Inside Bitcoin

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[] = {'\0', '\1', 'a',    'b',    'c',
24                                    'd',  'e',  '\xfd', '\xfe', '\xff'};
25  std::string result;
26  for (int i = 0; i < len; i++) {
27    result += kTestChars[rnd->Uniform(sizeof(kTestChars))];
28  }
29  return result;
30}
31
32Slice CompressibleString(Random* rnd, double compressed_fraction, size_t len,
33                         std::string* dst) {
34  int raw = static_cast<int>(len * compressed_fraction);
35  if (raw < 1) raw = 1;
36  std::string raw_data;
37  RandomString(rnd, raw, &raw_data);
38
39  // Duplicate the random data until we have filled "len" bytes
40  dst->clear();
41  while (dst->size() < len) {
42    dst->append(raw_data);
43  }
44  dst->resize(len);
45  return Slice(*dst);
46}
47
48}  // namespace test
49}  // namespace leveldb
50