From: Michihiro NAKAJIMA <ggcueroad@gmail.com>
Date: Thu, 28 Jul 2011 03:58:35 +0000 (-0400)
Subject: Improve the performance of the uudecode bidder when reading a very long line.
X-Git-Tag: v3.0.0a~224
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2d3cd81cde45645941aaa450d2ac40262bd211fc;p=thirdparty%2Flibarchive.git

Improve the performance of the uudecode bidder when reading a very long line.

SVN-Revision: 3507
---

diff --git a/libarchive/archive_read_support_filter_uu.c b/libarchive/archive_read_support_filter_uu.c
index fac7a10cb..56fb6623d 100644
--- a/libarchive/archive_read_support_filter_uu.c
+++ b/libarchive/archive_read_support_filter_uu.c
@@ -220,17 +220,26 @@ bid_get_line(struct archive_read_filter *filter,
 		len = 0;
 	} else
 		len = get_line(*b, *avail, nl);
+
 	/*
 	 * Read bytes more while it does not reach the end of line.
 	 */
-	while (*nl == 0 && len == *avail && !quit && *nbytes_read < UUENCODE_BID_MAX_READ) {
+	while (*nl == 0 && len == *avail && !quit &&
+	    *nbytes_read < UUENCODE_BID_MAX_READ) {
 		ssize_t diff = *ravail - *avail;
+		size_t nbytes_req = (*ravail+1023) & ~1023U;
+		ssize_t tested;
+
+		/* Increase reading bytes if it is not enough to at least
+		 * new two lines. */
+		if (nbytes_req < (size_t)*ravail + 160)
+			nbytes_req <<= 1;
 
-		*b = __archive_read_filter_ahead(filter, 160 + *ravail, avail);
+		*b = __archive_read_filter_ahead(filter, nbytes_req, avail);
 		if (*b == NULL) {
 			if (*ravail >= *avail)
 				return (0);
-			/* Reading bytes reaches the end of file. */
+			/* Reading bytes reaches the end of a stream. */
 			*b = __archive_read_filter_ahead(filter, *avail, avail);
 			quit = 1;
 		}
@@ -238,7 +247,10 @@ bid_get_line(struct archive_read_filter *filter,
 		*ravail = *avail;
 		*b += diff;
 		*avail -= diff;
-		len = get_line(*b, *avail, nl);
+		tested = len;/* Skip some bytes we already determinated. */
+		len = get_line(*b + tested, *avail - tested, nl);
+		if (len >= 0)
+			len += tested;
 	}
 	return (len);
 }