sort: -R now uses less memory on long lines with internal NULs

* lib/Makefile.am (libcoreutils_a_SOURCES): Remove xmemxfrm.c,
xmemxfrm.h.
* lib/memxfrm.c, lib/memxfrm.h, lib/xmemxfrm.c, lib/xmemxfrm.h: Remove.
* m4/memxfrm.m4: Likewise.
* m4/prereq.m4 (gl_PREREQ): Remove gl_MEMXFRM.
* po/POTFILES.in: Remove lib/xmemxfrm.c.
* src/sort.c: Don't include xmemxfrm.h.
(cmp_hashes): Remove.
(xstrxfrm): New function.
(compare_random): If a line contains NULs, don't create a big
buffer that contains the strxfrm output of each string in the line.
Instead, accumulate checksums and differences as we go, so that
at any one time we have to store at most the output of a single
strxfrm call when processing the line.  This removes the need for
an memxfrm function.

5 files changed, 1 insertions, 173 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index c89ef751d..b4a591b3f 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -20,8 +20,7 @@ include gnulib.mk
 AM_CFLAGS += $(GNULIB_WARN_CFLAGS) $(WERROR_CFLAGS)
 
 libcoreutils_a_SOURCES += \
-  buffer-lcm.c buffer-lcm.h \
-  xmemxfrm.c xmemxfrm.h
+  buffer-lcm.c buffer-lcm.h
 
 libcoreutils_a_LIBADD += $(LIBOBJS)
 libcoreutils_a_DEPENDENCIES += $(LIBOBJS)
diff --git a/lib/memxfrm.c b/lib/memxfrm.c
deleted file mode 100644
index 12a1ae9e4..000000000
--- a/lib/memxfrm.c
+++ /dev/null
@@ -1,105 +0,0 @@
-/* Locale-specific memory transformation
-
-   Copyright (C) 2006, 2009-2010 Free Software Foundation, Inc.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-
-   This program 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 General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Paul Eggert <eggert@cs.ucla.edu>.  */
-
-#include <config.h>
-
-#include "memxfrm.h"
-
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-
-/* Store into DEST (of size DESTSIZE) the text in SRC (of size SRCSIZE)
-   transformed so that the result of memcmp on two transformed texts
-   (with ties going to the longer text) is the same as the result of
-   memcoll on the two texts before their transformation.  Perhaps
-   temporarily modify the byte after SRC, but restore its original
-   contents before returning.
-
-   Return the size of the resulting text, or an indeterminate value if
-   there is an error.  Set errno to an error number if there is an
-   error, and to zero otherwise.  DEST contains an indeterminate value
-   if there is an error or if the resulting size is greater than
-   DESTSIZE.  */
-
-size_t
-memxfrm (char *restrict dest, size_t destsize,
-         char *restrict src, size_t srcsize)
-{
-#if HAVE_STRXFRM
-
-  size_t di = 0;
-  size_t si = 0;
-  size_t result = 0;
-
-  char ch = src[srcsize];
-  src[srcsize] = '\0';
-
-  while (si < srcsize)
-    {
-      size_t slen = strlen (src + si);
-
-      size_t result0 = result;
-      errno = 0;
-      result += strxfrm (dest + di, src + si, destsize - di) + 1;
-      if (errno != 0)
-        break;
-      if (result <= result0)
-        {
-          errno = ERANGE;
-          break;
-        }
-
-      if (result == destsize + 1 && si + slen == srcsize)
-        {
-          /* The destination is exactly the right size, but strxfrm wants
-             room for a trailing null.  Work around the problem with a
-             temporary buffer.  */
-          size_t bufsize = destsize - di + 1;
-          char stackbuf[4000];
-          char *buf = stackbuf;
-          if (sizeof stackbuf < bufsize)
-            {
-              buf = malloc (bufsize);
-              if (! buf)
-                break;
-            }
-          strxfrm (buf, src + si, bufsize);
-          memcpy (dest + di, buf, destsize - di);
-          if (sizeof stackbuf < bufsize)
-            free (buf);
-          errno = 0;
-        }
-
-      di = (result < destsize ? result : destsize);
-      si += slen + 1;
-    }
-
-  src[srcsize] = ch;
-  return result - (si != srcsize);
-
-#else
-
-  if (srcsize < destsize)
-    memcpy (dest, src, srcsize);
-  errno = 0;
-  return srcsize;
-
-#endif
-}
diff --git a/lib/memxfrm.h b/lib/memxfrm.h
deleted file mode 100644
index 605421dc2..000000000
--- a/lib/memxfrm.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#include <stddef.h>
-size_t memxfrm (char *restrict, size_t, char *restrict, size_t);
diff --git a/lib/xmemxfrm.c b/lib/xmemxfrm.c
deleted file mode 100644
index 9cdda9833..000000000
--- a/lib/xmemxfrm.c
+++ /dev/null
@@ -1,62 +0,0 @@
-/* Locale-specific memory transformation
-
-   Copyright (C) 2006, 2009-2010 Free Software Foundation, Inc.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-
-   This program 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 General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* Written by Paul Eggert <eggert@cs.ucla.edu>.  */
-
-#include <config.h>
-
-#include "xmemxfrm.h"
-
-#include <errno.h>
-#include <stdlib.h>
-
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-
-#include "error.h"
-#include "exitfail.h"
-#include "memxfrm.h"
-#include "quotearg.h"
-
-/* Store into DEST (of size DESTSIZE) the text in SRC (of size
-   SRCSIZE) transformed so that the result of memcmp on two
-   transformed texts (with ties going to the longer text) is the same
-   as the result of memcoll on the two texts before their
-   transformation.  Perhaps temporarily modify the byte after SRC, but
-   restore its original contents before returning.
-
-   Return the size of the resulting text.  DEST contains an
-   indeterminate value if the resulting size is greater than DESTSIZE.
-   Report an error and exit if there is an error.  */
-
-size_t
-xmemxfrm (char *restrict dest, size_t destsize,
-          char *restrict src, size_t srcsize)
-{
-  size_t translated_size = memxfrm (dest, destsize, src, srcsize);
-
-  if (errno)
-    {
-      error (0, errno, _("string transformation failed"));
-      error (0, 0, _("set LC_ALL='C' to work around the problem"));
-      error (exit_failure, 0,
-             _("the untransformed string was %s"),
-             quotearg_n_style_mem (0, locale_quoting_style, src, srcsize));
-    }
-
-  return translated_size;
-}
diff --git a/lib/xmemxfrm.h b/lib/xmemxfrm.h
deleted file mode 100644
index 7c4b8ad7c..000000000
--- a/lib/xmemxfrm.h
+++ /dev/null
@@ -1,2 +0,0 @@
-#include <stddef.h>
-size_t xmemxfrm (char *restrict, size_t, char *restrict, size_t);