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105 7u83 1 
/* Copyright (c) 1985 Regents of the University of California */
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/*
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 * These routines are for faster tag lookup.  They support the binary
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 * search used in tagfind() instead of the linear search.  The speedup
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 * is quite noticable looking for a tag at the end of a long tags
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 * file.  Define FASTTAG in the Makefile to use these routines.
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 */
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#ifdef FASTTAG
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#if	!defined(lint) && defined(DOSCCS)
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static char *sccsid = "@(#)ex_tagio.c	7.3 (Berkeley) 1/31/86";
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#endif
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107 7u83 15 
#include <fcntl.h>
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#include <stdio.h>
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105 7u83 18 
#include "ex.h"
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static long offset = -1;
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static long block = -1;
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static int bcnt = 0;
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static int b_size = MAXBSIZE;
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static char *ibuf;
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topen(file, buf)
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char *file, *buf;
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{
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	int fd;
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	struct stat statb;
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	offset = -1;
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	block = -1;
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	if ((fd = open(file, O_RDONLY, 0)) < 0)
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		return(-1);
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	if (fstat(fd, &statb) < 0) {
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		(void)close(fd);
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		return(-1);
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	}
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	ibuf = buf;
107 7u83 41 
/*	b_size = statb.st_blksize;*/
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	bsize = MAXBSIZE;
105 7u83 43 
	return(fd);
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}
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tseek(fd, off)
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int fd;
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long off;
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{
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	long nblock;
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	nblock = off / b_size * b_size;
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	offset = off % b_size;
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	if (nblock == block)
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		return(0);
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	block = nblock;
107 7u83 57 
	if (lseek(fd, nblock, SEEK_SET) < 0)
105 7u83 58 
		return(-1);
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	if ((bcnt = read(fd, ibuf, b_size)) < 0)
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		return(-1);
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	return(0);
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}
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tgets(buf, cnt, fd)
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register char *buf;
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int cnt;
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int fd;
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{
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	register char *cp;
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	register cc;
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	cc = offset;
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	if (cc == -1) {
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		if ((bcnt = read(fd, ibuf, b_size)) <= 0)
107 7u83 75 
			return 0;
105 7u83 76 
		cc = 0;
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		block = 0;
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	}
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	if (bcnt == 0)		/* EOF */
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		return 0;
105 7u83 81 
	cp = ibuf + cc;
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	while (--cnt > 0) {
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		if (++cc > bcnt) {
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			block += b_size;
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			if ((bcnt = read(fd, ibuf, b_size)) <= 0) {
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				offset = cc;
107 7u83 87 
				return 0;
105 7u83 88 
			}
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			cp = ibuf;
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			cc = 1;
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		}
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		if ((*buf++ = *cp++) == '\n')
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			break;
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	}
107 7u83 95 
	*--buf = 0;
105 7u83 96 
	offset = cc;
107 7u83 97 
	return 1;
105 7u83 98 
}
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tclose(fd)
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int fd;
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{
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	(void)close(fd);
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	offset = -1;
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	block = -1;
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	bcnt = 0;
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}
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#endif