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Revert "Make grep more memory-efficient"

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This reverts commit d9a098ae6bc07188cbaefcd188e5911dec41815d.

Conflicts:
	grep.c

Hiltjo Posthuma <hiltjo@codemadness.org> said:

(Re)compiling the regex for each line doesn't make sense (imho) and
slows it down a lot.

A simple test:

time seq 1 100000000 | grep 'a'

sbase grep (before patch):
    0m22.21s real     0m0.00s user     0m0.00s system

sbase grep (after patch):
    2m16.28s real     0m0.00s user     0m0.00s system

coreutils grep:
    0m1.15s real     0m0.00s user     0m0.00s system

So the patch should be reverted I think.
This commit is contained in:
sin 2014-05-12 11:59:39 +01:00
parent 5b3a0a9382
commit 4896bdf6de
1 changed files with 18 additions and 18 deletions
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36
grep.c
View File

@ -11,7 +11,7 @@
enum { Match = 0, NoMatch = 1, Error = 2 };
static void addpattern(const char *);
static bool grep(FILE *, const char *, int);
static bool grep(FILE *, const char *);
static bool eflag = false;
static bool vflag = false;
@ -20,6 +20,7 @@ static char mode = 0;
static struct plist {
char *pattern;
regex_t preg;
struct plist *next;
} *phead;
@ -34,7 +35,7 @@ main(int argc, char *argv[])
{
bool match = false;
struct plist *pnode, *tmp;
int i, flags = REG_NOSUB;
int i, n, flags = REG_NOSUB;
FILE *fp;
ARGBEGIN {
@ -61,9 +62,8 @@ main(int argc, char *argv[])
usage();
} ARGEND;
/* no pattern */
if(argc == 0 && !eflag)
usage();
usage(); /* no pattern */
/* If -e is not specified treat it as if it were */
if(!eflag) {
@ -72,14 +72,23 @@ main(int argc, char *argv[])
argv++;
}
/* Compile regex for all search patterns */
for(pnode = phead; pnode; pnode = pnode->next) {
if((n = regcomp(&pnode->preg, pnode->pattern, flags)) != 0) {
char buf[BUFSIZ];
regerror(n, &pnode->preg, buf, sizeof buf);
enprintf(Error, "invalid pattern: %s\n", buf);
}
}
many = (argc > 1);
if(argc == 0) {
match = grep(stdin, "<stdin>", flags);
match = grep(stdin, "<stdin>");
} else {
for(i = 0; i < argc; i++) {
if(!(fp = fopen(argv[i], "r")))
enprintf(Error, "fopen %s:", argv[i]);
if(grep(fp, argv[i], flags))
if(grep(fp, argv[i]))
match = true;
fclose(fp);
}
@ -87,6 +96,7 @@ main(int argc, char *argv[])
pnode = phead;
while(pnode) {
tmp = pnode->next;
regfree(&pnode->preg);
free(pnode->pattern);
free(pnode);
pnode = tmp;
@ -110,29 +120,20 @@ addpattern(const char *pattern)
}
bool
grep(FILE *fp, const char *str, int flags)
grep(FILE *fp, const char *str)
{
char err[BUFSIZ];
char *buf = NULL;
long n, c = 0;
int r;
static regex_t preg;
size_t size = 0, len;
struct plist *pnode;
bool match = false;
for(n = 1; afgets(&buf, &size, fp); n++) {
for(pnode = phead; pnode; pnode = pnode->next) {
if((r = regcomp(&preg, pnode->pattern, flags)) != 0) {
regerror(r, &preg, err, sizeof err);
enprintf(Error, "invalid pattern: %s\n", err);
}
if(buf[(len = strlen(buf))-1] == '\n')
buf[--len] = '\0';
if(regexec(&preg, buf, 0, NULL, 0) ^ vflag){
regfree(&preg);
if(regexec(&pnode->preg, buf, 0, NULL, 0) ^ vflag)
continue;
}
switch(mode) {
case 'c':
c++;
@ -158,7 +159,6 @@ grep(FILE *fp, const char *str, int flags)
end:
if(ferror(fp))
enprintf(Error, "%s: read error:", str);
regfree(&preg);
free(buf);
return match;
}