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Diffstat (limited to 'src/filelock.c')
-rw-r--r--src/filelock.c103
1 files changed, 86 insertions, 17 deletions
diff --git a/src/filelock.c b/src/filelock.c
index 81e72432c06..3850a527f14 100644
--- a/src/filelock.c
+++ b/src/filelock.c
@@ -20,20 +20,36 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <sys/types.h>
#include <sys/stat.h>
#include "config.h"
+#ifdef hpux
+/* needed by <pwd.h> */
+#include <stdio.h>
+#undef NULL
+#endif
+#include "lisp.h"
+#include "paths.h"
+#include "buffer.h"
+
+#ifdef VMS
+#include "vms-pwd.h"
+#else
#include <pwd.h>
+#endif
+
#include <errno.h>
#include <sys/file.h>
#ifdef USG
#include <fcntl.h>
#endif /* USG */
-#undef NULL
-#include "lisp.h"
-#include "paths.h"
-#include "buffer.h"
+#include "filetypes.h"
extern int errno;
+#ifdef VMS
+/* Prevent the file from being totally empty. */
+static dummy () {}
+#endif
+
#ifdef CLASH_DETECTION
/* If system does not have symbolic links, it does not have lstat.
@@ -78,6 +94,27 @@ lock_file_owner_name (lfname)
and put in the Emacs lock directory. */
/* (ie., /ka/king/junk.tex -> /!/!ka!king!junk.tex). */
+/* If SHORT_FILE_NAMES is defined, the lock file name is the hex
+ representation of a 14-bytes CRC generated from the file name
+ and put in the Emacs lock directory (not very nice, but it works).
+ (ie., /ka/king/junk.tex -> /!/ec92d3ed24a8f0). */
+
+#ifdef SHORT_FILE_NAMES
+
+# define CREATE_LOCK_FILE_NAME(lfname, fn) \
+ { lfname = (char *) alloca (14 + strlen (PATH_LOCK) + 1); \
+ fill_in_lock_short_file_name (lfname, fn); }
+
+#else
+
+# define CREATE_LOCK_FILE_NAME(lfname, fn) \
+ { lfname = (char *) alloca (XSTRING (fn)->size + strlen (PATH_LOCK) + 1); \
+ fill_in_lock_file_name (lfname, fn); }
+
+#endif
+
+
+
void
lock_file (fn)
register Lisp_Object fn;
@@ -86,8 +123,7 @@ lock_file (fn)
register char *lfname;
/* Create the name of the lock-file for file fn */
- lfname = (char *) alloca (XSTRING (fn)->size + strlen (PATH_LOCK) + 1);
- fill_in_lock_file_name (lfname, fn);
+ CREATE_LOCK_FILE_NAME (lfname, fn);
/* See if this file is visited and has changed on disk since it was visited. */
{
@@ -136,6 +172,41 @@ fill_in_lock_file_name (lockfile, fn)
}
}
+#ifdef SHORT_FILE_NAMES
+fill_in_lock_short_file_name (lockfile, fn)
+ register char *lockfile;
+ register Lisp_Object fn;
+{
+ register union
+ {
+ unsigned int word [2];
+ unsigned char byte [8];
+ } crc;
+ register unsigned char *p, new;
+
+ /* 7-bytes cyclic code for burst correction on byte-by-byte basis.
+ the used polynomial is D^7 + D^6 + D^3 +1. pot@fdt.CNUCE.CNR.IT */
+
+ crc.word[0] = crc.word[1] = 0;
+
+ for (p = XSTRING (fn)->data; new = *p++; )
+ {
+ new += crc.byte[7];
+ crc.byte[7] = crc.byte[6];
+ crc.byte[6] = crc.byte[5] + new;
+ crc.byte[5] = crc.byte[4];
+ crc.byte[4] = crc.byte[3];
+ crc.byte[3] = crc.byte[2] + new;
+ crc.byte[2] = crc.byte[1];
+ crc.byte[1] = crc.byte[0];
+ crc.byte[0] = new;
+ }
+ sprintf (lockfile, "%s%.2x%.2x%.2x%.2x%.2x%.2x%.2x", PATH_LOCK,
+ crc.byte[0], crc.byte[1], crc.byte[2], crc.byte[3],
+ crc.byte[4], crc.byte[5], crc.byte[6]);
+}
+#endif /* SHORT_FILE_NAMES */
+
/* Lock the lock file named LFNAME.
If MODE is O_WRONLY, we do so even if it is already locked.
If MODE is O_WRONLY | O_EXCL | O_CREAT, we do so only if it is free.
@@ -150,7 +221,7 @@ lock_file_1 (lfname, mode)
if ((fd = open (lfname, mode, 0666)) >= 0)
{
-#ifdef USG
+#ifdef NO_FCHMOD
chmod (lfname, 0666);
#else
fchmod (fd, 0666);
@@ -231,8 +302,7 @@ unlock_file (fn)
{
register char *lfname;
- lfname = (char *) alloca (XSTRING (fn)->size + strlen (PATH_LOCK) + 1);
- fill_in_lock_file_name (lfname, fn);
+ CREATE_LOCK_FILE_NAME (lfname, fn);
lock_superlock (lfname);
@@ -257,7 +327,7 @@ lock_superlock (lfname)
}
if (fd >= 0)
{
-#ifdef USG
+#ifdef NO_FCHMOD
chmod (PATH_SUPERLOCK, 0666);
#else
fchmod (fd, 0666);
@@ -286,7 +356,7 @@ unlock_all_files ()
DEFUN ("lock-buffer", Flock_buffer, Slock_buffer,
0, 1, 0,
- "Lock FILE, if current buffer is modified.\n\
+ "Locks FILE, if current buffer is modified.\n\
FILE defaults to current buffer's visited file,\n\
or else nothing is done if current buffer isn't visiting a file.")
(fn)
@@ -304,7 +374,7 @@ or else nothing is done if current buffer isn't visiting a file.")
DEFUN ("unlock-buffer", Funlock_buffer, Sunlock_buffer,
0, 0, 0,
- "Unlock the file visited in the current buffer,\n\
+ "Unlocks the file visited in the current buffer,\n\
if it should normally be locked.")
()
{
@@ -320,13 +390,13 @@ if it should normally be locked.")
unlock_buffer (buffer)
struct buffer *buffer;
{
- if (buffer->save_modified < BUF_MODIFF (buffer) &&
- XTYPE (buffer->filename) == Lisp_String)
+ if (buffer->save_modified < BUF_MODIFF (buffer)
+ && XTYPE (buffer->filename) == Lisp_String)
unlock_file (buffer->filename);
}
DEFUN ("file-locked-p", Ffile_locked_p, Sfile_locked_p, 0, 1, 0,
- "Return nil if the FILENAME is not locked,\n\
+ "Returns nil if the FILENAME is not locked,\n\
t if it is locked by you, else a string of the name of the locker.")
(fn)
Lisp_Object fn;
@@ -337,8 +407,7 @@ t if it is locked by you, else a string of the name of the locker.")
fn = Fexpand_file_name (fn, Qnil);
/* Create the name of the lock-file for file filename */
- lfname = (char *) alloca (XSTRING (fn)->size + strlen (PATH_LOCK) + 1);
- fill_in_lock_file_name (lfname, fn);
+ CREATE_LOCK_FILE_NAME (lfname, fn);
owner = current_lock_owner (lfname);
if (owner <= 0)
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-23 05:11:03 +0000