76 lines
1.9 KiB
C
76 lines
1.9 KiB
C
/* Copyright 1996,1997,1999,2001,2002,2009,2021 Alain Knaff.
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* This file is part of mtools.
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*
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* Mtools 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, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Mtools 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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*
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* You should have received a copy of the GNU General Public License
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* along with Mtools. If not, see <http://www.gnu.org/licenses/>.
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*
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* Force I/O to be done to complete transfer length
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*
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* written by:
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*
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* Alain L. Knaff
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* alain@knaff.lu
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*
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*/
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#include "sysincludes.h"
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#include "msdos.h"
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#include "stream.h"
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static ssize_t force_pio(Stream_t *Stream,
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char *buf, mt_off_t start, size_t len,
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ssize_t (*io)(Stream_t *, char *, mt_off_t, size_t))
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{
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ssize_t ret;
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int done=0;
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while(len){
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ret = io(Stream, buf, start, len);
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if ( ret <= 0 ){
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if (done)
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return done;
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else
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return ret;
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}
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assert((size_t)ret <= len);
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start += (size_t) ret;
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done += ret;
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len -= (size_t) ret;
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buf += ret;
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}
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return done;
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}
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static ssize_t write_wrapper(Stream_t *Stream, char *buf,
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mt_off_t start UNUSEDP, size_t len)
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{
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return Stream->Class->write(Stream, buf, len);
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}
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ssize_t force_write(Stream_t *Stream, char *buf, size_t len)
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{
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return force_pio(Stream, buf, 0, len, write_wrapper);
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}
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ssize_t force_pwrite(Stream_t *Stream, char *buf, mt_off_t start, size_t len)
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{
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return force_pio(Stream, buf, start, len,
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Stream->Class->pwrite);
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}
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ssize_t force_pread(Stream_t *Stream, char *buf, mt_off_t start, size_t len)
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{
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return force_pio(Stream, buf, start, len,
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Stream->Class->pread);
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}
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