[hackers] [sbase] Revert "Make grep more memory-efficient" || sin

From: <git_AT_suckless.org>
Date: Mon, 12 May 2014 13:06:43 +0200

commit 4896bdf6de4abc90f2c6a073f065683910d5d15a
Author: sin <sin_AT_2f30.org>
Date: Mon May 12 11:59:39 2014 +0100

    Revert "Make grep more memory-efficient"
    
    This reverts commit d9a098ae6bc07188cbaefcd188e5911dec41815d.
    
    Conflicts:
            grep.c
    
    Hiltjo Posthuma <hiltjo_AT_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.

diff --git a/grep.c b/grep.c
index 8651619..f4fe7df 100644
--- a/grep.c
+++ b/grep.c
_AT_@ -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;
_AT_@ -20,6 +20,7 @@ static char mode = 0;
 
 static struct plist {
         char *pattern;
+ regex_t preg;
         struct plist *next;
 } *phead;
 
_AT_@ -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 {
_AT_@ -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) {
_AT_@ -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
", 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);
                 }
_AT_@ -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;
_AT_@ -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
", err);
- }
                         if(buf[(len = strlen(buf))-1] == '
')
                                 buf[--len] = '
Received on Mon May 12 2014 - 13:06:43 CEST