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
|
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <string.h>
#include "machine_type.h"
#include "config.h"
#include "buffers.h"
// retval: OK
//
tUInt32 openbuf(tBuffer* hBuf,tUInt8 bufnum,char* filename)
{
unsigned int filenamelen=0;
if (filename == NULL)
return RETNOK;
filenamelen=strlen(filename);
if (filenamelen>510)
filenamelen=510;
hBuf->changesnum=0;
hBuf->valid=0;
hBuf->fresh=1;
hBuf->file=fopen(filename,"rb");
memcpy(hBuf->filename,filename,filenamelen+1);
hBuf->filename[511]=0;
if (hBuf->file)
{
hBuf->valid=1;
hBuf->filesize=getfilesize(hBuf->file);
hBuf->bufsize=hBuf->filesize;
hBuf->bufferpos=-1;
return RETOK;
} else return RETNOK;
}
tUInt32 readbuf(tBuffer* hBuf,tInt64 pos)
{
tBool havetoread=0;
tInt32 bytesread;
if (hBuf->fresh || pos<hBuf->bufferpos || pos>(hBuf->bufferpos+BUFFERSIZE))
{
havetoread=1;
hBuf->bufferpos=pos&(~(BUFFERSIZE-1)); // floor
}
else if ((hBuf->bufferpos+BUFFERMARGIN)>pos && hBuf->bufferpos>=(BUFFERSIZE/2))
{
havetoread=1;
hBuf->bufferpos-=(BUFFERSIZE/2);
}
else if ((hBuf->bufferpos+BUFFERSIZE-BUFFERMARGIN)<pos && (hBuf->bufferpos+(BUFFERSIZE/2))<hBuf->bufsize && hBuf->bufsize>BUFFERSIZE)
{
havetoread=1;
hBuf->bufferpos+=(BUFFERSIZE/2);
}
if (havetoread)
{
hBuf->fresh=0;
if (hBuf->filesize>hBuf->bufferpos)
{
if (setfilepos(hBuf->file,hBuf->bufferpos)!=RETOK)
{
return RETNOK;
}
bytesread=fread(hBuf->data,sizeof(tUInt8),BUFFERSIZE,hBuf->file);
if (bytesread!=BUFFERSIZE && ferror(hBuf->file))
{
return RETNOK;
}
if (bytesread!=BUFFERSIZE)
{
memset(&hBuf->data[bytesread],0,sizeof(tUInt8)*(BUFFERSIZE-bytesread)); // fill the rest with 0
}
} else {
memset(hBuf->data,0,sizeof(tUInt8)*BUFFERSIZE);
}
}
return RETOK;
}
tInt32 getbufferidx(tBuffer* hBuf,tInt64 pos)
{
tInt32 retval=RETOK;
if ((pos<(hBuf->bufferpos+BUFFERMARGIN)) || (pos>(hBuf->bufferpos+BUFFERSIZE-BUFFERMARGIN)))
{
retval=readbuf(hBuf,pos);
}
if (retval==RETOK)
{
retval=pos-(hBuf->bufferpos);
}
return retval;
}
tInt8 savechanges(tBuffer* hBuf)
{
int i;
size_t bytes_written;
// Close the file temporarily
fclose(hBuf->file);
if (hBuf->changesnum)
{
// Try to open for writing
hBuf->file = fopen(hBuf->filename, "r+b");
if (hBuf->file == NULL) {
// Failed to open for writing, try to reopen for reading
hBuf->file = fopen(hBuf->filename, "rb");
return RETNOK;
}
for (i = 0; i < hBuf->changesnum; i++)
{
if (setfilepos(hBuf->file, hBuf->changes[i].pos) == RETNOK)
{
fclose(hBuf->file);
// Try to reopen for reading
hBuf->file = fopen(hBuf->filename, "rb");
return RETNOK;
}
bytes_written = fwrite(&(hBuf->changes[i].after), sizeof(tUInt8), 1, hBuf->file);
if (bytes_written != 1)
{
fclose(hBuf->file);
// Try to reopen for reading
hBuf->file = fopen(hBuf->filename, "rb");
return RETNOK;
}
}
if (fclose(hBuf->file) == EOF)
{
// Try to reopen for reading
hBuf->file = fopen(hBuf->filename, "rb");
return RETNOK;
}
}
// Reopen for reading
hBuf->file = fopen(hBuf->filename, "rb");
if (hBuf->file == NULL) {
return RETNOK;
}
return RETOK;
}
|
