xref: /aosp_15_r20/external/leveldb/table/merger.h (revision 9507f98c5f32dee4b5f9e4a38cd499f3ff5c4490)
1*9507f98cSAndroid Build Coastguard Worker // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
2*9507f98cSAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be
3*9507f98cSAndroid Build Coastguard Worker // found in the LICENSE file. See the AUTHORS file for names of contributors.
4*9507f98cSAndroid Build Coastguard Worker 
5*9507f98cSAndroid Build Coastguard Worker #ifndef STORAGE_LEVELDB_TABLE_MERGER_H_
6*9507f98cSAndroid Build Coastguard Worker #define STORAGE_LEVELDB_TABLE_MERGER_H_
7*9507f98cSAndroid Build Coastguard Worker 
8*9507f98cSAndroid Build Coastguard Worker namespace leveldb {
9*9507f98cSAndroid Build Coastguard Worker 
10*9507f98cSAndroid Build Coastguard Worker class Comparator;
11*9507f98cSAndroid Build Coastguard Worker class Iterator;
12*9507f98cSAndroid Build Coastguard Worker 
13*9507f98cSAndroid Build Coastguard Worker // Return an iterator that provided the union of the data in
14*9507f98cSAndroid Build Coastguard Worker // children[0,n-1].  Takes ownership of the child iterators and
15*9507f98cSAndroid Build Coastguard Worker // will delete them when the result iterator is deleted.
16*9507f98cSAndroid Build Coastguard Worker //
17*9507f98cSAndroid Build Coastguard Worker // The result does no duplicate suppression.  I.e., if a particular
18*9507f98cSAndroid Build Coastguard Worker // key is present in K child iterators, it will be yielded K times.
19*9507f98cSAndroid Build Coastguard Worker //
20*9507f98cSAndroid Build Coastguard Worker // REQUIRES: n >= 0
21*9507f98cSAndroid Build Coastguard Worker Iterator* NewMergingIterator(const Comparator* comparator, Iterator** children,
22*9507f98cSAndroid Build Coastguard Worker                              int n);
23*9507f98cSAndroid Build Coastguard Worker 
24*9507f98cSAndroid Build Coastguard Worker }  // namespace leveldb
25*9507f98cSAndroid Build Coastguard Worker 
26*9507f98cSAndroid Build Coastguard Worker #endif  // STORAGE_LEVELDB_TABLE_MERGER_H_
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