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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/rocksdb/table/merging_iterator.h | |
parent | Initial commit. (diff) | |
download | ceph-upstream/18.2.2.tar.xz ceph-upstream/18.2.2.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/rocksdb/table/merging_iterator.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/src/rocksdb/table/merging_iterator.h b/src/rocksdb/table/merging_iterator.h new file mode 100644 index 000000000..16fc0877e --- /dev/null +++ b/src/rocksdb/table/merging_iterator.h @@ -0,0 +1,92 @@ +// 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 "db/range_del_aggregator.h" +#include "rocksdb/slice.h" +#include "rocksdb/types.h" + +namespace ROCKSDB_NAMESPACE { + +class Arena; +class ArenaWrappedDBIter; +class InternalKeyComparator; + +template <class TValue> +class InternalIteratorBase; +using InternalIterator = InternalIteratorBase<Slice>; + +// Return an iterator that provided the union of the data in +// children[0,n-1]. Takes ownership of the child iterators and +// will delete them when the result iterator is deleted. +// +// The result does no duplicate suppression. I.e., if a particular +// key is present in K child iterators, it will be yielded K times. +// +// REQUIRES: n >= 0 +extern InternalIterator* NewMergingIterator( + const InternalKeyComparator* comparator, InternalIterator** children, int n, + Arena* arena = nullptr, bool prefix_seek_mode = false); + +class MergingIterator; + +// A builder class to build a merging iterator by adding iterators one by one. +// User should call only one of AddIterator() or AddPointAndTombstoneIterator() +// exclusively for the same builder. +class MergeIteratorBuilder { + public: + // comparator: the comparator used in merging comparator + // arena: where the merging iterator needs to be allocated from. + explicit MergeIteratorBuilder(const InternalKeyComparator* comparator, + Arena* arena, bool prefix_seek_mode = false, + const Slice* iterate_upper_bound = nullptr); + ~MergeIteratorBuilder(); + + // Add iter to the merging iterator. + void AddIterator(InternalIterator* iter); + + // Add a point key iterator and a range tombstone iterator. + // `tombstone_iter_ptr` should and only be set by LevelIterator. + // *tombstone_iter_ptr will be set to where the merging iterator stores + // `tombstone_iter` when MergeIteratorBuilder::Finish() is called. This is + // used by LevelIterator to update range tombstone iters when switching to a + // different SST file. If a single point iterator with a nullptr range + // tombstone iterator is provided, and the point iterator is not a level + // iterator, then this builder will return the point iterator directly, + // instead of creating a merging iterator on top of it. Internally, if all + // point iterators are not LevelIterator, then range tombstone iterator is + // only added to the merging iter if there is a non-null `tombstone_iter`. + void AddPointAndTombstoneIterator( + InternalIterator* point_iter, TruncatedRangeDelIterator* tombstone_iter, + TruncatedRangeDelIterator*** tombstone_iter_ptr = nullptr); + + // Get arena used to build the merging iterator. It is called one a child + // iterator needs to be allocated. + Arena* GetArena() { return arena; } + + // Return the result merging iterator. + // If db_iter is not nullptr, then db_iter->SetMemtableRangetombstoneIter() + // will be called with pointer to where the merging iterator + // stores the memtable range tombstone iterator. + // This is used for DB iterator to refresh memtable range tombstones. + InternalIterator* Finish(ArenaWrappedDBIter* db_iter = nullptr); + + private: + MergingIterator* merge_iter; + InternalIterator* first_iter; + bool use_merging_iter; + Arena* arena; + // Used to set LevelIterator.range_tombstone_iter_. + // See AddRangeTombstoneIterator() implementation for more detail. + std::vector<std::pair<size_t, TruncatedRangeDelIterator***>> + range_del_iter_ptrs_; +}; + +} // namespace ROCKSDB_NAMESPACE |