = 500;
GenerateRandomKVs(&keys, &values, 0, num_records);
// Generate keys. Adding a trailing "1" to indicate existent keys.
// Later will Seeking for keys with a trailing "0" to test seeking
// non-existent keys.
for (int i = 0; i < num_records; i++) {
std::string ukey(keys[i] + "1" /* existing key marker */);
InternalKey ikey(ukey, 0, kTypeValue);
builder.Add(ikey.Encode().ToString(), values[i]);
}
// read serialized contents of the block
Slice rawblock = builder.Finish();
// create block reader
BlockContents contents;
contents.data = rawblock;
Block reader(std::move(contents));
const InternalKeyComparator icmp(BytewiseComparator());
// random seek existent keys
for (int i = 0; i < num_records; i++) {
auto iter = reader.NewDataIterator(&icmp, icmp.user_comparator(),
kDisableGlobalSequenceNumber);
// find a random key in the lookaside array
int index = rnd.Uniform(num_records);
std::string ukey(keys[index] + "1" /* existing key marker */);
InternalKey ikey(ukey, 0, kTypeValue);
// search in block for this key
bool may_exist = iter->SeekForGet(ikey.Encode().ToString());
ASSERT_TRUE(may_exist);
ASSERT_TRUE(iter->Valid());
ASSERT_EQ(values[index], iter->value());
delete iter;
}
// random seek non-existent user keys
// In this case A), the user_key cannot be found in HashIndex. The key may
// exist in the next block. So the iter is set invalidated to tell the
// caller to search the next block. This test case belongs to this case A).
//
// Note that for non-existent keys, there is possibility of false positive,
// i.e. the key is still hashed into some restart interval.
// Two additional possible outcome:
// B) linear seek the restart interval and not found, the iter stops at the
// starting of the next restart interval. The key does not exist
// anywhere.
// C) linear seek the restart interval and not found, the iter stops at the
// the end of the block, i.e. restarts_. The key may exist in the next
// block.
// So these combinations are possible when searching non-existent user_key:
//
// case# may_exist iter->Valid()
// A true false
// B false true
// C true false
for (int i = 0; i < num_records; i++) {
auto iter = reader.NewDataIterator(&icmp, icmp.user_comparator(),
kDisableGlobalSequenceNumber);
// find a random key in the lookaside array
int index = rnd.Uniform(num_records);
std::string ukey(keys[index] + "0" /* non-existing key marker */);
InternalKey ikey(ukey, 0, kTypeValue);
// search in block for this key
bool may_exist = iter->SeekForGet(ikey.Encode().ToString());
if (!may_exist) {
ASSERT_TRUE(iter->Valid());
}
if (!iter->Valid()) {
ASSERT_TRUE(may_exist);
}
delete iter;
}
}
// helper routine for DataBlockHashIndex.BlockBoundary
void TestBoundary(InternalKey& ik1, std::string& v1, InternalKey& ik2,
std::string& v2, InternalKey& seek_ikey,
GetContext& get_context, Options& options) {
std::unique_ptr<WritableFileWriter> file_writer;
std::unique_ptr<RandomAccessFileReader> file_reader;
std::unique_ptr<TableReader> table_reader;
int level_ = -1;
std::vector<std::string> keys;
const ImmutableCFOptions ioptions(options);
const MutableCFOptions moptions(options);
const InternalKeyComparator internal_comparator(options.comparator);
EnvOptions soptions;
soptions.use_mmap_reads = ioptions.allow_mmap_reads;
file_writer.reset(
test::GetWritableFileWriter(new test::StringSink(), "" /* don't care */));
std::unique_ptr<TableBuilder> builder;
std::vector<std::unique_ptr<IntTblPropCollectorFactory>>
int_tbl_prop_collector_factories;
std::string column_family_name;
builder.reset(ioptions.table_factory->NewTableBuilder(
TableBuilderOptions(ioptions, moptions, internal_comparator,
&int_tbl_prop_collector_factories,
options.compression, options.sample_for_compression,
CompressionOptions(), false /* skip_filters */,
column_family_name, level_),
TablePropertiesCollectorFactory::Context::kUnknownColumnFamily,
file_writer.get()));
builder->Add(ik1.Encode().ToString(), v1);
builder->Add(ik2.Encode().ToString(), v2);
EXPECT_TRUE(builder->status().ok());
Status s = builder->Finish();
file_writer->Flush();
EXPECT_TRUE(s.ok()) << s.ToString();
EXPECT_EQ(
test::GetStringSinkFromLegacyWriter(file_writer.get())->contents().size(),
builder->FileSize());
// Open the table
file_reader.reset(test::GetRandomAccessFileReader(new test::StringSource(
test::GetStringSinkFromLegacyWriter(file_writer.get())->contents(),
0 /*uniq_id*/, ioptions.allow_mmap_reads)));
const bool kSkipFilters = true;
const bool kImmortal = true;
ioptions.table_factory->NewTableReader(
TableReaderOptions(ioptions, moptions.prefix_extractor.get(), soptions,
internal_comparator, !kSkipFilters, !kImmortal,
level_),
std::move(file_reader),
test::GetStringSinkFromLegacyWriter(file_writer.get())->contents().size(),
&table_reader);
// Search using Get()
ReadOptions ro;
ASSERT_OK(table_reader->Get(ro, seek_ikey.Encode().ToString(), &get_context,
moptions.prefix_extractor.get()));
}
TEST(DataBlockHashIndex, BlockBoundary) {
BlockBasedTableOptions table_options;
table_options.data_block_index_type =
BlockBasedTableOptions::kDataBlockBinaryAndHash;
table_options.block_restart_interval = 1;
table_options.block_size = 4096;
Options options;
options.comparator = BytewiseComparator();
options.table_factory.reset(NewBlockBasedTableFactory(table_options));
// insert two large k/v pair. Given that the block_size is 4096, one k/v
// pair will take up one block.
// [ k1/v1 ][ k2/v2 ]
// [ Block N ][ Block N+1 ]
{
// [ "aab"@100 ][ "axy"@10 ]
// | Block N ][ Block N+1 ]
// seek for "axy"@60
std::string uk1("aab");
InternalKey ik1(uk1, 100, kTypeValue);
std::string v1(4100, '1'); // large value
std::string uk2("axy");
InternalKey ik2(uk2, 10, kTypeValue);
std::string v2(4100, '2'); // large value
PinnableSlice value;
std::string seek_ukey("axy");
InternalKey seek_ikey(seek_ukey, 60, kTypeValue);
GetContext get_context(options.comparator, nullptr, nullptr, nullptr,
GetContext::kNotFound, seek_ukey, &value, nullptr,
nullptr, true, nullptr, nullptr);
TestBoundary(ik1, v1, ik2, v2, seek_ikey, get_context, options);
ASSERT_EQ(get_context.State(), GetContext::kFound);
ASSERT_EQ(value, v2);
value.Reset();
}
{
// [ "axy"@100 ][ "axy"@10 ]
// | Block N ][ Block N+1 ]
// seek for "axy"@60
std::string uk1("axy");
InternalKey ik1(uk1, 100, kTypeValue);
std::string v1(4100, '1'); // large value
std::string uk2("axy");
InternalKey ik2(uk2, 10, kTypeValue);
std::string v2(4100, '2'); // large value
PinnableSlice value;
std::string seek_ukey("axy");
InternalKey seek_ikey(seek_ukey, 60, kTypeValue);
GetContext get_context(options.comparator, nullptr, nullptr, nullptr,
GetContext::kNotFound, seek_ukey, &value, nullptr,
nullptr, true, nullptr, nullptr);
TestBoundary(ik1, v1, ik2, v2, seek_ikey, get_context, options);
ASSERT_EQ(get_context.State(), GetContext::kFound);
ASSERT_EQ(value, v2);
value.Reset();
}
{
// [ "axy"@100 ][ "axy"@10 ]
// | Block N ][ Block N+1 ]
// seek for "axy"@120
std::string uk1("axy");
InternalKey ik1(uk1, 100, kTypeValue);
std::string v1(4100, '1'); // large value
std::string uk2("axy");
InternalKey ik2(uk2, 10, kTypeValue);
std::string v2(4100, '2'); // large value
PinnableSlice value;
std::string seek_ukey("axy");
InternalKey seek_ikey(seek_ukey, 120, kTypeValue);
GetContext get_context(options.comparator, nullptr, nullptr, nullptr,
GetContext::kNotFound, seek_ukey, &value, nullptr,
nullptr, true, nullptr, nullptr);
TestBoundary(ik1, v1, ik2, v2, seek_ikey, get_context, options);
ASSERT_EQ(get_context.State(), GetContext::kFound);
ASSERT_EQ(value, v1);
value.Reset();
}
{
// [ "axy"@100 ][ "axy"@10 ]
// | Block N ][ Block N+1 ]
// seek for "axy"@5
std::string uk1("axy");
InternalKey ik1(uk1, 100, kTypeValue);
std::string v1(4100, '1'); // large value
std::string uk2("axy");
InternalKey ik2(uk2, 10, kTypeValue);
std::string v2(4100, '2'); // large value
PinnableSlice value;
std::string seek_ukey("axy");
InternalKey seek_ikey(seek_ukey, 5, kTypeValue);
GetContext get_context(options.comparator, nullptr, nullptr, nullptr,
GetContext::kNotFound, seek_ukey, &value, nullptr,
nullptr, true, nullptr, nullptr);
TestBoundary(ik1, v1, ik2, v2, seek_ikey, get_context, options);
ASSERT_EQ(get_context.State(), GetContext::kNotFound);
value.Reset();
}
}
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}