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/* 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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new_length New file size
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filler If we don't have truncate, fill up all bytes after
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new_length with this character
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my_chsize() truncates file if shorter else fill with the filler character.
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The function also changes the file pointer. Usually it points to the end
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of the file after execution.
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int my_chsize(File fd, my_off_t newlength, int filler, myf MyFlags)
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DBUG_ENTER("my_chsize");
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DBUG_PRINT("my",("fd: %d length: %lu MyFlags: %d",fd,(ulong) newlength,
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if ((oldsize= my_seek(fd, 0L, MY_SEEK_END, MYF(MY_WME+MY_FAE))) == newlength)
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DBUG_PRINT("info",("old_size: %ld", (ulong) oldsize));
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if (oldsize > newlength)
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#if defined(HAVE_SETFILEPOINTER)
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/* This is for the moment only true on windows */
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HANDLE win_file= (HANDLE) _get_osfhandle(fd);
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long length_low, length_high;
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length_low= (long) (ulong) newlength;
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length_high= (long) ((ulonglong) newlength >> 32);
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is_success= SetFilePointer(win_file, length_low, &length_high, FILE_BEGIN);
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if (is_success == -1 && (my_errno= GetLastError()) != NO_ERROR)
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if (SetEndOfFile(win_file))
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my_errno= GetLastError();
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#elif defined(HAVE_FTRUNCATE)
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if (ftruncate(fd, (off_t) newlength))
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#elif defined(HAVE_CHSIZE)
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if (chsize(fd, (off_t) newlength))
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Fill space between requested length and true length with 'filler'
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We should never come here on any modern machine
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if (my_seek(fd, newlength, MY_SEEK_SET, MYF(MY_WME+MY_FAE))
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swap_variables(my_off_t, newlength, oldsize);
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/* Full file with 'filler' until it's as big as requested */
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bfill(buff, IO_SIZE, filler);
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while (newlength-oldsize > IO_SIZE)
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if (my_write(fd, buff, IO_SIZE, MYF(MY_NABP)))
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if (my_write(fd,buff,(size_t) (newlength-oldsize), MYF(MY_NABP)))
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DBUG_PRINT("error", ("errno: %d", errno));
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if (MyFlags & MY_WME)
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my_error(EE_CANT_CHSIZE, MYF(ME_BELL+ME_WAITTANG), my_errno);
added
removed
mysys/my_chsize.c
