src/leveldb/table/merger.h

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