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
|
/*
* Copyright © 1999-2001 NCSA
* All rights reserved.
*
* Programmer: Raymond Lu<slu@ncsa.uiuc.edu>
* Jan 3, 2003
*/
#include "H5private.h"
#include "H5Eprivate.h"
#include "H5MMprivate.h"
#include "H5Zprivate.h"
#ifdef H5_HAVE_FILTER_FLETCHER32
#define FLETCHER_LEN 4
/* Interface initialization */
#define PABLO_MASK H5Z_fletcher32_mask
#define INTERFACE_INIT NULL
static int interface_initialize_g = 0;
/*-------------------------------------------------------------------------
* Function: H5Z_filter_fletcher32_compute
*
* Purpose: Implement an Fletcher32 Checksum using 1's complement.
*
* Return: Success: Fletcher32 value
*
* Failure: Can't fail
*
* Programmer: Raymond Lu
* Jan 3, 2003
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
static unsigned int H5Z_filter_fletcher32_compute(unsigned short *buf, size_t len)
{
size_t count = len;
register unsigned int s1 = 0;
register unsigned int s2 = 0;
unsigned short *src = buf;
FUNC_ENTER_NOINIT(H5Z_filter_fletcher32_compute);
/* Compute checksum */
while(count > 1) {
s1 += *src++;
if(s1 & 0xFFFF0000) { /*Wrap around carry if occurred*/
s1 &= 0xFFFF;
s1++;
}
s2 += s1;
if(s2 & 0xFFFF0000) { /*Wrap around carry if occurred*/
s2 &= 0xFFFF;
s2++;
}
count -= 2;
}
if(count==1) {
s1 += *(unsigned char*)src;
if(s1 & 0xFFFF0000) { /*Wrap around carry if occurred*/
s1 &= 0xFFFF;
s1++;
}
s2 += s1;
if(s2 & 0xFFFF0000) { /*Wrap around carry if occurred*/
s2 &= 0xFFFF;
s2++;
}
}
FUNC_LEAVE_NOAPI((s2 << 16) + s1);
}
/*-------------------------------------------------------------------------
* Function: H5Z_filter_fletcher32
*
* Purpose: Implement an I/O filter of Fletcher32 Checksum
*
* Return: Success: size of data plus the size of Fletcher32 value
*
* Failure: 0
*
* Programmer: Raymond Lu
* Jan 3, 2003
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
size_t
H5Z_filter_fletcher32 (unsigned flags, size_t UNUSED cd_nelmts, const unsigned UNUSED cd_values[],
size_t nbytes, size_t *buf_size, void **buf)
{
size_t ret_value = 0;
void *outbuf = NULL;
unsigned char *src = (unsigned char*)(*buf);
unsigned int fletcher = 0;
FUNC_ENTER_NOAPI(H5Z_filter_fletcher32, 0);
assert(sizeof(unsigned int)==4);
if (flags & H5Z_FLAG_REVERSE) { /* Read */
size_t src_nbytes = nbytes;
unsigned int origin_fletcher;
/* Do checksum if it's enabled for read; otherwise skip it
* to save performance. */
if (!(flags & H5Z_FLAG_SKIP_EDC)) { /* Read */
unsigned char *tmp_src;
src_nbytes -= FLETCHER_LEN;
tmp_src=src+src_nbytes;
UINT32DECODE(tmp_src, origin_fletcher);
/* Compute checksum */
fletcher = H5Z_filter_fletcher32_compute((unsigned short*)src,src_nbytes);
if(origin_fletcher != fletcher)
HGOTO_ERROR(H5E_STORAGE, H5E_READERROR, 0, "data error detected by Fletcher32 checksum");
}
*buf_size = nbytes - FLETCHER_LEN;
ret_value = *buf_size;
} else { /* Write */
unsigned char *dst;
/* Compute checksum */
fletcher = H5Z_filter_fletcher32_compute((unsigned short*)src,nbytes);
if (NULL==(dst=outbuf=H5MM_malloc(nbytes+FLETCHER_LEN)))
HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, 0, "unable to allocate Fletcher32 checksum destination buffer");
/* Copy raw data */
HDmemcpy((void*)dst, (void*)(*buf), nbytes);
/* Append checksum to raw data */
dst += nbytes;
UINT32ENCODE(dst, fletcher);
*buf_size = nbytes + FLETCHER_LEN;
H5MM_xfree(*buf);
*buf = outbuf;
outbuf = NULL;
ret_value = *buf_size;
}
done:
if(outbuf)
H5MM_xfree(outbuf);
FUNC_LEAVE_NOAPI(ret_value);
}
#endif /* H5_HAVE_FILTER_FLETCHER32 */
|
