1 // Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
2 // This source code is licensed under both the GPLv2 (found in the
3 // COPYING file in the root directory) and Apache 2.0 License
4 // (found in the LICENSE.Apache file in the root directory).
5 //
6 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
7 // Use of this source code is governed by a BSD-style license that can be
8 // found in the LICENSE file. See the AUTHORS file for names of contributors.
9 #include "table/block_based/index_reader_common.h"
10
11 namespace ROCKSDB_NAMESPACE {
ReadIndexBlock(const BlockBasedTable * table,FilePrefetchBuffer * prefetch_buffer,const ReadOptions & read_options,bool use_cache,GetContext * get_context,BlockCacheLookupContext * lookup_context,CachableEntry<Block> * index_block)12 Status BlockBasedTable::IndexReaderCommon::ReadIndexBlock(
13 const BlockBasedTable* table, FilePrefetchBuffer* prefetch_buffer,
14 const ReadOptions& read_options, bool use_cache, GetContext* get_context,
15 BlockCacheLookupContext* lookup_context,
16 CachableEntry<Block>* index_block) {
17 PERF_TIMER_GUARD(read_index_block_nanos);
18
19 assert(table != nullptr);
20 assert(index_block != nullptr);
21 assert(index_block->IsEmpty());
22
23 const Rep* const rep = table->get_rep();
24 assert(rep != nullptr);
25
26 const Status s = table->RetrieveBlock(
27 prefetch_buffer, read_options, rep->footer.index_handle(),
28 UncompressionDict::GetEmptyDict(), index_block, BlockType::kIndex,
29 get_context, lookup_context, /* for_compaction */ false, use_cache);
30
31 return s;
32 }
33
GetOrReadIndexBlock(bool no_io,GetContext * get_context,BlockCacheLookupContext * lookup_context,CachableEntry<Block> * index_block) const34 Status BlockBasedTable::IndexReaderCommon::GetOrReadIndexBlock(
35 bool no_io, GetContext* get_context,
36 BlockCacheLookupContext* lookup_context,
37 CachableEntry<Block>* index_block) const {
38 assert(index_block != nullptr);
39
40 if (!index_block_.IsEmpty()) {
41 index_block->SetUnownedValue(index_block_.GetValue());
42 return Status::OK();
43 }
44
45 ReadOptions read_options;
46 if (no_io) {
47 read_options.read_tier = kBlockCacheTier;
48 }
49
50 return ReadIndexBlock(table_, /*prefetch_buffer=*/nullptr, read_options,
51 cache_index_blocks(), get_context, lookup_context,
52 index_block);
53 }
54 } // namespace ROCKSDB_NAMESPACE
55