sfeed

commit fb3e9d05d1cf81783ea49629a2180512f5a60ecf
parent b88aad839e5a541ef24ecc216d3824c5af3b59f6
Author: Hiltjo Posthuma <hiltjo@codemadness.org>
Date:   Sun, 31 Jan 2016 22:04:00 +0100

Revert "sfeed: realloc, faster near pow 2 bufsiz"

This reverts commit 5e43bd658e578ced54f6065e95f6efb4892e114c.

It is a neat bit trick, but it doesn't matter much in thiscase and it's
less readable and possibly less portable.

Diffstat:
M
sfeed.c
 | 
27
+++++++++++----------------

1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/sfeed.c b/sfeed.c
@@ -207,22 +207,15 @@ string_clear(String *s)
 static void
 string_buffer_realloc(String *s, size_t newlen)
 {
-	uint32_t v;
-	/* check if allocation is necessary, don't shrink buffer,
-	 * should be more than bufsiz ofcourse. */
-	if (newlen <= s->bufsiz)
-		return;
+	char *p;
+	size_t alloclen;
 
-	v = (uint32_t)newlen;
-	v |= v >> 1;
-	v |= v >> 2;
-	v |= v >> 4;
-	v |= v >> 8;
-	v |= v >> 16;
-	v++;
-	if (!(s->data = realloc(s->data, (size_t)v)))
+	for (alloclen = 64; alloclen <= newlen; alloclen *= 2)
+		;
+	if (!(p = realloc(s->data, alloclen)))
 		err(1, "realloc");
-	s->bufsiz = (size_t)v;
+	s->bufsiz = alloclen;
+	s->data = p;
 }
 
 static void
@@ -230,8 +223,10 @@ string_append(String *s, const char *data, size_t len)
 {
 	if (!len || *data == '\0')
 		return;
-
-	string_buffer_realloc(s, s->len + len + 1);
+	/* check if allocation is necesary, don't shrink buffer,
+	 * should be more than bufsiz ofcourse. */
+	if (s->len + len >= s->bufsiz)
+		string_buffer_realloc(s, s->len + len + 1);
 	memcpy(s->data + s->len, data, len);
 	s->len += len;
 	s->data[s->len] = '\0';