mirror of https://github.com/facebook/rocksdb.git
86 lines
3.1 KiB
C++
86 lines
3.1 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, Env::IOPriority rate_limiter_priority,
|
|
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
|