savedir: add streamsavedir, deprecate fdsavedir

* NEWS: Mention deprecation of fdsavedir.
* lib/savedir.c (streamsavedir): New extern function, whose name
ends in "savedir" to be consistent with the others.  This differs
from savedirstream in that it doesn't close its argument.  The
next version of GNU tar will use this instead of fdsavedir, to
avoid some race conditions and conserve file descriptors.
(savedirstream): Reimplement as a wrapper around streamsavedir.
(fdsavedir): Add a comment deprecating this function.  As far as
I know, only GNU tar used it, and GNU tar doesn't need it any more.
* lib/savedir.h (streamsavedir): New decl.
(fdsavedir): Add a comment deprecating this.

diff --git a/ChangeLog b/ChangeLog
index bdce4a3c0d7cea4ee215d7fd270b744303b077f4..8e6c3c23b44a3bbd458045c36e9d2fdf168be9e0 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2010-09-12  Paul Eggert  <eggert@cs.ucla.edu>
+
+       savedir: add streamsavedir, deprecate fdsavedir
+       * NEWS: Mention deprecation of fdsavedir.
+       * lib/savedir.c (streamsavedir): New extern function, whose name
+       ends in "savedir" to be consistent with the others.  This differs
+       from savedirstream in that it doesn't close its argument.  The
+       next version of GNU tar will use this instead of fdsavedir, to
+       avoid some race conditions and conserve file descriptors.
+       (savedirstream): Reimplement as a wrapper around streamsavedir.
+       (fdsavedir): Add a comment deprecating this function.  As far as
+       I know, only GNU tar used it, and GNU tar doesn't need it any more.
+       * lib/savedir.h (streamsavedir): New decl.
+       (fdsavedir): Add a comment deprecating this.
+
 2010-09-10  Bruno Haible  <bruno@clisp.org>
 
        langinfo: Fix last commit.

diff --git a/NEWS b/NEWS
index c23c316a6fccdc27ed8e269d4097cd9739dcfaf3..6311533e0825885bd114a03df3dab7b742893e56 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,8 @@ User visible incompatible changes
 
 Date        Modules         Changes
 
+2010-09-12  savedir         The fdsavedir function is now deprecated.
+
 2010-09-10  fcntl-h         This module now defaults O_CLOEXEC to 0, and
                             it defaults O_EXEC and O_SEARCH to O_RDONLY.
                             Use "#if O_CLOEXEC" instead of "#ifdef O_CLOEXEC".

diff --git a/lib/savedir.c b/lib/savedir.c
index 538f397cb6456aace6dc02cc4c70bc8b15a6338f..79d2fd0ff1da638dd69ee119a99d97f6a86e7301 100644 (file)
--- a/lib/savedir.c
+++ b/lib/savedir.c
@@ -44,11 +44,11 @@
 /* Return a freshly allocated string containing the file names
    in directory DIRP, separated by '\0' characters;
    the end is marked by two '\0' characters in a row.
-   Return NULL (setting errno) if DIRP cannot be read or closed.
+   Return NULL (setting errno) if DIRP cannot be read.
    If DIRP is NULL, return NULL without affecting errno.  */
 
-static char *
-savedirstream (DIR *dirp)
+char *
+streamsavedir (DIR *dirp)
 {
   char *name_space;
   size_t allocated = NAME_SIZE_DEFAULT;
@@ -96,8 +96,6 @@ savedirstream (DIR *dirp)
     }
   name_space[used] = '\0';
   save_errno = errno;
-  if (closedir (dirp) != 0)
-    save_errno = errno;
   if (save_errno != 0)
     {
       free (name_space);
@@ -107,6 +105,22 @@ savedirstream (DIR *dirp)
   return name_space;
 }
 
+/* Like savedirstreamp (DIRP), except also close DIRP.  */
+
+static char *
+savedirstream (DIR *dirp)
+{
+  char *name_space = streamsavedir (dirp);
+  if (dirp && closedir (dirp) != 0)
+    {
+      int save_errno = errno;
+      free (name_space);
+      errno = save_errno;
+      return NULL;
+    }
+  return name_space;
+}
+
 /* Return a freshly allocated string containing the file names
    in directory DIR, separated by '\0' characters;
    the end is marked by two '\0' characters in a row.
@@ -123,6 +137,7 @@ savedir (char const *dir)
    the end is marked by two '\0' characters in a row.
    Return NULL (setting errno) if FD cannot be read or closed.  */
 
+/* deprecated */
 char *
 fdsavedir (int fd)
 {

diff --git a/lib/savedir.h b/lib/savedir.h
index fb11f90b14d07b126bea77cc30c7157597b342cc..5a57fe3e636b43d015db2cb4dccc6d18d69aa99b 100644 (file)
--- a/lib/savedir.h
+++ b/lib/savedir.h
@@ -18,10 +18,12 @@
 
 /* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
 
-#if !defined SAVEDIR_H_
-# define SAVEDIR_H_
+#ifndef _GL_SAVEDIR_H
+#define _GL_SAVEDIR_H
 
+#include <dirent.h>
+char *streamsavedir (DIR *dirp);
 char *savedir (char const *dir);
-char *fdsavedir (int fd);
+char *fdsavedir (int fd); /* deprecated */
 
 #endif