aboutsummaryrefslogtreecommitdiff
path: root/mysql/mysys/my_read.c
diff options
context:
space:
mode:
Diffstat (limited to 'mysql/mysys/my_read.c')
-rw-r--r--mysql/mysys/my_read.c107
1 files changed, 107 insertions, 0 deletions
diff --git a/mysql/mysys/my_read.c b/mysql/mysys/my_read.c
new file mode 100644
index 0000000..c80ad1c
--- /dev/null
+++ b/mysql/mysys/my_read.c
@@ -0,0 +1,107 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+
+ 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; version 2 of the License.
+
+ 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+#include "mysys_priv.h"
+#include "my_sys.h"
+#include "mysys_err.h"
+#include <my_base.h>
+#include <errno.h>
+#include "my_thread_local.h"
+
+/*
+ Read a chunk of bytes from a file with retry's if needed
+
+ The parameters are:
+ File descriptor
+ Buffer to hold at least Count bytes
+ Bytes to read
+ Flags on what to do on error
+
+ Return:
+ -1 on error
+ 0 if flag has bits MY_NABP or MY_FNABP set
+ N number of bytes read.
+*/
+
+size_t my_read(File Filedes, uchar *Buffer, size_t Count, myf MyFlags)
+{
+ size_t readbytes, save_count;
+ DBUG_ENTER("my_read");
+ DBUG_PRINT("my",("fd: %d Buffer: %p Count: %lu MyFlags: %d",
+ Filedes, Buffer, (ulong) Count, MyFlags));
+ save_count= Count;
+
+ for (;;)
+ {
+ errno= 0; /* Linux, Windows don't reset this on EOF/success */
+#ifdef _WIN32
+ readbytes= my_win_read(Filedes, Buffer, Count);
+#else
+ readbytes= read(Filedes, Buffer, Count);
+#endif
+ DBUG_EXECUTE_IF ("simulate_file_read_error",
+ {
+ errno= ENOSPC;
+ readbytes= (size_t) -1;
+ DBUG_SET("-d,simulate_file_read_error");
+ DBUG_SET("-d,simulate_my_b_fill_error");
+ });
+
+ if (readbytes != Count)
+ {
+ set_my_errno(errno);
+ if (errno == 0 || (readbytes != (size_t) -1 &&
+ (MyFlags & (MY_NABP | MY_FNABP))))
+ set_my_errno(HA_ERR_FILE_TOO_SHORT);
+ DBUG_PRINT("warning",("Read only %d bytes off %lu from %d, errno: %d",
+ (int) readbytes, (ulong) Count, Filedes,
+ my_errno()));
+
+ if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
+ {
+ DBUG_PRINT("debug", ("my_read() was interrupted and returned %ld",
+ (long) readbytes));
+ continue; /* Interrupted */
+ }
+
+ if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
+ {
+ char errbuf[MYSYS_STRERROR_SIZE];
+ if (readbytes == (size_t) -1)
+ my_error(EE_READ, MYF(0), my_filename(Filedes),
+ my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
+ else if (MyFlags & (MY_NABP | MY_FNABP))
+ my_error(EE_EOFERR, MYF(0), my_filename(Filedes),
+ my_errno(), my_strerror(errbuf, sizeof(errbuf), my_errno()));
+ }
+ if (readbytes == (size_t) -1 ||
+ ((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO)))
+ DBUG_RETURN(MY_FILE_ERROR); /* Return with error */
+ if (readbytes != (size_t) -1 && (MyFlags & MY_FULL_IO))
+ {
+ Buffer+= readbytes;
+ Count-= readbytes;
+ continue;
+ }
+ }
+
+ if (MyFlags & (MY_NABP | MY_FNABP))
+ readbytes= 0; /* Ok on read */
+ else if (MyFlags & MY_FULL_IO)
+ readbytes= save_count;
+ break;
+ }
+ DBUG_RETURN(readbytes);
+} /* my_read */