Jeff King <peff@xxxxxxxx> writes:
> I am tempted to just call this new one strbuf_split and update all
> callers. There aren't that many.
Yes, that is indeed tempting, and because we have a new parameter the
compiler will catch any new callers that pop up in a mismerge so that
would be perfectly safe.
> -struct strbuf **strbuf_split(const struct strbuf *sb, int delim)
> +struct strbuf **strbuf_split_max(const struct strbuf *sb, int delim, int max)
> {
> int alloc = 2, pos = 0;
> char *n, *p;
> @@ -114,7 +114,10 @@ struct strbuf **strbuf_split(const struct strbuf *sb, int delim)
> p = n = sb->buf;
> while (n < sb->buf + sb->len) {
> int len;
> - n = memchr(n, delim, sb->len - (n - sb->buf));
> + if (max <= 0 || pos + 1 < max)
> + n = memchr(n, delim, sb->len - (n - sb->buf));
> + else
> + n = NULL;
> if (pos + 1 >= alloc) {
> alloc = alloc * 2;
> ret = xrealloc(ret, sizeof(struct strbuf *) * alloc);
Hmm, even when we know the value of max, we go exponential, and even do so
by hand without using ALLOC_GROW(). Somewhat sad.
Also do we currently rely on the bug that strbuf_split() returns (NULL,)
instead of ("", NULL) when given an empty string? If not, perhaps...
strbuf.c | 50 +++++++++++++++++++++++++++++++-------------------
1 files changed, 31 insertions(+), 19 deletions(-)
diff --git a/strbuf.c b/strbuf.c
index 09c43ae..7a8ee3a 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -103,31 +103,43 @@ void strbuf_ltrim(struct strbuf *sb)
sb->buf[sb->len] = '\0';
}
-struct strbuf **strbuf_split(const struct strbuf *sb, int delim)
+struct strbuf **strbuf_split_max(const struct strbuf *sb, int delim, int max)
{
- int alloc = 2, pos = 0;
char *n, *p;
- struct strbuf **ret;
+ struct strbuf **ret = NULL;
struct strbuf *t;
-
- ret = xcalloc(alloc, sizeof(struct strbuf *));
- p = n = sb->buf;
- while (n < sb->buf + sb->len) {
- int len;
- n = memchr(n, delim, sb->len - (n - sb->buf));
- if (pos + 1 >= alloc) {
- alloc = alloc * 2;
- ret = xrealloc(ret, sizeof(struct strbuf *) * alloc);
+ int pass, count = 0;
+
+ for (pass = 0; pass < 2; pass++) {
+ /* First pass counts, second pass allocates and fills */
+ if (pass)
+ ret = xcalloc(count + 1 + !count, sizeof(struct strbuf *));
+ count = 0;
+ n = sb->buf;
+ while (n < sb->buf + sb->len) {
+ p = n;
+ if (max <= 0 || count + 1 < max)
+ n = memchr(n, delim, sb->len - (n - sb->buf));
+ else
+ n = NULL;
+ if (!n)
+ n = sb->buf + sb->len - 1;
+
+ if (pass) {
+ int len = n - p + 1;
+ t = xmalloc(sizeof(struct strbuf));
+ strbuf_init(t, len);
+ strbuf_add(t, p, len);
+ ret[count] = t;
+ }
+ count++;
+ n++;
}
- if (!n)
- n = sb->buf + sb->len - 1;
- len = n - p + 1;
+ }
+ if (!count) {
t = xmalloc(sizeof(struct strbuf));
- strbuf_init(t, len);
- strbuf_add(t, p, len);
- ret[pos] = t;
- ret[++pos] = NULL;
- p = ++n;
+ strbuf_init(t, 0);
+ ret[0] = t;
}
return ret;
}
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