rocksdb/db/db_with_timestamp_compaction_test.cc
Peter Dillinger 54cb9c77d9 Prefer static_cast in place of most reinterpret_cast (#12308)
Summary:
The following are risks associated with pointer-to-pointer reinterpret_cast:
* Can produce the "wrong result" (crash or memory corruption). IIRC, in theory this can happen for any up-cast or down-cast for a non-standard-layout type, though in practice would only happen for multiple inheritance cases (where the base class pointer might be "inside" the derived object). We don't use multiple inheritance a lot, but we do.
* Can mask useful compiler errors upon code change, including converting between unrelated pointer types that you are expecting to be related, and converting between pointer and scalar types unintentionally.

I can only think of some obscure cases where static_cast could be troublesome when it compiles as a replacement:
* Going through `void*` could plausibly cause unnecessary or broken pointer arithmetic. Suppose we have
`struct Derived: public Base1, public Base2`.  If we have `Derived*` -> `void*` -> `Base2*` -> `Derived*` through reinterpret casts, this could plausibly work (though technical UB) assuming the `Base2*` is not dereferenced. Changing to static cast could introduce breaking pointer arithmetic.
* Unnecessary (but safe) pointer arithmetic could arise in a case like `Derived*` -> `Base2*` -> `Derived*` where before the Base2 pointer might not have been dereferenced. This could potentially affect performance.

With some light scripting, I tried replacing pointer-to-pointer reinterpret_casts with static_cast and kept the cases that still compile. Most occurrences of reinterpret_cast have successfully been changed (except for java/ and third-party/). 294 changed, 257 remain.

A couple of related interventions included here:
* Previously Cache::Handle was not actually derived from in the implementations and just used as a `void*` stand-in with reinterpret_cast. Now there is a relationship to allow static_cast. In theory, this could introduce pointer arithmetic (as described above) but is unlikely without multiple inheritance AND non-empty Cache::Handle.
* Remove some unnecessary casts to void* as this is allowed to be implicit (for better or worse).

Most of the remaining reinterpret_casts are for converting to/from raw bytes of objects. We could consider better idioms for these patterns in follow-up work.

I wish there were a way to implement a template variant of static_cast that would only compile if no pointer arithmetic is generated, but best I can tell, this is not possible. AFAIK the best you could do is a dynamic check that the void* conversion after the static cast is unchanged.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12308

Test Plan: existing tests, CI

Reviewed By: ltamasi

Differential Revision: D53204947

Pulled By: pdillinger

fbshipit-source-id: 9de23e618263b0d5b9820f4e15966876888a16e2
2024-02-07 10:44:11 -08:00

354 lines
12 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).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#include "db/compaction/compaction.h"
#include "db/db_test_util.h"
#include "port/stack_trace.h"
#include "test_util/testutil.h"
namespace ROCKSDB_NAMESPACE {
namespace {
std::string Key1(uint64_t key) {
std::string ret;
PutFixed64(&ret, key);
std::reverse(ret.begin(), ret.end());
return ret;
}
std::string Timestamp(uint64_t ts) {
std::string ret;
PutFixed64(&ret, ts);
return ret;
}
} // anonymous namespace
class TimestampCompatibleCompactionTest : public DBTestBase {
public:
TimestampCompatibleCompactionTest()
: DBTestBase("ts_compatible_compaction_test", /*env_do_fsync=*/true) {}
std::string Get(const std::string& key, uint64_t ts) {
ReadOptions read_opts;
std::string ts_str = Timestamp(ts);
Slice ts_slice = ts_str;
read_opts.timestamp = &ts_slice;
std::string value;
Status s = db_->Get(read_opts, key, &value);
if (s.IsNotFound()) {
value.assign("NOT_FOUND");
} else if (!s.ok()) {
value.assign(s.ToString());
}
return value;
}
};
TEST_F(TimestampCompatibleCompactionTest, UserKeyCrossFileBoundary) {
Options options = CurrentOptions();
options.env = env_;
options.compaction_style = kCompactionStyleLevel;
options.comparator = test::BytewiseComparatorWithU64TsWrapper();
options.level0_file_num_compaction_trigger = 3;
constexpr size_t kNumKeysPerFile = 101;
options.memtable_factory.reset(
test::NewSpecialSkipListFactory(kNumKeysPerFile));
DestroyAndReopen(options);
SyncPoint::GetInstance()->DisableProcessing();
SyncPoint::GetInstance()->ClearAllCallBacks();
SyncPoint::GetInstance()->SetCallBack(
"LevelCompactionPicker::PickCompaction:Return", [&](void* arg) {
const auto* compaction = static_cast<Compaction*>(arg);
ASSERT_NE(nullptr, compaction);
ASSERT_EQ(0, compaction->start_level());
ASSERT_EQ(1, compaction->num_input_levels());
// Check that all 3 L0 ssts are picked for level compaction.
ASSERT_EQ(3, compaction->num_input_files(0));
});
SyncPoint::GetInstance()->EnableProcessing();
// Write a L0 with keys 0, 1, ..., 99 with ts from 100 to 199.
uint64_t ts = 100;
uint64_t key = 0;
WriteOptions write_opts;
for (; key < kNumKeysPerFile - 1; ++key, ++ts) {
std::string ts_str = Timestamp(ts);
ASSERT_OK(
db_->Put(write_opts, Key1(key), ts_str, "foo_" + std::to_string(key)));
}
// Write another L0 with keys 99 with newer ts.
ASSERT_OK(Flush());
uint64_t saved_read_ts1 = ts++;
key = 99;
for (int i = 0; i < 4; ++i, ++ts) {
std::string ts_str = Timestamp(ts);
ASSERT_OK(
db_->Put(write_opts, Key1(key), ts_str, "bar_" + std::to_string(key)));
}
ASSERT_OK(Flush());
uint64_t saved_read_ts2 = ts++;
// Write another L0 with keys 99, 100, 101, ..., 150
for (; key <= 150; ++key, ++ts) {
std::string ts_str = Timestamp(ts);
ASSERT_OK(
db_->Put(write_opts, Key1(key), ts_str, "foo1_" + std::to_string(key)));
}
ASSERT_OK(Flush());
// Wait for compaction to finish
ASSERT_OK(dbfull()->TEST_WaitForCompact());
uint64_t read_ts = ts;
ASSERT_EQ("foo_99", Get(Key1(99), saved_read_ts1));
ASSERT_EQ("bar_99", Get(Key1(99), saved_read_ts2));
ASSERT_EQ("foo1_99", Get(Key1(99), read_ts));
SyncPoint::GetInstance()->ClearAllCallBacks();
SyncPoint::GetInstance()->DisableProcessing();
}
TEST_F(TimestampCompatibleCompactionTest, MultipleSubCompactions) {
Options options = CurrentOptions();
options.env = env_;
options.compaction_style = kCompactionStyleUniversal;
options.comparator = test::BytewiseComparatorWithU64TsWrapper();
options.level0_file_num_compaction_trigger = 3;
options.max_subcompactions = 3;
options.target_file_size_base = 1024;
options.statistics = CreateDBStatistics();
DestroyAndReopen(options);
uint64_t ts = 100;
uint64_t key = 0;
WriteOptions write_opts;
// Write keys 0, 1, ..., 499 with ts from 100 to 599.
{
for (; key <= 499; ++key, ++ts) {
std::string ts_str = Timestamp(ts);
ASSERT_OK(db_->Put(write_opts, Key1(key), ts_str,
"foo_" + std::to_string(key)));
}
}
// Write keys 500, ..., 999 with ts from 600 to 1099.
{
for (; key <= 999; ++key, ++ts) {
std::string ts_str = Timestamp(ts);
ASSERT_OK(db_->Put(write_opts, Key1(key), ts_str,
"foo_" + std::to_string(key)));
}
ASSERT_OK(Flush());
}
// Wait for compaction to finish
{
ASSERT_OK(dbfull()->RunManualCompaction(
static_cast_with_check<ColumnFamilyHandleImpl>(
db_->DefaultColumnFamily())
->cfd(),
0 /* input_level */, 1 /* output_level */, CompactRangeOptions(),
nullptr /* begin */, nullptr /* end */, true /* exclusive */,
true /* disallow_trivial_move */,
std::numeric_limits<uint64_t>::max() /* max_file_num_to_ignore */,
"" /*trim_ts*/));
}
// Check stats to make sure multiple subcompactions were scheduled for
// boundaries not to be nullptr.
{
HistogramData num_sub_compactions;
options.statistics->histogramData(NUM_SUBCOMPACTIONS_SCHEDULED,
&num_sub_compactions);
ASSERT_GT(num_sub_compactions.sum, 1);
}
for (key = 0; key <= 999; ++key) {
ASSERT_EQ("foo_" + std::to_string(key), Get(Key1(key), ts));
}
}
class TestFilePartitioner : public SstPartitioner {
public:
explicit TestFilePartitioner() = default;
~TestFilePartitioner() override = default;
const char* Name() const override { return "TestFilePartitioner"; }
PartitionerResult ShouldPartition(
const PartitionerRequest& /*request*/) override {
return PartitionerResult::kRequired;
}
bool CanDoTrivialMove(const Slice& /*smallest_user_key*/,
const Slice& /*largest_user_key*/) override {
return false;
}
};
class TestFilePartitionerFactory : public SstPartitionerFactory {
public:
explicit TestFilePartitionerFactory() = default;
std::unique_ptr<SstPartitioner> CreatePartitioner(
const SstPartitioner::Context& /*context*/) const override {
std::unique_ptr<SstPartitioner> ret =
std::make_unique<TestFilePartitioner>();
return ret;
}
const char* Name() const override { return "TestFilePartitionerFactory"; }
};
TEST_F(TimestampCompatibleCompactionTest, CompactFilesRangeCheckL0) {
Options options = CurrentOptions();
options.env = env_;
options.sst_partitioner_factory =
std::make_shared<TestFilePartitionerFactory>();
options.comparator = test::BytewiseComparatorWithU64TsWrapper();
options.disable_auto_compactions = true;
DestroyAndReopen(options);
constexpr int kNumFiles = 10;
constexpr int kKeysPerFile = 2;
const std::string user_key = "foo";
constexpr uint64_t start_ts = 10000;
uint64_t cur_ts = start_ts;
for (int k = 0; k < kNumFiles; ++k) {
for (int i = 0; i < kKeysPerFile; ++i) {
ASSERT_OK(db_->Put(WriteOptions(), user_key, Timestamp(cur_ts),
"v" + std::to_string(i)));
++cur_ts;
}
ASSERT_OK(db_->Flush(FlushOptions()));
}
std::vector<std::string> input_files{};
{
std::vector<std::string> files;
ASSERT_OK(env_->GetChildren(dbname_, &files));
for (const auto& f : files) {
uint64_t file_num = 0;
FileType file_type = FileType::kWalFile;
if (!ParseFileName(f, &file_num, &file_type) ||
file_type != FileType::kTableFile) {
continue;
}
input_files.emplace_back(f);
}
// sorting here by name, which also happens to sort by generation date.
std::sort(input_files.begin(), input_files.end());
assert(kNumFiles == input_files.size());
std::vector<std::string> tmp;
tmp.emplace_back(input_files[input_files.size() / 2]);
input_files.swap(tmp);
}
{
std::vector<std::string> output_file_names;
CompactionJobInfo compaction_job_info;
ASSERT_OK(db_->CompactFiles(CompactionOptions(), input_files,
/*output_level=*/1, /*output_path_id=*/-1,
&output_file_names, &compaction_job_info));
// We expect the L0 files older than the original provided input were all
// included in the compaction.
ASSERT_EQ(static_cast<size_t>(kNumFiles / 2 + 1),
compaction_job_info.input_files.size());
}
}
TEST_F(TimestampCompatibleCompactionTest, CompactFilesRangeCheckL1) {
Options options = CurrentOptions();
options.env = env_;
options.sst_partitioner_factory =
std::make_shared<TestFilePartitionerFactory>();
options.comparator = test::BytewiseComparatorWithU64TsWrapper();
constexpr int kNumFiles = 4;
options.level0_file_num_compaction_trigger = kNumFiles;
DestroyAndReopen(options);
constexpr int kKeysPerFile = 2;
const std::string user_key = "foo";
constexpr uint64_t start_ts = 10000;
uint64_t cur_ts = start_ts;
// Generate some initial files in both L0 and L1.
for (int k = 0; k < kNumFiles; ++k) {
for (int i = 0; i < kKeysPerFile; ++i) {
ASSERT_OK(db_->Put(WriteOptions(), user_key, Timestamp(cur_ts),
"v" + std::to_string(i)));
++cur_ts;
}
ASSERT_OK(db_->Flush(FlushOptions()));
}
ASSERT_OK(dbfull()->TEST_WaitForCompact());
ASSERT_EQ(0, NumTableFilesAtLevel(/*level=*/0, /*cf=*/0));
ASSERT_EQ(kNumFiles * kKeysPerFile,
NumTableFilesAtLevel(/*level=*/1, /*cf=*/0));
constexpr int additional_l0s = 2;
for (int i = 0; i < additional_l0s; ++i, ++cur_ts) {
ASSERT_OK(db_->Put(WriteOptions(), user_key, Timestamp(cur_ts), "v"));
ASSERT_OK(db_->Flush(FlushOptions()));
}
ASSERT_EQ(additional_l0s, NumTableFilesAtLevel(/*level=*/0, /*cf=*/0));
std::vector<std::string> inputs;
{
std::vector<LiveFileMetaData> fmetas;
db_->GetLiveFilesMetaData(&fmetas);
bool included_one_l1 = false;
for (const auto& meta : fmetas) {
if (meta.level == 0) {
inputs.emplace_back(meta.relative_filename);
} else if (!included_one_l1) {
inputs.emplace_back(meta.relative_filename);
included_one_l1 = true;
}
}
}
ASSERT_EQ(static_cast<size_t>(3), inputs.size());
{
std::vector<std::string> output_file_names;
CompactionJobInfo compaction_job_info;
ASSERT_OK(db_->CompactFiles(CompactionOptions(), inputs, /*output_level=*/1,
/*output_path_id=*/-1, &output_file_names,
&compaction_job_info));
ASSERT_EQ(kNumFiles * kKeysPerFile + 2, output_file_names.size());
ASSERT_EQ(kNumFiles * kKeysPerFile + 2,
static_cast<int>(compaction_job_info.input_files.size()));
}
}
TEST_F(TimestampCompatibleCompactionTest, EmptyCompactionOutput) {
Options options = CurrentOptions();
options.env = env_;
options.comparator = test::BytewiseComparatorWithU64TsWrapper();
DestroyAndReopen(options);
std::string ts_str = Timestamp(1);
WriteOptions wopts;
ASSERT_OK(
db_->DeleteRange(wopts, db_->DefaultColumnFamily(), "k1", "k3", ts_str));
ASSERT_OK(Flush());
ts_str = Timestamp(3);
Slice ts = ts_str;
CompactRangeOptions cro;
// range tombstone will be dropped during compaction
cro.full_history_ts_low = &ts;
cro.bottommost_level_compaction = BottommostLevelCompaction::kForce;
ASSERT_OK(db_->CompactRange(cro, nullptr, nullptr));
}
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}