commit: 53d7d24872527a69501f4c74a44e16e29aa3bb4a Author: Fabian Groffen <grobian <AT> gentoo <DOT> org> AuthorDate: Mon Dec 13 07:17:04 2021 +0000 Commit: Fabian Groffen <grobian <AT> gentoo <DOT> org> CommitDate: Mon Dec 13 07:17:04 2021 +0000 URL: https://gitweb.gentoo.org/proj/portage-utils.git/commit/?id=53d7d248
libq/copy_file: employ sendfile() if possible Signed-off-by: Fabian Groffen <grobian <AT> gentoo.org> libq/copy_file.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 67 insertions(+), 11 deletions(-) diff --git a/libq/copy_file.c b/libq/copy_file.c index e4619ce..955fd78 100644 --- a/libq/copy_file.c +++ b/libq/copy_file.c @@ -1,29 +1,85 @@ /* - * Copyright 2005-2019 Gentoo Foundation + * Copyright 2005-2021 Gentoo Foundation * Distributed under the terms of the GNU General Public License v2 * * Copyright 2011-2016 Mike Frysinger - <[email protected]> + * Copyright 2021- Fabian Groffen - <[email protected]> */ #include "main.h" #include "safe_io.h" #include "copy_file.h" +/* includes for when sendfile is available */ +#include <fcntl.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#if defined(HAVE_SENDFILE4_SUPPORT) +/* Linux/Solaris */ +# include <sys/sendfile.h> +#elif defined(HAVE_SENDFILE6_SUPPORT) || defined(HAVE_SENDFILE7_SUPPORT) +/* macOS (since Darwin 9) + FreeBSD */ +# include <sys/socket.h> +# include <sys/uio.h> +#endif + int copy_file_fd(int fd_src, int fd_dst) { - ssize_t rcnt, wcnt; - char buf[64 * 1024]; +#if defined(HAVE_SENDFILE4_SUPPORT) || \ + defined(HAVE_SENDFILE6_SUPPORT) || \ + defined(HAVE_SENDFILE7_SUPPORT) + struct stat stat_buf; + ssize_t ret; + size_t len; + off_t offset = 0; - while (1) { - rcnt = safe_read(fd_src, buf, sizeof(buf)); - if (rcnt < 0) - return -1; - else if (rcnt == 0) + if (fstat(fd_src, &stat_buf) != -1) { + len = (size_t)stat_buf.st_size; + +#if defined(HAVE_SENDFILE4_SUPPORT) + /* Linux/Solaris */ + ret = sendfile(fd_dst, fd_src, &offset, len); + /* everything looks fine, return success */ + if (ret == (ssize_t)len) return 0; +#elif defined(HAVE_SENDFILE6_SUPPORT) + /* macOS (since Darwin 9) */ + offset = len; + ret = (ssize_t)sendfile(fd_src, fd_dst, 0, &offset, NULL, 0); + /* everything looks fine, return success */ + if (offset == (off_t)len) + return 0; +#elif defined(HAVE_SENDFILE7_SUPPORT) + /* FreeBSD */ + ret = (ssize_t)sendfile(fd_src, fd_dst, offset, len, NULL, &offset, 0); + /* everything looks fine, return success */ + if (offset == (off_t)len) + return 0; +#endif - wcnt = safe_write(fd_dst, buf, rcnt); - if (wcnt == -1) - return -1; + /* fall back to read/write, rewind the fd */ + lseek(fd_src, 0, SEEK_SET); + } +#endif /* HAVE_SENDFILE */ + + /* fallback, keep in its own scope, so we avoid 64K stack alloc if + * sendfile works properly */ + { + 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; + } } }
