rocksdb/table/block_based/block_based_table_builder.cc
Zhichao Cao cddd637997 Merge adjacent file block reads in RocksDB MultiGet() and Add uncompressed block to cache (#6089)
Summary:
In the current MultiGet, if the KV-pairs do not belong to the data blocks in the block cache, multiple blocks are read from a SST. It will trigger one block read for each block request and read them in parallel. In some cases, if some data blocks are adjacent in the SST, the reads for these blocks can be combined to a single large read, which can reduce the system calls and reduce the read latency if possible.

Considering to fill the block cache, if multiple data blocks are in the same memory buffer, we need to copy them to the heap separately. Therefore, only in the case that 1) data block compression is enabled, and 2) compressed block cache is null, we can do combined read. Otherwise, extra memory copy is needed, which may cause extra overhead. In the current case, data blocks will be uncompressed to a new memory space.

Also, in the case that 1) data block compression is enabled, and 2) compressed block cache is null, it is possible the data block is actually not compressed. In the current logic, these data blocks will not be added to the uncompressed_cache. So if memory buffer is shared and the data block is not compressed, the data block are copied to the head and fill the cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6089

Test Plan: Added test case to ParallelIO.MultiGet. Pass make asan_check

Differential Revision: D18734668

Pulled By: zhichao-cao

fbshipit-source-id: 67c5615ed373e51e42635fd74b36f8f3a66d5da4
2019-12-16 16:26:03 -08:00

1206 lines
47 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 "table/block_based/block_based_table_builder.h"
#include <assert.h>
#include <stdio.h>
#include <list>
#include <map>
#include <memory>
#include <string>
#include <unordered_map>
#include <utility>
#include "db/dbformat.h"
#include "index_builder.h"
#include "rocksdb/cache.h"
#include "rocksdb/comparator.h"
#include "rocksdb/env.h"
#include "rocksdb/flush_block_policy.h"
#include "rocksdb/merge_operator.h"
#include "rocksdb/table.h"
#include "table/block_based/block.h"
#include "table/block_based/block_based_filter_block.h"
#include "table/block_based/block_based_table_factory.h"
#include "table/block_based/block_based_table_reader.h"
#include "table/block_based/block_builder.h"
#include "table/block_based/filter_block.h"
#include "table/block_based/filter_policy_internal.h"
#include "table/block_based/full_filter_block.h"
#include "table/block_based/partitioned_filter_block.h"
#include "table/format.h"
#include "table/table_builder.h"
#include "memory/memory_allocator.h"
#include "util/coding.h"
#include "util/compression.h"
#include "util/crc32c.h"
#include "util/stop_watch.h"
#include "util/string_util.h"
#include "util/xxhash.h"
namespace rocksdb {
extern const std::string kHashIndexPrefixesBlock;
extern const std::string kHashIndexPrefixesMetadataBlock;
typedef BlockBasedTableOptions::IndexType IndexType;
// Without anonymous namespace here, we fail the warning -Wmissing-prototypes
namespace {
// Create a filter block builder based on its type.
FilterBlockBuilder* CreateFilterBlockBuilder(
const ImmutableCFOptions& /*opt*/, const MutableCFOptions& mopt,
const FilterBuildingContext& context,
const bool use_delta_encoding_for_index_values,
PartitionedIndexBuilder* const p_index_builder) {
const BlockBasedTableOptions& table_opt = context.table_options;
if (table_opt.filter_policy == nullptr) return nullptr;
FilterBitsBuilder* filter_bits_builder =
BloomFilterPolicy::GetBuilderFromContext(context);
if (filter_bits_builder == nullptr) {
return new BlockBasedFilterBlockBuilder(mopt.prefix_extractor.get(),
table_opt);
} else {
if (table_opt.partition_filters) {
assert(p_index_builder != nullptr);
// Since after partition cut request from filter builder it takes time
// until index builder actully cuts the partition, we take the lower bound
// as partition size.
assert(table_opt.block_size_deviation <= 100);
auto partition_size =
static_cast<uint32_t>(((table_opt.metadata_block_size *
(100 - table_opt.block_size_deviation)) +
99) /
100);
partition_size = std::max(partition_size, static_cast<uint32_t>(1));
return new PartitionedFilterBlockBuilder(
mopt.prefix_extractor.get(), table_opt.whole_key_filtering,
filter_bits_builder, table_opt.index_block_restart_interval,
use_delta_encoding_for_index_values, p_index_builder, partition_size);
} else {
return new FullFilterBlockBuilder(mopt.prefix_extractor.get(),
table_opt.whole_key_filtering,
filter_bits_builder);
}
}
}
bool GoodCompressionRatio(size_t compressed_size, size_t raw_size) {
// Check to see if compressed less than 12.5%
return compressed_size < raw_size - (raw_size / 8u);
}
bool CompressBlockInternal(const Slice& raw,
const CompressionInfo& compression_info,
uint32_t format_version,
std::string* compressed_output) {
// Will return compressed block contents if (1) the compression method is
// supported in this platform and (2) the compression rate is "good enough".
switch (compression_info.type()) {
case kSnappyCompression:
return Snappy_Compress(compression_info, raw.data(), raw.size(),
compressed_output);
case kZlibCompression:
return Zlib_Compress(
compression_info,
GetCompressFormatForVersion(kZlibCompression, format_version),
raw.data(), raw.size(), compressed_output);
case kBZip2Compression:
return BZip2_Compress(
compression_info,
GetCompressFormatForVersion(kBZip2Compression, format_version),
raw.data(), raw.size(), compressed_output);
case kLZ4Compression:
return LZ4_Compress(
compression_info,
GetCompressFormatForVersion(kLZ4Compression, format_version),
raw.data(), raw.size(), compressed_output);
case kLZ4HCCompression:
return LZ4HC_Compress(
compression_info,
GetCompressFormatForVersion(kLZ4HCCompression, format_version),
raw.data(), raw.size(), compressed_output);
case kXpressCompression:
return XPRESS_Compress(raw.data(), raw.size(), compressed_output);
case kZSTD:
case kZSTDNotFinalCompression:
return ZSTD_Compress(compression_info, raw.data(), raw.size(),
compressed_output);
default:
// Do not recognize this compression type
return false;
}
}
} // namespace
// format_version is the block format as defined in include/rocksdb/table.h
Slice CompressBlock(const Slice& raw, const CompressionInfo& info,
CompressionType* type, uint32_t format_version,
bool do_sample, std::string* compressed_output,
std::string* sampled_output_fast,
std::string* sampled_output_slow) {
*type = info.type();
if (info.type() == kNoCompression && !info.SampleForCompression()) {
return raw;
}
// If requested, we sample one in every N block with a
// fast and slow compression algorithm and report the stats.
// The users can use these stats to decide if it is worthwhile
// enabling compression and they also get a hint about which
// compression algorithm wil be beneficial.
if (do_sample && info.SampleForCompression() &&
Random::GetTLSInstance()->OneIn((int)info.SampleForCompression()) &&
sampled_output_fast && sampled_output_slow) {
// Sampling with a fast compression algorithm
if (LZ4_Supported() || Snappy_Supported()) {
CompressionType c =
LZ4_Supported() ? kLZ4Compression : kSnappyCompression;
CompressionContext context(c);
CompressionOptions options;
CompressionInfo info_tmp(options, context,
CompressionDict::GetEmptyDict(), c,
info.SampleForCompression());
CompressBlockInternal(raw, info_tmp, format_version, sampled_output_fast);
}
// Sampling with a slow but high-compression algorithm
if (ZSTD_Supported() || Zlib_Supported()) {
CompressionType c = ZSTD_Supported() ? kZSTD : kZlibCompression;
CompressionContext context(c);
CompressionOptions options;
CompressionInfo info_tmp(options, context,
CompressionDict::GetEmptyDict(), c,
info.SampleForCompression());
CompressBlockInternal(raw, info_tmp, format_version, sampled_output_slow);
}
}
// Actually compress the data
if (*type != kNoCompression) {
if (CompressBlockInternal(raw, info, format_version, compressed_output) &&
GoodCompressionRatio(compressed_output->size(), raw.size())) {
return *compressed_output;
}
}
// Compression method is not supported, or not good
// compression ratio, so just fall back to uncompressed form.
*type = kNoCompression;
return raw;
}
// kBlockBasedTableMagicNumber was picked by running
// echo rocksdb.table.block_based | sha1sum
// and taking the leading 64 bits.
// Please note that kBlockBasedTableMagicNumber may also be accessed by other
// .cc files
// for that reason we declare it extern in the header but to get the space
// allocated
// it must be not extern in one place.
const uint64_t kBlockBasedTableMagicNumber = 0x88e241b785f4cff7ull;
// We also support reading and writing legacy block based table format (for
// backwards compatibility)
const uint64_t kLegacyBlockBasedTableMagicNumber = 0xdb4775248b80fb57ull;
// A collector that collects properties of interest to block-based table.
// For now this class looks heavy-weight since we only write one additional
// property.
// But in the foreseeable future, we will add more and more properties that are
// specific to block-based table.
class BlockBasedTableBuilder::BlockBasedTablePropertiesCollector
: public IntTblPropCollector {
public:
explicit BlockBasedTablePropertiesCollector(
BlockBasedTableOptions::IndexType index_type, bool whole_key_filtering,
bool prefix_filtering)
: index_type_(index_type),
whole_key_filtering_(whole_key_filtering),
prefix_filtering_(prefix_filtering) {}
Status InternalAdd(const Slice& /*key*/, const Slice& /*value*/,
uint64_t /*file_size*/) override {
// Intentionally left blank. Have no interest in collecting stats for
// individual key/value pairs.
return Status::OK();
}
virtual void BlockAdd(uint64_t /* blockRawBytes */,
uint64_t /* blockCompressedBytesFast */,
uint64_t /* blockCompressedBytesSlow */) override {
// Intentionally left blank. No interest in collecting stats for
// blocks.
return;
}
Status Finish(UserCollectedProperties* properties) override {
std::string val;
PutFixed32(&val, static_cast<uint32_t>(index_type_));
properties->insert({BlockBasedTablePropertyNames::kIndexType, val});
properties->insert({BlockBasedTablePropertyNames::kWholeKeyFiltering,
whole_key_filtering_ ? kPropTrue : kPropFalse});
properties->insert({BlockBasedTablePropertyNames::kPrefixFiltering,
prefix_filtering_ ? kPropTrue : kPropFalse});
return Status::OK();
}
// The name of the properties collector can be used for debugging purpose.
const char* Name() const override {
return "BlockBasedTablePropertiesCollector";
}
UserCollectedProperties GetReadableProperties() const override {
// Intentionally left blank.
return UserCollectedProperties();
}
private:
BlockBasedTableOptions::IndexType index_type_;
bool whole_key_filtering_;
bool prefix_filtering_;
};
struct BlockBasedTableBuilder::Rep {
const ImmutableCFOptions ioptions;
const MutableCFOptions moptions;
const BlockBasedTableOptions table_options;
const InternalKeyComparator& internal_comparator;
WritableFileWriter* file;
uint64_t offset = 0;
Status status;
size_t alignment;
BlockBuilder data_block;
// Buffers uncompressed data blocks and keys to replay later. Needed when
// compression dictionary is enabled so we can finalize the dictionary before
// compressing any data blocks.
// TODO(ajkr): ideally we don't buffer all keys and all uncompressed data
// blocks as it's redundant, but it's easier to implement for now.
std::vector<std::pair<std::string, std::vector<std::string>>>
data_block_and_keys_buffers;
BlockBuilder range_del_block;
InternalKeySliceTransform internal_prefix_transform;
std::unique_ptr<IndexBuilder> index_builder;
PartitionedIndexBuilder* p_index_builder_ = nullptr;
std::string last_key;
CompressionType compression_type;
uint64_t sample_for_compression;
CompressionOptions compression_opts;
std::unique_ptr<CompressionDict> compression_dict;
CompressionContext compression_ctx;
std::unique_ptr<UncompressionContext> verify_ctx;
std::unique_ptr<UncompressionDict> verify_dict;
size_t data_begin_offset = 0;
TableProperties props;
// States of the builder.
//
// - `kBuffered`: This is the initial state where zero or more data blocks are
// accumulated uncompressed in-memory. From this state, call
// `EnterUnbuffered()` to finalize the compression dictionary if enabled,
// compress/write out any buffered blocks, and proceed to the `kUnbuffered`
// state.
//
// - `kUnbuffered`: This is the state when compression dictionary is finalized
// either because it wasn't enabled in the first place or it's been created
// from sampling previously buffered data. In this state, blocks are simply
// compressed/written out as they fill up. From this state, call `Finish()`
// to complete the file (write meta-blocks, etc.), or `Abandon()` to delete
// the partially created file.
//
// - `kClosed`: This indicates either `Finish()` or `Abandon()` has been
// called, so the table builder is no longer usable. We must be in this
// state by the time the destructor runs.
enum class State {
kBuffered,
kUnbuffered,
kClosed,
};
State state;
const bool use_delta_encoding_for_index_values;
std::unique_ptr<FilterBlockBuilder> filter_builder;
char compressed_cache_key_prefix[BlockBasedTable::kMaxCacheKeyPrefixSize];
size_t compressed_cache_key_prefix_size;
BlockHandle pending_handle; // Handle to add to index block
std::string compressed_output;
std::unique_ptr<FlushBlockPolicy> flush_block_policy;
int level_at_creation;
uint32_t column_family_id;
const std::string& column_family_name;
uint64_t creation_time = 0;
uint64_t oldest_key_time = 0;
const uint64_t target_file_size;
uint64_t file_creation_time = 0;
std::vector<std::unique_ptr<IntTblPropCollector>> table_properties_collectors;
Rep(const ImmutableCFOptions& _ioptions, const MutableCFOptions& _moptions,
const BlockBasedTableOptions& table_opt,
const InternalKeyComparator& icomparator,
const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
int_tbl_prop_collector_factories,
uint32_t _column_family_id, WritableFileWriter* f,
const CompressionType _compression_type,
const uint64_t _sample_for_compression,
const CompressionOptions& _compression_opts, const bool skip_filters,
const int _level_at_creation, const std::string& _column_family_name,
const uint64_t _creation_time, const uint64_t _oldest_key_time,
const uint64_t _target_file_size, const uint64_t _file_creation_time)
: ioptions(_ioptions),
moptions(_moptions),
table_options(table_opt),
internal_comparator(icomparator),
file(f),
alignment(table_options.block_align
? std::min(table_options.block_size, kDefaultPageSize)
: 0),
data_block(table_options.block_restart_interval,
table_options.use_delta_encoding,
false /* use_value_delta_encoding */,
icomparator.user_comparator()
->CanKeysWithDifferentByteContentsBeEqual()
? BlockBasedTableOptions::kDataBlockBinarySearch
: table_options.data_block_index_type,
table_options.data_block_hash_table_util_ratio),
range_del_block(1 /* block_restart_interval */),
internal_prefix_transform(_moptions.prefix_extractor.get()),
compression_type(_compression_type),
sample_for_compression(_sample_for_compression),
compression_opts(_compression_opts),
compression_dict(),
compression_ctx(_compression_type),
verify_dict(),
state((_compression_opts.max_dict_bytes > 0) ? State::kBuffered
: State::kUnbuffered),
use_delta_encoding_for_index_values(table_opt.format_version >= 4 &&
!table_opt.block_align),
compressed_cache_key_prefix_size(0),
flush_block_policy(
table_options.flush_block_policy_factory->NewFlushBlockPolicy(
table_options, data_block)),
level_at_creation(_level_at_creation),
column_family_id(_column_family_id),
column_family_name(_column_family_name),
creation_time(_creation_time),
oldest_key_time(_oldest_key_time),
target_file_size(_target_file_size),
file_creation_time(_file_creation_time) {
if (table_options.index_type ==
BlockBasedTableOptions::kTwoLevelIndexSearch) {
p_index_builder_ = PartitionedIndexBuilder::CreateIndexBuilder(
&internal_comparator, use_delta_encoding_for_index_values,
table_options);
index_builder.reset(p_index_builder_);
} else {
index_builder.reset(IndexBuilder::CreateIndexBuilder(
table_options.index_type, &internal_comparator,
&this->internal_prefix_transform, use_delta_encoding_for_index_values,
table_options));
}
if (skip_filters) {
filter_builder = nullptr;
} else {
FilterBuildingContext context(table_options);
context.column_family_name = column_family_name;
context.compaction_style = ioptions.compaction_style;
context.level_at_creation = level_at_creation;
filter_builder.reset(CreateFilterBlockBuilder(
ioptions, moptions, context, use_delta_encoding_for_index_values,
p_index_builder_));
}
for (auto& collector_factories : *int_tbl_prop_collector_factories) {
table_properties_collectors.emplace_back(
collector_factories->CreateIntTblPropCollector(column_family_id));
}
table_properties_collectors.emplace_back(
new BlockBasedTablePropertiesCollector(
table_options.index_type, table_options.whole_key_filtering,
_moptions.prefix_extractor != nullptr));
if (table_options.verify_compression) {
verify_ctx.reset(new UncompressionContext(UncompressionContext::NoCache(),
compression_type));
}
}
Rep(const Rep&) = delete;
Rep& operator=(const Rep&) = delete;
~Rep() {}
};
BlockBasedTableBuilder::BlockBasedTableBuilder(
const ImmutableCFOptions& ioptions, const MutableCFOptions& moptions,
const BlockBasedTableOptions& table_options,
const InternalKeyComparator& internal_comparator,
const std::vector<std::unique_ptr<IntTblPropCollectorFactory>>*
int_tbl_prop_collector_factories,
uint32_t column_family_id, WritableFileWriter* file,
const CompressionType compression_type,
const uint64_t sample_for_compression,
const CompressionOptions& compression_opts, const bool skip_filters,
const std::string& column_family_name, const int level_at_creation,
const uint64_t creation_time, const uint64_t oldest_key_time,
const uint64_t target_file_size, const uint64_t file_creation_time) {
BlockBasedTableOptions sanitized_table_options(table_options);
if (sanitized_table_options.format_version == 0 &&
sanitized_table_options.checksum != kCRC32c) {
ROCKS_LOG_WARN(
ioptions.info_log,
"Silently converting format_version to 1 because checksum is "
"non-default");
// silently convert format_version to 1 to keep consistent with current
// behavior
sanitized_table_options.format_version = 1;
}
rep_ = new Rep(ioptions, moptions, sanitized_table_options,
internal_comparator, int_tbl_prop_collector_factories,
column_family_id, file, compression_type,
sample_for_compression, compression_opts, skip_filters,
level_at_creation, column_family_name, creation_time,
oldest_key_time, target_file_size, file_creation_time);
if (rep_->filter_builder != nullptr) {
rep_->filter_builder->StartBlock(0);
}
if (table_options.block_cache_compressed.get() != nullptr) {
BlockBasedTable::GenerateCachePrefix(
table_options.block_cache_compressed.get(), file->writable_file(),
&rep_->compressed_cache_key_prefix[0],
&rep_->compressed_cache_key_prefix_size);
}
}
BlockBasedTableBuilder::~BlockBasedTableBuilder() {
// Catch errors where caller forgot to call Finish()
assert(rep_->state == Rep::State::kClosed);
delete rep_;
}
void BlockBasedTableBuilder::Add(const Slice& key, const Slice& value) {
Rep* r = rep_;
assert(rep_->state != Rep::State::kClosed);
if (!ok()) return;
ValueType value_type = ExtractValueType(key);
if (IsValueType(value_type)) {
#ifndef NDEBUG
if (r->props.num_entries > r->props.num_range_deletions) {
assert(r->internal_comparator.Compare(key, Slice(r->last_key)) > 0);
}
#endif // NDEBUG
auto should_flush = r->flush_block_policy->Update(key, value);
if (should_flush) {
assert(!r->data_block.empty());
Flush();
if (r->state == Rep::State::kBuffered &&
r->data_begin_offset > r->target_file_size) {
EnterUnbuffered();
}
// Add item to index block.
// We do not emit the index entry for a block until we have seen the
// first key for the next data block. This allows us to use shorter
// keys in the index block. For example, consider a block boundary
// between the keys "the quick brown fox" and "the who". We can use
// "the r" as the key for the index block entry since it is >= all
// entries in the first block and < all entries in subsequent
// blocks.
if (ok() && r->state == Rep::State::kUnbuffered) {
r->index_builder->AddIndexEntry(&r->last_key, &key, r->pending_handle);
}
}
// Note: PartitionedFilterBlockBuilder requires key being added to filter
// builder after being added to index builder.
if (r->state == Rep::State::kUnbuffered && r->filter_builder != nullptr) {
size_t ts_sz = r->internal_comparator.user_comparator()->timestamp_size();
r->filter_builder->Add(ExtractUserKeyAndStripTimestamp(key, ts_sz));
}
r->last_key.assign(key.data(), key.size());
r->data_block.Add(key, value);
if (r->state == Rep::State::kBuffered) {
// Buffer keys to be replayed during `Finish()` once compression
// dictionary has been finalized.
if (r->data_block_and_keys_buffers.empty() || should_flush) {
r->data_block_and_keys_buffers.emplace_back();
}
r->data_block_and_keys_buffers.back().second.emplace_back(key.ToString());
} else {
r->index_builder->OnKeyAdded(key);
}
NotifyCollectTableCollectorsOnAdd(key, value, r->offset,
r->table_properties_collectors,
r->ioptions.info_log);
} else if (value_type == kTypeRangeDeletion) {
r->range_del_block.Add(key, value);
NotifyCollectTableCollectorsOnAdd(key, value, r->offset,
r->table_properties_collectors,
r->ioptions.info_log);
} else {
assert(false);
}
r->props.num_entries++;
r->props.raw_key_size += key.size();
r->props.raw_value_size += value.size();
if (value_type == kTypeDeletion || value_type == kTypeSingleDeletion) {
r->props.num_deletions++;
} else if (value_type == kTypeRangeDeletion) {
r->props.num_deletions++;
r->props.num_range_deletions++;
} else if (value_type == kTypeMerge) {
r->props.num_merge_operands++;
}
}
void BlockBasedTableBuilder::Flush() {
Rep* r = rep_;
assert(rep_->state != Rep::State::kClosed);
if (!ok()) return;
if (r->data_block.empty()) return;
WriteBlock(&r->data_block, &r->pending_handle, true /* is_data_block */);
}
void BlockBasedTableBuilder::WriteBlock(BlockBuilder* block,
BlockHandle* handle,
bool is_data_block) {
WriteBlock(block->Finish(), handle, is_data_block);
block->Reset();
}
void BlockBasedTableBuilder::WriteBlock(const Slice& raw_block_contents,
BlockHandle* handle,
bool is_data_block) {
// File format contains a sequence of blocks where each block has:
// block_data: uint8[n]
// type: uint8
// crc: uint32
assert(ok());
Rep* r = rep_;
auto type = r->compression_type;
uint64_t sample_for_compression = r->sample_for_compression;
Slice block_contents;
bool abort_compression = false;
StopWatchNano timer(
r->ioptions.env,
ShouldReportDetailedTime(r->ioptions.env, r->ioptions.statistics));
if (r->state == Rep::State::kBuffered) {
assert(is_data_block);
assert(!r->data_block_and_keys_buffers.empty());
r->data_block_and_keys_buffers.back().first = raw_block_contents.ToString();
r->data_begin_offset += r->data_block_and_keys_buffers.back().first.size();
return;
}
if (raw_block_contents.size() < kCompressionSizeLimit) {
const CompressionDict* compression_dict;
if (!is_data_block || r->compression_dict == nullptr) {
compression_dict = &CompressionDict::GetEmptyDict();
} else {
compression_dict = r->compression_dict.get();
}
assert(compression_dict != nullptr);
CompressionInfo compression_info(r->compression_opts, r->compression_ctx,
*compression_dict, type,
sample_for_compression);
std::string sampled_output_fast;
std::string sampled_output_slow;
block_contents = CompressBlock(
raw_block_contents, compression_info, &type,
r->table_options.format_version, is_data_block /* do_sample */,
&r->compressed_output, &sampled_output_fast, &sampled_output_slow);
// notify collectors on block add
NotifyCollectTableCollectorsOnBlockAdd(
r->table_properties_collectors, raw_block_contents.size(),
sampled_output_fast.size(), sampled_output_slow.size());
// Some of the compression algorithms are known to be unreliable. If
// the verify_compression flag is set then try to de-compress the
// compressed data and compare to the input.
if (type != kNoCompression && r->table_options.verify_compression) {
// Retrieve the uncompressed contents into a new buffer
const UncompressionDict* verify_dict;
if (!is_data_block || r->verify_dict == nullptr) {
verify_dict = &UncompressionDict::GetEmptyDict();
} else {
verify_dict = r->verify_dict.get();
}
assert(verify_dict != nullptr);
BlockContents contents;
UncompressionInfo uncompression_info(*r->verify_ctx, *verify_dict,
r->compression_type);
Status stat = UncompressBlockContentsForCompressionType(
uncompression_info, block_contents.data(), block_contents.size(),
&contents, r->table_options.format_version, r->ioptions);
if (stat.ok()) {
bool compressed_ok = contents.data.compare(raw_block_contents) == 0;
if (!compressed_ok) {
// The result of the compression was invalid. abort.
abort_compression = true;
ROCKS_LOG_ERROR(r->ioptions.info_log,
"Decompressed block did not match raw block");
r->status =
Status::Corruption("Decompressed block did not match raw block");
}
} else {
// Decompression reported an error. abort.
r->status = Status::Corruption("Could not decompress");
abort_compression = true;
}
}
} else {
// Block is too big to be compressed.
abort_compression = true;
}
// Abort compression if the block is too big, or did not pass
// verification.
if (abort_compression) {
RecordTick(r->ioptions.statistics, NUMBER_BLOCK_NOT_COMPRESSED);
type = kNoCompression;
block_contents = raw_block_contents;
} else if (type != kNoCompression) {
if (ShouldReportDetailedTime(r->ioptions.env, r->ioptions.statistics)) {
RecordTimeToHistogram(r->ioptions.statistics, COMPRESSION_TIMES_NANOS,
timer.ElapsedNanos());
}
RecordInHistogram(r->ioptions.statistics, BYTES_COMPRESSED,
raw_block_contents.size());
RecordTick(r->ioptions.statistics, NUMBER_BLOCK_COMPRESSED);
} else if (type != r->compression_type) {
RecordTick(r->ioptions.statistics, NUMBER_BLOCK_NOT_COMPRESSED);
}
WriteRawBlock(block_contents, type, handle, is_data_block);
r->compressed_output.clear();
if (is_data_block) {
if (r->filter_builder != nullptr) {
r->filter_builder->StartBlock(r->offset);
}
r->props.data_size = r->offset;
++r->props.num_data_blocks;
}
}
void BlockBasedTableBuilder::WriteRawBlock(const Slice& block_contents,
CompressionType type,
BlockHandle* handle,
bool is_data_block) {
Rep* r = rep_;
StopWatch sw(r->ioptions.env, r->ioptions.statistics, WRITE_RAW_BLOCK_MICROS);
handle->set_offset(r->offset);
handle->set_size(block_contents.size());
assert(r->status.ok());
r->status = r->file->Append(block_contents);
if (r->status.ok()) {
char trailer[kBlockTrailerSize];
trailer[0] = type;
char* trailer_without_type = trailer + 1;
switch (r->table_options.checksum) {
case kNoChecksum:
EncodeFixed32(trailer_without_type, 0);
break;
case kCRC32c: {
auto crc = crc32c::Value(block_contents.data(), block_contents.size());
crc = crc32c::Extend(crc, trailer, 1); // Extend to cover block type
EncodeFixed32(trailer_without_type, crc32c::Mask(crc));
break;
}
case kxxHash: {
XXH32_state_t* const state = XXH32_createState();
XXH32_reset(state, 0);
XXH32_update(state, block_contents.data(),
static_cast<uint32_t>(block_contents.size()));
XXH32_update(state, trailer, 1); // Extend to cover block type
EncodeFixed32(trailer_without_type, XXH32_digest(state));
XXH32_freeState(state);
break;
}
case kxxHash64: {
XXH64_state_t* const state = XXH64_createState();
XXH64_reset(state, 0);
XXH64_update(state, block_contents.data(),
static_cast<uint32_t>(block_contents.size()));
XXH64_update(state, trailer, 1); // Extend to cover block type
EncodeFixed32(
trailer_without_type,
static_cast<uint32_t>(XXH64_digest(state) & // lower 32 bits
uint64_t{0xffffffff}));
XXH64_freeState(state);
break;
}
}
assert(r->status.ok());
TEST_SYNC_POINT_CALLBACK(
"BlockBasedTableBuilder::WriteRawBlock:TamperWithChecksum",
static_cast<char*>(trailer));
r->status = r->file->Append(Slice(trailer, kBlockTrailerSize));
if (r->status.ok()) {
r->status = InsertBlockInCache(block_contents, type, handle);
}
if (r->status.ok()) {
r->offset += block_contents.size() + kBlockTrailerSize;
if (r->table_options.block_align && is_data_block) {
size_t pad_bytes =
(r->alignment - ((block_contents.size() + kBlockTrailerSize) &
(r->alignment - 1))) &
(r->alignment - 1);
r->status = r->file->Pad(pad_bytes);
if (r->status.ok()) {
r->offset += pad_bytes;
}
}
}
}
}
Status BlockBasedTableBuilder::status() const { return rep_->status; }
static void DeleteCachedBlockContents(const Slice& /*key*/, void* value) {
BlockContents* bc = reinterpret_cast<BlockContents*>(value);
delete bc;
}
//
// Make a copy of the block contents and insert into compressed block cache
//
Status BlockBasedTableBuilder::InsertBlockInCache(const Slice& block_contents,
const CompressionType type,
const BlockHandle* handle) {
Rep* r = rep_;
Cache* block_cache_compressed = r->table_options.block_cache_compressed.get();
if (type != kNoCompression && block_cache_compressed != nullptr) {
size_t size = block_contents.size();
auto ubuf =
AllocateBlock(size + 1, block_cache_compressed->memory_allocator());
memcpy(ubuf.get(), block_contents.data(), size);
ubuf[size] = type;
BlockContents* block_contents_to_cache =
new BlockContents(std::move(ubuf), size);
#ifndef NDEBUG
block_contents_to_cache->is_raw_block = true;
#endif // NDEBUG
// make cache key by appending the file offset to the cache prefix id
char* end = EncodeVarint64(
r->compressed_cache_key_prefix + r->compressed_cache_key_prefix_size,
handle->offset());
Slice key(r->compressed_cache_key_prefix,
static_cast<size_t>(end - r->compressed_cache_key_prefix));
// Insert into compressed block cache.
block_cache_compressed->Insert(
key, block_contents_to_cache,
block_contents_to_cache->ApproximateMemoryUsage(),
&DeleteCachedBlockContents);
// Invalidate OS cache.
r->file->InvalidateCache(static_cast<size_t>(r->offset), size);
}
return Status::OK();
}
void BlockBasedTableBuilder::WriteFilterBlock(
MetaIndexBuilder* meta_index_builder) {
BlockHandle filter_block_handle;
bool empty_filter_block = (rep_->filter_builder == nullptr ||
rep_->filter_builder->NumAdded() == 0);
if (ok() && !empty_filter_block) {
Status s = Status::Incomplete();
while (ok() && s.IsIncomplete()) {
Slice filter_content =
rep_->filter_builder->Finish(filter_block_handle, &s);
assert(s.ok() || s.IsIncomplete());
rep_->props.filter_size += filter_content.size();
WriteRawBlock(filter_content, kNoCompression, &filter_block_handle);
}
}
if (ok() && !empty_filter_block) {
// Add mapping from "<filter_block_prefix>.Name" to location
// of filter data.
std::string key;
if (rep_->filter_builder->IsBlockBased()) {
key = BlockBasedTable::kFilterBlockPrefix;
} else {
key = rep_->table_options.partition_filters
? BlockBasedTable::kPartitionedFilterBlockPrefix
: BlockBasedTable::kFullFilterBlockPrefix;
}
key.append(rep_->table_options.filter_policy->Name());
meta_index_builder->Add(key, filter_block_handle);
}
}
void BlockBasedTableBuilder::WriteIndexBlock(
MetaIndexBuilder* meta_index_builder, BlockHandle* index_block_handle) {
IndexBuilder::IndexBlocks index_blocks;
auto index_builder_status = rep_->index_builder->Finish(&index_blocks);
if (index_builder_status.IsIncomplete()) {
// We we have more than one index partition then meta_blocks are not
// supported for the index. Currently meta_blocks are used only by
// HashIndexBuilder which is not multi-partition.
assert(index_blocks.meta_blocks.empty());
} else if (ok() && !index_builder_status.ok()) {
rep_->status = index_builder_status;
}
if (ok()) {
for (const auto& item : index_blocks.meta_blocks) {
BlockHandle block_handle;
WriteBlock(item.second, &block_handle, false /* is_data_block */);
if (!ok()) {
break;
}
meta_index_builder->Add(item.first, block_handle);
}
}
if (ok()) {
if (rep_->table_options.enable_index_compression) {
WriteBlock(index_blocks.index_block_contents, index_block_handle, false);
} else {
WriteRawBlock(index_blocks.index_block_contents, kNoCompression,
index_block_handle);
}
}
// If there are more index partitions, finish them and write them out
Status s = index_builder_status;
while (ok() && s.IsIncomplete()) {
s = rep_->index_builder->Finish(&index_blocks, *index_block_handle);
if (!s.ok() && !s.IsIncomplete()) {
rep_->status = s;
return;
}
if (rep_->table_options.enable_index_compression) {
WriteBlock(index_blocks.index_block_contents, index_block_handle, false);
} else {
WriteRawBlock(index_blocks.index_block_contents, kNoCompression,
index_block_handle);
}
// The last index_block_handle will be for the partition index block
}
}
void BlockBasedTableBuilder::WritePropertiesBlock(
MetaIndexBuilder* meta_index_builder) {
BlockHandle properties_block_handle;
if (ok()) {
PropertyBlockBuilder property_block_builder;
rep_->props.column_family_id = rep_->column_family_id;
rep_->props.column_family_name = rep_->column_family_name;
rep_->props.filter_policy_name =
rep_->table_options.filter_policy != nullptr
? rep_->table_options.filter_policy->Name()
: "";
rep_->props.index_size =
rep_->index_builder->IndexSize() + kBlockTrailerSize;
rep_->props.comparator_name = rep_->ioptions.user_comparator != nullptr
? rep_->ioptions.user_comparator->Name()
: "nullptr";
rep_->props.merge_operator_name =
rep_->ioptions.merge_operator != nullptr
? rep_->ioptions.merge_operator->Name()
: "nullptr";
rep_->props.compression_name =
CompressionTypeToString(rep_->compression_type);
rep_->props.compression_options =
CompressionOptionsToString(rep_->compression_opts);
rep_->props.prefix_extractor_name =
rep_->moptions.prefix_extractor != nullptr
? rep_->moptions.prefix_extractor->Name()
: "nullptr";
std::string property_collectors_names = "[";
for (size_t i = 0;
i < rep_->ioptions.table_properties_collector_factories.size(); ++i) {
if (i != 0) {
property_collectors_names += ",";
}
property_collectors_names +=
rep_->ioptions.table_properties_collector_factories[i]->Name();
}
property_collectors_names += "]";
rep_->props.property_collectors_names = property_collectors_names;
if (rep_->table_options.index_type ==
BlockBasedTableOptions::kTwoLevelIndexSearch) {
assert(rep_->p_index_builder_ != nullptr);
rep_->props.index_partitions = rep_->p_index_builder_->NumPartitions();
rep_->props.top_level_index_size =
rep_->p_index_builder_->TopLevelIndexSize(rep_->offset);
}
rep_->props.index_key_is_user_key =
!rep_->index_builder->seperator_is_key_plus_seq();
rep_->props.index_value_is_delta_encoded =
rep_->use_delta_encoding_for_index_values;
rep_->props.creation_time = rep_->creation_time;
rep_->props.oldest_key_time = rep_->oldest_key_time;
rep_->props.file_creation_time = rep_->file_creation_time;
// Add basic properties
property_block_builder.AddTableProperty(rep_->props);
// Add use collected properties
NotifyCollectTableCollectorsOnFinish(rep_->table_properties_collectors,
rep_->ioptions.info_log,
&property_block_builder);
WriteRawBlock(property_block_builder.Finish(), kNoCompression,
&properties_block_handle);
}
if (ok()) {
#ifndef NDEBUG
{
uint64_t props_block_offset = properties_block_handle.offset();
uint64_t props_block_size = properties_block_handle.size();
TEST_SYNC_POINT_CALLBACK(
"BlockBasedTableBuilder::WritePropertiesBlock:GetPropsBlockOffset",
&props_block_offset);
TEST_SYNC_POINT_CALLBACK(
"BlockBasedTableBuilder::WritePropertiesBlock:GetPropsBlockSize",
&props_block_size);
}
#endif // !NDEBUG
meta_index_builder->Add(kPropertiesBlock, properties_block_handle);
}
}
void BlockBasedTableBuilder::WriteCompressionDictBlock(
MetaIndexBuilder* meta_index_builder) {
if (rep_->compression_dict != nullptr &&
rep_->compression_dict->GetRawDict().size()) {
BlockHandle compression_dict_block_handle;
if (ok()) {
WriteRawBlock(rep_->compression_dict->GetRawDict(), kNoCompression,
&compression_dict_block_handle);
#ifndef NDEBUG
Slice compression_dict = rep_->compression_dict->GetRawDict();
TEST_SYNC_POINT_CALLBACK(
"BlockBasedTableBuilder::WriteCompressionDictBlock:RawDict",
&compression_dict);
#endif // NDEBUG
}
if (ok()) {
meta_index_builder->Add(kCompressionDictBlock,
compression_dict_block_handle);
}
}
}
void BlockBasedTableBuilder::WriteRangeDelBlock(
MetaIndexBuilder* meta_index_builder) {
if (ok() && !rep_->range_del_block.empty()) {
BlockHandle range_del_block_handle;
WriteRawBlock(rep_->range_del_block.Finish(), kNoCompression,
&range_del_block_handle);
meta_index_builder->Add(kRangeDelBlock, range_del_block_handle);
}
}
void BlockBasedTableBuilder::WriteFooter(BlockHandle& metaindex_block_handle,
BlockHandle& index_block_handle) {
Rep* r = rep_;
// No need to write out new footer if we're using default checksum.
// We're writing legacy magic number because we want old versions of RocksDB
// be able to read files generated with new release (just in case if
// somebody wants to roll back after an upgrade)
// TODO(icanadi) at some point in the future, when we're absolutely sure
// nobody will roll back to RocksDB 2.x versions, retire the legacy magic
// number and always write new table files with new magic number
bool legacy = (r->table_options.format_version == 0);
// this is guaranteed by BlockBasedTableBuilder's constructor
assert(r->table_options.checksum == kCRC32c ||
r->table_options.format_version != 0);
Footer footer(
legacy ? kLegacyBlockBasedTableMagicNumber : kBlockBasedTableMagicNumber,
r->table_options.format_version);
footer.set_metaindex_handle(metaindex_block_handle);
footer.set_index_handle(index_block_handle);
footer.set_checksum(r->table_options.checksum);
std::string footer_encoding;
footer.EncodeTo(&footer_encoding);
assert(r->status.ok());
r->status = r->file->Append(footer_encoding);
if (r->status.ok()) {
r->offset += footer_encoding.size();
}
}
void BlockBasedTableBuilder::EnterUnbuffered() {
Rep* r = rep_;
assert(r->state == Rep::State::kBuffered);
r->state = Rep::State::kUnbuffered;
const size_t kSampleBytes = r->compression_opts.zstd_max_train_bytes > 0
? r->compression_opts.zstd_max_train_bytes
: r->compression_opts.max_dict_bytes;
Random64 generator{r->creation_time};
std::string compression_dict_samples;
std::vector<size_t> compression_dict_sample_lens;
if (!r->data_block_and_keys_buffers.empty()) {
while (compression_dict_samples.size() < kSampleBytes) {
size_t rand_idx =
static_cast<size_t>(
generator.Uniform(r->data_block_and_keys_buffers.size()));
size_t copy_len =
std::min(kSampleBytes - compression_dict_samples.size(),
r->data_block_and_keys_buffers[rand_idx].first.size());
compression_dict_samples.append(
r->data_block_and_keys_buffers[rand_idx].first, 0, copy_len);
compression_dict_sample_lens.emplace_back(copy_len);
}
}
// final data block flushed, now we can generate dictionary from the samples.
// OK if compression_dict_samples is empty, we'll just get empty dictionary.
std::string dict;
if (r->compression_opts.zstd_max_train_bytes > 0) {
dict = ZSTD_TrainDictionary(compression_dict_samples,
compression_dict_sample_lens,
r->compression_opts.max_dict_bytes);
} else {
dict = std::move(compression_dict_samples);
}
r->compression_dict.reset(new CompressionDict(dict, r->compression_type,
r->compression_opts.level));
r->verify_dict.reset(new UncompressionDict(
dict, r->compression_type == kZSTD ||
r->compression_type == kZSTDNotFinalCompression));
for (size_t i = 0; ok() && i < r->data_block_and_keys_buffers.size(); ++i) {
const auto& data_block = r->data_block_and_keys_buffers[i].first;
auto& keys = r->data_block_and_keys_buffers[i].second;
assert(!data_block.empty());
assert(!keys.empty());
for (const auto& key : keys) {
if (r->filter_builder != nullptr) {
size_t ts_sz =
r->internal_comparator.user_comparator()->timestamp_size();
r->filter_builder->Add(ExtractUserKeyAndStripTimestamp(key, ts_sz));
}
r->index_builder->OnKeyAdded(key);
}
WriteBlock(Slice(data_block), &r->pending_handle, true /* is_data_block */);
if (ok() && i + 1 < r->data_block_and_keys_buffers.size()) {
Slice first_key_in_next_block =
r->data_block_and_keys_buffers[i + 1].second.front();
Slice* first_key_in_next_block_ptr = &first_key_in_next_block;
r->index_builder->AddIndexEntry(&keys.back(), first_key_in_next_block_ptr,
r->pending_handle);
}
}
r->data_block_and_keys_buffers.clear();
}
Status BlockBasedTableBuilder::Finish() {
Rep* r = rep_;
assert(r->state != Rep::State::kClosed);
bool empty_data_block = r->data_block.empty();
Flush();
if (r->state == Rep::State::kBuffered) {
EnterUnbuffered();
}
// To make sure properties block is able to keep the accurate size of index
// block, we will finish writing all index entries first.
if (ok() && !empty_data_block) {
r->index_builder->AddIndexEntry(
&r->last_key, nullptr /* no next data block */, r->pending_handle);
}
// Write meta blocks, metaindex block and footer in the following order.
// 1. [meta block: filter]
// 2. [meta block: index]
// 3. [meta block: compression dictionary]
// 4. [meta block: range deletion tombstone]
// 5. [meta block: properties]
// 6. [metaindex block]
// 7. Footer
BlockHandle metaindex_block_handle, index_block_handle;
MetaIndexBuilder meta_index_builder;
WriteFilterBlock(&meta_index_builder);
WriteIndexBlock(&meta_index_builder, &index_block_handle);
WriteCompressionDictBlock(&meta_index_builder);
WriteRangeDelBlock(&meta_index_builder);
WritePropertiesBlock(&meta_index_builder);
if (ok()) {
// flush the meta index block
WriteRawBlock(meta_index_builder.Finish(), kNoCompression,
&metaindex_block_handle);
}
if (ok()) {
WriteFooter(metaindex_block_handle, index_block_handle);
}
r->state = Rep::State::kClosed;
return r->status;
}
void BlockBasedTableBuilder::Abandon() {
assert(rep_->state != Rep::State::kClosed);
rep_->state = Rep::State::kClosed;
}
uint64_t BlockBasedTableBuilder::NumEntries() const {
return rep_->props.num_entries;
}
uint64_t BlockBasedTableBuilder::FileSize() const { return rep_->offset; }
bool BlockBasedTableBuilder::NeedCompact() const {
for (const auto& collector : rep_->table_properties_collectors) {
if (collector->NeedCompact()) {
return true;
}
}
return false;
}
TableProperties BlockBasedTableBuilder::GetTableProperties() const {
TableProperties ret = rep_->props;
for (const auto& collector : rep_->table_properties_collectors) {
for (const auto& prop : collector->GetReadableProperties()) {
ret.readable_properties.insert(prop);
}
collector->Finish(&ret.user_collected_properties);
}
return ret;
}
const std::string BlockBasedTable::kFilterBlockPrefix = "filter.";
const std::string BlockBasedTable::kFullFilterBlockPrefix = "fullfilter.";
const std::string BlockBasedTable::kPartitionedFilterBlockPrefix =
"partitionedfilter.";
} // namespace rocksdb