0f0076ed5a
Summary: Currently, the in-memory hash index of blockbased table uses a precise hash map to track the prefix to block range mapping. In some use cases, especially when prefix itself is big, the memory overhead becomes a problem. This diff introduces a fixed hash bucket array that does not store the prefix and allows prefix collision, which is similar to the plaintable hash index, in order to reduce the memory consumption. Just a quick draft, still testing and refining. Test Plan: unit test and shadow testing Reviewers: dhruba, kailiu, sdong Reviewed By: sdong Subscribers: leveldb Differential Revision: https://reviews.facebook.net/D19047
813 lines
29 KiB
C++
813 lines
29 KiB
C++
// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file. See the AUTHORS file for names of contributors.
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#include "table/block_based_table_builder.h"
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#include <assert.h>
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#include <inttypes.h>
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#include <stdio.h>
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#include <map>
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#include <memory>
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#include <string>
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#include <unordered_map>
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#include "db/dbformat.h"
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#include "rocksdb/cache.h"
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#include "rocksdb/comparator.h"
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#include "rocksdb/env.h"
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#include "rocksdb/filter_policy.h"
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#include "rocksdb/flush_block_policy.h"
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#include "rocksdb/options.h"
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#include "rocksdb/table.h"
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#include "table/block.h"
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#include "table/block_based_table_reader.h"
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#include "table/block_builder.h"
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#include "table/filter_block.h"
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#include "table/format.h"
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#include "table/meta_blocks.h"
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#include "table/table_builder.h"
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#include "util/coding.h"
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#include "util/crc32c.h"
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#include "util/stop_watch.h"
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#include "util/xxhash.h"
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namespace rocksdb {
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extern const std::string kHashIndexPrefixesBlock;
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extern const std::string kHashIndexPrefixesMetadataBlock;
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namespace {
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typedef BlockBasedTableOptions::IndexType IndexType;
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// The interface for building index.
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// Instruction for adding a new concrete IndexBuilder:
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// 1. Create a subclass instantiated from IndexBuilder.
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// 2. Add a new entry associated with that subclass in TableOptions::IndexType.
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// 3. Add a create function for the new subclass in CreateIndexBuilder.
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// Note: we can devise more advanced design to simplify the process for adding
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// new subclass, which will, on the other hand, increase the code complexity and
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// catch unwanted attention from readers. Given that we won't add/change
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// indexes frequently, it makes sense to just embrace a more straightforward
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// design that just works.
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class IndexBuilder {
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public:
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// Index builder will construct a set of blocks which contain:
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// 1. One primary index block.
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// 2. (Optional) a set of metablocks that contains the metadata of the
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// primary index.
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struct IndexBlocks {
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Slice index_block_contents;
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std::unordered_map<std::string, Slice> meta_blocks;
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};
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explicit IndexBuilder(const Comparator* comparator)
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: comparator_(comparator) {}
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virtual ~IndexBuilder() {}
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// Add a new index entry to index block.
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// To allow further optimization, we provide `last_key_in_current_block` and
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// `first_key_in_next_block`, based on which the specific implementation can
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// determine the best index key to be used for the index block.
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// @last_key_in_current_block: this parameter maybe overridden with the value
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// "substitute key".
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// @first_key_in_next_block: it will be nullptr if the entry being added is
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// the last one in the table
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//
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// REQUIRES: Finish() has not yet been called.
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virtual void AddIndexEntry(std::string* last_key_in_current_block,
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const Slice* first_key_in_next_block,
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const BlockHandle& block_handle) = 0;
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// This method will be called whenever a key is added. The subclasses may
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// override OnKeyAdded() if they need to collect additional information.
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virtual void OnKeyAdded(const Slice& key) {}
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// Inform the index builder that all entries has been written. Block builder
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// may therefore perform any operation required for block finalization.
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//
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// REQUIRES: Finish() has not yet been called.
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virtual Status Finish(IndexBlocks* index_blocks) = 0;
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// Get the estimated size for index block.
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virtual size_t EstimatedSize() const = 0;
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protected:
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const Comparator* comparator_;
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};
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// This index builder builds space-efficient index block.
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//
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// Optimizations:
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// 1. Made block's `block_restart_interval` to be 1, which will avoid linear
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// search when doing index lookup.
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// 2. Shorten the key length for index block. Other than honestly using the
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// last key in the data block as the index key, we instead find a shortest
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// substitute key that serves the same function.
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class ShortenedIndexBuilder : public IndexBuilder {
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public:
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explicit ShortenedIndexBuilder(const Comparator* comparator)
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: IndexBuilder(comparator),
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index_block_builder_(1 /* block_restart_interval == 1 */, comparator) {}
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virtual void AddIndexEntry(std::string* last_key_in_current_block,
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const Slice* first_key_in_next_block,
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const BlockHandle& block_handle) override {
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if (first_key_in_next_block != nullptr) {
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comparator_->FindShortestSeparator(last_key_in_current_block,
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*first_key_in_next_block);
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} else {
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comparator_->FindShortSuccessor(last_key_in_current_block);
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}
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std::string handle_encoding;
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block_handle.EncodeTo(&handle_encoding);
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index_block_builder_.Add(*last_key_in_current_block, handle_encoding);
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}
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virtual Status Finish(IndexBlocks* index_blocks) {
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index_blocks->index_block_contents = index_block_builder_.Finish();
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return Status::OK();
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}
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virtual size_t EstimatedSize() const {
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return index_block_builder_.CurrentSizeEstimate();
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}
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private:
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BlockBuilder index_block_builder_;
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};
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// HashIndexBuilder contains a binary-searchable primary index and the
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// metadata for secondary hash index construction.
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// The metadata for hash index consists two parts:
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// - a metablock that compactly contains a sequence of prefixes. All prefixes
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// are stored consectively without any metadata (like, prefix sizes) being
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// stored, which is kept in the other metablock.
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// - a metablock contains the metadata of the prefixes, including prefix size,
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// restart index and number of block it spans. The format looks like:
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//
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// +-----------------+---------------------------+---------------------+ <=prefix 1
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// | length: 4 bytes | restart interval: 4 bytes | num-blocks: 4 bytes |
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// +-----------------+---------------------------+---------------------+ <=prefix 2
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// | length: 4 bytes | restart interval: 4 bytes | num-blocks: 4 bytes |
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// +-----------------+---------------------------+---------------------+
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// | |
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// | .... |
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// | |
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// +-----------------+---------------------------+---------------------+ <=prefix n
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// | length: 4 bytes | restart interval: 4 bytes | num-blocks: 4 bytes |
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// +-----------------+---------------------------+---------------------+
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//
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// The reason of separating these two metablocks is to enable the efficiently
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// reuse the first metablock during hash index construction without unnecessary
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// data copy or small heap allocations for prefixes.
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class HashIndexBuilder : public IndexBuilder {
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public:
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explicit HashIndexBuilder(const Comparator* comparator,
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const SliceTransform* hash_key_extractor)
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: IndexBuilder(comparator),
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primary_index_builder(comparator),
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hash_key_extractor_(hash_key_extractor) {}
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virtual void AddIndexEntry(std::string* last_key_in_current_block,
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const Slice* first_key_in_next_block,
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const BlockHandle& block_handle) override {
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++current_restart_index_;
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primary_index_builder.AddIndexEntry(last_key_in_current_block,
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first_key_in_next_block, block_handle);
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}
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virtual void OnKeyAdded(const Slice& key) override {
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auto key_prefix = hash_key_extractor_->Transform(key);
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bool is_first_entry = pending_block_num_ == 0;
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// Keys may share the prefix
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if (is_first_entry || pending_entry_prefix_ != key_prefix) {
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if (!is_first_entry) {
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FlushPendingPrefix();
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}
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// need a hard copy otherwise the underlying data changes all the time.
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// TODO(kailiu) ToString() is expensive. We may speed up can avoid data
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// copy.
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pending_entry_prefix_ = key_prefix.ToString();
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pending_block_num_ = 1;
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pending_entry_index_ = current_restart_index_;
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} else {
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// entry number increments when keys share the prefix reside in
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// differnt data blocks.
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auto last_restart_index = pending_entry_index_ + pending_block_num_ - 1;
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assert(last_restart_index <= current_restart_index_);
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if (last_restart_index != current_restart_index_) {
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++pending_block_num_;
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}
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}
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}
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virtual Status Finish(IndexBlocks* index_blocks) {
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FlushPendingPrefix();
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primary_index_builder.Finish(index_blocks);
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index_blocks->meta_blocks.insert(
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{kHashIndexPrefixesBlock.c_str(), prefix_block_});
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index_blocks->meta_blocks.insert(
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{kHashIndexPrefixesMetadataBlock.c_str(), prefix_meta_block_});
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return Status::OK();
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}
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virtual size_t EstimatedSize() const {
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return primary_index_builder.EstimatedSize() + prefix_block_.size() +
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prefix_meta_block_.size();
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}
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private:
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void FlushPendingPrefix() {
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prefix_block_.append(pending_entry_prefix_.data(),
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pending_entry_prefix_.size());
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PutVarint32(&prefix_meta_block_, pending_entry_prefix_.size());
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PutVarint32(&prefix_meta_block_, pending_entry_index_);
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PutVarint32(&prefix_meta_block_, pending_block_num_);
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}
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ShortenedIndexBuilder primary_index_builder;
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const SliceTransform* hash_key_extractor_;
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// stores a sequence of prefixes
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std::string prefix_block_;
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// stores the metadata of prefixes
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std::string prefix_meta_block_;
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// The following 3 variables keeps unflushed prefix and its metadata.
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// The details of block_num and entry_index can be found in
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// "block_hash_index.{h,cc}"
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uint32_t pending_block_num_ = 0;
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uint32_t pending_entry_index_ = 0;
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std::string pending_entry_prefix_;
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uint64_t current_restart_index_ = 0;
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};
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// Create a index builder based on its type.
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IndexBuilder* CreateIndexBuilder(IndexType type, const Comparator* comparator,
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const SliceTransform* prefix_extractor) {
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switch (type) {
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case BlockBasedTableOptions::kBinarySearch: {
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return new ShortenedIndexBuilder(comparator);
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}
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case BlockBasedTableOptions::kHashSearch: {
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return new HashIndexBuilder(comparator, prefix_extractor);
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}
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default: {
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assert(!"Do not recognize the index type ");
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return nullptr;
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}
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}
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// impossible.
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assert(false);
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return nullptr;
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}
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bool GoodCompressionRatio(size_t compressed_size, size_t raw_size) {
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// Check to see if compressed less than 12.5%
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return compressed_size < raw_size - (raw_size / 8u);
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}
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Slice CompressBlock(const Slice& raw,
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const CompressionOptions& compression_options,
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CompressionType* type, std::string* compressed_output) {
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if (*type == kNoCompression) {
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return raw;
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}
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// Will return compressed block contents if (1) the compression method is
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// supported in this platform and (2) the compression rate is "good enough".
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switch (*type) {
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case kSnappyCompression:
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if (port::Snappy_Compress(compression_options, raw.data(), raw.size(),
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compressed_output) &&
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GoodCompressionRatio(compressed_output->size(), raw.size())) {
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return *compressed_output;
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}
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break; // fall back to no compression.
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case kZlibCompression:
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if (port::Zlib_Compress(compression_options, raw.data(), raw.size(),
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compressed_output) &&
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GoodCompressionRatio(compressed_output->size(), raw.size())) {
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return *compressed_output;
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}
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break; // fall back to no compression.
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case kBZip2Compression:
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if (port::BZip2_Compress(compression_options, raw.data(), raw.size(),
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compressed_output) &&
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GoodCompressionRatio(compressed_output->size(), raw.size())) {
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return *compressed_output;
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}
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break; // fall back to no compression.
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case kLZ4Compression:
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if (port::LZ4_Compress(compression_options, raw.data(), raw.size(),
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compressed_output) &&
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GoodCompressionRatio(compressed_output->size(), raw.size())) {
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return *compressed_output;
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}
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break; // fall back to no compression.
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case kLZ4HCCompression:
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if (port::LZ4HC_Compress(compression_options, raw.data(), raw.size(),
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compressed_output) &&
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GoodCompressionRatio(compressed_output->size(), raw.size())) {
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return *compressed_output;
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}
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break; // fall back to no compression.
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default: {} // Do not recognize this compression type
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}
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// Compression method is not supported, or not good compression ratio, so just
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// fall back to uncompressed form.
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*type = kNoCompression;
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return raw;
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}
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} // anonymous namespace
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// kBlockBasedTableMagicNumber was picked by running
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// echo rocksdb.table.block_based | sha1sum
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// and taking the leading 64 bits.
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// Please note that kBlockBasedTableMagicNumber may also be accessed by
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// other .cc files so it have to be explicitly declared with "extern".
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extern const uint64_t kBlockBasedTableMagicNumber = 0x88e241b785f4cff7ull;
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// We also support reading and writing legacy block based table format (for
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// backwards compatibility)
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extern const uint64_t kLegacyBlockBasedTableMagicNumber = 0xdb4775248b80fb57ull;
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// A collector that collects properties of interest to block-based table.
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// For now this class looks heavy-weight since we only write one additional
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// property.
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// But in the forseeable future, we will add more and more properties that are
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// specific to block-based table.
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class BlockBasedTableBuilder::BlockBasedTablePropertiesCollector
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: public TablePropertiesCollector {
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public:
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explicit BlockBasedTablePropertiesCollector(
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BlockBasedTableOptions::IndexType index_type)
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: index_type_(index_type) {}
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virtual Status Add(const Slice& key, const Slice& value) {
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// Intentionally left blank. Have no interest in collecting stats for
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// individual key/value pairs.
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return Status::OK();
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}
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virtual Status Finish(UserCollectedProperties* properties) {
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std::string val;
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PutFixed32(&val, static_cast<uint32_t>(index_type_));
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properties->insert({BlockBasedTablePropertyNames::kIndexType, val});
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return Status::OK();
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}
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// The name of the properties collector can be used for debugging purpose.
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virtual const char* Name() const {
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return "BlockBasedTablePropertiesCollector";
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}
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virtual UserCollectedProperties GetReadableProperties() const {
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// Intentionally left blank.
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return UserCollectedProperties();
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}
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private:
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BlockBasedTableOptions::IndexType index_type_;
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};
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struct BlockBasedTableBuilder::Rep {
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Options options;
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const InternalKeyComparator& internal_comparator;
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WritableFile* file;
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uint64_t offset = 0;
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Status status;
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BlockBuilder data_block;
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InternalKeySliceTransform internal_prefix_transform;
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std::unique_ptr<IndexBuilder> index_builder;
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std::string last_key;
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CompressionType compression_type;
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ChecksumType checksum_type;
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TableProperties props;
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bool closed = false; // Either Finish() or Abandon() has been called.
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FilterBlockBuilder* filter_block;
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char compressed_cache_key_prefix[BlockBasedTable::kMaxCacheKeyPrefixSize];
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size_t compressed_cache_key_prefix_size;
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BlockHandle pending_handle; // Handle to add to index block
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std::string compressed_output;
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std::unique_ptr<FlushBlockPolicy> flush_block_policy;
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std::vector<std::unique_ptr<TablePropertiesCollector>>
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table_properties_collectors;
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Rep(const Options& opt, const InternalKeyComparator& icomparator,
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WritableFile* f, FlushBlockPolicyFactory* flush_block_policy_factory,
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CompressionType compression_type, IndexType index_block_type,
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ChecksumType checksum_type)
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: options(opt),
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internal_comparator(icomparator),
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file(f),
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data_block(options, &internal_comparator),
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internal_prefix_transform(options.prefix_extractor.get()),
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index_builder(CreateIndexBuilder(index_block_type, &internal_comparator,
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&this->internal_prefix_transform)),
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compression_type(compression_type),
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checksum_type(checksum_type),
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filter_block(opt.filter_policy == nullptr
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? nullptr
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: new FilterBlockBuilder(opt, &internal_comparator)),
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flush_block_policy(flush_block_policy_factory->NewFlushBlockPolicy(
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options, data_block)) {
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for (auto& collector_factories :
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options.table_properties_collector_factories) {
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table_properties_collectors.emplace_back(
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collector_factories->CreateTablePropertiesCollector());
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}
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table_properties_collectors.emplace_back(
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new BlockBasedTablePropertiesCollector(index_block_type));
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}
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};
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BlockBasedTableBuilder::BlockBasedTableBuilder(
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const Options& options, const BlockBasedTableOptions& table_options,
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const InternalKeyComparator& internal_comparator, WritableFile* file,
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CompressionType compression_type)
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: rep_(new Rep(options, internal_comparator, file,
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table_options.flush_block_policy_factory.get(),
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compression_type, table_options.index_type,
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table_options.checksum)) {
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if (rep_->filter_block != nullptr) {
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rep_->filter_block->StartBlock(0);
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}
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if (options.block_cache_compressed.get() != nullptr) {
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BlockBasedTable::GenerateCachePrefix(
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options.block_cache_compressed.get(), file,
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&rep_->compressed_cache_key_prefix[0],
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&rep_->compressed_cache_key_prefix_size);
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}
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}
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BlockBasedTableBuilder::~BlockBasedTableBuilder() {
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assert(rep_->closed); // Catch errors where caller forgot to call Finish()
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delete rep_->filter_block;
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delete rep_;
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}
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void BlockBasedTableBuilder::Add(const Slice& key, const Slice& value) {
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Rep* r = rep_;
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assert(!r->closed);
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if (!ok()) return;
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if (r->props.num_entries > 0) {
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assert(r->internal_comparator.Compare(key, Slice(r->last_key)) > 0);
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}
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auto should_flush = r->flush_block_policy->Update(key, value);
|
|
if (should_flush) {
|
|
assert(!r->data_block.empty());
|
|
Flush();
|
|
|
|
// 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->index_builder->AddIndexEntry(&r->last_key, &key, r->pending_handle);
|
|
}
|
|
}
|
|
|
|
if (r->filter_block != nullptr) {
|
|
r->filter_block->AddKey(key);
|
|
}
|
|
|
|
r->last_key.assign(key.data(), key.size());
|
|
r->data_block.Add(key, value);
|
|
r->props.num_entries++;
|
|
r->props.raw_key_size += key.size();
|
|
r->props.raw_value_size += value.size();
|
|
|
|
r->index_builder->OnKeyAdded(key);
|
|
NotifyCollectTableCollectorsOnAdd(key, value, r->table_properties_collectors,
|
|
r->options.info_log.get());
|
|
}
|
|
|
|
void BlockBasedTableBuilder::Flush() {
|
|
Rep* r = rep_;
|
|
assert(!r->closed);
|
|
if (!ok()) return;
|
|
if (r->data_block.empty()) return;
|
|
WriteBlock(&r->data_block, &r->pending_handle);
|
|
if (ok()) {
|
|
r->status = r->file->Flush();
|
|
}
|
|
if (r->filter_block != nullptr) {
|
|
r->filter_block->StartBlock(r->offset);
|
|
}
|
|
r->props.data_size = r->offset;
|
|
++r->props.num_data_blocks;
|
|
}
|
|
|
|
void BlockBasedTableBuilder::WriteBlock(BlockBuilder* block,
|
|
BlockHandle* handle) {
|
|
WriteBlock(block->Finish(), handle);
|
|
block->Reset();
|
|
}
|
|
|
|
void BlockBasedTableBuilder::WriteBlock(const Slice& raw_block_contents,
|
|
BlockHandle* handle) {
|
|
// 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;
|
|
Slice block_contents;
|
|
if (raw_block_contents.size() < kCompressionSizeLimit) {
|
|
block_contents =
|
|
CompressBlock(raw_block_contents, r->options.compression_opts, &type,
|
|
&r->compressed_output);
|
|
} else {
|
|
RecordTick(r->options.statistics.get(), NUMBER_BLOCK_NOT_COMPRESSED);
|
|
type = kNoCompression;
|
|
block_contents = raw_block_contents;
|
|
}
|
|
WriteRawBlock(block_contents, type, handle);
|
|
r->compressed_output.clear();
|
|
}
|
|
|
|
void BlockBasedTableBuilder::WriteRawBlock(const Slice& block_contents,
|
|
CompressionType type,
|
|
BlockHandle* handle) {
|
|
Rep* r = rep_;
|
|
StopWatch sw(r->options.env, r->options.statistics.get(),
|
|
WRITE_RAW_BLOCK_MICROS);
|
|
handle->set_offset(r->offset);
|
|
handle->set_size(block_contents.size());
|
|
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->checksum_type) {
|
|
case kNoChecksum:
|
|
// we don't support no checksum yet
|
|
assert(false);
|
|
// intentional fallthrough in release binary
|
|
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: {
|
|
void* xxh = XXH32_init(0);
|
|
XXH32_update(xxh, block_contents.data(), block_contents.size());
|
|
XXH32_update(xxh, trailer, 1); // Extend to cover block type
|
|
EncodeFixed32(trailer_without_type, XXH32_digest(xxh));
|
|
break;
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
Status BlockBasedTableBuilder::status() const {
|
|
return rep_->status;
|
|
}
|
|
|
|
static void DeleteCachedBlock(const Slice& key, void* value) {
|
|
Block* block = reinterpret_cast<Block*>(value);
|
|
delete block;
|
|
}
|
|
|
|
//
|
|
// 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->options.block_cache_compressed.get();
|
|
|
|
if (type != kNoCompression && block_cache_compressed != nullptr) {
|
|
|
|
Cache::Handle* cache_handle = nullptr;
|
|
size_t size = block_contents.size();
|
|
|
|
char* ubuf = new char[size]; // make a new copy
|
|
memcpy(ubuf, block_contents.data(), size);
|
|
|
|
BlockContents results;
|
|
Slice sl(ubuf, size);
|
|
results.data = sl;
|
|
results.cachable = true; // XXX
|
|
results.heap_allocated = true;
|
|
results.compression_type = type;
|
|
|
|
Block* block = new Block(results);
|
|
|
|
// 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.
|
|
cache_handle = block_cache_compressed->Insert(key, block, block->size(),
|
|
&DeleteCachedBlock);
|
|
block_cache_compressed->Release(cache_handle);
|
|
|
|
// Invalidate OS cache.
|
|
r->file->InvalidateCache(r->offset, size);
|
|
}
|
|
return Status::OK();
|
|
}
|
|
|
|
Status BlockBasedTableBuilder::Finish() {
|
|
Rep* r = rep_;
|
|
bool empty_data_block = r->data_block.empty();
|
|
Flush();
|
|
assert(!r->closed);
|
|
r->closed = true;
|
|
|
|
BlockHandle filter_block_handle,
|
|
metaindex_block_handle,
|
|
index_block_handle;
|
|
|
|
// Write filter block
|
|
if (ok() && r->filter_block != nullptr) {
|
|
auto filter_contents = r->filter_block->Finish();
|
|
r->props.filter_size = filter_contents.size();
|
|
WriteRawBlock(filter_contents, kNoCompression, &filter_block_handle);
|
|
}
|
|
|
|
// To make sure properties block is able to keep the accurate size of index
|
|
// block, we will finish writing all index entries here and flush them
|
|
// to storage after metaindex block is written.
|
|
if (ok() && !empty_data_block) {
|
|
r->index_builder->AddIndexEntry(
|
|
&r->last_key, nullptr /* no next data block */, r->pending_handle);
|
|
}
|
|
|
|
IndexBuilder::IndexBlocks index_blocks;
|
|
auto s = r->index_builder->Finish(&index_blocks);
|
|
if (!s.ok()) {
|
|
return s;
|
|
}
|
|
|
|
// Write meta blocks and metaindex block with the following order.
|
|
// 1. [meta block: filter]
|
|
// 2. [other meta blocks]
|
|
// 3. [meta block: properties]
|
|
// 4. [metaindex block]
|
|
// write meta blocks
|
|
MetaIndexBuilder meta_index_builder;
|
|
for (const auto& item : index_blocks.meta_blocks) {
|
|
BlockHandle block_handle;
|
|
WriteBlock(item.second, &block_handle);
|
|
meta_index_builder.Add(item.first, block_handle);
|
|
}
|
|
|
|
if (ok()) {
|
|
if (r->filter_block != nullptr) {
|
|
// Add mapping from "<filter_block_prefix>.Name" to location
|
|
// of filter data.
|
|
std::string key = BlockBasedTable::kFilterBlockPrefix;
|
|
key.append(r->options.filter_policy->Name());
|
|
meta_index_builder.Add(key, filter_block_handle);
|
|
}
|
|
|
|
// Write properties block.
|
|
{
|
|
PropertyBlockBuilder property_block_builder;
|
|
std::vector<std::string> failed_user_prop_collectors;
|
|
r->props.filter_policy_name = r->options.filter_policy != nullptr ?
|
|
r->options.filter_policy->Name() : "";
|
|
r->props.index_size =
|
|
r->index_builder->EstimatedSize() + kBlockTrailerSize;
|
|
|
|
// Add basic properties
|
|
property_block_builder.AddTableProperty(r->props);
|
|
|
|
// Add use collected properties
|
|
NotifyCollectTableCollectorsOnFinish(r->table_properties_collectors,
|
|
r->options.info_log.get(),
|
|
&property_block_builder);
|
|
|
|
BlockHandle properties_block_handle;
|
|
WriteRawBlock(
|
|
property_block_builder.Finish(),
|
|
kNoCompression,
|
|
&properties_block_handle
|
|
);
|
|
|
|
meta_index_builder.Add(kPropertiesBlock, properties_block_handle);
|
|
} // end of properties block writing
|
|
} // meta blocks
|
|
|
|
// Write index block
|
|
if (ok()) {
|
|
// flush the meta index block
|
|
WriteRawBlock(meta_index_builder.Finish(), kNoCompression,
|
|
&metaindex_block_handle);
|
|
WriteBlock(index_blocks.index_block_contents, &index_block_handle);
|
|
}
|
|
|
|
// Write footer
|
|
if (ok()) {
|
|
// 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->checksum_type == kCRC32c);
|
|
Footer footer(legacy ? kLegacyBlockBasedTableMagicNumber
|
|
: kBlockBasedTableMagicNumber);
|
|
footer.set_metaindex_handle(metaindex_block_handle);
|
|
footer.set_index_handle(index_block_handle);
|
|
footer.set_checksum(r->checksum_type);
|
|
std::string footer_encoding;
|
|
footer.EncodeTo(&footer_encoding);
|
|
r->status = r->file->Append(footer_encoding);
|
|
if (r->status.ok()) {
|
|
r->offset += footer_encoding.size();
|
|
}
|
|
}
|
|
|
|
// Print out the table stats
|
|
if (ok()) {
|
|
// user collected properties
|
|
std::string user_collected;
|
|
user_collected.reserve(1024);
|
|
for (const auto& collector : r->table_properties_collectors) {
|
|
for (const auto& prop : collector->GetReadableProperties()) {
|
|
user_collected.append(prop.first);
|
|
user_collected.append("=");
|
|
user_collected.append(prop.second);
|
|
user_collected.append("; ");
|
|
}
|
|
}
|
|
|
|
Log(
|
|
r->options.info_log,
|
|
"Table was constructed:\n"
|
|
" [basic properties]: %s\n"
|
|
" [user collected properties]: %s",
|
|
r->props.ToString().c_str(),
|
|
user_collected.c_str()
|
|
);
|
|
}
|
|
|
|
return r->status;
|
|
}
|
|
|
|
void BlockBasedTableBuilder::Abandon() {
|
|
Rep* r = rep_;
|
|
assert(!r->closed);
|
|
r->closed = true;
|
|
}
|
|
|
|
uint64_t BlockBasedTableBuilder::NumEntries() const {
|
|
return rep_->props.num_entries;
|
|
}
|
|
|
|
uint64_t BlockBasedTableBuilder::FileSize() const {
|
|
return rep_->offset;
|
|
}
|
|
|
|
const std::string BlockBasedTable::kFilterBlockPrefix = "filter.";
|
|
|
|
} // namespace rocksdb
|