1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2016 Edouard Griffiths, F4EXB. //
// //
// This is an adaptation of: https://github.com/lemire/runningmaxmin.git //
// //
// //
// This program is free software; you can redistribute it and/or modify //
// it under the terms of the GNU General Public License as published by //
// the Free Software Foundation as version 3 of the License, or //
// //
// This program is distributed in the hope that it will be useful, //
// but WITHOUT ANY WARRANTY; without even the implied warranty of //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
// GNU General Public License V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef RUNNINGMAXMIN_H_
#define RUNNINGMAXMIN_H_
#include <stdlib.h>
#include <stdint.h>
namespace DSDcc
{
// nextPowerOfTwo returns a power of two that is larger or equal than x.
inline uint32_t nextPowerOfTwo(uint32_t x)
{
uint32_t result = 1;
while (result < x)
{
result <<= 1;
}
return result;
}
// actual streaming implementation
template<typename valuetype>
class lemiremaxmintruestreaming
{
public:
explicit lemiremaxmintruestreaming(uint32_t width) :
up(), lo(), n(0), ww(width)
{
init(&up, ww);
init(&lo, ww);
}
~lemiremaxmintruestreaming()
{
freenodes(&up);
freenodes(&lo);
}
void resize(uint32_t width)
{
ww = width;
freenodes(&up);
freenodes(&lo);
init(&up, ww);
init(&lo, ww);
}
void update(valuetype value)
{
if (nonempty(&up) != 0)
{
if (value > tailvalue(&up))
{
prunetail(&up);
while (((nonempty(&up)) != 0) && (value >= tailvalue(&up)))
{
prunetail(&up);
}
}
else
{
prunetail(&lo);
while (((nonempty(&lo)) != 0) && (value <= tailvalue(&lo)))
{
prunetail(&lo);
}
}
}
push(&up, n, value);
if (n == ww + headindex(&up))
{
prunehead(&up);
}
push(&lo, n, value);
if (n == ww + headindex(&lo))
{
prunehead(&lo);
}
n++;
}
valuetype max()
{
return headvalue(&up);
}
valuetype min()
{
return headvalue(&lo);
}
private:
struct valuenode
{
uint32_t index;
valuetype value;
};
struct valuesqueue
{
valuenode * nodes;
uint32_t head;
uint32_t tail;
uint32_t mask;
};
// Dequeue methods
inline uint32_t count(valuesqueue * q)
{
return (q->tail - q->head) & q->mask;
}
inline void init(valuesqueue * q, uint32_t size)
{
size = nextPowerOfTwo(size + 1);
q->nodes = reinterpret_cast<valuenode *>(malloc(sizeof(valuenode) * size));
q->head = 0;
q->tail = 0;
q->mask = size - 1;
}
inline void freenodes(valuesqueue * q)
{
free(q->nodes);
}
inline uint32_t headindex(valuesqueue * q)
{
return q->nodes[q->head].index;
}
inline void push(valuesqueue * q, uint32_t index, valuetype value)
{
q->nodes[q->tail].index = index;
q->nodes[q->tail].value = value;
q->tail = (q->tail + 1) & q->mask;
}
inline valuetype tailvalue(valuesqueue * q)
{
return q->nodes[(q->tail - 1) & q->mask].value;
}
inline valuetype headvalue(valuesqueue * q)
{
return q->nodes[q->head].value;
}
inline void prunehead(valuesqueue * q)
{
q->head = (q->head + 1) & q->mask;
}
inline void prunetail(valuesqueue * q)
{
q->tail = (q->tail - 1) & q->mask;
}
inline int nonempty(valuesqueue * q)
{
return static_cast<int>(q->tail != q->head);
}
valuesqueue up;
valuesqueue lo;
uint32_t n;
uint32_t ww;
};
} // namespce DSDcc
#endif /* RUNNINGMAXMIN_H_ */
|
