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
|
/* Copyright (C) 2000 MySQL AB
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; either version 2 of the License, or
(at your option) any later version.
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 for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include "mysys_priv.h"
#include "mysys_err.h"
#include <errno.h>
#ifdef HAVE_PREAD
#include <unistd.h>
#endif
/* Read a chunk of bytes from a file */
uint my_pread(File Filedes, byte *Buffer, uint Count, my_off_t offset,
myf MyFlags)
{
uint readbytes;
int error;
DBUG_ENTER("my_pread");
DBUG_PRINT("my",("Fd: %d Seek: %lu Buffer: 0x%lx Count: %u MyFlags: %d",
Filedes, (ulong) offset, Buffer, Count, MyFlags));
for (;;)
{
#ifndef __WIN__
errno=0; /* Linux doesn't reset this */
#endif
#ifndef HAVE_PREAD
pthread_mutex_lock(&my_file_info[Filedes].mutex);
readbytes= (uint) -1;
error= (lseek(Filedes, offset, MY_SEEK_SET) == -1L ||
(readbytes = (uint) read(Filedes, Buffer, Count)) != Count);
pthread_mutex_unlock(&my_file_info[Filedes].mutex);
#else
error=((readbytes = (uint) pread(Filedes, Buffer, Count, offset)) != Count);
#endif
if (error)
{
my_errno=errno;
DBUG_PRINT("warning",("Read only %ld bytes off %ld from %d, errno: %d",
readbytes,Count,Filedes,my_errno));
#ifdef THREAD
if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
{
DBUG_PRINT("debug", ("my_pread() was interrupted and returned %d",
(int) readbytes));
continue; /* Interrupted */
}
#endif
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
if ((int) readbytes == -1)
my_error(EE_READ, MYF(ME_BELL+ME_WAITTANG),
my_filename(Filedes),my_errno);
else if (MyFlags & (MY_NABP | MY_FNABP))
my_error(EE_EOFERR, MYF(ME_BELL+ME_WAITTANG),
my_filename(Filedes),my_errno);
}
if ((int) readbytes == -1 || (MyFlags & (MY_FNABP | MY_NABP)))
DBUG_RETURN(MY_FILE_ERROR); /* Return with error */
}
if (MyFlags & (MY_NABP | MY_FNABP))
DBUG_RETURN(0); /* Read went ok; Return 0 */
DBUG_RETURN(readbytes); /* purecov: inspected */
}
} /* my_pread */
/* Write a chunk of bytes to a file */
uint my_pwrite(int Filedes, const byte *Buffer, uint Count, my_off_t offset,
myf MyFlags)
{
uint writenbytes,errors;
ulong written;
DBUG_ENTER("my_pwrite");
DBUG_PRINT("my",("Fd: %d Seek: %lu Buffer: 0x%lx Count: %d MyFlags: %d",
Filedes, (ulong) offset,Buffer, Count, MyFlags));
errors=0; written=0L;
for (;;)
{
#ifndef HAVE_PREAD
int error;
writenbytes= (uint) -1;
pthread_mutex_lock(&my_file_info[Filedes].mutex);
error=(lseek(Filedes, offset, MY_SEEK_SET) != -1L &&
(writenbytes = (uint) write(Filedes, Buffer, Count)) == Count);
pthread_mutex_unlock(&my_file_info[Filedes].mutex);
if (error)
break;
#else
if ((writenbytes = (uint) pwrite(Filedes, Buffer, Count,offset)) == Count)
break;
#endif
if ((int) writenbytes != -1)
{ /* Safegueard */
written+=writenbytes;
Buffer+=writenbytes;
Count-=writenbytes;
offset+=writenbytes;
}
my_errno=errno;
DBUG_PRINT("error",("Write only %d bytes",writenbytes));
#ifndef NO_BACKGROUND
#ifdef THREAD
if (my_thread_var->abort)
MyFlags&= ~ MY_WAIT_IF_FULL; /* End if aborted by user */
#endif
if ((my_errno == ENOSPC || my_errno == EDQUOT) &&
(MyFlags & MY_WAIT_IF_FULL))
{
if (!(errors++ % MY_WAIT_GIVE_USER_A_MESSAGE))
my_error(EE_DISK_FULL,MYF(ME_BELL | ME_NOREFRESH),
my_filename(Filedes),my_errno,MY_WAIT_FOR_USER_TO_FIX_PANIC);
VOID(sleep(MY_WAIT_FOR_USER_TO_FIX_PANIC));
continue;
}
if ((writenbytes > 0 && (uint) writenbytes != (uint) -1) ||
my_errno == EINTR)
continue; /* Retry */
#endif
if (MyFlags & (MY_NABP | MY_FNABP))
{
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
my_error(EE_WRITE, MYF(ME_BELL | ME_WAITTANG),
my_filename(Filedes),my_errno);
}
DBUG_RETURN(MY_FILE_ERROR); /* Error on read */
}
else
break; /* Return bytes written */
}
if (MyFlags & (MY_NABP | MY_FNABP))
DBUG_RETURN(0); /* Want only errors */
DBUG_RETURN(writenbytes+written); /* purecov: inspected */
} /* my_pwrite */
|
