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by brian
clean slate |
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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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#include <errno.h> |
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/*
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Read a chunk of bytes from a file with retry's if needed
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The parameters are:
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File descriptor
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Buffer to hold at least Count bytes
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Bytes to read
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Flags on what to do on error
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Return:
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-1 on error
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0 if flag has bits MY_NABP or MY_FNABP set
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N number of bytes read.
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*/
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size_t my_read(File Filedes, uchar *Buffer, size_t Count, myf MyFlags) |
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{
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size_t readbytes, save_count; |
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DBUG_ENTER("my_read"); |
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DBUG_PRINT("my",("Fd: %d Buffer: 0x%lx Count: %lu MyFlags: %d", |
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Filedes, (long) Buffer, (ulong) Count, MyFlags)); |
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save_count= Count; |
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for (;;) |
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{
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errno= 0; /* Linux doesn't reset this */ |
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if ((readbytes= read(Filedes, Buffer, Count)) != Count) |
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{
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my_errno= errno ? errno : -1; |
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DBUG_PRINT("warning",("Read only %d bytes off %lu from %d, errno: %d", |
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(int) readbytes, (ulong) Count, Filedes, |
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my_errno)); |
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if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR) |
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{
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DBUG_PRINT("debug", ("my_read() was interrupted and returned %ld", |
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(long) readbytes)); |
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continue; /* Interrupted */ |
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}
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if (MyFlags & (MY_WME | MY_FAE | MY_FNABP)) |
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{
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if (readbytes == (size_t) -1) |
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my_error(EE_READ, MYF(ME_BELL+ME_WAITTANG), |
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my_filename(Filedes),my_errno); |
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else if (MyFlags & (MY_NABP | MY_FNABP)) |
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my_error(EE_EOFERR, MYF(ME_BELL+ME_WAITTANG), |
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my_filename(Filedes),my_errno); |
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}
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if (readbytes == (size_t) -1 || |
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((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO))) |
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DBUG_RETURN(MY_FILE_ERROR); /* Return with error */ |
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if (readbytes != (size_t) -1 && (MyFlags & MY_FULL_IO)) |
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{
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Buffer+= readbytes; |
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Count-= readbytes; |
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continue; |
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}
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}
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if (MyFlags & (MY_NABP | MY_FNABP)) |
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readbytes= 0; /* Ok on read */ |
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else if (MyFlags & MY_FULL_IO) |
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readbytes= save_count; |
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break; |
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}
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DBUG_RETURN(readbytes); |
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} /* my_read */ |