base/rand_util.h

   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 #pragma once
   8
   9 #include <string>
  10
  11 #include "base/base_export.h"
  12 #include "base/basictypes.h"
  13
  14 namespace base {
  15
  16 // Returns a random number in range [0, kuint64max]. Thread-safe.
  17 BASE_EXPORT uint64 RandUint64();
  18
  19 // Returns a random number between min and max (inclusive). Thread-safe.
  20 BASE_EXPORT int RandInt(int min, int max);
  21
  22 // Returns a random number in range [0, range).  Thread-safe.
  23 //
  24 // Note that this can be used as an adapter for std::random_shuffle():
  25 // Given a pre-populated |std::vector<int> myvector|, shuffle it as
  26 //   std::random_shuffle(myvector.begin(), myvector.end(), base::RandGenerator);
  27 BASE_EXPORT uint64 RandGenerator(uint64 range);
  28
  29 // Returns a random double in range [0, 1). Thread-safe.
  30 BASE_EXPORT double RandDouble();
  31
  32 // Given input |bits|, convert with maximum precision to a double in
  33 // the range [0, 1). Thread-safe.
  34 BASE_EXPORT double BitsToOpenEndedUnitInterval(uint64 bits);
  35
  36 // Fills |output_length| bytes of |output| with cryptographically strong random
  37 // data.
  38 BASE_EXPORT void RandBytes(void* output, size_t output_length);
  39
  40 // Fills a string of length |length| with with cryptographically strong random
  41 // data and returns it.  |length| should be nonzero.
  42 //
  43 // Note that this is a variation of |RandBytes| with a different return type.
  44 BASE_EXPORT std::string RandBytesAsString(size_t length);
  45
  46 #ifdef OS_POSIX
  47 BASE_EXPORT int GetUrandomFD();
  48 #endif
  49
  50 }  // namespace base
  51
  52 #endif  // BASE_RAND_UTIL_H_