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rocksdb/table/block_based/index_builder.cc

222 lines
9.2 KiB

// 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/index_builder.h"
#include <assert.h>
#include <cinttypes>
#include <list>
#include <string>
#include "rocksdb/comparator.h"
#include "rocksdb/flush_block_policy.h"
#include "table/block_based/partitioned_filter_block.h"
#include "table/format.h"
// Without anonymous namespace here, we fail the warning -Wmissing-prototypes
namespace rocksdb {
// using namespace rocksdb;
// Create a index builder based on its type.
IndexBuilder* IndexBuilder::CreateIndexBuilder(
BlockBasedTableOptions::IndexType index_type,
const InternalKeyComparator* comparator,
const InternalKeySliceTransform* int_key_slice_transform,
const bool use_value_delta_encoding,
const BlockBasedTableOptions& table_opt) {
IndexBuilder* result = nullptr;
switch (index_type) {
case BlockBasedTableOptions::kBinarySearch: {
result = new ShortenedIndexBuilder(
comparator, table_opt.index_block_restart_interval,
table_opt.format_version, use_value_delta_encoding,
table_opt.index_shortening, /* include_first_key */ false);
} break;
case BlockBasedTableOptions::kHashSearch: {
// Currently kHashSearch is incompatible with index_block_restart_interval
// > 1
assert(table_opt.index_block_restart_interval == 1);
result = new HashIndexBuilder(
comparator, int_key_slice_transform,
table_opt.index_block_restart_interval, table_opt.format_version,
use_value_delta_encoding, table_opt.index_shortening);
} break;
case BlockBasedTableOptions::kTwoLevelIndexSearch: {
result = PartitionedIndexBuilder::CreateIndexBuilder(
comparator, use_value_delta_encoding, table_opt);
} break;
case BlockBasedTableOptions::kBinarySearchWithFirstKey: {
result = new ShortenedIndexBuilder(
comparator, table_opt.index_block_restart_interval,
table_opt.format_version, use_value_delta_encoding,
table_opt.index_shortening, /* include_first_key */ true);
} break;
default: {
assert(!"Do not recognize the index type ");
} break;
}
return result;
}
PartitionedIndexBuilder* PartitionedIndexBuilder::CreateIndexBuilder(
const InternalKeyComparator* comparator,
const bool use_value_delta_encoding,
const BlockBasedTableOptions& table_opt) {
return new PartitionedIndexBuilder(comparator, table_opt,
use_value_delta_encoding);
}
PartitionedIndexBuilder::PartitionedIndexBuilder(
const InternalKeyComparator* comparator,
const BlockBasedTableOptions& table_opt,
const bool use_value_delta_encoding)
: IndexBuilder(comparator),
index_block_builder_(table_opt.index_block_restart_interval,
true /*use_delta_encoding*/,
use_value_delta_encoding),
index_block_builder_without_seq_(table_opt.index_block_restart_interval,
true /*use_delta_encoding*/,
use_value_delta_encoding),
sub_index_builder_(nullptr),
table_opt_(table_opt),
// We start by false. After each partition we revise the value based on
// what the sub_index_builder has decided. If the feature is disabled
// entirely, this will be set to true after switching the first
// sub_index_builder. Otherwise, it could be set to true even one of the
// sub_index_builders could not safely exclude seq from the keys, then it
// wil be enforced on all sub_index_builders on ::Finish.
seperator_is_key_plus_seq_(false),
use_value_delta_encoding_(use_value_delta_encoding) {}
PartitionedIndexBuilder::~PartitionedIndexBuilder() {
delete sub_index_builder_;
}
void PartitionedIndexBuilder::MakeNewSubIndexBuilder() {
assert(sub_index_builder_ == nullptr);
sub_index_builder_ = new ShortenedIndexBuilder(
comparator_, table_opt_.index_block_restart_interval,
table_opt_.format_version, use_value_delta_encoding_,
table_opt_.index_shortening, /* include_first_key */ false);
flush_policy_.reset(FlushBlockBySizePolicyFactory::NewFlushBlockPolicy(
table_opt_.metadata_block_size, table_opt_.block_size_deviation,
// Note: this is sub-optimal since sub_index_builder_ could later reset
// seperator_is_key_plus_seq_ but the probability of that is low.
sub_index_builder_->seperator_is_key_plus_seq_
? sub_index_builder_->index_block_builder_
: sub_index_builder_->index_block_builder_without_seq_));
partition_cut_requested_ = false;
}
void PartitionedIndexBuilder::RequestPartitionCut() {
partition_cut_requested_ = true;
}
void PartitionedIndexBuilder::AddIndexEntry(
std::string* last_key_in_current_block,
const Slice* first_key_in_next_block, const BlockHandle& block_handle) {
// Note: to avoid two consecuitive flush in the same method call, we do not
// check flush policy when adding the last key
if (UNLIKELY(first_key_in_next_block == nullptr)) { // no more keys
if (sub_index_builder_ == nullptr) {
MakeNewSubIndexBuilder();
}
sub_index_builder_->AddIndexEntry(last_key_in_current_block,
first_key_in_next_block, block_handle);
if (sub_index_builder_->seperator_is_key_plus_seq_) {
// then we need to apply it to all sub-index builders
seperator_is_key_plus_seq_ = true;
}
sub_index_last_key_ = std::string(*last_key_in_current_block);
entries_.push_back(
{sub_index_last_key_,
std::unique_ptr<ShortenedIndexBuilder>(sub_index_builder_)});
sub_index_builder_ = nullptr;
cut_filter_block = true;
} else {
// apply flush policy only to non-empty sub_index_builder_
if (sub_index_builder_ != nullptr) {
std::string handle_encoding;
block_handle.EncodeTo(&handle_encoding);
bool do_flush =
partition_cut_requested_ ||
flush_policy_->Update(*last_key_in_current_block, handle_encoding);
if (do_flush) {
entries_.push_back(
{sub_index_last_key_,
std::unique_ptr<ShortenedIndexBuilder>(sub_index_builder_)});
cut_filter_block = true;
sub_index_builder_ = nullptr;
}
}
if (sub_index_builder_ == nullptr) {
MakeNewSubIndexBuilder();
}
sub_index_builder_->AddIndexEntry(last_key_in_current_block,
first_key_in_next_block, block_handle);
sub_index_last_key_ = std::string(*last_key_in_current_block);
if (sub_index_builder_->seperator_is_key_plus_seq_) {
// then we need to apply it to all sub-index builders
seperator_is_key_plus_seq_ = true;
}
}
}
Status PartitionedIndexBuilder::Finish(
IndexBlocks* index_blocks, const BlockHandle& last_partition_block_handle) {
if (partition_cnt_ == 0) {
partition_cnt_ = entries_.size();
}
// It must be set to null after last key is added
assert(sub_index_builder_ == nullptr);
if (finishing_indexes == true) {
Entry& last_entry = entries_.front();
std::string handle_encoding;
last_partition_block_handle.EncodeTo(&handle_encoding);
std::string handle_delta_encoding;
PutVarsignedint64(
&handle_delta_encoding,
last_partition_block_handle.size() - last_encoded_handle_.size());
last_encoded_handle_ = last_partition_block_handle;
const Slice handle_delta_encoding_slice(handle_delta_encoding);
index_block_builder_.Add(last_entry.key, handle_encoding,
&handle_delta_encoding_slice);
if (!seperator_is_key_plus_seq_) {
index_block_builder_without_seq_.Add(ExtractUserKey(last_entry.key),
handle_encoding,
&handle_delta_encoding_slice);
}
entries_.pop_front();
}
// If there is no sub_index left, then return the 2nd level index.
if (UNLIKELY(entries_.empty())) {
if (seperator_is_key_plus_seq_) {
index_blocks->index_block_contents = index_block_builder_.Finish();
} else {
index_blocks->index_block_contents =
index_block_builder_without_seq_.Finish();
}
top_level_index_size_ = index_blocks->index_block_contents.size();
index_size_ += top_level_index_size_;
return Status::OK();
} else {
// Finish the next partition index in line and Incomplete() to indicate we
// expect more calls to Finish
Entry& entry = entries_.front();
// Apply the policy to all sub-indexes
entry.value->seperator_is_key_plus_seq_ = seperator_is_key_plus_seq_;
auto s = entry.value->Finish(index_blocks);
index_size_ += index_blocks->index_block_contents.size();
finishing_indexes = true;
return s.ok() ? Status::Incomplete() : s;
}
}
size_t PartitionedIndexBuilder::NumPartitions() const { return partition_cnt_; }
} // namespace rocksdb