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change name of lock file to avoid problems with etags, byte-recompile-directory, etc. -------------------- ChangeLog entries follow: -------------------- src/ChangeLog addition: 2010-02-04 Ben Wing <ben@xemacs.org> * filelock.c: * filelock.c (fill_in_lock_file_name): Name the lock symlink file .#FN# instead of .#FN for file FN, so that the link file doesn't have a .c or .el or whatever extension, which confuses programs/functions that search by extension (e.g. etags, byte-recompile-directory, etc.).
author Ben Wing <ben@xemacs.org>
date Thu, 04 Feb 2010 05:58:40 -0600
parents 304aebb79cd3
children 16112448d484
comparison
equal deleted inserted replaced
4971:bcdf496e49d0 4972:c448f4c38d65
1 /* Copyright (C) 1985, 86, 87, 93, 94, 96 Free Software Foundation, Inc. 1 /* Copyright (C) 1985, 86, 87, 93, 94, 96 Free Software Foundation, Inc.
2 Copyright (C) 2001 Ben Wing. 2 Copyright (C) 2001, 2010 Ben Wing.
3 3
4 This file is part of XEmacs. 4 This file is part of XEmacs.
5 5
6 XEmacs is free software; you can redistribute it and/or modify 6 XEmacs is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by 7 it under the terms of the GNU General Public License as published by
36 Lisp_Object Qask_user_about_lock; 36 Lisp_Object Qask_user_about_lock;
37 int inhibit_clash_detection; 37 int inhibit_clash_detection;
38 38
39 #ifdef CLASH_DETECTION 39 #ifdef CLASH_DETECTION
40 40
41 /* The strategy: to lock a file FN, create a symlink .#FN in FN's 41 /* The strategy: to lock a file FN, create a symlink .#FN# in FN's
42 directory, with link data `user@host.pid'. This avoids a single 42 directory, with link data `user@host.pid'. This avoids a single
43 mount (== failure) point for lock files. 43 mount (== failure) point for lock files.
44 44
45 When the host in the lock data is the current host, we can check if 45 When the host in the lock data is the current host, we can check if
46 the pid is valid with kill. 46 the pid is valid with kill.
65 65
66 Similarly, we don't worry about a possible 14-character limit on 66 Similarly, we don't worry about a possible 14-character limit on
67 file names, because those are all the same systems that don't have 67 file names, because those are all the same systems that don't have
68 symlinks. 68 symlinks.
69 69
70 This is compatible with the locking scheme used by Interleaf (which 70 Originally we used a name .#FN without the final #; this may have been
71 has contributed this implementation for Emacs), and was designed by 71 compatible with the locking scheme used by Interleaf (which has
72 Ethan Jacobson, Kimbo Mundy, and others. 72 contributed this implementation for Emacs), and was designed by Ethan
73 Jacobson, Kimbo Mundy, and others.
73 74
74 --karl@cs.umb.edu/karl@hq.ileaf.com. */ 75 --karl@cs.umb.edu/karl@hq.ileaf.com. */
76
77 /* NOTE: We added the final # in the name .#FN# so that programs
78 that e.g. search for all .c files, such as etags, or try to
79 byte-compile all .el files in a directory (byte-recompile-directory),
80 won't get tripped up by the bogus symlink file. --ben */
75 81
76 82
77 /* Here is the structure that stores information about a lock. */ 83 /* Here is the structure that stores information about a lock. */
78 84
79 typedef struct 85 typedef struct
91 #define FREE_LOCK_INFO(i) do { \ 97 #define FREE_LOCK_INFO(i) do { \
92 xfree ((i).user, Ibyte *); \ 98 xfree ((i).user, Ibyte *); \
93 xfree ((i).host, Ibyte *); \ 99 xfree ((i).host, Ibyte *); \
94 } while (0) 100 } while (0)
95 101
96 /* Write the name of the lock file for FN into LFNAME. Length will be 102 /* Write the name of the lock file for FN into LFNAME. Length will be that
97 that of FN plus two more for the leading `.#' plus one for the null. */ 103 of FN plus two more for the leading `.#' plus one for the trailing #
104 plus one for the null. */
98 #define MAKE_LOCK_NAME(lock, file) \ 105 #define MAKE_LOCK_NAME(lock, file) \
99 (lock = alloca_ibytes (XSTRING_LENGTH (file) + 2 + 1), \ 106 (lock = alloca_ibytes (XSTRING_LENGTH (file) + 2 + 1 + 1), \
100 fill_in_lock_file_name (lock, file)) 107 fill_in_lock_file_name (lock, file))
101 108
102 static void 109 static void
103 fill_in_lock_file_name (Ibyte *lockfile, Lisp_Object fn) 110 fill_in_lock_file_name (Ibyte *lockfile, Lisp_Object fn)
104 { 111 {
114 121
115 memcpy (lockfile, file_name, dirlen); 122 memcpy (lockfile, file_name, dirlen);
116 p = lockfile + dirlen; 123 p = lockfile + dirlen;
117 *(p++) = '.'; 124 *(p++) = '.';
118 *(p++) = '#'; 125 *(p++) = '#';
119 memcpy (p, file_name + dirlen, XSTRING_LENGTH (fn) - dirlen + 1); 126 memcpy (p, file_name + dirlen, XSTRING_LENGTH (fn) - dirlen);
127 p += XSTRING_LENGTH (fn) - dirlen;
128 *(p++) = '#';
129 *p = '\0';
120 } 130 }
121 131
122 /* Lock the lock file named LFNAME. 132 /* Lock the lock file named LFNAME.
123 If FORCE is nonzero, we do so even if it is already locked. 133 If FORCE is nonzero, we do so even if it is already locked.
124 Return 1 if successful, 0 if not. */ 134 Return 1 if successful, 0 if not. */