rocksdb/table/block_based/partitioned_index_reader.h
sdong 722814e357 Get() to fail with underlying failures in PartitionIndexReader::CacheDependencies() (#7297)
Summary:
Right now all I/O failures under PartitionIndexReader::CacheDependencies() is swallowed. This doesn't impact correctness but we've made a decision that any I/O error in read path now should be returned to users for awareness. Return errors in those cases instead.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7297

Test Plan: Add a new unit test that ingest errors in this code path and see Get() fails. Only one I/O path is hit in PartitionIndexReader::CacheDependencies(). Several option changes are attempt but not able to got other pread paths triggered. Not sure whether other failure cases would be even possible. Would rely on continuous stress test to validate it.

Reviewed By: anand1976

Differential Revision: D23257950

fbshipit-source-id: 859dbc92fa239996e1bb378329344d3d54168c03
2020-08-25 19:01:05 -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, const ReadOptions& ro,
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;
Status CacheDependencies(const ReadOptions& ro, 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