rocksdb/table/block_based/index_reader_common.h
sdong 674cf41732 Divide block_based_table_reader.cc (#6527)
Summary:
block_based_table_reader.cc is a giant file, which makes it hard for users to navigate the code. Divide the files to multiple files.
Some class templates cannot be moved to .cc file. They are moved to .h files. It is still better than including them all in block_based_table_reader.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6527

Test Plan: "make all check" and "make release". Also build using cmake.

Differential Revision: D20428455

fbshipit-source-id: ca713c698469f07f35bc0c271358c0874ed4eb28
2020-03-12 21:41:50 -07:00

86 lines
3 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once
#include "table/block_based/block_based_table_reader.h"
#include "table/block_based/reader_common.h"
namespace ROCKSDB_NAMESPACE {
// Encapsulates common functionality for the various index reader
// implementations. Provides access to the index block regardless of whether
// it is owned by the reader or stored in the cache, or whether it is pinned
// in the cache or not.
class BlockBasedTable::IndexReaderCommon : public BlockBasedTable::IndexReader {
public:
IndexReaderCommon(const BlockBasedTable* t,
CachableEntry<Block>&& index_block)
: table_(t), index_block_(std::move(index_block)) {
assert(table_ != nullptr);
}
protected:
static Status ReadIndexBlock(const BlockBasedTable* table,
FilePrefetchBuffer* prefetch_buffer,
const ReadOptions& read_options, bool use_cache,
GetContext* get_context,
BlockCacheLookupContext* lookup_context,
CachableEntry<Block>* index_block);
const BlockBasedTable* table() const { return table_; }
const InternalKeyComparator* internal_comparator() const {
assert(table_ != nullptr);
assert(table_->get_rep() != nullptr);
return &table_->get_rep()->internal_comparator;
}
bool index_has_first_key() const {
assert(table_ != nullptr);
assert(table_->get_rep() != nullptr);
return table_->get_rep()->index_has_first_key;
}
bool index_key_includes_seq() const {
assert(table_ != nullptr);
assert(table_->get_rep() != nullptr);
return table_->get_rep()->index_key_includes_seq;
}
bool index_value_is_full() const {
assert(table_ != nullptr);
assert(table_->get_rep() != nullptr);
return table_->get_rep()->index_value_is_full;
}
bool cache_index_blocks() const {
assert(table_ != nullptr);
assert(table_->get_rep() != nullptr);
return table_->get_rep()->table_options.cache_index_and_filter_blocks;
}
Status GetOrReadIndexBlock(bool no_io, GetContext* get_context,
BlockCacheLookupContext* lookup_context,
CachableEntry<Block>* index_block) const;
size_t ApproximateIndexBlockMemoryUsage() const {
assert(!index_block_.GetOwnValue() || index_block_.GetValue() != nullptr);
return index_block_.GetOwnValue()
? index_block_.GetValue()->ApproximateMemoryUsage()
: 0;
}
private:
const BlockBasedTable* table_;
CachableEntry<Block> index_block_;
};
} // namespace ROCKSDB_NAMESPACE