File: [local] / src / usr.bin / diff / diffreg.c (download)
Revision 1.11, Wed Jun 25 03:50:27 2003 UTC (20 years, 11 months ago) by deraadt
Branch: MAIN
Changes since 1.10: +9 -7 lines
more knf
|
/* $OpenBSD: diffreg.c,v 1.11 2003/06/25 03:50:27 deraadt Exp $ */
/*
* Copyright (C) Caldera International Inc. 2001-2002.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code and documentation must retain the above
* copyright notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed or owned by Caldera
* International, Inc.
* 4. Neither the name of Caldera International, Inc. nor the names of other
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
* INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
* INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include "diff.h"
#include "pathnames.h"
#if 0
static char const sccsid[] = "@(#)diffreg.c 4.21 4/6/90";
#endif
/*
* 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)
FILE *input[2];
struct cand {
int x;
int y;
int pred;
} cand;
struct line {
int serial;
int value;
} *file[2];
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] */
u_char *chrtran; /* translation table for case-folding */
static void fetch(long *, int, int, FILE *, char *, int);
static void output(void);
static void check(void);
static void range(int, int, char *);
static void dump_context_vec(void);
static void prepare(int, FILE *);
static void prune(void);
static void equiv(struct line *, int, struct line *, int, int *);
static void unravel(int);
static void unsort(struct line *, int, int *);
static void change(int, int, int, int);
static void sort(struct line *, int);
static int newcand(int, int, int);
static int search(int *, int, int);
static int skipline(int);
static int asciifile(FILE *);
static int stone(int *, int, int *, int *);
static int readhash(FILE *);
/*
* chrtran points to one of 2 translation tables: cup2low if folding upper to
* lower case clow2low if not folding case
*/
u_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
};
u_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
};
void
diffreg(void)
{
char buf1[BUFSIZ], buf2[BUFSIZ];
FILE *f1, *f2;
int i, j;
if (hflag) {
diffargv[0] = "diffh";
execv(diffh, diffargv);
fprintf(stderr, "diff: ");
perror(diffh);
done(0);
}
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(0);
}
} else if ((stb2.st_mode & S_IFMT) == S_IFDIR) {
file2 = splice(file2, file1);
if (stat(file2, &stb2) < 0) {
fprintf(stderr, "diff: ");
perror(file2);
done(0);
}
} else if ((stb1.st_mode & S_IFMT) != S_IFREG || !strcmp(file1, "-")) {
if (!strcmp(file2, "-")) {
fprintf(stderr, "diff: can't specify - -\n");
done(0);
}
file1 = copytemp();
if (stat(file1, &stb1) < 0) {
fprintf(stderr, "diff: ");
perror(file1);
done(0);
}
} else if ((stb2.st_mode & S_IFMT) != S_IFREG || !strcmp(file2, "-")) {
file2 = copytemp();
if (stat(file2, &stb2) < 0) {
fprintf(stderr, "diff: ");
perror(file2);
done(0);
}
}
if ((f1 = fopen(file1, "r")) == NULL) {
fprintf(stderr, "diff: ");
perror(file1);
done(0);
}
if ((f2 = fopen(file2, "r")) == NULL) {
fprintf(stderr, "diff: ");
perror(file2);
fclose(f1);
done(0);
}
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(0);
}
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 = ralloc(member, (slen[1] + 2) * sizeof(int));
class = (int *)file[0];
unsort(sfile[0], slen[0], class);
class = ralloc(class, (slen[0] + 2) * sizeof(int));
klist = talloc((slen[0] + 2) * sizeof(int));
clist = talloc(sizeof(cand));
i = stone(class, slen[0], member, klist);
free(member);
free(class);
J = talloc((len[0] + 2) * sizeof(int));
unravel(klist[i]);
free(clist);
free(klist);
ixold = talloc((len[0] + 2) * sizeof(long));
ixnew = talloc((len[1] + 2) * sizeof(long));
check();
output();
status = anychange;
same:
if (opt == D_CONTEXT && anychange == 0)
printf("No differences encountered\n");
done(0);
}
char *tempfile = _PATH_TMP;
char *
copytemp(void)
{
char buf[BUFSIZ];
int i, f;
signal(SIGHUP, catchsig);
signal(SIGINT, catchsig);
signal(SIGPIPE, catchsig);
signal(SIGTERM, catchsig);
f = mkstemp(tempfile);
if (f < 0) {
fprintf(stderr, "diff: ");
perror(tempfile);
done(0);
}
while ((i = read(0, buf, BUFSIZ)) > 0)
if (write(f, buf, i) != i) {
fprintf(stderr, "diff: ");
perror(tempfile);
done(0);
}
close(f);
return (tempfile);
}
char *
splice(char *dir, char *file)
{
char *tail, buf[BUFSIZ];
if (!strcmp(file, "-")) {
fprintf(stderr, "diff: can't specify - with other arg directory\n");
done(0);
}
tail = strrchr(file, '/');
if (tail == 0)
tail = file;
else
tail++;
snprintf(buf, sizeof buf, "%s/%s", dir, tail);
return (strdup(buf));
}
static void
prepare(int i, FILE *fd)
{
struct line *p;
int j, h;
fseek(fd, 0, 0);
p = talloc(3 * sizeof(struct line));
for (j = 0; (h = readhash(fd));) {
p = ralloc(p, (++j + 3) * sizeof(struct line));
p[j].value = h;
}
len[i] = j;
file[i] = p;
}
static void
prune(void)
{
int 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;
}
}
static void
equiv(struct line *a, int n, struct line *b, int m, int *c)
{
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;
}
static int
stone(int *a, int n, int *b, int *c)
{
int i, k, y, j, l;
int oldc, tc, 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);
}
static int
newcand(int x, int y, int pred)
{
struct cand *q;
clist = ralloc(clist, ++clen * sizeof(cand));
q = clist + clen - 1;
q->x = x;
q->y = y;
q->pred = pred;
return (clen - 1);
}
static int
search(int *c, int k, int y)
{
int i, j, l, 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);
}
static void
unravel(int p)
{
struct cand *q;
int i;
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
*/
static void
check(void)
{
int i, j, jackpot, c, d;
long ctold, ctnew;
if ((input[0] = fopen(file1, "r")) == NULL) {
perror(file1);
done(0);
}
if ((input[1] = fopen(file2, "r")) == NULL) {
perror(file2);
done(0);
}
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++;
} while (isspace(d = getc(input[1])));
} else if (wflag) {
while (isspace(c) && c != '\n') {
c = getc(input[0]);
ctold++;
}
while (isspace(d) && d != '\n') {
d = getc(input[1]);
ctnew++;
}
}
if (chrtran[c] != chrtran[d]) {
jackpot++;
J[i] = 0;
if (c != '\n')
ctold += skipline(0);
if (d != '\n')
ctnew += skipline(1);
break;
}
if (c == '\n')
break;
}
} else {
for (;;) {
ctold++;
ctnew++;
if ((c = getc(input[0])) != (d = getc(input[1]))) {
/* jackpot++; */
J[i] = 0;
if (c != '\n')
ctold += skipline(0);
if (d != '\n')
ctnew += skipline(1);
break;
}
if (c == '\n')
break;
}
}
ixold[i] = ctold;
ixnew[j] = ctnew;
j++;
}
for (; j <= len[1]; j++) {
ixnew[j] = ctnew += skipline(1);
}
fclose(input[0]);
fclose(input[1]);
/*
* if (jackpot)
* fprintf(stderr, "jackpot\n");
*/
}
/* shellsort CACM #201 */
static void
sort(struct line *a, int n)
{
struct line *ai, *aim, w;
int j, m = 0, k;
if (n == 0)
return;
for (j = 1; j <= n; j *= 2)
m = 2 * j - 1;
for (m /= 2; m != 0; m /= 2) {
k = n - m;
for (j = 1; j <= k; j++) {
for (ai = &a[j]; ai > a; ai -= m) {
aim = &ai[m];
if (aim < ai)
break; /* wraparound */
if (aim->value > ai[0].value ||
(aim->value == ai[0].value &&
aim->serial > ai[0].serial))
break;
w.value = ai[0].value;
ai[0].value = aim->value;
aim->value = w.value;
w.serial = ai[0].serial;
ai[0].serial = aim->serial;
aim->serial = w.serial;
}
}
}
}
static void
unsort(struct line *f, int l, int *b)
{
int *a, i;
a = talloc((l + 1) * sizeof(int));
for (i = 1; i <= l; i++)
a[f[i].serial] = f[i].value;
for (i = 1; i <= l; i++)
b[i] = a[i];
free(a);
}
static int
skipline(int f)
{
int i, c;
for (i = 1; (c = getc(input[f])) != '\n'; i++)
if (c < 0)
return (i);
return (i);
}
static void
output(void)
{
int m, i0, i1, j0, j1;
input[0] = fopen(file1, "r");
input[1] = fopen(file2, "r");
m = len[0];
J[0] = 0;
J[m + 1] = len[1] + 1;
if (opt != D_EDIT) {
for (i0 = 1; i0 <= m; i0 = i1 + 1) {
while (i0 <= m && J[i0] == J[i0 - 1] + 1)
i0++;
j0 = J[i0 - 1] + 1;
i1 = i0 - 1;
while (i1 < m && J[i1 + 1] == 0)
i1++;
j1 = J[i1 + 1] - 1;
J[i1] = j1;
change(i0, i1, j0, j1);
}
} else {
for (i0 = m; i0 >= 1; i0 = i1 - 1) {
while (i0 >= 1 && J[i0] == J[i0 + 1] - 1 && J[i0] != 0)
i0--;
j0 = J[i0 + 1] - 1;
i1 = i0 + 1;
while (i1 > 1 && J[i1 - 1] == 0)
i1--;
j1 = J[i1 - 1] + 1;
J[i1] = j1;
change(i1, i0, j1, j0);
}
}
if (m == 0)
change(1, 0, 1, len[1]);
if (opt == D_IFDEF) {
for (;;) {
#define c i0
c = getc(input[0]);
if (c < 0)
return;
putchar(c);
}
#undef c
}
if (anychange && opt == D_CONTEXT)
dump_context_vec();
}
/*
* The following struct is used to record change information when
* doing a "context" diff. (see routine "change" to understand the
* highly mneumonic field names)
*/
struct context_vec {
int a; /* start line in old file */
int b; /* end line in old file */
int c; /* start line in new file */
int d; /* end line in new file */
};
struct context_vec *context_vec_start, *context_vec_end, *context_vec_ptr;
#define MAX_CONTEXT 128
/*
* indicate that there is a difference between lines a and b of the from file
* to get to lines c to d of the to file. If a is greater then b then there
* are no lines in the from file involved and this means that there were
* lines appended (beginning at b). If c is greater than d then there are
* lines missing from the to file.
*/
static void
change(int a, int b, int c, int d)
{
struct stat stbuf;
if (opt != D_IFDEF && a > b && c > d)
return;
if (anychange == 0) {
anychange = 1;
if (opt == D_CONTEXT) {
printf("*** %s ", file1);
stat(file1, &stbuf);
printf("%s--- %s ",
ctime(&stbuf.st_mtime), file2);
stat(file2, &stbuf);
printf("%s", ctime(&stbuf.st_mtime));
context_vec_start = talloc(MAX_CONTEXT *
sizeof(struct context_vec));
context_vec_end = context_vec_start + MAX_CONTEXT;
context_vec_ptr = context_vec_start - 1;
}
}
if (opt == D_CONTEXT) {
/*
* if this new change is within 'context' lines of
* the previous change, just add it to the change
* record. If the record is full or if this
* change is more than 'context' lines from the previous
* change, dump the record, reset it & add the new change.
*/
if (context_vec_ptr >= context_vec_end ||
(context_vec_ptr >= context_vec_start &&
a > (context_vec_ptr->b + 2 * context) &&
c > (context_vec_ptr->d + 2 * context)))
dump_context_vec();
context_vec_ptr++;
context_vec_ptr->a = a;
context_vec_ptr->b = b;
context_vec_ptr->c = c;
context_vec_ptr->d = d;
return;
}
switch (opt) {
case D_NORMAL:
case D_EDIT:
range(a, b, ",");
putchar(a > b ? 'a' : c > d ? 'd' : 'c');
if (opt == D_NORMAL)
range(c, d, ",");
putchar('\n');
break;
case D_REVERSE:
putchar(a > b ? 'a' : c > d ? 'd' : 'c');
range(a, b, " ");
putchar('\n');
break;
case D_NREVERSE:
if (a > b)
printf("a%d %d\n", b, d - c + 1);
else {
printf("d%d %d\n", a, b - a + 1);
if (!(c > d))
/* add changed lines */
printf("a%d %d\n", b, d - c + 1);
}
break;
}
if (opt == D_NORMAL || opt == D_IFDEF) {
fetch(ixold, a, b, input[0], "< ", 1);
if (a <= b && c <= d && opt == D_NORMAL)
prints("---\n");
}
fetch(ixnew, c, d, input[1], opt == D_NORMAL ? "> " : "", 0);
if ((opt == D_EDIT || opt == D_REVERSE) && c <= d)
prints(".\n");
if (inifdef) {
fprintf(stdout, "#endif /* %s */\n", endifname);
inifdef = 0;
}
}
static void
range(int a, int b, char *separator)
{
printf("%d", a > b ? b : a);
if (a < b)
printf("%s%d", separator, b);
}
static void
fetch(long *f, int a, int b, FILE *lb, char *s, int oldfile)
{
int oneflag = (*ifdef1 != '\0') != (*ifdef2 != '\0');
int i, j, c, col, nc;
/*
* When doing #ifdef's, copy down to current line
* if this is the first file, so that stuff makes it to output.
*/
if (opt == D_IFDEF && oldfile) {
long curpos = ftell(lb);
/* print through if append (a>b), else to (nb: 0 vs 1 orig) */
nc = f[a > b ? b : a - 1] - curpos;
for (i = 0; i < nc; i++)
putchar(getc(lb));
}
if (a > b)
return;
if (opt == D_IFDEF) {
if (inifdef)
fprintf(stdout, "#else /* %s%s */\n",
oneflag && oldfile == 1 ? "!" : "", ifdef2);
else {
if (oneflag) {
/* There was only one ifdef given */
endifname = ifdef2;
if (oldfile)
fprintf(stdout, "#ifndef %s\n", endifname);
else
fprintf(stdout, "#ifdef %s\n", endifname);
} else {
endifname = oldfile ? ifdef1 : ifdef2;
fprintf(stdout, "#ifdef %s\n", endifname);
}
}
inifdef = 1 + oldfile;
}
for (i = a; i <= b; i++) {
fseek(lb, f[i - 1], 0);
nc = f[i] - f[i - 1];
if (opt != D_IFDEF)
prints(s);
col = 0;
for (j = 0; j < nc; j++) {
c = getc(lb);
if (c == '\t' && tflag)
do
putchar(' ');
while (++col & 7)
;
else {
putchar(c);
col++;
}
}
}
if (inifdef && !wantelses) {
fprintf(stdout, "#endif /* %s */\n", endifname);
inifdef = 0;
}
}
#define POW2 /* define only if HALFLONG is 2**n */
#define HALFLONG 16
#define low(x) (x&((1L<<HALFLONG)-1))
#define high(x) (x>>HALFLONG)
/*
* hashing has the effect of
* arranging line in 7-bit bytes and then
* summing 1-s complement in 16-bit hunks
*/
static int
readhash(FILE *f)
{
unsigned int shift;
int t, space;
long sum;
sum = 1;
space = 0;
if (!bflag && !wflag) {
if (iflag)
for (shift = 0; (t = getc(f)) != '\n'; shift += 7) {
if (t == -1)
return (0);
sum += (long)chrtran[t] << (shift
#ifdef POW2
&= HALFLONG - 1);
#else
%= HALFLONG);
#endif
}
else
for (shift = 0; (t = getc(f)) != '\n'; shift += 7) {
if (t == -1)
return (0);
sum += (long)t << (shift
#ifdef POW2
&= HALFLONG - 1);
#else
%= HALFLONG);
#endif
}
} else {
for (shift = 0;;) {
switch (t = getc(f)) {
case -1:
return (0);
case '\t':
case ' ':
space++;
continue;
default:
if (space && !wflag) {
shift += 7;
space = 0;
}
sum += (long)chrtran[t] << (shift
#ifdef POW2
&= HALFLONG - 1);
#else
%= HALFLONG);
#endif
shift += 7;
continue;
case '\n':
break;
}
break;
}
}
sum = low(sum) + high(sum);
return ((short) low(sum) + (short) high(sum));
}
static int
asciifile(FILE *f)
{
char buf[BUFSIZ], *cp;
int cnt;
fseek(f, 0, 0);
cnt = fread(buf, 1, BUFSIZ, f);
cp = buf;
while (--cnt >= 0)
if (*cp++ & 0200)
return (0);
return (1);
}
/* dump accumulated "context" diff changes */
static void
dump_context_vec(void)
{
struct context_vec *cvp = context_vec_start;
int lowa, upb, lowc, upd, do_output;
int a, b, c, d;
char ch;
if (cvp > context_vec_ptr)
return;
b = d = 0; /* gcc */
lowa = max(1, cvp->a - context);
upb = min(len[0], context_vec_ptr->b + context);
lowc = max(1, cvp->c - context);
upd = min(len[1], context_vec_ptr->d + context);
printf("***************\n*** ");
range(lowa, upb, ",");
printf(" ****\n");
/*
* output changes to the "old" file. The first loop suppresses
* output if there were no changes to the "old" file (we'll see
* the "old" lines as context in the "new" list).
*/
do_output = 0;
for (; cvp <= context_vec_ptr; cvp++)
if (cvp->a <= cvp->b) {
cvp = context_vec_start;
do_output++;
break;
}
if (do_output) {
while (cvp <= context_vec_ptr) {
a = cvp->a;
b = cvp->b;
c = cvp->c;
d = cvp->d;
if (a <= b && c <= d)
ch = 'c';
else
ch = (a <= b) ? 'd' : 'a';
if (ch == 'a')
fetch(ixold, lowa, b, input[0], " ", 0);
else {
fetch(ixold, lowa, a - 1, input[0], " ", 0);
fetch(ixold, a, b, input[0],
ch == 'c' ? "! " : "- ", 0);
}
lowa = b + 1;
cvp++;
}
fetch(ixold, b + 1, upb, input[0], " ", 0);
}
/* output changes to the "new" file */
printf("--- ");
range(lowc, upd, ",");
printf(" ----\n");
do_output = 0;
for (cvp = context_vec_start; cvp <= context_vec_ptr; cvp++)
if (cvp->c <= cvp->d) {
cvp = context_vec_start;
do_output++;
break;
}
if (do_output) {
while (cvp <= context_vec_ptr) {
a = cvp->a;
b = cvp->b;
c = cvp->c;
d = cvp->d;
if (a <= b && c <= d)
ch = 'c';
else
ch = (a <= b) ? 'd' : 'a';
if (ch == 'd')
fetch(ixnew, lowc, d, input[1], " ", 0);
else {
fetch(ixnew, lowc, c - 1, input[1], " ", 0);
fetch(ixnew, c, d, input[1],
ch == 'c' ? "! " : "+ ", 0);
}
lowc = d + 1;
cvp++;
}
fetch(ixnew, d + 1, upd, input[1], " ", 0);
}
context_vec_ptr = context_vec_start - 1;
}