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33d72d80bc
Use prototypes instead of old-style functions. (block_read): Don't assume that int is no wider than size_t.
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/* Buffer primitives for comparison operations.
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Copyright (C) 1993, 1995, 1998, 2001 Free Software Foundation, Inc.
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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; either version 2, or (at your option)
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any later version.
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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; see the file COPYING.
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If not, write to the Free Software Foundation,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#if HAVE_UNISTD_H
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# include <unistd.h>
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#endif
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#include <sys/types.h>
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#include "cmpbuf.h"
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/* Read NBYTES bytes from descriptor FD into BUF.
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Return the number of characters successfully read.
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On error, return (size_t) -1.
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The number returned is always NBYTES unless end-of-file or error. */
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size_t
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block_read (int fd, char *buf, size_t nbytes)
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{
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char *bp = buf;
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char const *buflim = buf + nbytes;
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do
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{
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ssize_t nread = read (fd, bp, buflim - bp);
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if (nread < 0)
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return -1;
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if (nread == 0)
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break;
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bp += nread;
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}
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while (bp < buflim);
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return bp - buf;
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}
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/* Least common multiple of two buffer sizes A and B. */
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size_t
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buffer_lcm (size_t a, size_t b)
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{
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size_t m, n, r;
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/* Yield reasonable values if buffer sizes are zero. */
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if (!a)
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return b ? b : 8 * 1024;
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if (!b)
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return a;
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/* n = gcd (a, b) */
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for (m = a, n = b; (r = m % n) != 0; m = n, n = r)
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continue;
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return a/n * b;
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}
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