xemacs-beta: src/fileio.c comparison

comparison src/fileio.c @ 276:6330739388db r21-0b36

Import from CVS: tag r21-0b36

author	cvs
date	Mon, 13 Aug 2007 10:30:37 +0200
parents	ca9a9ec9c1c1
children	90d73dddcdc4

comparison

equal deleted inserted replaced

-:a68ae4439f57
+:6330739388db
 int disable_auto_save_when_buffer_shrinks;
 Lisp_Object Qfile_name_handler_alist;
-/* Syncing with FSF 19.34.6 note: although labelled as NT-specific, these
-two lisp variables are compiled in even when not defined(DOS_NT).
-Need to check if we should bracket them between #ifdef's.
---marcpa */
-/* On NT, specifies the directory separator character, used (eg.) when
-expanding file names.  This can be bound to / or \.
-This needs to be initialized statically, because file name functions
-are called during initialization.  */
 Lisp_Object Vdirectory_sep_char;
 /* These variables describe handlers that have "already" had a chance
 to handle the current operation.
 static char *
 file_name_as_directory (char *out, char *in)
 {
-int size = strlen (in) - 1;
+int size = strlen (in);
-strcpy (out, in);
+if (size == 0)
+{
-/* For Unix syntax, Append a slash if necessary */
+out[0] = '.';
-if (!IS_ANY_SEP (out[size]))
+out[1] = DIRECTORY_SEP;
-{
+out[2] = '\0';
-out[size + 1] = DIRECTORY_SEP;
+}
-out[size + 2] = '\0';
+else
+{
+strcpy (out, in);
+/* Append a slash if necessary */
+if (!IS_ANY_SEP (out[size-1]))
+	{
+	  out[size] = DIRECTORY_SEP;
+	  out[size + 1] = '\0';
+	}
 }
 #ifdef WINDOWSNT
 CORRECT_DIR_SEPS (out);
 #endif
 return out;
 Return a string representing file FILENAME interpreted as a directory.
 This operation exists because a directory is also a file, but its name as
 a directory is different from its name as a file.
 The result can be used as the value of `default-directory'
 or passed as second argument to `expand-file-name'.
-For a Unix-syntax file name, just appends a slash.
+For a Unix-syntax file name, just appends a slash,
+except for (file-name-as-directory \"\") => \"./\".
 */
 (file))
 {
 /* This function can GC.  GC checked 1997.04.06. */
 char *buf;
 return build_string (buf);
 }
 /* Fmake_temp_name used to be a simple wrapper around mktemp(), but it
 proved too broken for our purposes (it supported only 26 or 62
-unique names under some implementations).  For instance, the stupid
+unique names under some implementations).  For example, this
-limit broke Gnus Incoming* files generation.
+arbitrary limit broke generation of Gnus Incoming* files.
-NB, this implementation is better than what one usually finds in
+This implementation is better than what one usually finds in libc.
-libc.  --hniksic */
+--hniksic */
-#define MTN_RANDOM(x) ((int) (random () % x))
-#define MTN_INC(var, limit) (var = ((var == (limit) - 1) ? 0 : (var + 1)))
-#define MTN_LOOP(var, limit, keep)				\
-for (keep = var = MTN_RANDOM (limit), MTN_INC (var, limit);	\
-var != keep;						\
-MTN_INC (var, limit))
 DEFUN ("make-temp-name", Fmake_temp_name, 1, 1, 0, /*
 Generate temporary file name starting with PREFIX.
 The Emacs process number forms part of the result, so there is no
 danger of generating a name being used by another process.
 'Q','R','S','T','U','V','W','X',
 'Y','Z','a','b','c','d','e','f',
 'g','h','i','j','k','l','m','n',
 'o','p','q','r','s','t','u','v',
 'w','x','y','z','0','1','2','3',
-'4','5','6','7','8','9','-','_'
+'4','5','6','7','8','9','-','_' };
-};
+static unsigned count, count_initialized_p;
 Lisp_Object val;
 Bytecount len;
-int pid;
-int i, j, k, keep1, keep2, keep3;
 Bufbyte *p, *data;
+unsigned pid;
 CHECK_STRING (prefix);
 /* I was tempted to apply Fexpand_file_name on PREFIX here, but it's
 a bad idea because:
 2) It breaks under many unforeseeable circumstances, such as with
 the code that uses (make-temp-name "") instead of
 (make-temp-name "./").
-3) It might yield unexpected results in the presence of EFS and
+3) It might yield unexpected (to stat(2)) results in the presence
-file name handlers.  */
+of EFS and file name handlers.  */
 len = XSTRING_LENGTH (prefix);
 val = make_uninit_string (len + 6);
 data = XSTRING_DATA (val);
 memcpy (data, XSTRING_DATA (prefix), len);
 /* `val' is created by adding 6 characters to PREFIX.  The first
 three are the PID of this process, in base 64, and the second
 three are incremented if the file already exists.  This ensures
 262144 unique file names per PID per PREFIX.  */
-pid = (int)getpid ();
+pid = (unsigned)getpid ();
 *p++ = tbl[pid & 63], pid >>= 6;
 *p++ = tbl[pid & 63], pid >>= 6;
 *p++ = tbl[pid & 63], pid >>= 6;
-/* Here we employ some trickery to minimize useless stat'ing when
+/* Here we try to minimize useless stat'ing when this function is
-this function is invoked many times successively with the same
+invoked many times successively with the same PREFIX.  We achieve
-PREFIX.  Instead of looping from 0 to 63, each of the variables
+this by initializing count to a random value, and incrementing it
-is assigned a random number less than 64, and is incremented up
+afterwards.  */
-to 63 and back to zero, until the initial value is reached again.
+if (!count_initialized_p)
+{
-In other words, MTN_LOOP (i, 64, keep1) is equivalent to
+count = (unsigned)time (NULL);
-for (i = 0; i < 64; i++) with the difference that the beginning
+count_initialized_p = 1;
-value needn't be 0 -- all that matters is that i is guaranteed to
+}
-loop through all the values in the [0, 64) range.  */
-MTN_LOOP (i, 64, keep1)
+while (1)
 {
-p[0] = tbl[i];
+struct stat ignored;
-MTN_LOOP (j, 64, keep2)
+unsigned num = count++;
+p[0] = tbl[num & 63], num >>= 6;
+p[1] = tbl[num & 63], num >>= 6;
+p[2] = tbl[num & 63], num >>= 6;
+if (stat ((const char *) data, &ignored) < 0)
 	{
-	  p[1] = tbl[j];
+	  /* We want to return only if errno is ENOENT.  */
-	  MTN_LOOP (k, 64, keep3)
+	  if (errno == ENOENT)
-	    {
+	    return val;
-	      struct stat ignored;
+	  else
-	      p[2] = tbl[k];
+	    /* The error here is dubious, but there is little else we
-	      if (stat (data, &ignored) < 0)
+	       can do.  The alternatives are to return nil, which is
-		{
+	       as bad as (and in many cases worse than) throwing the
-		  /* We want to return only if errno is ENOENT.  */
+	       error, or to ignore the error, which will likely result
-		  if (errno == ENOENT)
+	       in looping through 262144 stat's, which is not only
-		    return val;
+	       dog-slow, but also useless since it will fallback to
-		  else
+	       the errow below, anyway.  */
-		    /* The error here is dubious, but there is little
+	    report_file_error ("Cannot create temporary name for prefix",
-		       else we can do.  The alternatives are to return
+			       list1 (prefix));
-		       nil, which is as bad as (and in many cases
+	  /* not reached */
-		       worse than) throwing the error, or to ignore
-		       the error, which will likely result in looping
-		       through 262144 stat's, which is not only SLOW,
-		       but also useless since it will fallback to the
-		       errow below, anyway.  */
-		    report_file_error
-		      ("Cannot create temporary name for prefix",
-		       list1 (prefix));
-		  /* not reached */
-		}
-	    }
 	}
 }
 signal_simple_error ("Cannot create temporary name for prefix", prefix);
 RETURN_NOT_REACHED (Qnil);
 }
 if (newdir)
 {
 /* Get rid of any slash at the end of newdir, unless newdir is
 	 just // (an incomplete UNC name).  */
 length = strlen ((char *) newdir);
-if (length > 0 && IS_DIRECTORY_SEP (newdir[length - 1])
+if (length > 1 && IS_DIRECTORY_SEP (newdir[length - 1])
 #ifdef WINDOWSNT
 	  && !(length == 2 && IS_DIRECTORY_SEP (newdir[0]))
 #endif
 	  )
 	{
 (This has supposedly been fixed in Sunos 4,
 but who knows about all the other machines with NFS?)  */
 /* On VMS and APOLLO, must do the stat after the close
 since closing changes the modtime.  */
-#if 0 /* !defined (VMS) && !defined (APOLLO) */
+#if 1 /* !defined (VMS) && !defined (APOLLO) */
 fstat (desc, &st);
 #endif
 /* NFS can report a write failure now.  */
 if (close (desc) < 0)
 XCAR (desc_locative) = Qnil;
 unbind_to (speccount, Qnil);
 }
-#if 1 /* defined (VMS) || defined (APOLLO) */
+#if 0 /* defined (VMS) || defined (APOLLO) */
 stat ((char *) XSTRING_DATA (fn), &st);
 #endif
 #ifdef CLASH_DETECTION
 if (!auto_saving)
 The value should be either ?/ or ?\\ (any other value is treated as ?\\).
 This variable affects the built-in functions only on Windows,
 on other platforms, it is initialized so that Lisp code can find out
 what the normal separator is.
 */ );
-Vdirectory_sep_char = make_char('/');
+Vdirectory_sep_char = make_char(DIRECTORY_SEP);
 }

Mercurial > hg > xemacs-beta

comparison src/fileio.c @ 276:6330739388db r21-0b36