sbase

suckless unix tools
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commit 06f57259eb10dea848864057b641ca43f290a265
parent a2e479beb42b569683f222ace3b1bfc11e1ef210
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Tue May  5 13:41:43 +0200

sort: reuse buffer in columns()

speeds up sorting for huge input aswell.

Diffstat:
sort.c | 34++++++++++++++++++++--------------
1 file changed, 20 insertions(+), 14 deletions(-)
diff --git a/sort.c b/sort.c @@ -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) @@ -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; @@ -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++) @@ -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 @@ -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.