split out copy_file_fd

diff --git a/src/fileio.c b/src/fileio.c
index 6e2fe2f0b82f44155a5c57c46892dab7af5c8158..91e0efc0a83dd81e5fd6c0a117276ca7eca95a70 100644 (file)
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1989,6 +1989,55 @@ clone_file (int dest, int source)
 }
 #endif
 
+/* Copy data to OFD from IFD if possible.  Return NEWSIZE.  */
+off_t
+copy_file_fd (int ofd, int ifd, struct stat *st, Lisp_Object newname,
+             Lisp_Object file)
+{
+  off_t newsize;
+
+  if (clone_file (ofd, ifd))
+    newsize = st->st_size;
+  else
+    {
+      off_t insize = st->st_size;
+      ssize_t copied;
+
+      for (newsize = 0; newsize < insize; newsize += copied)
+       {
+         /* Copy at most COPY_MAX bytes at a time; this is min
+            (PTRDIFF_MAX, SIZE_MAX) truncated to a value that is
+            surely aligned well.  */
+         ssize_t ssize_max = TYPE_MAXIMUM (ssize_t);
+         ptrdiff_t copy_max = min (ssize_max, SIZE_MAX) >> 30 << 30;
+         off_t intail = insize - newsize;
+         ptrdiff_t len = min (intail, copy_max);
+         copied = copy_file_range (ifd, NULL, ofd, NULL, len, 0);
+         if (copied <= 0)
+           break;
+         maybe_quit ();
+       }
+
+      /* Fall back on read+write if copy_file_range failed, or if the
+        input is empty and so could be a /proc file.  read+write will
+        either succeed, or report an error more precisely than
+        copy_file_range would.  */
+      if (newsize != insize || insize == 0)
+       {
+         char buf[MAX_ALLOCA];
+         for (; (copied = emacs_read_quit (ifd, buf, sizeof buf));
+              newsize += copied)
+           {
+             if (copied < 0)
+               report_file_error ("Read error", file);
+             if (emacs_write_quit (ofd, buf, copied) != copied)
+               report_file_error ("Write error", newname);
+           }
+       }
+    }
+  return newsize;
+}
+
 DEFUN ("copy-file", Fcopy_file, Scopy_file, 2, 6,
        "fCopy file: \nGCopy %s to file: \np\nP",
        doc: /* Copy FILE to NEWNAME.  Both args must be strings.
@@ -2143,45 +2192,7 @@ permissions.  */)
 
   maybe_quit ();
 
-  if (clone_file (ofd, ifd))
-    newsize = st.st_size;
-  else
-    {
-      off_t insize = st.st_size;
-      ssize_t copied;
-
-      for (newsize = 0; newsize < insize; newsize += copied)
-       {
-         /* Copy at most COPY_MAX bytes at a time; this is min
-            (PTRDIFF_MAX, SIZE_MAX) truncated to a value that is
-            surely aligned well.  */
-         ssize_t ssize_max = TYPE_MAXIMUM (ssize_t);
-         ptrdiff_t copy_max = min (ssize_max, SIZE_MAX) >> 30 << 30;
-         off_t intail = insize - newsize;
-         ptrdiff_t len = min (intail, copy_max);
-         copied = copy_file_range (ifd, NULL, ofd, NULL, len, 0);
-         if (copied <= 0)
-           break;
-         maybe_quit ();
-       }
-
-      /* Fall back on read+write if copy_file_range failed, or if the
-        input is empty and so could be a /proc file.  read+write will
-        either succeed, or report an error more precisely than
-        copy_file_range would.  */
-      if (newsize != insize || insize == 0)
-       {
-         char buf[MAX_ALLOCA];
-         for (; (copied = emacs_read_quit (ifd, buf, sizeof buf));
-              newsize += copied)
-           {
-             if (copied < 0)
-               report_file_error ("Read error", file);
-             if (emacs_write_quit (ofd, buf, copied) != copied)
-               report_file_error ("Write error", newname);
-           }
-       }
-    }
+  newsize = copy_file_fd (ofd, ifd, &st, newname, file);
 
   /* Truncate any existing output file after writing the data.  This
      is more likely to work than truncation before writing, if the

diff --git a/src/lisp.h b/src/lisp.h
index 05d6ef0d22a0558274252219c14b248036221a07..7a4b3517574bbe3e0d6438736589f7b4f95e3643 100644 (file)
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -34,6 +34,8 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <intprops.h>
 #include <verify.h>
 
+#include <sys/stat.h>
+
 INLINE_HEADER_BEGIN
 
 /* Define a TYPE constant ID as an externally visible name.  Use like this:
@@ -4325,6 +4327,7 @@ extern char *splice_dir_file (char *, char const *, char const *);
 extern bool file_name_absolute_p (const char *);
 extern char const *get_homedir (void);
 extern Lisp_Object expand_and_dir_to_file (Lisp_Object);
+extern off_t copy_file_fd (int, int, struct stat *, Lisp_Object, Lisp_Object);
 extern Lisp_Object write_region (Lisp_Object, Lisp_Object, Lisp_Object,
                                 Lisp_Object, Lisp_Object, Lisp_Object,
                                 Lisp_Object, int);