[gentoo-commits] proj/portage-utils:master commit in: libq/

[Mike Frysinger]

commit:     2863e563f7b37d9e9cbb56551c8a4c033f802750
Author:     Mike Frysinger <vapier <AT> gentoo <DOT> org>
AuthorDate: Wed Dec 28 22:14:25 2016 +0000
Commit:     Mike Frysinger <vapier <AT> gentoo <DOT> org>
CommitDate: Wed Dec 28 22:14:25 2016 +0000
URL:        https://gitweb.gentoo.org/proj/portage-utils.git/commit/?id=2863e563

copy_file: rewrite to use fds

This avoids FILE* leakage and produces a little bit smaller code.

 libq/copy_file.c | 63 ++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 41 insertions(+), 22 deletions(-)

diff --git a/libq/copy_file.c b/libq/copy_file.c
index ee1338d..4230b73 100644
--- a/libq/copy_file.c
+++ b/libq/copy_file.c
@@ -1,31 +1,50 @@
-static int copy_file_fd(int fd_src, int fd_dst)
+static ssize_t safe_read(int fd, void *buf, size_t len)
 {
-	FILE *fp_src, *fp_dst;
-	size_t rcnt, wcnt;
-	char buf[BUFSIZE];
+	ssize_t ret;
 
-	/* dont fclose() as that implicitly close()'s */
+	while (1) {
+		ret = read(fd, buf, len);
+		if (ret >= 0)
+			break;
+		else if (errno != EINTR)
+			break;
+	}
 
-	fp_src = fdopen(fd_src, "r");
-	if (!fp_src)
-		return -1;
+	return ret;
+}
 
-	fp_dst = fdopen(fd_dst, "w");
-	if (!fp_dst)
-		return -1;
+static ssize_t safe_write(int fd, const void *buf, size_t len)
+{
+	ssize_t ret;
 
-	while (1) {
-		rcnt = fread(buf, sizeof(buf[0]), sizeof(buf), fp_src);
-		if (!rcnt) {
-			fflush(fp_dst);
-			return feof(fp_src) ? 0 : -1;
+	while (len) {
+		ret = write(fd, buf, len);
+		if (ret < 0) {
+			if (errno == EINTR)
+				continue;
+			return -1;
 		}
+		buf += ret;
+		len -= ret;
+	}
 
-		wcnt = fwrite(buf, sizeof(buf[0]), rcnt, fp_dst);
-		if (wcnt != rcnt) {
-			if (ferror(fp_dst))
-				return -1;
-			fseek(fp_src, wcnt - rcnt, SEEK_CUR);
-		}
+	return ret;
+}
+
+static int copy_file_fd(int fd_src, int fd_dst)
+{
+	ssize_t rcnt, wcnt;
+	char buf[64 * 1024];
+
+	while (1) {
+		rcnt = safe_read(fd_src, buf, sizeof(buf));
+		if (rcnt < 0)
+			return -1;
+		else if (rcnt == 0)
+			return 0;
+
+		wcnt = safe_write(fd_dst, buf, rcnt);
+		if (wcnt == -1)
+			return -1;
 	}
 }