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#include "util/testutil.h"
6
7#include "util/random.h"
8
9namespace leveldb {
10namespace test {
11
12Slice RandomString(Random* rnd, int len, std::string* dst) {
13  dst->resize(len);
14  for (int i = 0; i < len; i++) {
15    (*dst)[i] = static_cast<char>(' ' + rnd->Uniform(95));   // ' ' .. '~'
16  }
17  return Slice(*dst);
18}
19
20std::string RandomKey(Random* rnd, int len) {
21  // Make sure to generate a wide variety of characters so we
22  // test the boundary conditions for short-key optimizations.
23  static const char kTestChars[] = {
24    '\0', '\1', 'a', 'b', 'c', 'd', 'e', '\xfd', '\xfe', '\xff'
25  };
26  std::string result;
27  for (int i = 0; i < len; i++) {
28    result += kTestChars[rnd->Uniform(sizeof(kTestChars))];
29  }
30  return result;
31}
32
33
34extern Slice CompressibleString(Random* rnd, double compressed_fraction,
35                                size_t len, std::string* dst) {
36  int raw = static_cast<int>(len * compressed_fraction);
37  if (raw < 1) raw = 1;
38  std::string raw_data;
39  RandomString(rnd, raw, &raw_data);
40
41  // Duplicate the random data until we have filled "len" bytes
42  dst->clear();
43  while (dst->size() < len) {
44    dst->append(raw_data);
45  }
46  dst->resize(len);
47  return Slice(*dst);
48}
49
50}  // namespace test
51}  // namespace leveldb
52