From: Tim Kientzle <kientzle@gmail.com>
Date: Sun, 19 Jul 2009 07:04:26 +0000 (-0400)
Subject: More code simplifications on the seek implementation.
X-Git-Tag: v2.8.0~524
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=864ba4d7eb3d3ef5bdfc3f112247d93529974ee3;p=thirdparty%2Flibarchive.git

More code simplifications on the seek implementation.

SVN-Revision: 1237
---

diff --git a/tar/write.c b/tar/write.c
index d93b2ec38..a0d681e81 100644
--- a/tar/write.c
+++ b/tar/write.c
@@ -142,26 +142,20 @@ static void		 write_hierarchy(struct bsdtar *, struct archive *,
 			     const char *);
 
 #if defined(_WIN32) && !defined(__CYGWIN__)
-#define open _open
-#define close _close
-#define read _read
-
-static void
-seek_file(int fd, int64_t length)
+/* Not a full lseek() emulation, but enough for our needs here. */
+static int
+seek_file(int fd, int64_t offset, int whence)
 {
 	LARGE_INTEGER distance;
-	distance.QuadPart = length;
-	if (!SetFilePointerEx((HANDLE)_get_osfhandle(fd),
-		distance, NULL, FILE_BEGIN))
-		lafe_errc(1, 0, "Could not seek to archive end");
-}
-#else
-static void
-seek_file(int fd, int64_t length)
-{
-	if (lseek(fd, length, SEEK_SET) < 0)
-		lafe_errc(1, errno, "Could not seek to archive end");
+	(void)whence; /* UNUSED */
+	distance.QuadPart = offset;
+	return (SetFilePointerEx((HANDLE)_get_osfhandle(fd),
+		distance, NULL, FILE_BEGIN) ? 1 : -1);
 }
+#define open _open
+#define close _close
+#define read _read
+#define lseek seek_file
 #endif
 
 void
@@ -324,7 +318,8 @@ tar_mode_r(struct bsdtar *bsdtar)
 			format = ARCHIVE_FORMAT_TAR_PAX_RESTRICTED;
 		archive_write_set_format(a, format);
 	}
-	seek_file(bsdtar->fd, end_offset);
+	if (lseek(bsdtar->fd, end_offset, SEEK_SET) < 0)
+		lafe_errc(1, errno, "Could not seek to archive end");
 	if (ARCHIVE_OK != archive_write_set_options(a, bsdtar->option_options))
 		lafe_errc(1, 0, archive_error_string(a));
 	if (ARCHIVE_OK != archive_write_open_fd(a, bsdtar->fd))
@@ -406,7 +401,8 @@ tar_mode_u(struct bsdtar *bsdtar)
 		    bsdtar->bytes_per_block);
 	} else
 		archive_write_set_bytes_per_block(a, DEFAULT_BYTES_PER_BLOCK);
-	seek_file(bsdtar->fd, end_offset);
+	if (lseek(bsdtar->fd, end_offset, SEEK_SET) < 0)
+		lafe_errc(1, errno, "Could not seek to archive end");
 	if (ARCHIVE_OK != archive_write_set_options(a, bsdtar->option_options))
 		lafe_errc(1, 0, archive_error_string(a));
 	if (ARCHIVE_OK != archive_write_open_fd(a, bsdtar->fd))