[hackers] [sbase] sort: reuse buffer in columns() || Hiltjo Posthuma

From: <git_AT_suckless.org>
Date: Thu, 7 May 2015 19:18:55 +0200 (CEST)

commit 72250324b1af5c8d7d9a036fe8860252487a533f
Author: Hiltjo Posthuma <hiltjo_AT_codemadness.org>
Date: Tue May 5 13:41:43 2015 +0200

    sort: reuse buffer in columns()
    
    speeds up sorting for huge input aswell.

diff --git a/sort.c b/sort.c
index 901189e..8ec14c3 100644
--- a/sort.c
+++ b/sort.c
_AT_@ -38,10 +38,12 @@ static int parse_keydef(struct keydef *, char *, int);
 static char *skipblank(char *);
 static char *skipnonblank(char *);
 static char *skipcolumn(char *, char *, int);
-static char *columns(char *, const struct keydef *);
+static size_t columns(char *, const struct keydef *, char **, size_t *);
 
 static int Cflag = 0, cflag = 0, uflag = 0;
 static char *fieldsep = NULL;
+static char *col1, *col2;
+static size_t col1siz, col2siz;
 
 static void
 addkeydef(char *def, int flags)
_AT_@ -81,32 +83,28 @@ check(FILE *fp)
 static int
 linecmp(const char **a, const char **b)
 {
- char *s1, *s2;
         int res = 0;
         long double x, y;
         struct kdlist *node;
 
         for (node = head; node && res == 0; node = node->next) {
- s1 = columns((char *)*a, &node->keydef);
- s2 = columns((char *)*b, &node->keydef);
+ columns((char *)*a, &node->keydef, &col1, &col1siz);
+ columns((char *)*b, &node->keydef, &col2, &col2siz);
 
                 /* if -u is given, don't use default key definition
                  * unless it is the only one */
                 if (uflag && node == tail && head != tail) {
                         res = 0;
                 } else if (node->keydef.flags & MOD_N) {
- x = strtold(s1, NULL);
- y = strtold(s2, NULL);
+ x = strtold(col1, NULL);
+ y = strtold(col2, NULL);
                         res = x < y ? -1 : x > y;
                 } else {
- res = strcmp(s1, s2);
+ res = strcmp(col1, col2);
                 }
 
                 if (node->keydef.flags & MOD_R)
                         res = -res;
-
- free(s1);
- free(s2);
         }
 
         return res;
_AT_@ -202,10 +200,11 @@ skipcolumn(char *s, char *eol, int next_col)
         return s;
 }
 
-static char *
-columns(char *line, const struct keydef *kd)
+static size_t
+columns(char *line, const struct keydef *kd, char **col, size_t *colsiz)
 {
         char *start, *end, *eol = strchr(line, '\n');
+ size_t len;
         int i;
 
         for (i = 1, start = line; i < kd->start_column; i++)
_AT_@ -226,7 +225,14 @@ columns(char *line, const struct keydef *kd)
         } else {
                 end = eol;
         }
- return enstrndup(2, start, start > end ? 0 : end - start);
+ len = start > end ? 0 : end - start;
+ if (!*col || *colsiz < len)
+ *col = erealloc(*col, len + 1);
+ memcpy(*col, start, len);
+ (*col)[len] = '\0';
+ if (*colsiz < len)
+ *colsiz = len;
+ return len;
 }
 
 static void
_AT_@ -258,7 +264,7 @@ main(int argc, char *argv[])
                 addkeydef(EARGF(usage()), global_flags);
                 break;
         case 'm':
- /* more or less for free, but for perfomance-reasons,
+ /* more or less for free, but for performance-reasons,
                  * we should keep this flag in mind and maybe some later
                  * day implement it properly so we don't run out of memory
                  * while merging large sorted files.
Received on Thu May 07 2015 - 19:18:55 CEST