steveh@hammer.UUCP (Stephen Hemminger) (09/28/85)
The following change speeds up xstr substantially (it can be a big cpu hog
if you are building a big program.
Gprof says most of the time was spent in istail which was doing lots
of strlen's. By finding the length of the string once at the start of
the loop, and storing the length of the hash element in the table
things go a lot faster (it becomes IO bound).
It also incorporates Guy's fixes (in a different form).
-------------------------
*** xstr.c.orig Sat Sep 28 09:46:46 1985
--- xstr.c Sat Sep 28 10:15:17 1985
***************
*** 11,17
* November, 1978
*/
! #define ignore(a) Ignore((char *) a)
char *calloc();
off_t tellpt;
--- 11,17 -----
* November, 1978
*/
! #define ignore(a) ((void) a)
/*NOSTRICT*/
char *
***************
*** 13,19
#define ignore(a) Ignore((char *) a)
! char *calloc();
off_t tellpt;
off_t hashit();
char *mktemp();
--- 13,33 -----
#define ignore(a) ((void) a)
! /*NOSTRICT*/
! char *
! emalloc(size)
! unsigned size;
! {
! register char *p;
! extern char *malloc();
!
! if( (p = malloc(size)) == NULL) {
! fprintf(stderr, "xstr: out of memory\n");
! exit(8);
! }
! return p;
! }
!
off_t tellpt;
off_t hashit();
char *mktemp();
***************
*** 18,24
off_t hashit();
char *mktemp();
int onintr();
- char *savestr();
char *strcat();
char *strcpy();
off_t yankstr();
--- 32,37 -----
off_t hashit();
char *mktemp();
int onintr();
char *strcat();
char *strcpy();
off_t yankstr();
***************
*** 59,65
} while (*cp);
}
if (signal(SIGINT, SIG_IGN) == SIG_DFL)
! signal(SIGINT, onintr);
if (cflg || argc == 0 && !readstd)
inithash();
else
--- 72,78 -----
} while (*cp);
}
if (signal(SIGINT, SIG_IGN) == SIG_DFL)
! ignore(signal(SIGINT, onintr));
if (cflg || argc == 0 && !readstd)
inithash();
else
***************
*** 63,69
if (cflg || argc == 0 && !readstd)
inithash();
else
! strings = mktemp(savestr("/tmp/xstrXXXXXX"));
while (readstd || argc > 0) {
if (freopen("x.c", "w", stdout) == NULL)
perror("x.c"), exit(1);
--- 76,82 -----
if (cflg || argc == 0 && !readstd)
inithash();
else
! strings = mktemp("/tmp/xstrXXXXXX");
while (readstd || argc > 0) {
if (freopen("x.c", "w", stdout) == NULL)
perror("x.c"), exit(1);
***************
*** 91,97
register int c;
register int incomm = 0;
! printf("char\txstr[];\n");
for (;;) {
if (fgets(linebuf, sizeof linebuf, stdin) == NULL) {
if (ferror(stdin)) {
--- 104,110 -----
register int c;
register int incomm = 0;
! printf("extern char\txstr[];\n");
for (;;) {
if (fgets(linebuf, sizeof linebuf, stdin) == NULL) {
if (ferror(stdin)) {
***************
*** 248,255
#define BUCKETS 128
struct hash {
- off_t hpt;
- char *hstr;
struct hash *hnext;
short hnew;
} bucket[BUCKETS];
--- 261,266 -----
#define BUCKETS 128
struct hash {
struct hash *hnext;
char *hstr;
int hlen;
***************
*** 251,256
off_t hpt;
char *hstr;
struct hash *hnext;
short hnew;
} bucket[BUCKETS];
--- 262,270 -----
struct hash {
struct hash *hnext;
+ char *hstr;
+ int hlen;
+ off_t hpt;
short hnew;
} bucket[BUCKETS];
***************
*** 259,265
char *str;
int new;
{
- int i;
register struct hash *hp, *hp0;
hp = hp0 = &bucket[lastchr(str) & 0177];
--- 273,278 -----
char *str;
int new;
{
register struct hash *hp, *hp0;
register int i, len;
***************
*** 261,266
{
int i;
register struct hash *hp, *hp0;
hp = hp0 = &bucket[lastchr(str) & 0177];
while (hp->hnext) {
--- 274,280 -----
int new;
{
register struct hash *hp, *hp0;
+ register int i, len;
hp0 = &bucket[lastchr(str) & 0177];
len = strlen(str);
***************
*** 262,272
int i;
register struct hash *hp, *hp0;
! hp = hp0 = &bucket[lastchr(str) & 0177];
! while (hp->hnext) {
! hp = hp->hnext;
! i = istail(str, hp->hstr);
! if (i >= 0)
return (hp->hpt + i);
}
hp = (struct hash *) calloc(1, sizeof (*hp));
--- 276,286 -----
register struct hash *hp, *hp0;
register int i, len;
! hp0 = &bucket[lastchr(str) & 0177];
! len = strlen(str);
! for (hp = hp0; hp; hp = hp->hnext) {
! i = hp->hlen - len;
! if(i >= 0 && strcmp(&hp->hstr[i], str) == 0)
return (hp->hpt + i);
}
hp = (struct hash *) emalloc(sizeof (*hp));
***************
*** 269,275
if (i >= 0)
return (hp->hpt + i);
}
! hp = (struct hash *) calloc(1, sizeof (*hp));
hp->hpt = mesgpt;
hp->hstr = savestr(str);
mesgpt += strlen(hp->hstr) + 1;
--- 283,289 -----
if(i >= 0 && strcmp(&hp->hstr[i], str) == 0)
return (hp->hpt + i);
}
! hp = (struct hash *) emalloc(sizeof (*hp));
hp->hpt = mesgpt;
hp->hlen = len;
hp->hstr = strcpy(emalloc(len+1), str);
***************
*** 271,278
}
hp = (struct hash *) calloc(1, sizeof (*hp));
hp->hpt = mesgpt;
! hp->hstr = savestr(str);
! mesgpt += strlen(hp->hstr) + 1;
hp->hnext = hp0->hnext;
hp->hnew = new;
hp0->hnext = hp;
--- 285,293 -----
}
hp = (struct hash *) emalloc(sizeof (*hp));
hp->hpt = mesgpt;
! hp->hlen = len;
! hp->hstr = strcpy(emalloc(len+1), str);
! mesgpt += len + 1;
hp->hnext = hp0->hnext;
hp->hnew = new;
hp0->hnext = hp;
***************
*** 301,307
for (hp = bucket[i].hnext; hp != NULL; hp = hp->hnext) {
found(hp->hnew, hp->hpt, hp->hstr);
if (hp->hnew) {
! fseek(mesgwrit, hp->hpt, 0);
ignore(fwrite(hp->hstr, strlen(hp->hstr) + 1, 1, mesgwrit));
if (ferror(mesgwrit))
perror(strings), exit(4);
--- 316,322 -----
for (hp = bucket[i].hnext; hp != NULL; hp = hp->hnext) {
found(hp->hnew, hp->hpt, hp->hstr);
if (hp->hnew) {
! ignore(fseek(mesgwrit, hp->hpt, 0));
ignore(fwrite(hp->hstr, strlen(hp->hstr) + 1, 1, mesgwrit));
if (ferror(mesgwrit))
perror(strings), exit(4);
***************
*** 307,313
perror(strings), exit(4);
}
}
! ignore(fclose(mesgwrit));
}
found(new, off, str)
--- 322,329 -----
perror(strings), exit(4);
}
}
! if(fclose(mesgwrit) == EOF)
! perror(strings), exit(4);
}
found(new, off, str)
***************
*** 315,322
off_t off;
char *str;
{
- register char *cp;
-
if (vflg == 0)
return;
if (!new)
--- 331,336 -----
off_t off;
char *str;
{
if (vflg == 0)
return;
if (!new)
***************
*** 377,405
ignore(fclose(strf));
}
- char *
- savestr(cp)
- register char *cp;
- {
- register char *dp = (char *) calloc(1, strlen(cp) + 1);
-
- return (strcpy(dp, cp));
- }
-
- Ignore(a)
- char *a;
- {
-
- a = a;
- }
-
- ignorf(a)
- int (*a)();
- {
-
- a = a;
- }
-
lastchr(cp)
register char *cp;
{
--- 391,396 -----
ignore(fclose(strf));
}
lastchr(cp)
register char *cp;
{
***************
*** 409,424
return (*cp);
}
- istail(str, of)
- register char *str, *of;
- {
- register int d = strlen(of) - strlen(str);
-
- if (d < 0 || strcmp(&of[d], str) != 0)
- return (-1);
- return (d);
- }
-
onintr()
{
--- 400,405 -----
return (*cp);
}
onintr()
{
***************
*** 422,428
onintr()
{
! ignorf(signal(SIGINT, SIG_IGN));
if (strings[0] == '/')
ignore(unlink(strings));
ignore(unlink("x.c"));
--- 403,409 -----
onintr()
{
! ignore(signal(SIGINT, SIG_IGN));
if (strings[0] == '/')
ignore(unlink(strings));
ignore(unlink("x.c"));