(scandir): Add __builtin_expect where useful.

[kopensolaris-gnu/glibc.git] / grp / fgetgrent.c

diff --git a/grp/fgetgrent.c b/grp/fgetgrent.c
index 95ae2ec..69507d9 100644 (file)
--- a/grp/fgetgrent.c
+++ b/grp/fgetgrent.c
@@ -1,31 +1,96 @@
-/* Copyright (C) 1991, 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
+/* Copyright (C) 1991, 1996, 1997, 1999, 2000 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
 
-The GNU C Library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
 
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
 
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB.  If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
 
+#include <errno.h>
 #include <grp.h>
+#include <bits/libc-lock.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 
+/* We need to protect the dynamic buffer handling.  */
+__libc_lock_define_initialized (static, lock);
+
+static char *buffer;
+
 /* Read one entry from the given stream.  */
 struct group *
 fgetgrent (FILE *stream)
 {
-  static char buffer[BUFSIZ];
-  static struct group result;
+  static size_t buffer_size;
+  static struct group resbuf;
+  fpos_t pos;
+  struct group *result;
+  int save;
+
+  if (__builtin_expect (fgetpos (stream, &pos), 0) != 0)
+    return NULL;
+
+  /* Get lock.  */
+  __libc_lock_lock (lock);
+
+  /* Allocate buffer if not yet available.  */
+  if (buffer == NULL)
+    {
+      buffer_size = NSS_BUFLEN_GROUP;
+      buffer = malloc (buffer_size);
+    }
+
+  while (buffer != NULL
+        && (__fgetgrent_r (stream, &resbuf, buffer, buffer_size, &result)
+            == ERANGE))
+    {
+      char *new_buf;
+      buffer_size += NSS_BUFLEN_GROUP;
+      new_buf = realloc (buffer, buffer_size);
+      if (__builtin_expect (new_buf == NULL, 0))
+       {
+         /* We are out of memory.  Free the current buffer so that the
+            process gets a chance for a normal termination.  */
+         save = errno;
+         free (buffer);
+         __set_errno (save);
+       }
+      buffer = new_buf;
+
+      /* Reset the stream.  */
+      if (fsetpos (stream, &pos) != 0)
+       buffer = NULL;
+    }
 
-  return __fgetgrent_r (stream, &result, buffer, sizeof buffer);
+  if (buffer == NULL)
+    result = NULL;
+
+  /* Release lock.  Preserve error value.  */
+  save = errno;
+  __libc_lock_unlock (lock);
+  __set_errno (save);
+
+  return result;
 }
+
+
+/* Free all resources if necessary.  */
+static void __attribute__ ((unused))
+free_mem (void)
+{
+  if (buffer != NULL)
+    free (buffer);
+}
+
+text_set_element (__libc_subfreeres, free_mem);