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	mysys/my_seek.c: Give error if MY_WME is used sql/sql_insert.cc: Fixed compiler warning storage/maria/ha_maria.cc: Changed driver of Maria storage engine project
		
			
				
	
	
		
			108 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Copyright (C) 2000 MySQL AB
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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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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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  reg1 os_off_t newpos= -1;
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  DBUG_ENTER("my_seek");
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  DBUG_PRINT("my",("fd: %d  Hpos: %lu  Pos: %lu  Whence: %d  MyFlags: %d",
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		   fd, (ulong) (((ulonglong) pos) >> 32), (ulong) pos, 
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		   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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#if defined(THREAD) && !defined(HAVE_PREAD)
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  if (MyFlags & MY_THREADSAFE)
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  {
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    pthread_mutex_lock(&my_file_info[fd].mutex);
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    newpos= lseek(fd, pos, whence);
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    pthread_mutex_unlock(&my_file_info[fd].mutex);
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  }
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  else
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#endif
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    newpos= lseek(fd, pos, whence);
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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: %lu  errno: %d", (ulong) 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: %lu", (ulong) 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: %d",fd, MyFlags));
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  DBUG_ASSERT(fd >= 0);
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#ifdef HAVE_TELL
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  pos=tell(fd);
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#else
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  pos=lseek(fd, 0L, MY_SEEK_CUR);
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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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  }
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  DBUG_PRINT("exit",("pos: %lu", (ulong) pos));
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  DBUG_RETURN((my_off_t) pos);
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} /* my_tell */
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