1// Copyright (c) 2012 The Chromium 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.
4
5#ifndef BASE_RAND_UTIL_H_
6#define BASE_RAND_UTIL_H_
7
8#include <string>
9
10#include "base/base_export.h"
11#include "base/basictypes.h"
12
13namespace base {
14
15// Returns a random number in range [0, kuint64max]. Thread-safe.
16BASE_EXPORT uint64 RandUint64();
17
18// Returns a random number between min and max (inclusive). Thread-safe.
19BASE_EXPORT int RandInt(int min, int max);
20
21// Returns a random number in range [0, range).  Thread-safe.
22//
23// Note that this can be used as an adapter for std::random_shuffle():
24// Given a pre-populated |std::vector<int> myvector|, shuffle it as
25//   std::random_shuffle(myvector.begin(), myvector.end(), base::RandGenerator);
26BASE_EXPORT uint64 RandGenerator(uint64 range);
27
28// Returns a random double in range [0, 1). Thread-safe.
29BASE_EXPORT double RandDouble();
30
31// Given input |bits|, convert with maximum precision to a double in
32// the range [0, 1). Thread-safe.
33BASE_EXPORT double BitsToOpenEndedUnitInterval(uint64 bits);
34
35// Fills |output_length| bytes of |output| with random data.
36//
37// WARNING:
38// Do not use for security-sensitive purposes.
39// See crypto/ for cryptographically secure random number generation APIs.
40BASE_EXPORT void RandBytes(void* output, size_t output_length);
41
42// Fills a string of length |length| with random data and returns it.
43// |length| should be nonzero.
44//
45// Note that this is a variation of |RandBytes| with a different return type.
46// The returned string is likely not ASCII/UTF-8. Use with care.
47//
48// WARNING:
49// Do not use for security-sensitive purposes.
50// See crypto/ for cryptographically secure random number generation APIs.
51BASE_EXPORT std::string RandBytesAsString(size_t length);
52
53#if defined(OS_POSIX)
54BASE_EXPORT int GetUrandomFD();
55#endif
56
57}  // namespace base
58
59#endif  // BASE_RAND_UTIL_H_
60