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_TWO_LEVEL_ITERATOR_H_ 6 #define STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_ 7 8 #include "leveldb/iterator.h" 9 10 namespace leveldb { 11 12 struct ReadOptions; 13 14 // Return a new two level iterator. A two-level iterator contains an 15 // index iterator whose values point to a sequence of blocks where 16 // each block is itself a sequence of key,value pairs. The returned 17 // two-level iterator yields the concatenation of all key/value pairs 18 // in the sequence of blocks. Takes ownership of "index_iter" and 19 // will delete it when no longer needed. 20 // 21 // Uses a supplied function to convert an index_iter value into 22 // an iterator over the contents of the corresponding block. 23 Iterator* NewTwoLevelIterator( 24 Iterator* index_iter, 25 Iterator* (*block_function)(void* arg, const ReadOptions& options, 26 const Slice& index_value), 27 void* arg, const ReadOptions& options); 28 29 } // namespace leveldb 30 31 #endif // STORAGE_LEVELDB_TABLE_TWO_LEVEL_ITERATOR_H_ 32