*
* Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
#include "libbb.h"
-
-
-#if BUFSIZ < 4096
-#undef BUFSIZ
-#define BUFSIZ 4096
+#if ENABLE_FEATURE_USE_SENDFILE
+# include <sys/sendfile.h>
+#else
+# define sendfile(a,b,c,d) (-1)
#endif
+/*
+ * We were using 0x7fff0000 as sendfile chunk size, but it
+ * was seen to cause largish delays when user tries to ^C a file copy.
+ * Let's use a saner size.
+ * Note: needs to be >= max(CONFIG_FEATURE_COPYBUF_KB),
+ * or else "copy to eof" code will use needlesly short reads.
+ */
+#define SENDFILE_BIGBUF (16*1024*1024)
+/* Used by NOFORK applets (e.g. cat) - must not use xmalloc.
+ * size < 0 means "ignore write errors", used by tar --to-command
+ * size = 0 means "copy till EOF"
+ */
static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
{
int status = -1;
off_t total = 0;
- RESERVE_CONFIG_BUFFER(buffer,BUFSIZ);
+ bool continue_on_write_error = 0;
+ ssize_t sendfile_sz;
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ char *buffer = buffer; /* for compiler */
+ int buffer_size = 0;
+#else
+ char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
+ enum { buffer_size = sizeof(buffer) };
+#endif
+
+ if (size < 0) {
+ size = -size;
+ continue_on_write_error = 1;
+ }
- if (src_fd < 0) goto out;
- while (!size || total < size) {
- ssize_t wr, rd;
+ if (src_fd < 0)
+ goto out;
- rd = safe_read(src_fd, buffer,
- (!size || size - total > BUFSIZ) ? BUFSIZ : size - total);
+ sendfile_sz = !ENABLE_FEATURE_USE_SENDFILE
+ ? 0
+ : SENDFILE_BIGBUF;
+ if (!size) {
+ size = SENDFILE_BIGBUF;
+ status = 1; /* copy until eof */
+ }
- if (rd > 0) {
- /* A -1 dst_fd means we need to fake it... */
- wr = (dst_fd < 0) ? rd : full_write(dst_fd, buffer, rd);
- if (wr < rd) {
- bb_perror_msg(bb_msg_write_error);
- break;
+ while (1) {
+ ssize_t rd;
+
+ if (sendfile_sz) {
+ /* dst_fd == -1 is a fake, else... */
+ if (dst_fd >= 0) {
+ rd = sendfile(dst_fd, src_fd, NULL,
+ size > sendfile_sz ? sendfile_sz : size);
+ if (rd >= 0)
+ goto read_ok;
+ }
+ sendfile_sz = 0; /* do not try sendfile anymore */
+ }
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ if (buffer_size == 0) {
+ if (size > 0 && size <= 4 * 1024)
+ goto use_small_buf;
+ /* We want page-aligned buffer, just in case kernel is clever
+ * and can do page-aligned io more efficiently */
+ buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON,
+ /* ignored: */ -1, 0);
+ buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
+ if (buffer == MAP_FAILED) {
+ use_small_buf:
+ buffer = alloca(4 * 1024);
+ buffer_size = 4 * 1024;
}
- total += wr;
- if (total == size) status = 0;
- } else if (rd < 0) {
- bb_perror_msg(bb_msg_read_error);
+ }
+#endif
+ rd = safe_read(src_fd, buffer,
+ size > buffer_size ? buffer_size : size);
+ if (rd < 0) {
+ bb_simple_perror_msg(bb_msg_read_error);
break;
- } else { /* eof - all done. */
+ }
+ read_ok:
+ if (!rd) { /* eof - all done */
status = 0;
break;
}
+ /* dst_fd == -1 is a fake, else... */
+ if (dst_fd >= 0 && !sendfile_sz) {
+ ssize_t wr = full_write(dst_fd, buffer, rd);
+ if (wr < rd) {
+ if (!continue_on_write_error) {
+ bb_simple_perror_msg(bb_msg_write_error);
+ break;
+ }
+ dst_fd = -1;
+ }
+ }
+ total += rd;
+ if (status < 0) { /* if we aren't copying till EOF... */
+ size -= rd;
+ if (!size) {
+ /* 'size' bytes copied - all done */
+ status = 0;
+ break;
+ }
+ }
}
+ out:
-out:
- RELEASE_CONFIG_BUFFER(buffer);
-
- return status ? status : total;
+/* some environments don't have munmap(), hide it in #if */
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ if (buffer_size > 4 * 1024)
+ munmap(buffer, buffer_size);
+#endif
+ return status ? -1 : total;
}
-off_t bb_copyfd_size(int fd1, int fd2, off_t size)
+#if 0
+void FAST_FUNC complain_copyfd_and_die(off_t sz)
+{
+ if (sz != -1)
+ bb_error_msg_and_die("short read");
+ /* if sz == -1, bb_copyfd_XX already complained */
+ xfunc_die();
+}
+#endif
+
+off_t FAST_FUNC bb_copyfd_size(int fd1, int fd2, off_t size)
{
if (size) {
return bb_full_fd_action(fd1, fd2, size);
return 0;
}
-off_t bb_copyfd_eof(int fd1, int fd2)
+void FAST_FUNC bb_copyfd_exact_size(int fd1, int fd2, off_t size)
+{
+ off_t sz = bb_copyfd_size(fd1, fd2, size);
+ if (sz == (size >= 0 ? size : -size))
+ return;
+ if (sz != -1)
+ bb_simple_error_msg_and_die("short read");
+ /* if sz == -1, bb_copyfd_XX already complained */
+ xfunc_die();
+}
+
+off_t FAST_FUNC bb_copyfd_eof(int fd1, int fd2)
{
return bb_full_fd_action(fd1, fd2, 0);
}
projects / oweals / busybox.git / blobdiff