digests, copy-file: increase the IO buffer size from 4KiB to 32KiB

[gnulib.git] / lib / copy-file.c

diff --git a/lib/copy-file.c b/lib/copy-file.c
index 1587905..939fd07 100644 (file)
--- a/lib/copy-file.c
+++ b/lib/copy-file.c
@@ -42,6 +42,7 @@
 #include "acl.h"
 #include "binary-io.h"
 #include "gettext.h"
+#include "xalloc.h"
 
 #define _(str) gettext (str)
 
@@ -50,6 +51,7 @@
 #undef open
 #undef close
 
+enum { IO_SIZE = 32 * 1024 };
 
 void
 copy_file_preserving (const char *src_filename, const char *dest_filename)
@@ -58,8 +60,7 @@ copy_file_preserving (const char *src_filename, const char *dest_filename)
   struct stat statbuf;
   int mode;
   int dest_fd;
-  char buf[4096];
-  const size_t buf_size = sizeof (buf);
+  char *buf = xmalloc (IO_SIZE);
 
   src_fd = open (src_filename, O_RDONLY | O_BINARY);
   if (src_fd < 0 || fstat (src_fd, &statbuf) < 0)
@@ -76,7 +77,7 @@ copy_file_preserving (const char *src_filename, const char *dest_filename)
   /* Copy the file contents.  */
   for (;;)
     {
-      size_t n_read = safe_read (src_fd, buf, buf_size);
+      size_t n_read = safe_read (src_fd, buf, IO_SIZE);
       if (n_read == SAFE_READ_ERROR)
        error (EXIT_FAILURE, errno, _("error reading \"%s\""), src_filename);
       if (n_read == 0)
@@ -86,6 +87,8 @@ copy_file_preserving (const char *src_filename, const char *dest_filename)
        error (EXIT_FAILURE, errno, _("error writing \"%s\""), dest_filename);
     }
 
+  free (buf);
+
 #if !USE_ACL
   if (close (dest_fd) < 0)
     error (EXIT_FAILURE, errno, _("error writing \"%s\""), dest_filename);