1  // Copyright (c) 2013 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  // Test for issue 200: when iterator switches direction from backward
 6  // to forward, the current key can be yielded unexpectedly if a new
 7  // mutation has been added just before the current key.
 8  
 9  #include "leveldb/db.h"
10  #include "util/testharness.h"
11  
12  namespace leveldb {
13  
14  class Issue200 {};
15  
16  TEST(Issue200, Test) {
17    // Get rid of any state from an old run.
18    std::string dbpath = test::TmpDir() + "/leveldb_issue200_test";
19    DestroyDB(dbpath, Options());
20  
21    DB* db;
22    Options options;
23    options.create_if_missing = true;
24    ASSERT_OK(DB::Open(options, dbpath, &db));
25  
26    WriteOptions write_options;
27    ASSERT_OK(db->Put(write_options, "1", "b"));
28    ASSERT_OK(db->Put(write_options, "2", "c"));
29    ASSERT_OK(db->Put(write_options, "3", "d"));
30    ASSERT_OK(db->Put(write_options, "4", "e"));
31    ASSERT_OK(db->Put(write_options, "5", "f"));
32  
33    ReadOptions read_options;
34    Iterator* iter = db->NewIterator(read_options);
35  
36    // Add an element that should not be reflected in the iterator.
37    ASSERT_OK(db->Put(write_options, "25", "cd"));
38  
39    iter->Seek("5");
40    ASSERT_EQ(iter->key().ToString(), "5");
41    iter->Prev();
42    ASSERT_EQ(iter->key().ToString(), "4");
43    iter->Prev();
44    ASSERT_EQ(iter->key().ToString(), "3");
45    iter->Next();
46    ASSERT_EQ(iter->key().ToString(), "4");
47    iter->Next();
48    ASSERT_EQ(iter->key().ToString(), "5");
49  
50    delete iter;
51    delete db;
52    DestroyDB(dbpath, options);
53  }
54  
55  }  // namespace leveldb
56  
57  int main(int argc, char** argv) { return leveldb::test::RunAllTests(); }