my_fstream.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:5k
- /* 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 */
- /* USE_MY_STREAM isn't set because we can't thrust my_fclose! */
- #include "mysys_priv.h"
- #include "mysys_err.h"
- #include <errno.h>
- #include <stdio.h>
- #ifdef HAVE_FSEEKO
- #undef ftell
- #undef fseek
- #define ftell(A) ftello(A)
- #define fseek(A,B,C) fseeko((A),(B),(C))
- #endif
- /* Read a chunk of bytes from a file */
- /* Returns (uint) -1 if error as my_read() */
- uint my_fread(FILE *stream, byte *Buffer, uint Count, myf MyFlags)
- /* File descriptor */
- /* Buffer must be at least count bytes */
- /* Max number of bytes returnd */
- /* Flags on what to do on error */
- {
- uint readbytes;
- DBUG_ENTER("my_fread");
- DBUG_PRINT("my",("stream: 0x%lx Buffer: 0x%lx Count: %u MyFlags: %d",
- stream, Buffer, Count, MyFlags));
- if ((readbytes = (uint) fread(Buffer,sizeof(char),(size_t) Count,stream))
- != Count)
- {
- DBUG_PRINT("error",("Read only %d bytes",readbytes));
- if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
- {
- if (ferror(stream))
- my_error(EE_READ, MYF(ME_BELL+ME_WAITTANG),
- my_filename(fileno(stream)),errno);
- else
- if (MyFlags & (MY_NABP | MY_FNABP))
- my_error(EE_EOFERR, MYF(ME_BELL+ME_WAITTANG),
- my_filename(fileno(stream)),errno);
- }
- my_errno=errno ? errno : -1;
- if (ferror(stream) || MyFlags & (MY_NABP | MY_FNABP))
- DBUG_RETURN((uint) -1); /* Return with error */
- }
- if (MyFlags & (MY_NABP | MY_FNABP))
- DBUG_RETURN(0); /* Read ok */
- DBUG_RETURN(readbytes);
- } /* my_fread */
- /*
- ** Write a chunk of bytes to a stream
- ** Returns (uint) -1 if error as my_write()
- ** Does retries if interrupted
- */
- uint my_fwrite(FILE *stream, const byte *Buffer, uint Count, myf MyFlags)
- {
- uint writenbytes=0;
- off_t seekptr;
- #if !defined(NO_BACKGROUND) && defined(USE_MY_STREAM)
- uint errors;
- #endif
- DBUG_ENTER("my_fwrite");
- DBUG_PRINT("my",("stream: 0x%lx Buffer: 0x%lx Count: %u MyFlags: %d",
- stream, Buffer, Count, MyFlags));
- #if !defined(NO_BACKGROUND) && defined(USE_MY_STREAM)
- errors=0;
- #endif
- seekptr=ftell(stream);
- for (;;)
- {
- uint writen;
- if ((writen = (uint) fwrite((char*) Buffer,sizeof(char),
- (size_t) Count, stream)) != Count)
- {
- DBUG_PRINT("error",("Write only %d bytes",writenbytes));
- my_errno=errno;
- if (writen != (uint) -1)
- {
- seekptr+=writen;
- Buffer+=writen;
- writenbytes+=writen;
- Count-=writen;
- }
- #ifdef EINTR
- if (errno == EINTR)
- {
- VOID(my_fseek(stream,seekptr,MY_SEEK_SET,MYF(0)));
- continue;
- }
- #endif
- #if !defined(NO_BACKGROUND) && defined(USE_MY_STREAM)
- #ifdef THREAD
- if (my_thread_var->abort)
- MyFlags&= ~ MY_WAIT_IF_FULL; /* End if aborted by user */
- #endif
- if ((errno == ENOSPC || errno == EDQUOT) &&
- (MyFlags & MY_WAIT_IF_FULL))
- {
- if (!(errors++ % MY_WAIT_GIVE_USER_A_MESSAGE))
- my_error(EE_DISK_FULL,MYF(ME_BELL | ME_NOREFRESH),
- "[stream]",my_errno,MY_WAIT_FOR_USER_TO_FIX_PANIC);
- VOID(sleep(MY_WAIT_FOR_USER_TO_FIX_PANIC));
- VOID(my_fseek(stream,seekptr,MY_SEEK_SET,MYF(0)));
- continue;
- }
- #endif
- if (ferror(stream) || (MyFlags & (MY_NABP | MY_FNABP)))
- {
- if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
- {
- my_error(EE_WRITE, MYF(ME_BELL+ME_WAITTANG),
- my_filename(fileno(stream)),errno);
- }
- writenbytes=(uint) -1; /* Return that we got error */
- break;
- }
- }
- if (MyFlags & (MY_NABP | MY_FNABP))
- writenbytes=0; /* Everything OK */
- else
- writenbytes+=writen;
- break;
- }
- DBUG_RETURN(writenbytes);
- } /* my_fwrite */
- /* Seek to position in file */
- /* ARGSUSED */
- my_off_t my_fseek(FILE *stream, my_off_t pos, int whence,
- myf MyFlags __attribute__((unused)))
- {
- DBUG_ENTER("my_fseek");
- DBUG_PRINT("my",("stream: 0x%lx pos: %lu whence: %d MyFlags: %d",
- stream, pos, whence, MyFlags));
- DBUG_RETURN(fseek(stream, (off_t) pos, whence) ?
- MY_FILEPOS_ERROR : (my_off_t) ftell(stream));
- } /* my_seek */
- /* Tell current position of file */
- /* ARGSUSED */
- my_off_t my_ftell(FILE *stream, myf MyFlags __attribute__((unused)))
- {
- off_t pos;
- DBUG_ENTER("my_ftell");
- DBUG_PRINT("my",("stream: 0x%lx MyFlags: %d",stream, MyFlags));
- pos=ftell(stream);
- DBUG_PRINT("exit",("ftell: %lu",(ulong) pos));
- DBUG_RETURN((my_off_t) pos);
- } /* my_ftell */