diffreg.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 1,111 行 · 第 1/2 页

#ifndef lint
static char *sccsid = "@(#)diffreg.c	4.1	ULTRIX	7/17/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1988 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/************************************************************************
 *	Modification History
 *      --------------------
 *
 *	10-Nov-88		Tim N
 *			Took 4.3-5 sources and added changes made to
 *			previous version's sources.  Includes DL's 8
 *			bit clean changes.
 *			This 4.3-5 source had id:
 *				"@(#)diffreg.c 4.17 10/22/87";
 ************************************************************************/



#include "diff.h"
/*
 * diff - compare two files.
 */

/*
 *	Uses an algorithm due to Harold Stone, which finds
 *	a pair of longest identical subsequences in the two
 *	files.
 *
 *	The major goal is to generate the match vector J.
 *	J[i] is the index of the line in file1 corresponding
 *	to line i file0. J[i] = 0 if there is no
 *	such line in file1.
 *
 *	Lines are hashed so as to work in core. All potential
 *	matches are located by sorting the lines of each file
 *	on the hash (called ``value''). In particular, this
 *	collects the equivalence classes in file1 together.
 *	Subroutine equiv replaces the value of each line in
 *	file0 by the index of the first element of its 
 *	matching equivalence in (the reordered) file1.
 *	To save space equiv squeezes file1 into a single
 *	array member in which the equivalence classes
 *	are simply concatenated, except that their first
 *	members are flagged by changing sign.
 *
 *	Next the indices that point into member are unsorted into
 *	array class according to the original order of file0.
 *
 *	The cleverness lies in routine stone. This marches
 *	through the lines of file0, developing a vector klist
 *	of "k-candidates". At step i a k-candidate is a matched
 *	pair of lines x,y (x in file0 y in file1) such that
 *	there is a common subsequence of length k
 *	between the first i lines of file0 and the first y 
 *	lines of file1, but there is no such subsequence for
 *	any smaller y. x is the earliest possible mate to y
 *	that occurs in such a subsequence.
 *
 *	Whenever any of the members of the equivalence class of
 *	lines in file1 matable to a line in file0 has serial number 
 *	less than the y of some k-candidate, that k-candidate 
 *	with the smallest such y is replaced. The new 
 *	k-candidate is chained (via pred) to the current
 *	k-1 candidate so that the actual subsequence can
 *	be recovered. When a member has serial number greater
 *	that the y of all k-candidates, the klist is extended.
 *	At the end, the longest subsequence is pulled out
 *	and placed in the array J by unravel
 *
 *	With J in hand, the matches there recorded are
 *	check'ed against reality to assure that no spurious
 *	matches have crept in due to hashing. If they have,
 *	they are broken, and "jackpot" is recorded--a harmless
 *	matter except that a true match for a spuriously
 *	mated line may now be unnecessarily reported as a change.
 *
 *	Much of the complexity of the program comes simply
 *	from trying to minimize core utilization and
 *	maximize the range of doable problems by dynamically
 *	allocating what is needed and reusing what is not.
 *	The core requirements for problems larger than somewhat
 *	are (in words) 2*length(file0) + length(file1) +
 *	3*(number of k-candidates installed),  typically about
 *	6n words for files of length n. 
 */

#define	prints(s)	fputs(s,stdout)
#define	ismulti(c)	((c & 0xff) >= 0xa0 && (c & 0xff) <= 0xff)

FILE	*input[2];
FILE	*fopen();

struct cand {
	int	x;
	int	y;
	int	pred;
} cand;
struct line {
	int	serial;
	int	value;
} *file[2], line;
int	len[2];
struct	line *sfile[2];	/* shortened by pruning common prefix and suffix */
int	slen[2];
int	pref, suff;	/* length of prefix and suffix */
int	*class;		/* will be overlaid on file[0] */
int	*member;	/* will be overlaid on file[1] */
int	*klist;		/* will be overlaid on file[0] after class */
struct	cand *clist;	/* merely a free storage pot for candidates */
int	clen = 0;
int	*J;		/* will be overlaid on class */
long	*ixold;		/* will be overlaid on klist */
long	*ixnew;		/* will be overlaid on file[1] */
char	*chrtran;	/* translation table for case-folding */

/* chrtran points to one of 2 translation tables:
 *	cup2low if folding upper to lower case
 *	clow2low if not folding case
 */
char	clow2low[256] = {
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f,
0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f,
0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,
0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f,
0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,
0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf,
0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,
0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xdb,0xdc,0xdd,0xde,0xdf,
0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
};

char	cup2low[256] = {
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f,
0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f,
0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8a,0x8b,0x8c,0x8d,0x8e,0x8f,
0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9a,0x9b,0x9c,0x9d,0x9e,0x9f,
0xa0,0xa1,0xa2,0xa3,0xa4,0xa5,0xa6,0xa7,0xa8,0xa9,0xaa,0xab,0xac,0xad,0xae,0xaf,
0xb0,0xb1,0xb2,0xb3,0xb4,0xb5,0xb6,0xb7,0xb8,0xb9,0xba,0xbb,0xbc,0xbd,0xbe,0xbf,
0xc0,0xc1,0xc2,0xc3,0xc4,0xc5,0xc6,0xc7,0xc8,0xc9,0xca,0xcb,0xcc,0xcd,0xce,0xcf,
0xd0,0xd1,0xd2,0xd3,0xd4,0xd5,0xd6,0xd7,0xd8,0xd9,0xda,0xdb,0xdc,0xdd,0xde,0xdf,
0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
};

diffreg()
{
	register int i, j;
	FILE *f1, *f2;
	char buf1[BUFSIZ], buf2[BUFSIZ];

	if (hflag) {
		diffargv[0] = "diffh";
		execv(diffh, diffargv);
		fprintf(stderr, "diff: ");
		perror(diffh);
		done();
	}
	chrtran = (iflag? cup2low : clow2low);
	if ((stb1.st_mode & S_IFMT) == S_IFDIR) {
		file1 = splice(file1, file2);
		if (stat(file1, &stb1) < 0) {
			fprintf(stderr, "diff: ");
			perror(file1);
			done();
		}
	} else if ((stb2.st_mode & S_IFMT) == S_IFDIR) {
		file2 = splice(file2, file1);
		if (stat(file2, &stb2) < 0) {
			fprintf(stderr, "diff: ");
			perror(file2);
			done();
		}
	} else if (!strcmp(file1, "-")) {
		if (!strcmp(file2, "-")) {
			fprintf(stderr, "diff: can't specify - -\n");
			done();
		}
		file1 = copytemp();
		if (stat(file1, &stb1) < 0) {
			fprintf(stderr, "diff: ");
			perror(file1);
			done();
		}
	} else if (!strcmp(file2, "-")) {
		file2 = copytemp();
		if (stat(file2, &stb2) < 0) {
			fprintf(stderr, "diff: ");
			perror(file2);
			done();
		}
	}
	if ((f1 = fopen(file1, "r")) == NULL) {
		fprintf(stderr, "diff: ");
		perror(file1);
		done();
	}
	if ((f2 = fopen(file2, "r")) == NULL) {
		fprintf(stderr, "diff: ");
		perror(file2);
		fclose(f1);
		done();
	}
	if (stb1.st_size != stb2.st_size)
		goto notsame;
	for (;;) {
		i = fread(buf1, 1, BUFSIZ, f1);
		j = fread(buf2, 1, BUFSIZ, f2);
		if (i < 0 || j < 0 || i != j)
			goto notsame;
		if (i == 0 && j == 0) {
			fclose(f1);
			fclose(f2);
			status = 0;		/* files don't differ */
			goto same;
		}
		for (j = 0; j < i; j++)
			if (buf1[j] != buf2[j])
				goto notsame;
	}
notsame:
	/*
	 *	Files certainly differ at this point; set status accordingly
	 */
	status = 1;
	if (!asciifile(f1) || !asciifile(f2)) {
		printf("Binary files %s and %s differ\n", file1, file2);
		fclose(f1);
		fclose(f2);
		done();
	}
	prepare(0, f1);
	prepare(1, f2);
	fclose(f1);
	fclose(f2);
	prune();
	sort(sfile[0],slen[0]);
	sort(sfile[1],slen[1]);

	member = (int *)file[1];
	equiv(sfile[0], slen[0], sfile[1], slen[1], member);
	member = (int *)ralloc((char *)member,(slen[1]+2)*sizeof(int));

	class = (int *)file[0];
	unsort(sfile[0], slen[0], class);
	class = (int *)ralloc((char *)class,(slen[0]+2)*sizeof(int));

	klist = (int *)talloc((slen[0]+2)*sizeof(int));
	clist = (struct cand *)talloc(sizeof(cand));
	i = stone(class, slen[0], member, klist);
	free((char *)member);
	free((char *)class);

	J = (int *)talloc((len[0]+2)*sizeof(int));
	unravel(klist[i]);
	free((char *)clist);
	free((char *)klist);

	ixold = (long *)talloc((len[0]+2)*sizeof(long));
	ixnew = (long *)talloc((len[1]+2)*sizeof(long));
	check();
	output();
	status = anychange;
same:
	if (opt == D_CONTEXT && anychange == 0)
		printf("No differences encountered\n");
	done();
}

#include <sys/param.h>
char *
copytemp()
{
	char buf[MAXBSIZE];
	register int i, f;

	signal(SIGHUP,done);
	signal(SIGINT,done);
	signal(SIGPIPE,done);
	signal(SIGTERM,done);
	tempfile = mktemp("/tmp/dXXXXX");
	f = creat(tempfile,0600);
	if (f < 0) {
		fprintf(stderr, "diff: ");
		perror(tempfile);
		done();
	}
	while ((i = read(0,buf,sizeof(buf))) > 0)
		if (write(f,buf,i) != i) {
			fprintf(stderr, "diff: ");
			perror(tempfile);
			done();
		}
	close(f);
	return (tempfile);
}

char *
splice(dir, file)
	char *dir, *file;
{
	char *tail;
	char buf[BUFSIZ];

	if (!strcmp(file, "-")) {
		fprintf(stderr, "diff: can't specify - with other arg directory\n");
		done();
	}
	tail = rindex(file, '/');
	if (tail == 0)
		tail = file;
	else
		tail++;
	(void)sprintf(buf, "%s/%s", dir, tail);
	return (savestr(buf));
}

prepare(i, fd)
	int i;
	FILE *fd;
{
	register struct line *p;
	register j,h;

	fseek(fd, (long)0, 0);
	p = (struct line *)talloc(3*sizeof(line));
	for(j=0; h=readhash(fd);) {
		p = (struct line *)ralloc((char *)p,(++j+3)*sizeof(line));
		p[j].value = h;
	}
	len[i] = j;
	file[i] = p;
}

prune()
{
	register i,j;
	for(pref=0;pref<len[0]&&pref<len[1]&&
		file[0][pref+1].value==file[1][pref+1].value;
		pref++ ) ;
	for(suff=0;suff<len[0]-pref&&suff<len[1]-pref&&
		file[0][len[0]-suff].value==file[1][len[1]-suff].value;
		suff++) ;
	for(j=0;j<2;j++) {
		sfile[j] = file[j]+pref;
		slen[j] = len[j]-pref-suff;
		for(i=0;i<=slen[j];i++)
			sfile[j][i].serial = i;
	}
}

equiv(a,n,b,m,c)
struct line *a, *b;
int *c;
{
	register int i, j;
	i = j = 1;
	while(i<=n && j<=m) {
		if(a[i].value <b[j].value)
			a[i++].value = 0;
		else if(a[i].value == b[j].value)
			a[i++].value = j;
		else
			j++;
	}
	while(i <= n)
		a[i++].value = 0;
	b[m+1].value = 0;
	j = 0;
	while(++j <= m) {
		c[j] = -b[j].serial;
		while(b[j+1].value == b[j].value) {
			j++;
			c[j] = b[j].serial;
		}
	}
	c[j] = -1;
}

stone(a,n,b,c)
int *a;
int *b;
register int *c;
{
	register int i, k,y;
	int j, l;
	int oldc, tc;
	int oldl;
	k = 0;
	c[0] = newcand(0,0,0);
	for(i=1; i<=n; i++) {
		j = a[i];
		if(j==0)
			continue;
		y = -b[j];
		oldl = 0;
		oldc = c[0];
		do {
			if(y <= clist[oldc].y)
				continue;
			l = search(c, k, y);
			if(l!=oldl+1)
				oldc = c[l-1];
			if(l<=k) {
				if(clist[c[l]].y <= y)
					continue;
				tc = c[l];
				c[l] = newcand(i,y,oldc);
				oldc = tc;
				oldl = l;
			} else {
				c[l] = newcand(i,y,oldc);
				k++;
				break;
			}
		} while((y=b[++j]) > 0);
	}
	return(k);
}

newcand(x,y,pred)
{
	register struct cand *q;
	clist = (struct cand *)ralloc((char *)clist,++clen*sizeof(cand));
	q = clist + clen -1;
	q->x = x;
	q->y = y;
	q->pred = pred;
	return(clen-1);
}

search(c, k, y)
int *c;
{
	register int i, j, l;
	int t;
	if(clist[c[k]].y<y)	/*quick look for typical case*/
		return(k+1);
	i = 0;
	j = k+1;
	while (1) {
		l = i + j;
		if ((l >>= 1) <= i) 
			break;
		t = clist[c[l]].y;
		if(t > y)
			j = l;
		else if(t < y)
			i = l;
		else
			return(l);
	}
	return(l+1);
}

unravel(p)
{
	register int i;
	register struct cand *q;
	for(i=0; i<=len[0]; i++)
		J[i] =	i<=pref ? i:
			i>len[0]-suff ? i+len[1]-len[0]:
			0;
	for(q=clist+p;q->y!=0;q=clist+q->pred)
		J[q->x+pref] = q->y+pref;
}

/* check does double duty:
1.  ferret out any fortuitous correspondences due
to confounding by hashing (which result in "jackpot")
2.  collect random access indexes to the two files */

check()
{
	register int i, j;
	int jackpot;
	register long ctold, ctnew;
	register int c,d;

	if ((input[0] = fopen(file1,"r")) == NULL) {
		perror(file1);
		done();
	}
	if ((input[1] = fopen(file2,"r")) == NULL) {
		perror(file2);
		done();
	}
	j = 1;
	ixold[0] = ixnew[0] = 0;
	jackpot = 0;
	ctold = ctnew = 0;
	for(i=1;i<=len[0];i++) {
		if(J[i]==0) {
			ixold[i] = ctold += skipline(0);
			continue;
		}
		while(j<J[i]) {
			ixnew[j] = ctnew += skipline(1);
			j++;
		}
		if(bflag || wflag || iflag) {
			for(;;) {
				c = getc(input[0]);
				d = getc(input[1]);
				ctold++;
				ctnew++;
				if(bflag && isspace(c) && isspace(d)) {
					do {
						if(c=='\n')
							break;
						ctold++;
					} while(isspace(c=getc(input[0])));
					do {
						if(d=='\n')
							break;
						ctnew++;