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-rw-r--r--mysys/my_read.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/mysys/my_read.c b/mysys/my_read.c
new file mode 100644
index 00000000..6b4f17e9
--- /dev/null
+++ b/mysys/my_read.c
@@ -0,0 +1,112 @@
+/* Copyright (c) 2000, 2013, 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 02110-1335 USA */
+
+#include "mysys_priv.h"
+#include "mysys_err.h"
+#include <my_base.h>
+#include <errno.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= 0;
+ DBUG_ENTER("my_read");
+ DBUG_PRINT("my",("fd: %d Buffer: %p Count: %lu MyFlags: %lu",
+ Filedes, Buffer, (ulong) Count, MyFlags));
+ if (!(MyFlags & (MY_WME | MY_FAE | MY_FNABP)))
+ MyFlags|= my_global_flags;
+
+ 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)
+ {
+ int got_errno= my_errno= errno;
+ DBUG_PRINT("warning",("Read only %d bytes off %lu from %d, errno: %d",
+ (int) readbytes, (ulong) Count, Filedes,
+ got_errno));
+
+ if (got_errno == 0 || (readbytes != (size_t) -1 &&
+ (MyFlags & (MY_NABP | MY_FNABP))))
+ my_errno= HA_ERR_FILE_TOO_SHORT;
+
+ if ((readbytes == 0 || (int) readbytes == -1) && got_errno == EINTR)
+ {
+ DBUG_PRINT("debug", ("my_read() was interrupted and returned %ld",
+ (long) readbytes));
+ continue; /* Interrupted */
+ }
+
+ /* Do a read retry if we didn't get enough data on first read */
+ if (readbytes != (size_t) -1 && readbytes != 0 &&
+ (MyFlags & MY_FULL_IO))
+ {
+ Buffer+= readbytes;
+ Count-= readbytes;
+ save_count+= readbytes;
+ continue;
+ }
+
+ if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
+ {
+ if (readbytes == (size_t) -1)
+ my_error(EE_READ,
+ MYF(ME_BELL | (MyFlags & (ME_NOTE | ME_ERROR_LOG))),
+ my_filename(Filedes), got_errno);
+ else if (MyFlags & (MY_NABP | MY_FNABP))
+ my_error(EE_EOFERR,
+ MYF(ME_BELL | (MyFlags & (ME_NOTE | ME_ERROR_LOG))),
+ my_filename(Filedes), got_errno);
+ }
+ if (readbytes == (size_t) -1 ||
+ ((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO)))
+ DBUG_RETURN(MY_FILE_ERROR); /* Return with error */
+ }
+
+ if (MyFlags & (MY_NABP | MY_FNABP))
+ readbytes= 0; /* Ok on read */
+ else
+ readbytes+= save_count;
+ break;
+ }
+ DBUG_RETURN(readbytes);
+} /* my_read */