89 lines
2.8 KiB
C
89 lines
2.8 KiB
C
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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, (uint) 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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#ifdef THREAD
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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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#endif
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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 */
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