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4ca4d606ac
AIX detects tell in the configure however it really isn't there. Use the my_seek aka lseek implementation.
103 lines
3.4 KiB
C
103 lines
3.4 KiB
C
/*
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Copyright (c) 2000, 2010, Oracle and/or its affiliates
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
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#include "mysys_priv.h"
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#include "mysys_err.h"
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/*
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Seek to a position in a file.
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ARGUMENTS
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File fd The file descriptor
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my_off_t pos The expected position (absolute or relative)
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int whence A direction parameter and one of
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{SEEK_SET, SEEK_CUR, SEEK_END}
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myf MyFlags MY_THREADSAFE must be set in case my_seek may be mixed
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with my_pread/my_pwrite calls and fd is shared among
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threads.
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DESCRIPTION
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The my_seek function is a wrapper around the system call lseek and
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repositions the offset of the file descriptor fd to the argument
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offset according to the directive whence as follows:
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SEEK_SET The offset is set to offset bytes.
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SEEK_CUR The offset is set to its current location plus offset bytes
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SEEK_END The offset is set to the size of the file plus offset bytes
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RETURN VALUE
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my_off_t newpos The new position in the file.
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MY_FILEPOS_ERROR An error was encountered while performing
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the seek. my_errno is set to indicate the
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actual error.
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*/
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my_off_t my_seek(File fd, my_off_t pos, int whence, myf MyFlags)
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{
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os_off_t newpos= -1;
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DBUG_ENTER("my_seek");
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DBUG_PRINT("my",("fd: %d Pos: %llu Whence: %d MyFlags: %lu",
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fd, (ulonglong) pos, whence, MyFlags));
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DBUG_ASSERT(pos != MY_FILEPOS_ERROR); /* safety check */
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/*
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Make sure we are using a valid file descriptor!
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*/
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DBUG_ASSERT(fd != -1);
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#ifdef _WIN32
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newpos= my_win_lseek(fd, pos, whence);
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#else
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newpos= lseek(fd, pos, whence);
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#endif
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if (newpos == (os_off_t) -1)
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{
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my_errno= errno;
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if (MyFlags & MY_WME)
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my_error(EE_CANT_SEEK, MYF(0), my_filename(fd), my_errno);
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DBUG_PRINT("error", ("lseek: %llu errno: %d", (ulonglong) newpos, errno));
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DBUG_RETURN(MY_FILEPOS_ERROR);
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}
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if ((my_off_t) newpos != pos)
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{
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DBUG_PRINT("exit",("pos: %llu", (ulonglong) newpos));
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}
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DBUG_RETURN((my_off_t) newpos);
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} /* my_seek */
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/* Tell current position of file */
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/* ARGSUSED */
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my_off_t my_tell(File fd, myf MyFlags)
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{
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os_off_t pos;
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DBUG_ENTER("my_tell");
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DBUG_PRINT("my",("fd: %d MyFlags: %lu",fd, MyFlags));
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DBUG_ASSERT(fd >= 0);
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#if defined (HAVE_TELL) && !defined (_WIN32) && !defined(_AIX)
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pos= tell(fd);
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#else
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pos= my_seek(fd, 0L, MY_SEEK_CUR,0);
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#endif
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if (pos == (os_off_t) -1)
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{
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my_errno= errno;
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if (MyFlags & MY_WME)
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my_error(EE_CANT_SEEK, MYF(0), my_filename(fd), my_errno);
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DBUG_PRINT("error", ("tell: %llu errno: %d", (ulonglong) pos, my_errno));
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}
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DBUG_PRINT("exit",("pos: %llu", (ulonglong) pos));
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DBUG_RETURN((my_off_t) pos);
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} /* my_tell */
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