/* Copyright (C) 2000 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "mysys_priv.h" #include "mysys_err.h" #include <errno.h> /* Read a chunk of bytes from a file with retry's if needed The parameters are: File descriptor Buffer to hold at least Count bytes Bytes to read Flags on what to do on error Return: -1 on error 0 if flag has bits MY_NABP or MY_FNABP set N number of bytes read. */ uint my_read(File Filedes, byte *Buffer, uint Count, myf MyFlags) { uint readbytes, save_count; DBUG_ENTER("my_read"); DBUG_PRINT("my",("Fd: %d Buffer: 0x%lx Count: %u MyFlags: %d", Filedes, Buffer, Count, MyFlags)); save_count= Count; for (;;) { errno= 0; /* Linux doesn't reset this */ if ((readbytes= (uint) read(Filedes, Buffer, Count)) != Count) { my_errno= errno ? errno : -1; DBUG_PRINT("warning",("Read only %ld bytes off %ld from %d, errno: %d", readbytes, Count, Filedes, my_errno)); #ifdef THREAD if ((int) readbytes <= 0 && errno == EINTR) { DBUG_PRINT("debug", ("my_read() was interrupted and returned %d", (int) readbytes)); continue; /* Interrupted */ } #endif if (MyFlags & (MY_WME | MY_FAE | MY_FNABP)) { if ((int) readbytes == -1) my_error(EE_READ, MYF(ME_BELL+ME_WAITTANG), my_filename(Filedes),my_errno); else if (MyFlags & (MY_NABP | MY_FNABP)) my_error(EE_EOFERR, MYF(ME_BELL+ME_WAITTANG), my_filename(Filedes),my_errno); } if ((int) readbytes == -1 || ((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO))) DBUG_RETURN(MY_FILE_ERROR); /* Return with error */ if (readbytes > 0 && (MyFlags & MY_FULL_IO)) { Buffer+= readbytes; Count-= readbytes; continue; } } if (MyFlags & (MY_NABP | MY_FNABP)) readbytes= 0; /* Ok on read */ else if (MyFlags & MY_FULL_IO) readbytes= save_count; break; } DBUG_RETURN(readbytes); } /* my_read */