Remove preemptive allocations.

Careful profiling shows that we spend more time guessing what pattern
allocation will have, whereas we can delay it only at the point where
add_rfc2047 will be used and don't allocate huge memory area for the many
cases where it's not.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/commit.c b/commit.c
index 13af93363e3dba43baf1d0a3ff2a2a3938fe5da7..85889f966457bf11004daa40c2cbe664baf96fb4 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -501,6 +501,7 @@ static void add_rfc2047(struct strbuf *sb, const char *line, int len,
        return;
 
 needquote:
+       strbuf_grow(sb, len * 3 + strlen(encoding) + 100);
        strbuf_addf(sb, "=?%s?q?", encoding);
        for (i = last = 0; i < len; i++) {
                unsigned ch = line[i] & 0xFF;
@@ -520,14 +521,6 @@ needquote:
        strbuf_addstr(sb, "?=");
 }
 
-static unsigned long bound_rfc2047(unsigned long len, const char *encoding)
-{
-       /* upper bound of q encoded string of length 'len' */
-       unsigned long elen = strlen(encoding);
-
-       return len * 3 + elen + 100;
-}
-
 static void add_user_info(const char *what, enum cmit_fmt fmt, struct strbuf *sb,
                         const char *line, enum date_mode dmode,
                         const char *encoding)
@@ -560,8 +553,7 @@ static void add_user_info(const char *what, enum cmit_fmt fmt, struct strbuf *sb
                add_rfc2047(sb, line, display_name_length, encoding);
                strbuf_add(sb, name_tail, namelen - display_name_length);
                strbuf_addch(sb, '\n');
-       }
-       else {
+       } else {
                strbuf_addf(sb, "%s: %.*s%.*s\n", what,
                              (fmt == CMIT_FMT_FULLER) ? 4 : 0,
                              filler, namelen, line);
@@ -955,19 +947,12 @@ static void pp_header(enum cmit_fmt fmt,
                 * FULLER shows both authors and dates.
                 */
                if (!memcmp(line, "author ", 7)) {
-                       unsigned long len = linelen;
-                       if (fmt == CMIT_FMT_EMAIL)
-                               len = bound_rfc2047(linelen, encoding);
-                       strbuf_grow(sb, len + 80);
+                       strbuf_grow(sb, linelen + 80);
                        add_user_info("Author", fmt, sb, line + 7, dmode, encoding);
                }
-
                if (!memcmp(line, "committer ", 10) &&
                    (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER)) {
-                       unsigned long len = linelen;
-                       if (fmt == CMIT_FMT_EMAIL)
-                               len = bound_rfc2047(linelen, encoding);
-                       strbuf_grow(sb, len + 80);
+                       strbuf_grow(sb, linelen + 80);
                        add_user_info("Commit", fmt, sb, line + 10, dmode, encoding);
                }
        }
@@ -982,7 +967,6 @@ static void pp_title_line(enum cmit_fmt fmt,
                          int plain_non_ascii)
 {
        struct strbuf title;
-       unsigned long len;
 
        strbuf_init(&title, 80);
 
@@ -1004,16 +988,7 @@ static void pp_title_line(enum cmit_fmt fmt,
                strbuf_add(&title, line, linelen);
        }
 
-       /* Enough slop for the MIME header and rfc2047 */
-       len = bound_rfc2047(title.len, encoding) + 1000;
-       if (subject)
-               len += strlen(subject);
-       if (after_subject)
-               len += strlen(after_subject);
-       if (encoding)
-               len += strlen(encoding);
-
-       strbuf_grow(sb, title.len + len);
+       strbuf_grow(sb, title.len + 1024);
        if (subject) {
                strbuf_addstr(sb, subject);
                add_rfc2047(sb, title.buf, title.len, encoding);