1 /* Copyright (c) 2000, 2021, Oracle and/or its affiliates.
2
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License, version 2.0,
5 as published by the Free Software Foundation.
6
7 This program is also distributed with certain software (including
8 but not limited to OpenSSL) that is licensed under separate terms,
9 as designated in a particular file or component or in included license
10 documentation. The authors of MySQL hereby grant you an additional
11 permission to link the program and your derivative works with the
12 separately licensed software that they have included with MySQL.
13
14 Without limiting anything contained in the foregoing, this file,
15 which is part of C Driver for MySQL (Connector/C), is also subject to the
16 Universal FOSS Exception, version 1.0, a copy of which can be found at
17 http://oss.oracle.com/licenses/universal-foss-exception.
18
19 This program is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 GNU General Public License, version 2.0, for more details.
23
24 You should have received a copy of the GNU General Public License
25 along with this program; if not, write to the Free Software
26 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
27
28 #include "mysys_priv.h"
29 #include "my_sys.h"
30 #include "mysys_err.h"
31 #include <errno.h>
32 #include "my_thread_local.h"
33
34
35 /**
36 Write a chunk of bytes to a file
37
38 if (MyFlags & (MY_NABP | MY_FNABP))
39 @returns
40 0 if Count == 0
41 On succes, 0
42 On failure, (size_t)-1 == MY_FILE_ERROR
43
44 otherwise
45 @returns
46 0 if Count == 0
47 On success, the number of bytes written.
48 On partial success (if less than Count bytes could be written),
49 the actual number of bytes written.
50 On failure, (size_t)-1 == MY_FILE_ERROR
51 */
my_write(File Filedes,const uchar * Buffer,size_t Count,myf MyFlags)52 size_t my_write(File Filedes, const uchar *Buffer, size_t Count, myf MyFlags)
53 {
54 size_t writtenbytes;
55 size_t sum_written= 0;
56 uint errors= 0;
57 const size_t initial_count= Count;
58
59 DBUG_ENTER("my_write");
60 DBUG_PRINT("my",("fd: %d Buffer: %p Count: %lu MyFlags: %d",
61 Filedes, Buffer, (ulong) Count, MyFlags));
62
63 /* The behavior of write(fd, buf, 0) is not portable */
64 if (unlikely(!Count))
65 DBUG_RETURN(0);
66
67 DBUG_EXECUTE_IF ("simulate_no_free_space_error",
68 { DBUG_SET("+d,simulate_file_write_error");});
69 for (;;)
70 {
71 errno= 0;
72 #ifdef _WIN32
73 writtenbytes= my_win_write(Filedes, Buffer, Count);
74 #else
75 writtenbytes= write(Filedes, Buffer, Count);
76 #endif
77 DBUG_EXECUTE_IF("simulate_file_write_error",
78 {
79 errno= ENOSPC;
80 writtenbytes= (size_t) -1;
81 });
82 if (writtenbytes == Count)
83 {
84 sum_written+= writtenbytes;
85 break;
86 }
87 if (writtenbytes != (size_t) -1)
88 { /* Safeguard */
89 sum_written+= writtenbytes;
90 Buffer+= writtenbytes;
91 Count-= writtenbytes;
92 }
93 set_my_errno(errno);
94 DBUG_PRINT("error",("Write only %ld bytes, error: %d",
95 (long) writtenbytes, my_errno()));
96 if (is_killed_hook(NULL))
97 MyFlags&= ~ MY_WAIT_IF_FULL; /* End if aborted by user */
98
99 if ((my_errno() == ENOSPC || my_errno() == EDQUOT) &&
100 (MyFlags & MY_WAIT_IF_FULL))
101 {
102 wait_for_free_space(my_filename(Filedes), errors);
103 errors++;
104 DBUG_EXECUTE_IF("simulate_no_free_space_error",
105 { DBUG_SET("-d,simulate_file_write_error");});
106 continue;
107 }
108
109 if (writtenbytes != 0 && writtenbytes != (size_t) -1)
110 continue; /* Retry if something written */
111 else if (my_errno() == EINTR)
112 {
113 DBUG_PRINT("debug", ("my_write() was interrupted and returned %ld",
114 (long) writtenbytes));
115 continue; /* Interrupted, retry */
116 }
117 else if (writtenbytes == 0 && !errors++) /* Retry once */
118 {
119 /* We may come here if the file quota is exeeded */
120 continue;
121 }
122 break;
123 }
124 if (MyFlags & (MY_NABP | MY_FNABP))
125 {
126 if (sum_written == initial_count)
127 DBUG_RETURN(0); /* Want only errors, not bytes written */
128 if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
129 {
130 char errbuf[MYSYS_STRERROR_SIZE];
131 my_error(EE_WRITE, MYF(0), my_filename(Filedes),
132 my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
133 }
134 DBUG_RETURN(MY_FILE_ERROR);
135 }
136
137 if (sum_written == 0)
138 DBUG_RETURN(MY_FILE_ERROR);
139
140 DBUG_RETURN(sum_written);
141 } /* my_write */
142