rocksdb/table/block_based_table_reader.cc
Maysam Yabandeh 0712d541d1 Delegate Cleanables
Summary:
Cleanable objects will perform the registered cleanups when
they are destructed. We however rather to delay this cleaning like when
we are gathering the merge operands. Current approach is to create the
Cleanable object on heap (instead of on stack) and delay deleting it.

By allowing Cleanables to delegate their cleanups to another cleanable
object we can delay the cleaning without however the need to craete the
cleanable object on heap and keeping it around. This patch applies this
technique for the cleanups of BlockIter and shows improved performance
for some in-memory benchmarks:
+1.8% for merge worklaod, +6.4% for non-merge workload when the merge
operator is specified.
https://our.intern.facebook.com/intern/tasks?t=15168163

Non-merge benchmark:
TEST_TMPDIR=/dev/shm/v100nocomp/ ./db_bench --benchmarks=fillrandom
--num=1000000 -value_size=100 -compression_type=none

Reading random with no merge operator specified:
TEST_TMPDIR=/dev/shm/v100nocomp/ ./db_bench
--benchmarks="read
Closes https://github.com/facebook/rocksdb/pull/1711

Differential Revision: D4361163

Pulled By: maysamyabandeh

fbshipit-source-id: 9801e07
2016-12-29 15:54:19 -08:00

2168 lines
79 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same 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_table_reader.h"
#include <algorithm>
#include <limits>
#include <string>
#include <utility>
#include <vector>
#include "db/dbformat.h"
#include "db/pinned_iterators_manager.h"
#include "rocksdb/cache.h"
#include "rocksdb/comparator.h"
#include "rocksdb/env.h"
#include "rocksdb/filter_policy.h"
#include "rocksdb/iterator.h"
#include "rocksdb/options.h"
#include "rocksdb/statistics.h"
#include "rocksdb/table.h"
#include "rocksdb/table_properties.h"
#include "table/block.h"
#include "table/block_based_filter_block.h"
#include "table/block_based_table_factory.h"
#include "table/block_prefix_index.h"
#include "table/filter_block.h"
#include "table/format.h"
#include "table/full_filter_block.h"
#include "table/get_context.h"
#include "table/internal_iterator.h"
#include "table/meta_blocks.h"
#include "table/persistent_cache_helper.h"
#include "table/sst_file_writer_collectors.h"
#include "table/two_level_iterator.h"
#include "util/coding.h"
#include "util/file_reader_writer.h"
#include "util/perf_context_imp.h"
#include "util/stop_watch.h"
#include "util/string_util.h"
#include "util/sync_point.h"
namespace rocksdb {
extern const uint64_t kBlockBasedTableMagicNumber;
extern const std::string kHashIndexPrefixesBlock;
extern const std::string kHashIndexPrefixesMetadataBlock;
using std::unique_ptr;
typedef BlockBasedTable::IndexReader IndexReader;
namespace {
// Read the block identified by "handle" from "file".
// The only relevant option is options.verify_checksums for now.
// On failure return non-OK.
// On success fill *result and return OK - caller owns *result
// @param compression_dict Data for presetting the compression library's
// dictionary.
Status ReadBlockFromFile(RandomAccessFileReader* file, const Footer& footer,
const ReadOptions& options, const BlockHandle& handle,
std::unique_ptr<Block>* result,
const ImmutableCFOptions& ioptions, bool do_uncompress,
const Slice& compression_dict,
const PersistentCacheOptions& cache_options,
SequenceNumber global_seqno,
size_t read_amp_bytes_per_bit) {
BlockContents contents;
Status s = ReadBlockContents(file, footer, options, handle, &contents, ioptions,
do_uncompress, compression_dict, cache_options);
if (s.ok()) {
result->reset(new Block(std::move(contents), global_seqno,
read_amp_bytes_per_bit, ioptions.statistics));
}
return s;
}
// Delete the resource that is held by the iterator.
template <class ResourceType>
void DeleteHeldResource(void* arg, void* ignored) {
delete reinterpret_cast<ResourceType*>(arg);
}
// Delete the entry resided in the cache.
template <class Entry>
void DeleteCachedEntry(const Slice& key, void* value) {
auto entry = reinterpret_cast<Entry*>(value);
delete entry;
}
void DeleteCachedFilterEntry(const Slice& key, void* value);
void DeleteCachedIndexEntry(const Slice& key, void* value);
// Release the cached entry and decrement its ref count.
void ReleaseCachedEntry(void* arg, void* h) {
Cache* cache = reinterpret_cast<Cache*>(arg);
Cache::Handle* handle = reinterpret_cast<Cache::Handle*>(h);
cache->Release(handle);
}
Slice GetCacheKeyFromOffset(const char* cache_key_prefix,
size_t cache_key_prefix_size, uint64_t offset,
char* cache_key) {
assert(cache_key != nullptr);
assert(cache_key_prefix_size != 0);
assert(cache_key_prefix_size <= BlockBasedTable::kMaxCacheKeyPrefixSize);
memcpy(cache_key, cache_key_prefix, cache_key_prefix_size);
char* end = EncodeVarint64(cache_key + cache_key_prefix_size, offset);
return Slice(cache_key, static_cast<size_t>(end - cache_key));
}
Cache::Handle* GetEntryFromCache(Cache* block_cache, const Slice& key,
Tickers block_cache_miss_ticker,
Tickers block_cache_hit_ticker,
Statistics* statistics) {
auto cache_handle = block_cache->Lookup(key, statistics);
if (cache_handle != nullptr) {
PERF_COUNTER_ADD(block_cache_hit_count, 1);
// overall cache hit
RecordTick(statistics, BLOCK_CACHE_HIT);
// total bytes read from cache
RecordTick(statistics, BLOCK_CACHE_BYTES_READ,
block_cache->GetUsage(cache_handle));
// block-type specific cache hit
RecordTick(statistics, block_cache_hit_ticker);
} else {
// overall cache miss
RecordTick(statistics, BLOCK_CACHE_MISS);
// block-type specific cache miss
RecordTick(statistics, block_cache_miss_ticker);
}
return cache_handle;
}
} // namespace
// -- IndexReader and its subclasses
// IndexReader is the interface that provide the functionality for index access.
class BlockBasedTable::IndexReader {
public:
explicit IndexReader(const Comparator* comparator, Statistics* stats)
: comparator_(comparator), statistics_(stats) {}
virtual ~IndexReader() {}
// Create an iterator for index access.
// An iter is passed in, if it is not null, update this one and return it
// If it is null, create a new Iterator
virtual InternalIterator* NewIterator(BlockIter* iter = nullptr,
bool total_order_seek = true) = 0;
// The size of the index.
virtual size_t size() const = 0;
// Memory usage of the index block
virtual size_t usable_size() const = 0;
// return the statistics pointer
virtual Statistics* statistics() const { return statistics_; }
// Report an approximation of how much memory has been used other than memory
// that was allocated in block cache.
virtual size_t ApproximateMemoryUsage() const = 0;
protected:
const Comparator* comparator_;
private:
Statistics* statistics_;
};
// Index that allows binary search lookup for the first key of each block.
// This class can be viewed as a thin wrapper for `Block` class which already
// supports binary search.
class BinarySearchIndexReader : public IndexReader {
public:
// Read index from the file and create an intance for
// `BinarySearchIndexReader`.
// On success, index_reader will be populated; otherwise it will remain
// unmodified.
static Status Create(RandomAccessFileReader* file, const Footer& footer,
const BlockHandle& index_handle,
const ImmutableCFOptions &ioptions,
const Comparator* comparator, IndexReader** index_reader,
const PersistentCacheOptions& cache_options) {
std::unique_ptr<Block> index_block;
auto s = ReadBlockFromFile(
file, footer, ReadOptions(), index_handle, &index_block, ioptions,
true /* decompress */, Slice() /*compression dict*/, cache_options,
kDisableGlobalSequenceNumber, 0 /* read_amp_bytes_per_bit */);
if (s.ok()) {
*index_reader = new BinarySearchIndexReader(
comparator, std::move(index_block), ioptions.statistics);
}
return s;
}
virtual InternalIterator* NewIterator(BlockIter* iter = nullptr,
bool dont_care = true) override {
return index_block_->NewIterator(comparator_, iter, true);
}
virtual size_t size() const override { return index_block_->size(); }
virtual size_t usable_size() const override {
return index_block_->usable_size();
}
virtual size_t ApproximateMemoryUsage() const override {
assert(index_block_);
return index_block_->ApproximateMemoryUsage();
}
private:
BinarySearchIndexReader(const Comparator* comparator,
std::unique_ptr<Block>&& index_block,
Statistics* stats)
: IndexReader(comparator, stats), index_block_(std::move(index_block)) {
assert(index_block_ != nullptr);
}
std::unique_ptr<Block> index_block_;
};
// Index that leverages an internal hash table to quicken the lookup for a given
// key.
class HashIndexReader : public IndexReader {
public:
static Status Create(const SliceTransform* hash_key_extractor,
const Footer& footer, RandomAccessFileReader* file,
const ImmutableCFOptions& ioptions,
const Comparator* comparator,
const BlockHandle& index_handle,
InternalIterator* meta_index_iter,
IndexReader** index_reader,
bool hash_index_allow_collision,
const PersistentCacheOptions& cache_options) {
std::unique_ptr<Block> index_block;
auto s = ReadBlockFromFile(
file, footer, ReadOptions(), index_handle, &index_block, ioptions,
true /* decompress */, Slice() /*compression dict*/, cache_options,
kDisableGlobalSequenceNumber, 0 /* read_amp_bytes_per_bit */);
if (!s.ok()) {
return s;
}
// Note, failure to create prefix hash index does not need to be a
// hard error. We can still fall back to the original binary search index.
// So, Create will succeed regardless, from this point on.
auto new_index_reader =
new HashIndexReader(comparator, std::move(index_block),
ioptions.statistics);
*index_reader = new_index_reader;
// Get prefixes block
BlockHandle prefixes_handle;
s = FindMetaBlock(meta_index_iter, kHashIndexPrefixesBlock,
&prefixes_handle);
if (!s.ok()) {
// TODO: log error
return Status::OK();
}
// Get index metadata block
BlockHandle prefixes_meta_handle;
s = FindMetaBlock(meta_index_iter, kHashIndexPrefixesMetadataBlock,
&prefixes_meta_handle);
if (!s.ok()) {
// TODO: log error
return Status::OK();
}
// Read contents for the blocks
BlockContents prefixes_contents;
s = ReadBlockContents(file, footer, ReadOptions(), prefixes_handle,
&prefixes_contents, ioptions, true /* decompress */,
Slice() /*compression dict*/, cache_options);
if (!s.ok()) {
return s;
}
BlockContents prefixes_meta_contents;
s = ReadBlockContents(file, footer, ReadOptions(), prefixes_meta_handle,
&prefixes_meta_contents, ioptions, true /* decompress */,
Slice() /*compression dict*/, cache_options);
if (!s.ok()) {
// TODO: log error
return Status::OK();
}
BlockPrefixIndex* prefix_index = nullptr;
s = BlockPrefixIndex::Create(hash_key_extractor, prefixes_contents.data,
prefixes_meta_contents.data, &prefix_index);
// TODO: log error
if (s.ok()) {
new_index_reader->index_block_->SetBlockPrefixIndex(prefix_index);
}
return Status::OK();
}
virtual InternalIterator* NewIterator(BlockIter* iter = nullptr,
bool total_order_seek = true) override {
return index_block_->NewIterator(comparator_, iter, total_order_seek);
}
virtual size_t size() const override { return index_block_->size(); }
virtual size_t usable_size() const override {
return index_block_->usable_size();
}
virtual size_t ApproximateMemoryUsage() const override {
assert(index_block_);
return index_block_->ApproximateMemoryUsage() +
prefixes_contents_.data.size();
}
private:
HashIndexReader(const Comparator* comparator,
std::unique_ptr<Block>&& index_block, Statistics* stats)
: IndexReader(comparator, stats), index_block_(std::move(index_block)) {
assert(index_block_ != nullptr);
}
~HashIndexReader() {
}
std::unique_ptr<Block> index_block_;
BlockContents prefixes_contents_;
};
// CachableEntry represents the entries that *may* be fetched from block cache.
// field `value` is the item we want to get.
// field `cache_handle` is the cache handle to the block cache. If the value
// was not read from cache, `cache_handle` will be nullptr.
template <class TValue>
struct BlockBasedTable::CachableEntry {
CachableEntry(TValue* _value, Cache::Handle* _cache_handle)
: value(_value), cache_handle(_cache_handle) {}
CachableEntry() : CachableEntry(nullptr, nullptr) {}
void Release(Cache* cache) {
if (cache_handle) {
cache->Release(cache_handle);
value = nullptr;
cache_handle = nullptr;
}
}
bool IsSet() const { return cache_handle != nullptr; }
TValue* value = nullptr;
// if the entry is from the cache, cache_handle will be populated.
Cache::Handle* cache_handle = nullptr;
};
struct BlockBasedTable::Rep {
Rep(const ImmutableCFOptions& _ioptions, const EnvOptions& _env_options,
const BlockBasedTableOptions& _table_opt,
const InternalKeyComparator& _internal_comparator, bool skip_filters)
: ioptions(_ioptions),
env_options(_env_options),
table_options(_table_opt),
filter_policy(skip_filters ? nullptr : _table_opt.filter_policy.get()),
internal_comparator(_internal_comparator),
filter_type(FilterType::kNoFilter),
whole_key_filtering(_table_opt.whole_key_filtering),
prefix_filtering(true),
range_del_handle(BlockHandle::NullBlockHandle()),
global_seqno(kDisableGlobalSequenceNumber) {}
const ImmutableCFOptions& ioptions;
const EnvOptions& env_options;
const BlockBasedTableOptions& table_options;
const FilterPolicy* const filter_policy;
const InternalKeyComparator& internal_comparator;
Status status;
unique_ptr<RandomAccessFileReader> file;
char cache_key_prefix[kMaxCacheKeyPrefixSize];
size_t cache_key_prefix_size = 0;
char persistent_cache_key_prefix[kMaxCacheKeyPrefixSize];
size_t persistent_cache_key_prefix_size = 0;
char compressed_cache_key_prefix[kMaxCacheKeyPrefixSize];
size_t compressed_cache_key_prefix_size = 0;
uint64_t dummy_index_reader_offset =
0; // ID that is unique for the block cache.
PersistentCacheOptions persistent_cache_options;
// Footer contains the fixed table information
Footer footer;
// index_reader and filter will be populated and used only when
// options.block_cache is nullptr; otherwise we will get the index block via
// the block cache.
unique_ptr<IndexReader> index_reader;
unique_ptr<FilterBlockReader> filter;
enum class FilterType {
kNoFilter,
kFullFilter,
kBlockFilter,
};
FilterType filter_type;
BlockHandle filter_handle;
std::shared_ptr<const TableProperties> table_properties;
// Block containing the data for the compression dictionary. We take ownership
// for the entire block struct, even though we only use its Slice member. This
// is easier because the Slice member depends on the continued existence of
// another member ("allocation").
std::unique_ptr<const BlockContents> compression_dict_block;
BlockBasedTableOptions::IndexType index_type;
bool hash_index_allow_collision;
bool whole_key_filtering;
bool prefix_filtering;
// TODO(kailiu) It is very ugly to use internal key in table, since table
// module should not be relying on db module. However to make things easier
// and compatible with existing code, we introduce a wrapper that allows
// block to extract prefix without knowing if a key is internal or not.
unique_ptr<SliceTransform> internal_prefix_transform;
// only used in level 0 files:
// when pin_l0_filter_and_index_blocks_in_cache is true, we do use the
// LRU cache, but we always keep the filter & idndex block's handle checked
// out here (=we don't call Release()), plus the parsed out objects
// the LRU cache will never push flush them out, hence they're pinned
CachableEntry<FilterBlockReader> filter_entry;
CachableEntry<IndexReader> index_entry;
// range deletion meta-block is pinned through reader's lifetime when LRU
// cache is enabled.
CachableEntry<Block> range_del_entry;
BlockHandle range_del_handle;
// If global_seqno is used, all Keys in this file will have the same
// seqno with value `global_seqno`.
//
// A value of kDisableGlobalSequenceNumber means that this feature is disabled
// and every key have it's own seqno.
SequenceNumber global_seqno;
};
BlockBasedTable::~BlockBasedTable() {
Close();
delete rep_;
}
// Helper function to setup the cache key's prefix for the Table.
void BlockBasedTable::SetupCacheKeyPrefix(Rep* rep, uint64_t file_size) {
assert(kMaxCacheKeyPrefixSize >= 10);
rep->cache_key_prefix_size = 0;
rep->compressed_cache_key_prefix_size = 0;
if (rep->table_options.block_cache != nullptr) {
GenerateCachePrefix(rep->table_options.block_cache.get(), rep->file->file(),
&rep->cache_key_prefix[0], &rep->cache_key_prefix_size);
// Create dummy offset of index reader which is beyond the file size.
rep->dummy_index_reader_offset =
file_size + rep->table_options.block_cache->NewId();
}
if (rep->table_options.persistent_cache != nullptr) {
GenerateCachePrefix(/*cache=*/nullptr, rep->file->file(),
&rep->persistent_cache_key_prefix[0],
&rep->persistent_cache_key_prefix_size);
}
if (rep->table_options.block_cache_compressed != nullptr) {
GenerateCachePrefix(rep->table_options.block_cache_compressed.get(),
rep->file->file(), &rep->compressed_cache_key_prefix[0],
&rep->compressed_cache_key_prefix_size);
}
}
void BlockBasedTable::GenerateCachePrefix(Cache* cc,
RandomAccessFile* file, char* buffer, size_t* size) {
// generate an id from the file
*size = file->GetUniqueId(buffer, kMaxCacheKeyPrefixSize);
// If the prefix wasn't generated or was too long,
// create one from the cache.
if (cc && *size == 0) {
char* end = EncodeVarint64(buffer, cc->NewId());
*size = static_cast<size_t>(end - buffer);
}
}
void BlockBasedTable::GenerateCachePrefix(Cache* cc,
WritableFile* file, char* buffer, size_t* size) {
// generate an id from the file
*size = file->GetUniqueId(buffer, kMaxCacheKeyPrefixSize);
// If the prefix wasn't generated or was too long,
// create one from the cache.
if (*size == 0) {
char* end = EncodeVarint64(buffer, cc->NewId());
*size = static_cast<size_t>(end - buffer);
}
}
namespace {
// Return True if table_properties has `user_prop_name` has a `true` value
// or it doesn't contain this property (for backward compatible).
bool IsFeatureSupported(const TableProperties& table_properties,
const std::string& user_prop_name, Logger* info_log) {
auto& props = table_properties.user_collected_properties;
auto pos = props.find(user_prop_name);
// Older version doesn't have this value set. Skip this check.
if (pos != props.end()) {
if (pos->second == kPropFalse) {
return false;
} else if (pos->second != kPropTrue) {
Log(InfoLogLevel::WARN_LEVEL, info_log,
"Property %s has invalidate value %s", user_prop_name.c_str(),
pos->second.c_str());
}
}
return true;
}
SequenceNumber GetGlobalSequenceNumber(const TableProperties& table_properties,
Logger* info_log) {
auto& props = table_properties.user_collected_properties;
auto version_pos = props.find(ExternalSstFilePropertyNames::kVersion);
auto seqno_pos = props.find(ExternalSstFilePropertyNames::kGlobalSeqno);
if (version_pos == props.end()) {
if (seqno_pos != props.end()) {
// This is not an external sst file, global_seqno is not supported.
assert(false);
Log(InfoLogLevel::ERROR_LEVEL, info_log,
"A non-external sst file have global seqno property with value %s",
seqno_pos->second.c_str());
}
return kDisableGlobalSequenceNumber;
}
uint32_t version = DecodeFixed32(version_pos->second.c_str());
if (version < 2) {
if (seqno_pos != props.end() || version != 1) {
// This is a v1 external sst file, global_seqno is not supported.
assert(false);
Log(InfoLogLevel::ERROR_LEVEL, info_log,
"An external sst file with version %u have global seqno property "
"with value %s",
version, seqno_pos->second.c_str());
}
return kDisableGlobalSequenceNumber;
}
SequenceNumber global_seqno = DecodeFixed64(seqno_pos->second.c_str());
if (global_seqno > kMaxSequenceNumber) {
assert(false);
Log(InfoLogLevel::ERROR_LEVEL, info_log,
"An external sst file with version %u have global seqno property "
"with value %llu, which is greater than kMaxSequenceNumber",
version, global_seqno);
}
return global_seqno;
}
} // namespace
Slice BlockBasedTable::GetCacheKey(const char* cache_key_prefix,
size_t cache_key_prefix_size,
const BlockHandle& handle, char* cache_key) {
assert(cache_key != nullptr);
assert(cache_key_prefix_size != 0);
assert(cache_key_prefix_size <= kMaxCacheKeyPrefixSize);
memcpy(cache_key, cache_key_prefix, cache_key_prefix_size);
char* end =
EncodeVarint64(cache_key + cache_key_prefix_size, handle.offset());
return Slice(cache_key, static_cast<size_t>(end - cache_key));
}
Status BlockBasedTable::Open(const ImmutableCFOptions& ioptions,
const EnvOptions& env_options,
const BlockBasedTableOptions& table_options,
const InternalKeyComparator& internal_comparator,
unique_ptr<RandomAccessFileReader>&& file,
uint64_t file_size,
unique_ptr<TableReader>* table_reader,
const bool prefetch_index_and_filter_in_cache,
const bool skip_filters, const int level) {
table_reader->reset();
Footer footer;
auto s = ReadFooterFromFile(file.get(), file_size, &footer,
kBlockBasedTableMagicNumber);
if (!s.ok()) {
return s;
}
if (!BlockBasedTableSupportedVersion(footer.version())) {
return Status::Corruption(
"Unknown Footer version. Maybe this file was created with newer "
"version of RocksDB?");
}
// We've successfully read the footer and the index block: we're
// ready to serve requests.
// Better not mutate rep_ after the creation. eg. internal_prefix_transform
// raw pointer will be used to create HashIndexReader, whose reset may
// access a dangling pointer.
Rep* rep = new BlockBasedTable::Rep(ioptions, env_options, table_options,
internal_comparator, skip_filters);
rep->file = std::move(file);
rep->footer = footer;
rep->index_type = table_options.index_type;
rep->hash_index_allow_collision = table_options.hash_index_allow_collision;
// We need to wrap data with internal_prefix_transform to make sure it can
// handle prefix correctly.
rep->internal_prefix_transform.reset(
new InternalKeySliceTransform(rep->ioptions.prefix_extractor));
SetupCacheKeyPrefix(rep, file_size);
unique_ptr<BlockBasedTable> new_table(new BlockBasedTable(rep));
// page cache options
rep->persistent_cache_options =
PersistentCacheOptions(rep->table_options.persistent_cache,
std::string(rep->persistent_cache_key_prefix,
rep->persistent_cache_key_prefix_size),
rep->ioptions.statistics);
// Read meta index
std::unique_ptr<Block> meta;
std::unique_ptr<InternalIterator> meta_iter;
s = ReadMetaBlock(rep, &meta, &meta_iter);
if (!s.ok()) {
return s;
}
// Find filter handle and filter type
if (rep->filter_policy) {
for (auto prefix : {kFullFilterBlockPrefix, kFilterBlockPrefix}) {
std::string filter_block_key = prefix;
filter_block_key.append(rep->filter_policy->Name());
if (FindMetaBlock(meta_iter.get(), filter_block_key, &rep->filter_handle)
.ok()) {
rep->filter_type = (prefix == kFullFilterBlockPrefix)
? Rep::FilterType::kFullFilter
: Rep::FilterType::kBlockFilter;
break;
}
}
}
// Read the properties
bool found_properties_block = true;
s = SeekToPropertiesBlock(meta_iter.get(), &found_properties_block);
if (!s.ok()) {
Log(InfoLogLevel::WARN_LEVEL, rep->ioptions.info_log,
"Error when seeking to properties block from file: %s",
s.ToString().c_str());
} else if (found_properties_block) {
s = meta_iter->status();
TableProperties* table_properties = nullptr;
if (s.ok()) {
s = ReadProperties(meta_iter->value(), rep->file.get(), rep->footer,
rep->ioptions, &table_properties);
}
if (!s.ok()) {
Log(InfoLogLevel::WARN_LEVEL, rep->ioptions.info_log,
"Encountered error while reading data from properties "
"block %s", s.ToString().c_str());
} else {
rep->table_properties.reset(table_properties);
}
} else {
Log(InfoLogLevel::ERROR_LEVEL, rep->ioptions.info_log,
"Cannot find Properties block from file.");
}
// Read the compression dictionary meta block
bool found_compression_dict;
s = SeekToCompressionDictBlock(meta_iter.get(), &found_compression_dict);
if (!s.ok()) {
Log(InfoLogLevel::WARN_LEVEL, rep->ioptions.info_log,
"Error when seeking to compression dictionary block from file: %s",
s.ToString().c_str());
} else if (found_compression_dict) {
// TODO(andrewkr): Add to block cache if cache_index_and_filter_blocks is
// true.
unique_ptr<BlockContents> compression_dict_block{new BlockContents()};
// TODO(andrewkr): ReadMetaBlock repeats SeekToCompressionDictBlock().
// maybe decode a handle from meta_iter
// and do ReadBlockContents(handle) instead
s = rocksdb::ReadMetaBlock(rep->file.get(), file_size,
kBlockBasedTableMagicNumber, rep->ioptions,
rocksdb::kCompressionDictBlock,
compression_dict_block.get());
if (!s.ok()) {
Log(InfoLogLevel::WARN_LEVEL, rep->ioptions.info_log,
"Encountered error while reading data from compression dictionary "
"block %s",
s.ToString().c_str());
} else {
rep->compression_dict_block = std::move(compression_dict_block);
}
}
// Read the range del meta block
bool found_range_del_block;
s = SeekToRangeDelBlock(meta_iter.get(), &found_range_del_block,
&rep->range_del_handle);
if (!s.ok()) {
Log(InfoLogLevel::WARN_LEVEL, rep->ioptions.info_log,
"Error when seeking to range delete tombstones block from file: %s",
s.ToString().c_str());
} else {
if (found_range_del_block && !rep->range_del_handle.IsNull()) {
ReadOptions read_options;
s = MaybeLoadDataBlockToCache(rep, read_options, rep->range_del_handle,
Slice() /* compression_dict */,
&rep->range_del_entry);
if (!s.ok()) {
Log(InfoLogLevel::WARN_LEVEL, rep->ioptions.info_log,
"Encountered error while reading data from range del block %s",
s.ToString().c_str());
}
}
}
// Determine whether whole key filtering is supported.
if (rep->table_properties) {
rep->whole_key_filtering &=
IsFeatureSupported(*(rep->table_properties),
BlockBasedTablePropertyNames::kWholeKeyFiltering,
rep->ioptions.info_log);
rep->prefix_filtering &= IsFeatureSupported(
*(rep->table_properties),
BlockBasedTablePropertyNames::kPrefixFiltering, rep->ioptions.info_log);
rep->global_seqno = GetGlobalSequenceNumber(*(rep->table_properties),
rep->ioptions.info_log);
}
// pre-fetching of blocks is turned on
// Will use block cache for index/filter blocks access
// Always prefetch index and filter for level 0
if (table_options.cache_index_and_filter_blocks) {
if (prefetch_index_and_filter_in_cache || level == 0) {
assert(table_options.block_cache != nullptr);
// Hack: Call NewIndexIterator() to implicitly add index to the
// block_cache
// if pin_l0_filter_and_index_blocks_in_cache is true and this is
// a level0 file, then we will pass in this pointer to rep->index
// to NewIndexIterator(), which will save the index block in there
// else it's a nullptr and nothing special happens
CachableEntry<IndexReader>* index_entry = nullptr;
if (rep->table_options.pin_l0_filter_and_index_blocks_in_cache &&
level == 0) {
index_entry = &rep->index_entry;
}
unique_ptr<InternalIterator> iter(
new_table->NewIndexIterator(ReadOptions(), nullptr, index_entry));
s = iter->status();
if (s.ok()) {
// Hack: Call GetFilter() to implicitly add filter to the block_cache
auto filter_entry = new_table->GetFilter();
// if pin_l0_filter_and_index_blocks_in_cache is true, and this is
// a level0 file, then save it in rep_->filter_entry; it will be
// released in the destructor only, hence it will be pinned in the
// cache while this reader is alive
if (rep->table_options.pin_l0_filter_and_index_blocks_in_cache &&
level == 0) {
rep->filter_entry = filter_entry;
} else {
filter_entry.Release(table_options.block_cache.get());
}
}
}
} else {
// If we don't use block cache for index/filter blocks access, we'll
// pre-load these blocks, which will kept in member variables in Rep
// and with a same life-time as this table object.
IndexReader* index_reader = nullptr;
s = new_table->CreateIndexReader(&index_reader, meta_iter.get());
if (s.ok()) {
rep->index_reader.reset(index_reader);
// Set filter block
if (rep->filter_policy) {
rep->filter.reset(ReadFilter(rep));
}
} else {
delete index_reader;
}
}
if (s.ok()) {
*table_reader = std::move(new_table);
}
return s;
}
void BlockBasedTable::SetupForCompaction() {
switch (rep_->ioptions.access_hint_on_compaction_start) {
case Options::NONE:
break;
case Options::NORMAL:
rep_->file->file()->Hint(RandomAccessFile::NORMAL);
break;
case Options::SEQUENTIAL:
rep_->file->file()->Hint(RandomAccessFile::SEQUENTIAL);
break;
case Options::WILLNEED:
rep_->file->file()->Hint(RandomAccessFile::WILLNEED);
break;
default:
assert(false);
}
compaction_optimized_ = true;
}
std::shared_ptr<const TableProperties> BlockBasedTable::GetTableProperties()
const {
return rep_->table_properties;
}
size_t BlockBasedTable::ApproximateMemoryUsage() const {
size_t usage = 0;
if (rep_->filter) {
usage += rep_->filter->ApproximateMemoryUsage();
}
if (rep_->index_reader) {
usage += rep_->index_reader->ApproximateMemoryUsage();
}
return usage;
}
// Load the meta-block from the file. On success, return the loaded meta block
// and its iterator.
Status BlockBasedTable::ReadMetaBlock(Rep* rep,
std::unique_ptr<Block>* meta_block,
std::unique_ptr<InternalIterator>* iter) {
// TODO(sanjay): Skip this if footer.metaindex_handle() size indicates
// it is an empty block.
// TODO: we never really verify check sum for meta index block
std::unique_ptr<Block> meta;
Status s = ReadBlockFromFile(
rep->file.get(), rep->footer, ReadOptions(),
rep->footer.metaindex_handle(), &meta, rep->ioptions,
true /* decompress */, Slice() /*compression dict*/,
rep->persistent_cache_options, kDisableGlobalSequenceNumber,
0 /* read_amp_bytes_per_bit */);
if (!s.ok()) {
Log(InfoLogLevel::ERROR_LEVEL, rep->ioptions.info_log,
"Encountered error while reading data from properties"
" block %s", s.ToString().c_str());
return s;
}
*meta_block = std::move(meta);
// meta block uses bytewise comparator.
iter->reset(meta_block->get()->NewIterator(BytewiseComparator()));
return Status::OK();
}
Status BlockBasedTable::GetDataBlockFromCache(
const Slice& block_cache_key, const Slice& compressed_block_cache_key,
Cache* block_cache, Cache* block_cache_compressed,
const ImmutableCFOptions& ioptions, const ReadOptions& read_options,
BlockBasedTable::CachableEntry<Block>* block, uint32_t format_version,
const Slice& compression_dict, size_t read_amp_bytes_per_bit) {
Status s;
Block* compressed_block = nullptr;
Cache::Handle* block_cache_compressed_handle = nullptr;
Statistics* statistics = ioptions.statistics;
// Lookup uncompressed cache first
if (block_cache != nullptr) {
block->cache_handle =
GetEntryFromCache(block_cache, block_cache_key, BLOCK_CACHE_DATA_MISS,
BLOCK_CACHE_DATA_HIT, statistics);
if (block->cache_handle != nullptr) {
block->value =
reinterpret_cast<Block*>(block_cache->Value(block->cache_handle));
return s;
}
}
// If not found, search from the compressed block cache.
assert(block->cache_handle == nullptr && block->value == nullptr);
if (block_cache_compressed == nullptr) {
return s;
}
assert(!compressed_block_cache_key.empty());
block_cache_compressed_handle =
block_cache_compressed->Lookup(compressed_block_cache_key);
// if we found in the compressed cache, then uncompress and insert into
// uncompressed cache
if (block_cache_compressed_handle == nullptr) {
RecordTick(statistics, BLOCK_CACHE_COMPRESSED_MISS);
return s;
}
// found compressed block
RecordTick(statistics, BLOCK_CACHE_COMPRESSED_HIT);
compressed_block = reinterpret_cast<Block*>(
block_cache_compressed->Value(block_cache_compressed_handle));
assert(compressed_block->compression_type() != kNoCompression);
// Retrieve the uncompressed contents into a new buffer
BlockContents contents;
s = UncompressBlockContents(compressed_block->data(),
compressed_block->size(), &contents,
format_version, compression_dict,
ioptions);
// Insert uncompressed block into block cache
if (s.ok()) {
block->value =
new Block(std::move(contents), compressed_block->global_seqno(),
read_amp_bytes_per_bit,
statistics); // uncompressed block
assert(block->value->compression_type() == kNoCompression);
if (block_cache != nullptr && block->value->cachable() &&
read_options.fill_cache) {
s = block_cache->Insert(
block_cache_key, block->value, block->value->usable_size(),
&DeleteCachedEntry<Block>, &(block->cache_handle));
if (s.ok()) {
RecordTick(statistics, BLOCK_CACHE_ADD);
RecordTick(statistics, BLOCK_CACHE_DATA_ADD);
RecordTick(statistics, BLOCK_CACHE_DATA_BYTES_INSERT,
block->value->usable_size());
RecordTick(statistics, BLOCK_CACHE_BYTES_WRITE,
block->value->usable_size());
} else {
RecordTick(statistics, BLOCK_CACHE_ADD_FAILURES);
delete block->value;
block->value = nullptr;
}
}
}
// Release hold on compressed cache entry
block_cache_compressed->Release(block_cache_compressed_handle);
return s;
}
Status BlockBasedTable::PutDataBlockToCache(
const Slice& block_cache_key, const Slice& compressed_block_cache_key,
Cache* block_cache, Cache* block_cache_compressed,
const ReadOptions& read_options, const ImmutableCFOptions& ioptions,
CachableEntry<Block>* block, Block* raw_block, uint32_t format_version,
const Slice& compression_dict, size_t read_amp_bytes_per_bit) {
assert(raw_block->compression_type() == kNoCompression ||
block_cache_compressed != nullptr);
Status s;
// Retrieve the uncompressed contents into a new buffer
BlockContents contents;
Statistics* statistics = ioptions.statistics;
if (raw_block->compression_type() != kNoCompression) {
s = UncompressBlockContents(raw_block->data(), raw_block->size(), &contents,
format_version, compression_dict, ioptions);
}
if (!s.ok()) {
delete raw_block;
return s;
}
if (raw_block->compression_type() != kNoCompression) {
block->value = new Block(std::move(contents), raw_block->global_seqno(),
read_amp_bytes_per_bit,
statistics); // uncompressed block
} else {
block->value = raw_block;
raw_block = nullptr;
}
// Insert compressed block into compressed block cache.
// Release the hold on the compressed cache entry immediately.
if (block_cache_compressed != nullptr && raw_block != nullptr &&
raw_block->cachable()) {
s = block_cache_compressed->Insert(compressed_block_cache_key, raw_block,
raw_block->usable_size(),
&DeleteCachedEntry<Block>);
if (s.ok()) {
// Avoid the following code to delete this cached block.
raw_block = nullptr;
RecordTick(statistics, BLOCK_CACHE_COMPRESSED_ADD);
} else {
RecordTick(statistics, BLOCK_CACHE_COMPRESSED_ADD_FAILURES);
}
}
delete raw_block;
// insert into uncompressed block cache
assert((block->value->compression_type() == kNoCompression));
if (block_cache != nullptr && block->value->cachable()) {
s = block_cache->Insert(block_cache_key, block->value,
block->value->usable_size(),
&DeleteCachedEntry<Block>, &(block->cache_handle));
if (s.ok()) {
assert(block->cache_handle != nullptr);
RecordTick(statistics, BLOCK_CACHE_ADD);
RecordTick(statistics, BLOCK_CACHE_DATA_ADD);
RecordTick(statistics, BLOCK_CACHE_DATA_BYTES_INSERT,
block->value->usable_size());
RecordTick(statistics, BLOCK_CACHE_BYTES_WRITE,
block->value->usable_size());
assert(reinterpret_cast<Block*>(
block_cache->Value(block->cache_handle)) == block->value);
} else {
RecordTick(statistics, BLOCK_CACHE_ADD_FAILURES);
delete block->value;
block->value = nullptr;
}
}
return s;
}
FilterBlockReader* BlockBasedTable::ReadFilter(Rep* rep) {
// TODO: We might want to unify with ReadBlockFromFile() if we start
// requiring checksum verification in Table::Open.
if (rep->filter_type == Rep::FilterType::kNoFilter) {
return nullptr;
}
BlockContents block;
if (!ReadBlockContents(rep->file.get(), rep->footer, ReadOptions(),
rep->filter_handle, &block, rep->ioptions,
false /* decompress */, Slice() /*compression dict*/,
rep->persistent_cache_options)
.ok()) {
// Error reading the block
return nullptr;
}
assert(rep->filter_policy);
if (rep->filter_type == Rep::FilterType::kBlockFilter) {
return new BlockBasedFilterBlockReader(
rep->prefix_filtering ? rep->ioptions.prefix_extractor : nullptr,
rep->table_options, rep->whole_key_filtering, std::move(block),
rep->ioptions.statistics);
} else if (rep->filter_type == Rep::FilterType::kFullFilter) {
auto filter_bits_reader =
rep->filter_policy->GetFilterBitsReader(block.data);
if (filter_bits_reader != nullptr) {
return new FullFilterBlockReader(
rep->prefix_filtering ? rep->ioptions.prefix_extractor : nullptr,
rep->whole_key_filtering, std::move(block), filter_bits_reader,
rep->ioptions.statistics);
}
}
// filter_type is either kNoFilter (exited the function at the first if),
// kBlockFilter or kFullFilter. there is no way for the execution to come here
assert(false);
return nullptr;
}
BlockBasedTable::CachableEntry<FilterBlockReader> BlockBasedTable::GetFilter(
bool no_io) const {
// If cache_index_and_filter_blocks is false, filter should be pre-populated.
// We will return rep_->filter anyway. rep_->filter can be nullptr if filter
// read fails at Open() time. We don't want to reload again since it will
// most probably fail again.
if (!rep_->table_options.cache_index_and_filter_blocks) {
return {rep_->filter.get(), nullptr /* cache handle */};
}
Cache* block_cache = rep_->table_options.block_cache.get();
if (rep_->filter_policy == nullptr /* do not use filter */ ||
block_cache == nullptr /* no block cache at all */) {
return {nullptr /* filter */, nullptr /* cache handle */};
}
// we have a pinned filter block
if (rep_->filter_entry.IsSet()) {
return rep_->filter_entry;
}
PERF_TIMER_GUARD(read_filter_block_nanos);
// Fetching from the cache
char cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
auto key = GetCacheKey(rep_->cache_key_prefix, rep_->cache_key_prefix_size,
rep_->footer.metaindex_handle(),
cache_key);
Statistics* statistics = rep_->ioptions.statistics;
auto cache_handle =
GetEntryFromCache(block_cache, key, BLOCK_CACHE_FILTER_MISS,
BLOCK_CACHE_FILTER_HIT, statistics);
FilterBlockReader* filter = nullptr;
if (cache_handle != nullptr) {
filter = reinterpret_cast<FilterBlockReader*>(
block_cache->Value(cache_handle));
} else if (no_io) {
// Do not invoke any io.
return CachableEntry<FilterBlockReader>();
} else {
filter = ReadFilter(rep_);
if (filter != nullptr) {
assert(filter->size() > 0);
Status s = block_cache->Insert(
key, filter, filter->size(), &DeleteCachedFilterEntry, &cache_handle,
rep_->table_options.cache_index_and_filter_blocks_with_high_priority
? Cache::Priority::HIGH
: Cache::Priority::LOW);
if (s.ok()) {
RecordTick(statistics, BLOCK_CACHE_ADD);
RecordTick(statistics, BLOCK_CACHE_FILTER_ADD);
RecordTick(statistics, BLOCK_CACHE_FILTER_BYTES_INSERT, filter->size());
RecordTick(statistics, BLOCK_CACHE_BYTES_WRITE, filter->size());
} else {
RecordTick(statistics, BLOCK_CACHE_ADD_FAILURES);
delete filter;
return CachableEntry<FilterBlockReader>();
}
}
}
return { filter, cache_handle };
}
InternalIterator* BlockBasedTable::NewIndexIterator(
const ReadOptions& read_options, BlockIter* input_iter,
CachableEntry<IndexReader>* index_entry) {
// index reader has already been pre-populated.
if (rep_->index_reader) {
return rep_->index_reader->NewIterator(
input_iter, read_options.total_order_seek);
}
// we have a pinned index block
if (rep_->index_entry.IsSet()) {
return rep_->index_entry.value->NewIterator(input_iter,
read_options.total_order_seek);
}
PERF_TIMER_GUARD(read_index_block_nanos);
bool no_io = read_options.read_tier == kBlockCacheTier;
Cache* block_cache = rep_->table_options.block_cache.get();
char cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
auto key =
GetCacheKeyFromOffset(rep_->cache_key_prefix, rep_->cache_key_prefix_size,
rep_->dummy_index_reader_offset, cache_key);
Statistics* statistics = rep_->ioptions.statistics;
auto cache_handle =
GetEntryFromCache(block_cache, key, BLOCK_CACHE_INDEX_MISS,
BLOCK_CACHE_INDEX_HIT, statistics);
if (cache_handle == nullptr && no_io) {
if (input_iter != nullptr) {
input_iter->SetStatus(Status::Incomplete("no blocking io"));
return input_iter;
} else {
return NewErrorInternalIterator(Status::Incomplete("no blocking io"));
}
}
IndexReader* index_reader = nullptr;
if (cache_handle != nullptr) {
index_reader =
reinterpret_cast<IndexReader*>(block_cache->Value(cache_handle));
} else {
// Create index reader and put it in the cache.
Status s;
TEST_SYNC_POINT("BlockBasedTable::NewIndexIterator::thread2:2");
s = CreateIndexReader(&index_reader);
TEST_SYNC_POINT("BlockBasedTable::NewIndexIterator::thread1:1");
TEST_SYNC_POINT("BlockBasedTable::NewIndexIterator::thread2:3");
TEST_SYNC_POINT("BlockBasedTable::NewIndexIterator::thread1:4");
if (s.ok()) {
assert(index_reader != nullptr);
s = block_cache->Insert(
key, index_reader, index_reader->usable_size(),
&DeleteCachedIndexEntry, &cache_handle,
rep_->table_options.cache_index_and_filter_blocks_with_high_priority
? Cache::Priority::HIGH
: Cache::Priority::LOW);
}
if (s.ok()) {
size_t usable_size = index_reader->usable_size();
RecordTick(statistics, BLOCK_CACHE_ADD);
RecordTick(statistics, BLOCK_CACHE_INDEX_ADD);
RecordTick(statistics, BLOCK_CACHE_INDEX_BYTES_INSERT, usable_size);
RecordTick(statistics, BLOCK_CACHE_BYTES_WRITE, usable_size);
} else {
if (index_reader != nullptr) {
delete index_reader;
}
RecordTick(statistics, BLOCK_CACHE_ADD_FAILURES);
// make sure if something goes wrong, index_reader shall remain intact.
if (input_iter != nullptr) {
input_iter->SetStatus(s);
return input_iter;
} else {
return NewErrorInternalIterator(s);
}
}
}
assert(cache_handle);
auto* iter = index_reader->NewIterator(
input_iter, read_options.total_order_seek);
// the caller would like to take ownership of the index block
// don't call RegisterCleanup() in this case, the caller will take care of it
if (index_entry != nullptr) {
*index_entry = {index_reader, cache_handle};
} else {
iter->RegisterCleanup(&ReleaseCachedEntry, block_cache, cache_handle);
}
return iter;
}
// Convert an index iterator value (i.e., an encoded BlockHandle)
// into an iterator over the contents of the corresponding block.
// If input_iter is null, new a iterator
// If input_iter is not null, update this iter and return it
InternalIterator* BlockBasedTable::NewDataBlockIterator(
Rep* rep, const ReadOptions& ro, const Slice& index_value,
BlockIter* input_iter) {
PERF_TIMER_GUARD(new_table_block_iter_nanos);
const bool no_io = (ro.read_tier == kBlockCacheTier);
Cache* block_cache = rep->table_options.block_cache.get();
CachableEntry<Block> block;
BlockHandle handle;
Slice input = index_value;
// We intentionally allow extra stuff in index_value so that we
// can add more features in the future.
Status s = handle.DecodeFrom(&input);
Slice compression_dict;
if (s.ok()) {
if (rep->compression_dict_block) {
compression_dict = rep->compression_dict_block->data;
}
s = MaybeLoadDataBlockToCache(rep, ro, handle, compression_dict, &block);
}
// Didn't get any data from block caches.
if (s.ok() && block.value == nullptr) {
if (no_io) {
// Could not read from block_cache and can't do IO
if (input_iter != nullptr) {
input_iter->SetStatus(Status::Incomplete("no blocking io"));
return input_iter;
} else {
return NewErrorInternalIterator(Status::Incomplete("no blocking io"));
}
}
std::unique_ptr<Block> block_value;
s = ReadBlockFromFile(
rep->file.get(), rep->footer, ro, handle, &block_value, rep->ioptions,
true /* compress */, compression_dict, rep->persistent_cache_options,
rep->global_seqno, rep->table_options.read_amp_bytes_per_bit);
if (s.ok()) {
block.value = block_value.release();
}
}
InternalIterator* iter;
if (s.ok()) {
assert(block.value != nullptr);
iter = block.value->NewIterator(&rep->internal_comparator, input_iter, true,
rep->ioptions.statistics);
if (block.cache_handle != nullptr) {
iter->RegisterCleanup(&ReleaseCachedEntry, block_cache,
block.cache_handle);
} else {
iter->RegisterCleanup(&DeleteHeldResource<Block>, block.value, nullptr);
}
} else {
assert(block.value == nullptr);
if (input_iter != nullptr) {
input_iter->SetStatus(s);
iter = input_iter;
} else {
iter = NewErrorInternalIterator(s);
}
}
return iter;
}
Status BlockBasedTable::MaybeLoadDataBlockToCache(
Rep* rep, const ReadOptions& ro, const BlockHandle& handle,
Slice compression_dict, CachableEntry<Block>* block_entry) {
const bool no_io = (ro.read_tier == kBlockCacheTier);
Cache* block_cache = rep->table_options.block_cache.get();
Cache* block_cache_compressed =
rep->table_options.block_cache_compressed.get();
// If either block cache is enabled, we'll try to read from it.
Status s;
if (block_cache != nullptr || block_cache_compressed != nullptr) {
Statistics* statistics = rep->ioptions.statistics;
char cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
char compressed_cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
Slice key, /* key to the block cache */
ckey /* key to the compressed block cache */;
// create key for block cache
if (block_cache != nullptr) {
key = GetCacheKey(rep->cache_key_prefix, rep->cache_key_prefix_size,
handle, cache_key);
}
if (block_cache_compressed != nullptr) {
ckey = GetCacheKey(rep->compressed_cache_key_prefix,
rep->compressed_cache_key_prefix_size, handle,
compressed_cache_key);
}
s = GetDataBlockFromCache(
key, ckey, block_cache, block_cache_compressed, rep->ioptions, ro,
block_entry, rep->table_options.format_version, compression_dict,
rep->table_options.read_amp_bytes_per_bit);
if (block_entry->value == nullptr && !no_io && ro.fill_cache) {
std::unique_ptr<Block> raw_block;
{
StopWatch sw(rep->ioptions.env, statistics, READ_BLOCK_GET_MICROS);
s = ReadBlockFromFile(
rep->file.get(), rep->footer, ro, handle, &raw_block, rep->ioptions,
block_cache_compressed == nullptr, compression_dict,
rep->persistent_cache_options, rep->global_seqno,
rep->table_options.read_amp_bytes_per_bit);
}
if (s.ok()) {
s = PutDataBlockToCache(
key, ckey, block_cache, block_cache_compressed, ro, rep->ioptions,
block_entry, raw_block.release(), rep->table_options.format_version,
compression_dict, rep->table_options.read_amp_bytes_per_bit);
}
}
}
return s;
}
class BlockBasedTable::BlockEntryIteratorState : public TwoLevelIteratorState {
public:
BlockEntryIteratorState(BlockBasedTable* table,
const ReadOptions& read_options, bool skip_filters)
: TwoLevelIteratorState(table->rep_->ioptions.prefix_extractor !=
nullptr),
table_(table),
read_options_(read_options),
skip_filters_(skip_filters) {}
InternalIterator* NewSecondaryIterator(const Slice& index_value) override {
return NewDataBlockIterator(table_->rep_, read_options_, index_value);
}
bool PrefixMayMatch(const Slice& internal_key) override {
if (read_options_.total_order_seek || skip_filters_) {
return true;
}
return table_->PrefixMayMatch(internal_key);
}
private:
// Don't own table_
BlockBasedTable* table_;
const ReadOptions read_options_;
bool skip_filters_;
};
// This will be broken if the user specifies an unusual implementation
// of Options.comparator, or if the user specifies an unusual
// definition of prefixes in BlockBasedTableOptions.filter_policy.
// In particular, we require the following three properties:
//
// 1) key.starts_with(prefix(key))
// 2) Compare(prefix(key), key) <= 0.
// 3) If Compare(key1, key2) <= 0, then Compare(prefix(key1), prefix(key2)) <= 0
//
// Otherwise, this method guarantees no I/O will be incurred.
//
// REQUIRES: this method shouldn't be called while the DB lock is held.
bool BlockBasedTable::PrefixMayMatch(const Slice& internal_key) {
if (!rep_->filter_policy) {
return true;
}
assert(rep_->ioptions.prefix_extractor != nullptr);
auto user_key = ExtractUserKey(internal_key);
if (!rep_->ioptions.prefix_extractor->InDomain(user_key) ||
rep_->table_properties->prefix_extractor_name.compare(
rep_->ioptions.prefix_extractor->Name()) != 0) {
return true;
}
auto prefix = rep_->ioptions.prefix_extractor->Transform(user_key);
InternalKey internal_key_prefix(prefix, kMaxSequenceNumber, kTypeValue);
auto internal_prefix = internal_key_prefix.Encode();
bool may_match = true;
Status s;
// To prevent any io operation in this method, we set `read_tier` to make
// sure we always read index or filter only when they have already been
// loaded to memory.
ReadOptions no_io_read_options;
no_io_read_options.read_tier = kBlockCacheTier;
// First, try check with full filter
auto filter_entry = GetFilter(true /* no io */);
FilterBlockReader* filter = filter_entry.value;
if (filter != nullptr) {
if (!filter->IsBlockBased()) {
may_match = filter->PrefixMayMatch(prefix);
} else {
// Then, try find it within each block
unique_ptr<InternalIterator> iiter(NewIndexIterator(no_io_read_options));
iiter->Seek(internal_prefix);
if (!iiter->Valid()) {
// we're past end of file
// if it's incomplete, it means that we avoided I/O
// and we're not really sure that we're past the end
// of the file
may_match = iiter->status().IsIncomplete();
} else if (ExtractUserKey(iiter->key())
.starts_with(ExtractUserKey(internal_prefix))) {
// we need to check for this subtle case because our only
// guarantee is that "the key is a string >= last key in that data
// block" according to the doc/table_format.txt spec.
//
// Suppose iiter->key() starts with the desired prefix; it is not
// necessarily the case that the corresponding data block will
// contain the prefix, since iiter->key() need not be in the
// block. However, the next data block may contain the prefix, so
// we return true to play it safe.
may_match = true;
} else if (filter->IsBlockBased()) {
// iiter->key() does NOT start with the desired prefix. Because
// Seek() finds the first key that is >= the seek target, this
// means that iiter->key() > prefix. Thus, any data blocks coming
// after the data block corresponding to iiter->key() cannot
// possibly contain the key. Thus, the corresponding data block
// is the only on could potentially contain the prefix.
Slice handle_value = iiter->value();
BlockHandle handle;
s = handle.DecodeFrom(&handle_value);
assert(s.ok());
may_match = filter->PrefixMayMatch(prefix, handle.offset());
}
}
}
Statistics* statistics = rep_->ioptions.statistics;
RecordTick(statistics, BLOOM_FILTER_PREFIX_CHECKED);
if (!may_match) {
RecordTick(statistics, BLOOM_FILTER_PREFIX_USEFUL);
}
// if rep_->filter_entry is not set, we should call Release(); otherwise
// don't call, in this case we have a local copy in rep_->filter_entry,
// it's pinned to the cache and will be released in the destructor
if (!rep_->filter_entry.IsSet()) {
filter_entry.Release(rep_->table_options.block_cache.get());
}
return may_match;
}
InternalIterator* BlockBasedTable::NewIterator(const ReadOptions& read_options,
Arena* arena,
bool skip_filters) {
return NewTwoLevelIterator(
new BlockEntryIteratorState(this, read_options, skip_filters),
NewIndexIterator(read_options), arena);
}
InternalIterator* BlockBasedTable::NewRangeTombstoneIterator(
const ReadOptions& read_options) {
if (rep_->range_del_handle.IsNull()) {
return nullptr;
}
std::string str;
rep_->range_del_handle.EncodeTo(&str);
// Even though range_del_entry already references the meta-block when block
// cache is enabled, we still call the below function to get another reference
// since the caller may need the iterator beyond this table reader's lifetime.
return NewDataBlockIterator(rep_, read_options, Slice(str));
}
bool BlockBasedTable::FullFilterKeyMayMatch(const ReadOptions& read_options,
FilterBlockReader* filter,
const Slice& internal_key) const {
if (filter == nullptr || filter->IsBlockBased()) {
return true;
}
Slice user_key = ExtractUserKey(internal_key);
if (filter->whole_key_filtering()) {
return filter->KeyMayMatch(user_key);
}
if (!read_options.total_order_seek && rep_->ioptions.prefix_extractor &&
rep_->table_properties->prefix_extractor_name.compare(
rep_->ioptions.prefix_extractor->Name()) == 0 &&
rep_->ioptions.prefix_extractor->InDomain(user_key) &&
!filter->PrefixMayMatch(
rep_->ioptions.prefix_extractor->Transform(user_key))) {
return false;
}
return true;
}
Status BlockBasedTable::Get(const ReadOptions& read_options, const Slice& key,
GetContext* get_context, bool skip_filters) {
Status s;
CachableEntry<FilterBlockReader> filter_entry;
if (!skip_filters) {
filter_entry = GetFilter(read_options.read_tier == kBlockCacheTier);
}
FilterBlockReader* filter = filter_entry.value;
// First check the full filter
// If full filter not useful, Then go into each block
if (!FullFilterKeyMayMatch(read_options, filter, key)) {
RecordTick(rep_->ioptions.statistics, BLOOM_FILTER_USEFUL);
} else {
BlockIter iiter;
NewIndexIterator(read_options, &iiter);
PinnedIteratorsManager* pinned_iters_mgr = get_context->pinned_iters_mgr();
bool pin_blocks = pinned_iters_mgr && pinned_iters_mgr->PinningEnabled();
bool done = false;
for (iiter.Seek(key); iiter.Valid() && !done; iiter.Next()) {
Slice handle_value = iiter.value();
BlockHandle handle;
bool not_exist_in_filter =
filter != nullptr && filter->IsBlockBased() == true &&
handle.DecodeFrom(&handle_value).ok() &&
!filter->KeyMayMatch(ExtractUserKey(key), handle.offset());
if (not_exist_in_filter) {
// Not found
// TODO: think about interaction with Merge. If a user key cannot
// cross one data block, we should be fine.
RecordTick(rep_->ioptions.statistics, BLOOM_FILTER_USEFUL);
break;
} else {
BlockIter biter;
NewDataBlockIterator(rep_, read_options, iiter.value(), &biter);
if (read_options.read_tier == kBlockCacheTier &&
biter.status().IsIncomplete()) {
// couldn't get block from block_cache
// Update Saver.state to Found because we are only looking for whether
// we can guarantee the key is not there when "no_io" is set
get_context->MarkKeyMayExist();
break;
}
if (!biter.status().ok()) {
s = biter.status();
break;
}
// Call the *saver function on each entry/block until it returns false
for (biter.Seek(key); biter.Valid(); biter.Next()) {
ParsedInternalKey parsed_key;
if (!ParseInternalKey(biter.key(), &parsed_key)) {
s = Status::Corruption(Slice());
}
if (!get_context->SaveValue(parsed_key, biter.value(), pin_blocks)) {
done = true;
break;
}
}
s = biter.status();
if (pin_blocks && get_context->State() == GetContext::kMerge) {
// Pin blocks as long as we are merging
biter.DelegateCleanupsTo(pinned_iters_mgr);
}
}
}
if (s.ok()) {
s = iiter.status();
}
}
// if rep_->filter_entry is not set, we should call Release(); otherwise
// don't call, in this case we have a local copy in rep_->filter_entry,
// it's pinned to the cache and will be released in the destructor
if (!rep_->filter_entry.IsSet()) {
filter_entry.Release(rep_->table_options.block_cache.get());
}
return s;
}
Status BlockBasedTable::Prefetch(const Slice* const begin,
const Slice* const end) {
auto& comparator = rep_->internal_comparator;
// pre-condition
if (begin && end && comparator.Compare(*begin, *end) > 0) {
return Status::InvalidArgument(*begin, *end);
}
BlockIter iiter;
NewIndexIterator(ReadOptions(), &iiter);
if (!iiter.status().ok()) {
// error opening index iterator
return iiter.status();
}
// indicates if we are on the last page that need to be pre-fetched
bool prefetching_boundary_page = false;
for (begin ? iiter.Seek(*begin) : iiter.SeekToFirst(); iiter.Valid();
iiter.Next()) {
Slice block_handle = iiter.value();
if (end && comparator.Compare(iiter.key(), *end) >= 0) {
if (prefetching_boundary_page) {
break;
}
// The index entry represents the last key in the data block.
// We should load this page into memory as well, but no more
prefetching_boundary_page = true;
}
// Load the block specified by the block_handle into the block cache
BlockIter biter;
NewDataBlockIterator(rep_, ReadOptions(), block_handle, &biter);
if (!biter.status().ok()) {
// there was an unexpected error while pre-fetching
return biter.status();
}
}
return Status::OK();
}
bool BlockBasedTable::TEST_KeyInCache(const ReadOptions& options,
const Slice& key) {
std::unique_ptr<InternalIterator> iiter(NewIndexIterator(options));
iiter->Seek(key);
assert(iiter->Valid());
CachableEntry<Block> block;
BlockHandle handle;
Slice input = iiter->value();
Status s = handle.DecodeFrom(&input);
assert(s.ok());
Cache* block_cache = rep_->table_options.block_cache.get();
assert(block_cache != nullptr);
char cache_key_storage[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
Slice cache_key =
GetCacheKey(rep_->cache_key_prefix, rep_->cache_key_prefix_size,
handle, cache_key_storage);
Slice ckey;
s = GetDataBlockFromCache(
cache_key, ckey, block_cache, nullptr, rep_->ioptions, options, &block,
rep_->table_options.format_version,
rep_->compression_dict_block ? rep_->compression_dict_block->data
: Slice(),
0 /* read_amp_bytes_per_bit */);
assert(s.ok());
bool in_cache = block.value != nullptr;
if (in_cache) {
ReleaseCachedEntry(block_cache, block.cache_handle);
}
return in_cache;
}
// REQUIRES: The following fields of rep_ should have already been populated:
// 1. file
// 2. index_handle,
// 3. options
// 4. internal_comparator
// 5. index_type
Status BlockBasedTable::CreateIndexReader(
IndexReader** index_reader, InternalIterator* preloaded_meta_index_iter) {
// Some old version of block-based tables don't have index type present in
// table properties. If that's the case we can safely use the kBinarySearch.
auto index_type_on_file = BlockBasedTableOptions::kBinarySearch;
if (rep_->table_properties) {
auto& props = rep_->table_properties->user_collected_properties;
auto pos = props.find(BlockBasedTablePropertyNames::kIndexType);
if (pos != props.end()) {
index_type_on_file = static_cast<BlockBasedTableOptions::IndexType>(
DecodeFixed32(pos->second.c_str()));
}
}
auto file = rep_->file.get();
auto comparator = &rep_->internal_comparator;
const Footer& footer = rep_->footer;
if (index_type_on_file == BlockBasedTableOptions::kHashSearch &&
rep_->ioptions.prefix_extractor == nullptr) {
Log(InfoLogLevel::WARN_LEVEL, rep_->ioptions.info_log,
"BlockBasedTableOptions::kHashSearch requires "
"options.prefix_extractor to be set."
" Fall back to binary search index.");
index_type_on_file = BlockBasedTableOptions::kBinarySearch;
}
switch (index_type_on_file) {
case BlockBasedTableOptions::kBinarySearch: {
return BinarySearchIndexReader::Create(
file, footer, footer.index_handle(), rep_->ioptions, comparator,
index_reader, rep_->persistent_cache_options);
}
case BlockBasedTableOptions::kHashSearch: {
std::unique_ptr<Block> meta_guard;
std::unique_ptr<InternalIterator> meta_iter_guard;
auto meta_index_iter = preloaded_meta_index_iter;
if (meta_index_iter == nullptr) {
auto s = ReadMetaBlock(rep_, &meta_guard, &meta_iter_guard);
if (!s.ok()) {
// we simply fall back to binary search in case there is any
// problem with prefix hash index loading.
Log(InfoLogLevel::WARN_LEVEL, rep_->ioptions.info_log,
"Unable to read the metaindex block."
" Fall back to binary search index.");
return BinarySearchIndexReader::Create(
file, footer, footer.index_handle(), rep_->ioptions, comparator,
index_reader, rep_->persistent_cache_options);
}
meta_index_iter = meta_iter_guard.get();
}
return HashIndexReader::Create(
rep_->internal_prefix_transform.get(), footer, file, rep_->ioptions,
comparator, footer.index_handle(), meta_index_iter, index_reader,
rep_->hash_index_allow_collision, rep_->persistent_cache_options);
}
default: {
std::string error_message =
"Unrecognized index type: " + ToString(rep_->index_type);
return Status::InvalidArgument(error_message.c_str());
}
}
}
uint64_t BlockBasedTable::ApproximateOffsetOf(const Slice& key) {
unique_ptr<InternalIterator> index_iter(NewIndexIterator(ReadOptions()));
index_iter->Seek(key);
uint64_t result;
if (index_iter->Valid()) {
BlockHandle handle;
Slice input = index_iter->value();
Status s = handle.DecodeFrom(&input);
if (s.ok()) {
result = handle.offset();
} else {
// Strange: we can't decode the block handle in the index block.
// We'll just return the offset of the metaindex block, which is
// close to the whole file size for this case.
result = rep_->footer.metaindex_handle().offset();
}
} else {
// key is past the last key in the file. If table_properties is not
// available, approximate the offset by returning the offset of the
// metaindex block (which is right near the end of the file).
result = 0;
if (rep_->table_properties) {
result = rep_->table_properties->data_size;
}
// table_properties is not present in the table.
if (result == 0) {
result = rep_->footer.metaindex_handle().offset();
}
}
return result;
}
bool BlockBasedTable::TEST_filter_block_preloaded() const {
return rep_->filter != nullptr;
}
bool BlockBasedTable::TEST_index_reader_preloaded() const {
return rep_->index_reader != nullptr;
}
Status BlockBasedTable::GetKVPairsFromDataBlocks(
std::vector<KVPairBlock>* kv_pair_blocks) {
std::unique_ptr<InternalIterator> blockhandles_iter(
NewIndexIterator(ReadOptions()));
Status s = blockhandles_iter->status();
if (!s.ok()) {
// Cannot read Index Block
return s;
}
for (blockhandles_iter->SeekToFirst(); blockhandles_iter->Valid();
blockhandles_iter->Next()) {
s = blockhandles_iter->status();
if (!s.ok()) {
break;
}
std::unique_ptr<InternalIterator> datablock_iter;
datablock_iter.reset(
NewDataBlockIterator(rep_, ReadOptions(), blockhandles_iter->value()));
s = datablock_iter->status();
if (!s.ok()) {
// Error reading the block - Skipped
continue;
}
KVPairBlock kv_pair_block;
for (datablock_iter->SeekToFirst(); datablock_iter->Valid();
datablock_iter->Next()) {
s = datablock_iter->status();
if (!s.ok()) {
// Error reading the block - Skipped
break;
}
const Slice& key = datablock_iter->key();
const Slice& value = datablock_iter->value();
std::string key_copy = std::string(key.data(), key.size());
std::string value_copy = std::string(value.data(), value.size());
kv_pair_block.push_back(
std::make_pair(std::move(key_copy), std::move(value_copy)));
}
kv_pair_blocks->push_back(std::move(kv_pair_block));
}
return Status::OK();
}
Status BlockBasedTable::DumpTable(WritableFile* out_file) {
// Output Footer
out_file->Append(
"Footer Details:\n"
"--------------------------------------\n"
" ");
out_file->Append(rep_->footer.ToString().c_str());
out_file->Append("\n");
// Output MetaIndex
out_file->Append(
"Metaindex Details:\n"
"--------------------------------------\n");
std::unique_ptr<Block> meta;
std::unique_ptr<InternalIterator> meta_iter;
Status s = ReadMetaBlock(rep_, &meta, &meta_iter);
if (s.ok()) {
for (meta_iter->SeekToFirst(); meta_iter->Valid(); meta_iter->Next()) {
s = meta_iter->status();
if (!s.ok()) {
return s;
}
if (meta_iter->key() == rocksdb::kPropertiesBlock) {
out_file->Append(" Properties block handle: ");
out_file->Append(meta_iter->value().ToString(true).c_str());
out_file->Append("\n");
} else if (meta_iter->key() == rocksdb::kCompressionDictBlock) {
out_file->Append(" Compression dictionary block handle: ");
out_file->Append(meta_iter->value().ToString(true).c_str());
out_file->Append("\n");
} else if (strstr(meta_iter->key().ToString().c_str(),
"filter.rocksdb.") != nullptr) {
out_file->Append(" Filter block handle: ");
out_file->Append(meta_iter->value().ToString(true).c_str());
out_file->Append("\n");
} else if (meta_iter->key() == rocksdb::kRangeDelBlock) {
out_file->Append(" Range deletion block handle: ");
out_file->Append(meta_iter->value().ToString(true).c_str());
out_file->Append("\n");
}
}
out_file->Append("\n");
} else {
return s;
}
// Output TableProperties
const rocksdb::TableProperties* table_properties;
table_properties = rep_->table_properties.get();
if (table_properties != nullptr) {
out_file->Append(
"Table Properties:\n"
"--------------------------------------\n"
" ");
out_file->Append(table_properties->ToString("\n ", ": ").c_str());
out_file->Append("\n");
}
// Output Filter blocks
if (!rep_->filter && !table_properties->filter_policy_name.empty()) {
// Support only BloomFilter as off now
rocksdb::BlockBasedTableOptions table_options;
table_options.filter_policy.reset(rocksdb::NewBloomFilterPolicy(1));
if (table_properties->filter_policy_name.compare(
table_options.filter_policy->Name()) == 0) {
std::string filter_block_key = kFilterBlockPrefix;
filter_block_key.append(table_properties->filter_policy_name);
BlockHandle handle;
if (FindMetaBlock(meta_iter.get(), filter_block_key, &handle).ok()) {
BlockContents block;
if (ReadBlockContents(
rep_->file.get(), rep_->footer, ReadOptions(), handle, &block,
rep_->ioptions, false /*decompress*/,
Slice() /*compression dict*/, rep_->persistent_cache_options)
.ok()) {
rep_->filter.reset(new BlockBasedFilterBlockReader(
rep_->ioptions.prefix_extractor, table_options,
table_options.whole_key_filtering, std::move(block),
rep_->ioptions.statistics));
}
}
}
}
if (rep_->filter) {
out_file->Append(
"Filter Details:\n"
"--------------------------------------\n"
" ");
out_file->Append(rep_->filter->ToString().c_str());
out_file->Append("\n");
}
// Output Index block
s = DumpIndexBlock(out_file);
if (!s.ok()) {
return s;
}
// Output range deletions block
auto* range_del_iter = NewRangeTombstoneIterator(ReadOptions());
if (range_del_iter != nullptr) {
range_del_iter->SeekToFirst();
if (range_del_iter->Valid()) {
out_file->Append(
"Range deletions:\n"
"--------------------------------------\n"
" ");
for (; range_del_iter->Valid(); range_del_iter->Next()) {
DumpKeyValue(range_del_iter->key(), range_del_iter->value(), out_file);
}
out_file->Append("\n");
}
delete range_del_iter;
}
// Output Data blocks
s = DumpDataBlocks(out_file);
return s;
}
void BlockBasedTable::Close() {
rep_->filter_entry.Release(rep_->table_options.block_cache.get());
rep_->index_entry.Release(rep_->table_options.block_cache.get());
rep_->range_del_entry.Release(rep_->table_options.block_cache.get());
// cleanup index and filter blocks to avoid accessing dangling pointer
if (!rep_->table_options.no_block_cache) {
char cache_key[kMaxCacheKeyPrefixSize + kMaxVarint64Length];
// Get the filter block key
auto key = GetCacheKey(rep_->cache_key_prefix, rep_->cache_key_prefix_size,
rep_->footer.metaindex_handle(), cache_key);
rep_->table_options.block_cache.get()->Erase(key);
// Get the index block key
key = GetCacheKeyFromOffset(rep_->cache_key_prefix,
rep_->cache_key_prefix_size,
rep_->dummy_index_reader_offset, cache_key);
rep_->table_options.block_cache.get()->Erase(key);
}
}
Status BlockBasedTable::DumpIndexBlock(WritableFile* out_file) {
out_file->Append(
"Index Details:\n"
"--------------------------------------\n");
std::unique_ptr<InternalIterator> blockhandles_iter(
NewIndexIterator(ReadOptions()));
Status s = blockhandles_iter->status();
if (!s.ok()) {
out_file->Append("Can not read Index Block \n\n");
return s;
}
out_file->Append(" Block key hex dump: Data block handle\n");
out_file->Append(" Block key ascii\n\n");
for (blockhandles_iter->SeekToFirst(); blockhandles_iter->Valid();
blockhandles_iter->Next()) {
s = blockhandles_iter->status();
if (!s.ok()) {
break;
}
Slice key = blockhandles_iter->key();
InternalKey ikey;
ikey.DecodeFrom(key);
out_file->Append(" HEX ");
out_file->Append(ikey.user_key().ToString(true).c_str());
out_file->Append(": ");
out_file->Append(blockhandles_iter->value().ToString(true).c_str());
out_file->Append("\n");
std::string str_key = ikey.user_key().ToString();
std::string res_key("");
char cspace = ' ';
for (size_t i = 0; i < str_key.size(); i++) {
res_key.append(&str_key[i], 1);
res_key.append(1, cspace);
}
out_file->Append(" ASCII ");
out_file->Append(res_key.c_str());
out_file->Append("\n ------\n");
}
out_file->Append("\n");
return Status::OK();
}
Status BlockBasedTable::DumpDataBlocks(WritableFile* out_file) {
std::unique_ptr<InternalIterator> blockhandles_iter(
NewIndexIterator(ReadOptions()));
Status s = blockhandles_iter->status();
if (!s.ok()) {
out_file->Append("Can not read Index Block \n\n");
return s;
}
uint64_t datablock_size_min = std::numeric_limits<uint64_t>::max();
uint64_t datablock_size_max = 0;
uint64_t datablock_size_sum = 0;
size_t block_id = 1;
for (blockhandles_iter->SeekToFirst(); blockhandles_iter->Valid();
block_id++, blockhandles_iter->Next()) {
s = blockhandles_iter->status();
if (!s.ok()) {
break;
}
Slice bh_val = blockhandles_iter->value();
BlockHandle bh;
bh.DecodeFrom(&bh_val);
uint64_t datablock_size = bh.size();
datablock_size_min = std::min(datablock_size_min, datablock_size);
datablock_size_max = std::max(datablock_size_max, datablock_size);
datablock_size_sum += datablock_size;
out_file->Append("Data Block # ");
out_file->Append(rocksdb::ToString(block_id));
out_file->Append(" @ ");
out_file->Append(blockhandles_iter->value().ToString(true).c_str());
out_file->Append("\n");
out_file->Append("--------------------------------------\n");
std::unique_ptr<InternalIterator> datablock_iter;
datablock_iter.reset(
NewDataBlockIterator(rep_, ReadOptions(), blockhandles_iter->value()));
s = datablock_iter->status();
if (!s.ok()) {
out_file->Append("Error reading the block - Skipped \n\n");
continue;
}
for (datablock_iter->SeekToFirst(); datablock_iter->Valid();
datablock_iter->Next()) {
s = datablock_iter->status();
if (!s.ok()) {
out_file->Append("Error reading the block - Skipped \n");
break;
}
DumpKeyValue(datablock_iter->key(), datablock_iter->value(), out_file);
}
out_file->Append("\n");
}
uint64_t num_datablocks = block_id - 1;
if (num_datablocks) {
double datablock_size_avg =
static_cast<double>(datablock_size_sum) / num_datablocks;
out_file->Append("Data Block Summary:\n");
out_file->Append("--------------------------------------");
out_file->Append("\n # data blocks: ");
out_file->Append(rocksdb::ToString(num_datablocks));
out_file->Append("\n min data block size: ");
out_file->Append(rocksdb::ToString(datablock_size_min));
out_file->Append("\n max data block size: ");
out_file->Append(rocksdb::ToString(datablock_size_max));
out_file->Append("\n avg data block size: ");
out_file->Append(rocksdb::ToString(datablock_size_avg));
out_file->Append("\n");
}
return Status::OK();
}
void BlockBasedTable::DumpKeyValue(const Slice& key, const Slice& value,
WritableFile* out_file) {
InternalKey ikey;
ikey.DecodeFrom(key);
out_file->Append(" HEX ");
out_file->Append(ikey.user_key().ToString(true).c_str());
out_file->Append(": ");
out_file->Append(value.ToString(true).c_str());
out_file->Append("\n");
std::string str_key = ikey.user_key().ToString();
std::string str_value = value.ToString();
std::string res_key(""), res_value("");
char cspace = ' ';
for (size_t i = 0; i < str_key.size(); i++) {
res_key.append(&str_key[i], 1);
res_key.append(1, cspace);
}
for (size_t i = 0; i < str_value.size(); i++) {
res_value.append(&str_value[i], 1);
res_value.append(1, cspace);
}
out_file->Append(" ASCII ");
out_file->Append(res_key.c_str());
out_file->Append(": ");
out_file->Append(res_value.c_str());
out_file->Append("\n ------\n");
}
namespace {
void DeleteCachedFilterEntry(const Slice& key, void* value) {
FilterBlockReader* filter = reinterpret_cast<FilterBlockReader*>(value);
if (filter->statistics() != nullptr) {
RecordTick(filter->statistics(), BLOCK_CACHE_FILTER_BYTES_EVICT,
filter->size());
}
delete filter;
}
void DeleteCachedIndexEntry(const Slice& key, void* value) {
IndexReader* index_reader = reinterpret_cast<IndexReader*>(value);
if (index_reader->statistics() != nullptr) {
RecordTick(index_reader->statistics(), BLOCK_CACHE_INDEX_BYTES_EVICT,
index_reader->usable_size());
}
delete index_reader;
}
} // anonymous namespace
} // namespace rocksdb