rocksdb/table/block_based/index_reader_common.cc

63 lines
2.3 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.
#include "table/block_based/index_reader_common.h"
#include "block_cache.h"
namespace ROCKSDB_NAMESPACE {
Status BlockBasedTable::IndexReaderCommon::ReadIndexBlock(
const BlockBasedTable* table, FilePrefetchBuffer* prefetch_buffer,
const ReadOptions& read_options, bool use_cache, GetContext* get_context,
BlockCacheLookupContext* lookup_context,
CachableEntry<Block>* index_block) {
PERF_TIMER_GUARD(read_index_block_nanos);
assert(table != nullptr);
assert(index_block != nullptr);
assert(index_block->IsEmpty());
const Rep* const rep = table->get_rep();
assert(rep != nullptr);
const Status s = table->RetrieveBlock(
prefetch_buffer, read_options, rep->index_handle,
UncompressionDict::GetEmptyDict(), &index_block->As<Block_kIndex>(),
get_context, lookup_context, /* for_compaction */ false, use_cache,
/* async_read */ false, /* use_block_cache_for_lookup */ true);
return s;
}
Status BlockBasedTable::IndexReaderCommon::GetOrReadIndexBlock(
GetContext* get_context, BlockCacheLookupContext* lookup_context,
CachableEntry<Block>* index_block, const ReadOptions& ro) const {
assert(index_block != nullptr);
if (!index_block_.IsEmpty()) {
index_block->SetUnownedValue(index_block_.GetValue());
return Status::OK();
}
return ReadIndexBlock(table_, /*prefetch_buffer=*/nullptr, ro,
cache_index_blocks(), get_context, lookup_context,
index_block);
}
void BlockBasedTable::IndexReaderCommon::EraseFromCacheBeforeDestruction(
uint32_t uncache_aggressiveness) {
if (uncache_aggressiveness > 0) {
if (index_block_.IsCached()) {
index_block_.ResetEraseIfLastRef();
} else {
table()->EraseFromCache(table()->get_rep()->index_handle);
}
}
}
} // namespace ROCKSDB_NAMESPACE