/sparrowhawk/foundation/ESFRand.h

 1/** @file ESFRand.h
 2 *  @brief A pseudo-random number generator
 3 *
 4 * Copyright (c) 2009 Yahoo! Inc.
 5 * The copyrights embodied in the content of this file are licensed by Yahoo! Inc.
 6 * under the BSD (revised) open source license.
 7 *
 8 * Derived from code that is Copyright (c) 2009 Joshua Blatt and offered under both
 9 * BSD and Apache 2.0 licenses (http://sourceforge.net/projects/sparrowhawk/).
10 *
11 *    $Author: blattj $
12 *  $Date: 2009/05/25 21:51:08 $
13 *    $Name:  $
14 *    $Revision: 1.3 $
15 */
16
17#ifndef ESF_RAND_H
18#define ESF_RAND_H
19
20#ifndef ESF_CONFIG_H
21#include <ESFConfig.h>
22#endif
23
24#ifndef ESF_ALLOCATOR_H
25#include <ESFAllocator.h>
26#endif
27
28/** ESFRand generates pseudorandom numbers using the C Standard Library or
29 *  POSIX.1 random number generator.
30 *
31 *  @ingroup util
32 */
33class ESFRand {
34public:
35
36    /** Default constructor.  The seed is initialized to the current system
37     *  time.
38     */
39    ESFRand();
40
41    /** Constructor.
42     *
43     * @param seed The seed for the random number generator
44     */
45    ESFRand(unsigned int seed);
46
47    /** Default destructor. */
48    virtual ~ESFRand();
49
50    /** Generate a random number between 0.0 inclusive and 1.0 exclusive.
51     *
52     *    @return A random number.
53     */
54    double generateRandom();
55
56    /** Generate a random integer within a given range.
57     *
58     *    @param lowerBound The lowerbound of the range.  Inclusive.
59     *    @param upperBound The upperbound of the range.  Inclusive.
60     *    @return A random number within the given range.
61     */
62    int generateRandom(int lowerBound, int upperBound);
63
64    /** Placement new.
65     *
66     *  @param size The size of the object.
67     *  @param allocator The source of the object's memory.
68     *  @return The new object or NULL of the memory allocation failed.
69     */
70    inline void *operator new(size_t size, ESFAllocator *allocator) {
71        return allocator->allocate(size);
72    }
73
74private:
75
76#ifdef HAVE_RAND_R
77    unsigned int _seed;
78#endif
79
80};
81
82#endif /* ! ESF_RAND_H */