rocksdb/table/block_based/partitioned_index_reader.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

52 lines
2.2 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/index_reader_common.h"
namespace ROCKSDB_NAMESPACE {
// Index that allows binary search lookup in a two-level index structure.
class PartitionIndexReader : public BlockBasedTable::IndexReaderCommon {
public:
// Read the partition index from the file and create an instance for
// `PartitionIndexReader`.
// On success, index_reader will be populated; otherwise it will remain
// unmodified.
static Status Create(const BlockBasedTable* table,
FilePrefetchBuffer* prefetch_buffer, bool use_cache,
bool prefetch, bool pin,
BlockCacheLookupContext* lookup_context,
std::unique_ptr<IndexReader>* index_reader);
// return a two-level iterator: first level is on the partition index
InternalIteratorBase<IndexValue>* NewIterator(
const ReadOptions& read_options, bool /* disable_prefix_seek */,
IndexBlockIter* iter, GetContext* get_context,
BlockCacheLookupContext* lookup_context) override;
void CacheDependencies(bool pin) override;
size_t ApproximateMemoryUsage() const override {
size_t usage = ApproximateIndexBlockMemoryUsage();
#ifdef ROCKSDB_MALLOC_USABLE_SIZE
usage += malloc_usable_size(const_cast<PartitionIndexReader*>(this));
#else
usage += sizeof(*this);
#endif // ROCKSDB_MALLOC_USABLE_SIZE
// TODO(myabandeh): more accurate estimate of partition_map_ mem usage
return usage;
}
private:
PartitionIndexReader(const BlockBasedTable* t,
CachableEntry<Block>&& index_block)
: IndexReaderCommon(t, std::move(index_block)) {}
std::unordered_map<uint64_t, CachableEntry<Block>> partition_map_;
};
} // namespace ROCKSDB_NAMESPACE