https://github.com/facebook/rocksdb
block_fetcher_test.cc
// 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 "table/block_fetcher.h"
#include "db/table_properties_collector.h"
#include "file/file_util.h"
#include "options/options_helper.h"
#include "port/port.h"
#include "port/stack_trace.h"
#include "rocksdb/db.h"
#include "rocksdb/file_system.h"
#include "table/block_based/binary_search_index_reader.h"
#include "table/block_based/block_based_table_builder.h"
#include "table/block_based/block_based_table_factory.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/format.h"
#include "test_util/testharness.h"
namespace ROCKSDB_NAMESPACE {
namespace {
class CountedMemoryAllocator : public MemoryAllocator {
public:
const char* Name() const override { return "CountedMemoryAllocator"; }
void* Allocate(size_t size) override {
num_allocations_++;
return static_cast<void*>(new char[size]);
}
void Deallocate(void* p) override {
num_deallocations_++;
delete[] static_cast<char*>(p);
}
int GetNumAllocations() const { return num_allocations_; }
int GetNumDeallocations() const { return num_deallocations_; }
private:
int num_allocations_ = 0;
int num_deallocations_ = 0;
};
struct MemcpyStats {
int num_stack_buf_memcpy;
int num_heap_buf_memcpy;
int num_compressed_buf_memcpy;
};
struct BufAllocationStats {
int num_heap_buf_allocations;
int num_compressed_buf_allocations;
};
struct TestStats {
MemcpyStats memcpy_stats;
BufAllocationStats buf_allocation_stats;
};
class BlockFetcherTest : public testing::Test {
public:
enum class Mode {
kBufferedRead = 0,
kBufferedMmap,
kDirectRead,
kNumModes,
};
// use NumModes as array size to avoid "size of array '...' has non-integral
// type" errors.
const static int NumModes = static_cast<int>(Mode::kNumModes);
protected:
void SetUp() override {
SetupSyncPointsToMockDirectIO();
test_dir_ = test::PerThreadDBPath("block_fetcher_test");
env_ = Env::Default();
fs_ = FileSystem::Default();
ASSERT_OK(fs_->CreateDir(test_dir_, IOOptions(), nullptr));
}
void TearDown() override { EXPECT_OK(DestroyDir(env_, test_dir_)); }
void AssertSameBlock(const std::string& block1, const std::string& block2) {
ASSERT_EQ(block1, block2);
}
// Creates a table with kv pairs (i, i) where i ranges from 0 to 9, inclusive.
void CreateTable(const std::string& table_name,
const CompressionType& compression_type) {
std::unique_ptr<WritableFileWriter> writer;
NewFileWriter(table_name, &writer);
// Create table builder.
ImmutableOptions ioptions(options_);
InternalKeyComparator comparator(options_.comparator);
ColumnFamilyOptions cf_options(options_);
MutableCFOptions moptions(cf_options);
IntTblPropCollectorFactories factories;
std::unique_ptr<TableBuilder> table_builder(table_factory_.NewTableBuilder(
TableBuilderOptions(ioptions, moptions, comparator, &factories,
compression_type, CompressionOptions(),
0 /* column_family_id */, kDefaultColumnFamilyName,
-1 /* level */),
writer.get()));
// Build table.
for (int i = 0; i < 9; i++) {
std::string key = ToInternalKey(std::to_string(i));
// Append "00000000" to string value to enhance compression ratio
std::string value = "00000000" + std::to_string(i);
table_builder->Add(key, value);
}
ASSERT_OK(table_builder->Finish());
}
void FetchIndexBlock(const std::string& table_name,
CountedMemoryAllocator* heap_buf_allocator,
CountedMemoryAllocator* compressed_buf_allocator,
MemcpyStats* memcpy_stats, BlockContents* index_block,
std::string* result) {
FileOptions fopt(options_);
std::unique_ptr<RandomAccessFileReader> file;
NewFileReader(table_name, fopt, &file);
// Get handle of the index block.
Footer footer;
ReadFooter(file.get(), &footer);
const BlockHandle& index_handle = footer.index_handle();
CompressionType compression_type;
FetchBlock(file.get(), index_handle, BlockType::kIndex,
false /* compressed */, false /* do_uncompress */,
heap_buf_allocator, compressed_buf_allocator, index_block,
memcpy_stats, &compression_type);
ASSERT_EQ(compression_type, CompressionType::kNoCompression);
result->assign(index_block->data.ToString());
}
// Fetches the first data block in both direct IO and non-direct IO mode.
//
// compressed: whether the data blocks are compressed;
// do_uncompress: whether the data blocks should be uncompressed on fetching.
// compression_type: the expected compression type.
//
// Expects:
// Block contents are the same.
// Bufferr allocation and memory copy statistics are expected.
void TestFetchDataBlock(
const std::string& table_name_prefix, bool compressed, bool do_uncompress,
std::array<TestStats, NumModes> expected_stats_by_mode) {
for (CompressionType compression_type : GetSupportedCompressions()) {
bool do_compress = compression_type != kNoCompression;
if (compressed != do_compress) continue;
std::string compression_type_str =
CompressionTypeToString(compression_type);
std::string table_name = table_name_prefix + compression_type_str;
CreateTable(table_name, compression_type);
CompressionType expected_compression_type_after_fetch =
(compressed && !do_uncompress) ? compression_type : kNoCompression;
BlockContents blocks[NumModes];
std::string block_datas[NumModes];
MemcpyStats memcpy_stats[NumModes];
CountedMemoryAllocator heap_buf_allocators[NumModes];
CountedMemoryAllocator compressed_buf_allocators[NumModes];
for (int i = 0; i < NumModes; ++i) {
SetMode(static_cast<Mode>(i));
FetchFirstDataBlock(table_name, compressed, do_uncompress,
expected_compression_type_after_fetch,
&heap_buf_allocators[i],
&compressed_buf_allocators[i], &blocks[i],
&block_datas[i], &memcpy_stats[i]);
}
for (int i = 0; i < NumModes - 1; ++i) {
AssertSameBlock(block_datas[i], block_datas[i + 1]);
}
// Check memcpy and buffer allocation statistics.
for (int i = 0; i < NumModes; ++i) {
const TestStats& expected_stats = expected_stats_by_mode[i];
ASSERT_EQ(memcpy_stats[i].num_stack_buf_memcpy,
expected_stats.memcpy_stats.num_stack_buf_memcpy);
ASSERT_EQ(memcpy_stats[i].num_heap_buf_memcpy,
expected_stats.memcpy_stats.num_heap_buf_memcpy);
ASSERT_EQ(memcpy_stats[i].num_compressed_buf_memcpy,
expected_stats.memcpy_stats.num_compressed_buf_memcpy);
if (kXpressCompression == compression_type) {
// XPRESS allocates memory internally, thus does not support for
// custom allocator verification
continue;
} else {
ASSERT_EQ(
heap_buf_allocators[i].GetNumAllocations(),
expected_stats.buf_allocation_stats.num_heap_buf_allocations);
ASSERT_EQ(compressed_buf_allocators[i].GetNumAllocations(),
expected_stats.buf_allocation_stats
.num_compressed_buf_allocations);
// The allocated buffers are not deallocated until
// the block content is deleted.
ASSERT_EQ(heap_buf_allocators[i].GetNumDeallocations(), 0);
ASSERT_EQ(compressed_buf_allocators[i].GetNumDeallocations(), 0);
blocks[i].allocation.reset();
ASSERT_EQ(
heap_buf_allocators[i].GetNumDeallocations(),
expected_stats.buf_allocation_stats.num_heap_buf_allocations);
ASSERT_EQ(compressed_buf_allocators[i].GetNumDeallocations(),
expected_stats.buf_allocation_stats
.num_compressed_buf_allocations);
}
}
}
}
void SetMode(Mode mode) {
switch (mode) {
case Mode::kBufferedRead:
options_.use_direct_reads = false;
options_.allow_mmap_reads = false;
break;
case Mode::kBufferedMmap:
options_.use_direct_reads = false;
options_.allow_mmap_reads = true;
break;
case Mode::kDirectRead:
options_.use_direct_reads = true;
options_.allow_mmap_reads = false;
break;
case Mode::kNumModes:
assert(false);
}
}
private:
std::string test_dir_;
Env* env_;
std::shared_ptr<FileSystem> fs_;
BlockBasedTableFactory table_factory_;
Options options_;
std::string Path(const std::string& fname) { return test_dir_ + "/" + fname; }
void WriteToFile(const std::string& content, const std::string& filename) {
std::unique_ptr<FSWritableFile> f;
ASSERT_OK(fs_->NewWritableFile(Path(filename), FileOptions(), &f, nullptr));
ASSERT_OK(f->Append(content, IOOptions(), nullptr));
ASSERT_OK(f->Close(IOOptions(), nullptr));
}
void NewFileWriter(const std::string& filename,
std::unique_ptr<WritableFileWriter>* writer) {
std::string path = Path(filename);
FileOptions file_options;
ASSERT_OK(WritableFileWriter::Create(env_->GetFileSystem(), path,
file_options, writer, nullptr));
}
void NewFileReader(const std::string& filename, const FileOptions& opt,
std::unique_ptr<RandomAccessFileReader>* reader) {
std::string path = Path(filename);
std::unique_ptr<FSRandomAccessFile> f;
ASSERT_OK(fs_->NewRandomAccessFile(path, opt, &f, nullptr));
reader->reset(new RandomAccessFileReader(std::move(f), path,
env_->GetSystemClock().get()));
}
void NewTableReader(const ImmutableOptions& ioptions,
const FileOptions& foptions,
const InternalKeyComparator& comparator,
const std::string& table_name,
std::unique_ptr<BlockBasedTable>* table) {
std::unique_ptr<RandomAccessFileReader> file;
NewFileReader(table_name, foptions, &file);
uint64_t file_size = 0;
ASSERT_OK(env_->GetFileSize(Path(table_name), &file_size));
std::unique_ptr<TableReader> table_reader;
ReadOptions ro;
const auto* table_options =
table_factory_.GetOptions<BlockBasedTableOptions>();
ASSERT_NE(table_options, nullptr);
ASSERT_OK(BlockBasedTable::Open(ro, ioptions, EnvOptions(), *table_options,
comparator, std::move(file), file_size,
&table_reader));
table->reset(reinterpret_cast<BlockBasedTable*>(table_reader.release()));
}
std::string ToInternalKey(const std::string& key) {
InternalKey internal_key(key, 0, ValueType::kTypeValue);
return internal_key.Encode().ToString();
}
void ReadFooter(RandomAccessFileReader* file, Footer* footer) {
uint64_t file_size = 0;
ASSERT_OK(env_->GetFileSize(file->file_name(), &file_size));
IOOptions opts;
ASSERT_OK(ReadFooterFromFile(opts, file, nullptr /* prefetch_buffer */,
file_size, footer,
kBlockBasedTableMagicNumber));
}
// NOTE: compression_type returns the compression type of the fetched block
// contents, so if the block is fetched and uncompressed, then it's
// kNoCompression.
void FetchBlock(RandomAccessFileReader* file, const BlockHandle& block,
BlockType block_type, bool compressed, bool do_uncompress,
MemoryAllocator* heap_buf_allocator,
MemoryAllocator* compressed_buf_allocator,
BlockContents* contents, MemcpyStats* stats,
CompressionType* compresstion_type) {
ImmutableOptions ioptions(options_);
ReadOptions roptions;
PersistentCacheOptions persistent_cache_options;
Footer footer;
ReadFooter(file, &footer);
std::unique_ptr<BlockFetcher> fetcher(new BlockFetcher(
file, nullptr /* prefetch_buffer */, footer, roptions, block, contents,
ioptions, do_uncompress, compressed, block_type,
UncompressionDict::GetEmptyDict(), persistent_cache_options,
heap_buf_allocator, compressed_buf_allocator));
ASSERT_OK(fetcher->ReadBlockContents());
stats->num_stack_buf_memcpy = fetcher->TEST_GetNumStackBufMemcpy();
stats->num_heap_buf_memcpy = fetcher->TEST_GetNumHeapBufMemcpy();
stats->num_compressed_buf_memcpy =
fetcher->TEST_GetNumCompressedBufMemcpy();
*compresstion_type = fetcher->get_compression_type();
}
// NOTE: expected_compression_type is the expected compression
// type of the fetched block content, if the block is uncompressed,
// then the expected compression type is kNoCompression.
void FetchFirstDataBlock(const std::string& table_name, bool compressed,
bool do_uncompress,
CompressionType expected_compression_type,
MemoryAllocator* heap_buf_allocator,
MemoryAllocator* compressed_buf_allocator,
BlockContents* block, std::string* result,
MemcpyStats* memcpy_stats) {
ImmutableOptions ioptions(options_);
InternalKeyComparator comparator(options_.comparator);
FileOptions foptions(options_);
// Get block handle for the first data block.
std::unique_ptr<BlockBasedTable> table;
NewTableReader(ioptions, foptions, comparator, table_name, &table);
std::unique_ptr<BlockBasedTable::IndexReader> index_reader;
ReadOptions ro;
ASSERT_OK(BinarySearchIndexReader::Create(
table.get(), ro, nullptr /* prefetch_buffer */, false /* use_cache */,
false /* prefetch */, false /* pin */, nullptr /* lookup_context */,
&index_reader));
std::unique_ptr<InternalIteratorBase<IndexValue>> iter(
index_reader->NewIterator(
ReadOptions(), false /* disable_prefix_seek */, nullptr /* iter */,
nullptr /* get_context */, nullptr /* lookup_context */));
ASSERT_OK(iter->status());
iter->SeekToFirst();
BlockHandle first_block_handle = iter->value().handle;
// Fetch first data block.
std::unique_ptr<RandomAccessFileReader> file;
NewFileReader(table_name, foptions, &file);
CompressionType compression_type;
FetchBlock(file.get(), first_block_handle, BlockType::kData, compressed,
do_uncompress, heap_buf_allocator, compressed_buf_allocator,
block, memcpy_stats, &compression_type);
ASSERT_EQ(compression_type, expected_compression_type);
result->assign(block->data.ToString());
}
};
// Skip the following tests in lite mode since direct I/O is unsupported.
#ifndef ROCKSDB_LITE
// Fetch index block under both direct IO and non-direct IO.
// Expects:
// the index block contents are the same for both read modes.
TEST_F(BlockFetcherTest, FetchIndexBlock) {
for (CompressionType compression : GetSupportedCompressions()) {
std::string table_name =
"FetchIndexBlock" + CompressionTypeToString(compression);
CreateTable(table_name, compression);
CountedMemoryAllocator allocator;
MemcpyStats memcpy_stats;
BlockContents indexes[NumModes];
std::string index_datas[NumModes];
for (int i = 0; i < NumModes; ++i) {
SetMode(static_cast<Mode>(i));
FetchIndexBlock(table_name, &allocator, &allocator, &memcpy_stats,
&indexes[i], &index_datas[i]);
}
for (int i = 0; i < NumModes - 1; ++i) {
AssertSameBlock(index_datas[i], index_datas[i + 1]);
}
}
}
// Data blocks are not compressed,
// fetch data block under direct IO, mmap IO,and non-direct IO.
// Expects:
// 1. in non-direct IO mode, allocate a heap buffer and memcpy the block
// into the buffer;
// 2. in direct IO mode, allocate a heap buffer and memcpy from the
// direct IO buffer to the heap buffer.
TEST_F(BlockFetcherTest, FetchUncompressedDataBlock) {
TestStats expected_non_mmap_stats = {
{
0 /* num_stack_buf_memcpy */,
1 /* num_heap_buf_memcpy */,
0 /* num_compressed_buf_memcpy */,
},
{
1 /* num_heap_buf_allocations */,
0 /* num_compressed_buf_allocations */,
}};
TestStats expected_mmap_stats = {{
0 /* num_stack_buf_memcpy */,
0 /* num_heap_buf_memcpy */,
0 /* num_compressed_buf_memcpy */,
},
{
0 /* num_heap_buf_allocations */,
0 /* num_compressed_buf_allocations */,
}};
std::array<TestStats, NumModes> expected_stats_by_mode{{
expected_non_mmap_stats /* kBufferedRead */,
expected_mmap_stats /* kBufferedMmap */,
expected_non_mmap_stats /* kDirectRead */,
}};
TestFetchDataBlock("FetchUncompressedDataBlock", false, false,
expected_stats_by_mode);
}
// Data blocks are compressed,
// fetch data block under both direct IO and non-direct IO,
// but do not uncompress.
// Expects:
// 1. in non-direct IO mode, allocate a compressed buffer and memcpy the block
// into the buffer;
// 2. in direct IO mode, allocate a compressed buffer and memcpy from the
// direct IO buffer to the compressed buffer.
TEST_F(BlockFetcherTest, FetchCompressedDataBlock) {
TestStats expected_non_mmap_stats = {
{
0 /* num_stack_buf_memcpy */,
0 /* num_heap_buf_memcpy */,
1 /* num_compressed_buf_memcpy */,
},
{
0 /* num_heap_buf_allocations */,
1 /* num_compressed_buf_allocations */,
}};
TestStats expected_mmap_stats = {{
0 /* num_stack_buf_memcpy */,
0 /* num_heap_buf_memcpy */,
0 /* num_compressed_buf_memcpy */,
},
{
0 /* num_heap_buf_allocations */,
0 /* num_compressed_buf_allocations */,
}};
std::array<TestStats, NumModes> expected_stats_by_mode{{
expected_non_mmap_stats /* kBufferedRead */,
expected_mmap_stats /* kBufferedMmap */,
expected_non_mmap_stats /* kDirectRead */,
}};
TestFetchDataBlock("FetchCompressedDataBlock", true, false,
expected_stats_by_mode);
}
// Data blocks are compressed,
// fetch and uncompress data block under both direct IO and non-direct IO.
// Expects:
// 1. in non-direct IO mode, since the block is small, so it's first memcpyed
// to the stack buffer, then a heap buffer is allocated and the block is
// uncompressed into the heap.
// 2. in direct IO mode mode, allocate a heap buffer, then directly uncompress
// and memcpy from the direct IO buffer to the heap buffer.
TEST_F(BlockFetcherTest, FetchAndUncompressCompressedDataBlock) {
TestStats expected_buffered_read_stats = {
{
1 /* num_stack_buf_memcpy */,
1 /* num_heap_buf_memcpy */,
0 /* num_compressed_buf_memcpy */,
},
{
1 /* num_heap_buf_allocations */,
0 /* num_compressed_buf_allocations */,
}};
TestStats expected_mmap_stats = {{
0 /* num_stack_buf_memcpy */,
1 /* num_heap_buf_memcpy */,
0 /* num_compressed_buf_memcpy */,
},
{
1 /* num_heap_buf_allocations */,
0 /* num_compressed_buf_allocations */,
}};
TestStats expected_direct_read_stats = {
{
0 /* num_stack_buf_memcpy */,
1 /* num_heap_buf_memcpy */,
0 /* num_compressed_buf_memcpy */,
},
{
1 /* num_heap_buf_allocations */,
0 /* num_compressed_buf_allocations */,
}};
std::array<TestStats, NumModes> expected_stats_by_mode{{
expected_buffered_read_stats,
expected_mmap_stats,
expected_direct_read_stats,
}};
TestFetchDataBlock("FetchAndUncompressCompressedDataBlock", true, true,
expected_stats_by_mode);
}
#endif // ROCKSDB_LITE
} // namespace
} // namespace ROCKSDB_NAMESPACE
int main(int argc, char** argv) {
ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
