common/mark.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * See the LICENSE file for redistribution information.
   8  */
   9
  10 #include "config.h"
  11
  12 #ifndef lint
  13 static const char sccsid[] = "$Id: mark.c,v 10.14 2000/04/21 19:00:33 skimo Exp $ (Berkeley) $Date: 2000/04/21 19:00:33 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18
  19 #include <bitstring.h>
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "common.h"
  27
  28 static LMARK *mark_find __P((SCR *, ARG_CHAR_T));
  29
  30 /*
  31  * Marks are maintained in a key sorted doubly linked list.  We can't
  32  * use arrays because we have no idea how big an index key could be.
  33  * The underlying assumption is that users don't have more than, say,
  34  * 10 marks at any one time, so this will be is fast enough.
  35  *
  36  * Marks are fixed, and modifications to the line don't update the mark's
  37  * position in the line.  This can be hard.  If you add text to the line,
  38  * place a mark in that text, undo the addition and use ` to move to the
  39  * mark, the location will have disappeared.  It's tempting to try to adjust
  40  * the mark with the changes in the line, but this is hard to do, especially
  41  * if we've given the line to v_ntext.c:v_ntext() for editing.  Historic vi
  42  * would move to the first non-blank on the line when the mark location was
  43  * past the end of the line.  This can be complicated by deleting to a mark
  44  * that has disappeared using the ` command.  Historic vi treated this as
  45  * a line-mode motion and deleted the line.  This implementation complains to
  46  * the user.
  47  *
  48  * In historic vi, marks returned if the operation was undone, unless the
  49  * mark had been subsequently reset.  Tricky.  This is hard to start with,
  50  * but in the presence of repeated undo it gets nasty.  When a line is
  51  * deleted, we delete (and log) any marks on that line.  An undo will create
  52  * the mark.  Any mark creations are noted as to whether the user created
  53  * it or if it was created by an undo.  The former cannot be reset by another
  54  * undo, but the latter may.
  55  *
  56  * All of these routines translate ABSMARK2 to ABSMARK1.  Setting either of
  57  * the absolute mark locations sets both, so that "m'" and "m`" work like
  58  * they, ah, for lack of a better word, "should".
  59  */
  60
  61 /*
  62  * mark_init --
  63  *      Set up the marks.
  64  *
  65  * PUBLIC: int mark_init __P((SCR *, EXF *));
  66  */
  67 int
  68 mark_init(sp, ep)
  69         SCR *sp;
  70         EXF *ep;
  71 {
  72         /*
  73          * !!!
  74          * ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
  75          *
  76          * Set up the marks.
  77          */
  78         LIST_INIT(&ep->marks);
  79         return (0);
  80 }
  81
  82 /*
  83  * mark_end --
  84  *      Free up the marks.
  85  *
  86  * PUBLIC: int mark_end __P((SCR *, EXF *));
  87  */
  88 int
  89 mark_end(sp, ep)
  90         SCR *sp;
  91         EXF *ep;
  92 {
  93         LMARK *lmp;
  94
  95         /*
  96          * !!!
  97          * ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
  98          */
  99         while ((lmp = ep->marks.lh_first) != NULL) {
 100                 LIST_REMOVE(lmp, q);
 101                 free(lmp);
 102         }
 103         return (0);
 104 }
 105
 106 /*
 107  * mark_get --
 108  *      Get the location referenced by a mark.
 109  *
 110  * PUBLIC: int mark_get __P((SCR *, ARG_CHAR_T, MARK *, mtype_t));
 111  */
 112 int
 113 mark_get(sp, key, mp, mtype)
 114         SCR *sp;
 115         ARG_CHAR_T key;
 116         MARK *mp;
 117         mtype_t mtype;
 118 {
 119         LMARK *lmp;
 120
 121         if (key == ABSMARK2)
 122                 key = ABSMARK1;
 123
 124         lmp = mark_find(sp, key);
 125         if (lmp == NULL || lmp->name != key) {
 126                 msgq(sp, mtype, "017|Mark %s: not set", KEY_NAME(sp, key));
 127                 return (1);
 128         }
 129         if (F_ISSET(lmp, MARK_DELETED)) {
 130                 msgq(sp, mtype,
 131                     "018|Mark %s: the line was deleted", KEY_NAME(sp, key));
 132                 return (1);
 133         }
 134
 135         /*
 136          * !!!
 137          * The absolute mark is initialized to lno 1/cno 0, and historically
 138          * you could use it in an empty file.  Make such a mark always work.
 139          */
 140         if ((lmp->lno != 1 || lmp->cno != 0) && !db_exist(sp, lmp->lno)) {
 141                 msgq(sp, mtype,
 142                     "019|Mark %s: cursor position no longer exists",
 143                     KEY_NAME(sp, key));
 144                 return (1);
 145         }
 146         mp->lno = lmp->lno;
 147         mp->cno = lmp->cno;
 148         return (0);
 149 }
 150
 151 /*
 152  * mark_set --
 153  *      Set the location referenced by a mark.
 154  *
 155  * PUBLIC: int mark_set __P((SCR *, ARG_CHAR_T, MARK *, int));
 156  */
 157 int
 158 mark_set(sp, key, value, userset)
 159         SCR *sp;
 160         ARG_CHAR_T key;
 161         MARK *value;
 162         int userset;
 163 {
 164         LMARK *lmp, *lmt;
 165
 166         if (key == ABSMARK2)
 167                 key = ABSMARK1;
 168
 169         /*
 170          * The rules are simple.  If the user is setting a mark (if it's a
 171          * new mark this is always true), it always happens.  If not, it's
 172          * an undo, and we set it if it's not already set or if it was set
 173          * by a previous undo.
 174          */
 175         lmp = mark_find(sp, key);
 176         if (lmp == NULL || lmp->name != key) {
 177                 MALLOC_RET(sp, lmt, LMARK *, sizeof(LMARK));
 178                 if (lmp == NULL) {
 179                         LIST_INSERT_HEAD(&sp->ep->marks, lmt, q);
 180                 } else
 181                         LIST_INSERT_AFTER(lmp, lmt, q);
 182                 lmp = lmt;
 183         } else if (!userset &&
 184             !F_ISSET(lmp, MARK_DELETED) && F_ISSET(lmp, MARK_USERSET))
 185                 return (0);
 186
 187         lmp->lno = value->lno;
 188         lmp->cno = value->cno;
 189         lmp->name = key;
 190         lmp->flags = userset ? MARK_USERSET : 0;
 191         return (0);
 192 }
 193
 194 /*
 195  * mark_find --
 196  *      Find the requested mark, or, the slot immediately before
 197  *      where it would go.
 198  */
 199 static LMARK *
 200 mark_find(sp, key)
 201         SCR *sp;
 202         ARG_CHAR_T key;
 203 {
 204         LMARK *lmp, *lastlmp;
 205
 206         /*
 207          * Return the requested mark or the slot immediately before
 208          * where it should go.
 209          */
 210         for (lastlmp = NULL, lmp = sp->ep->marks.lh_first;
 211             lmp != NULL; lastlmp = lmp, lmp = lmp->q.le_next)
 212                 if (lmp->name >= key)
 213                         return (lmp->name == key ? lmp : lastlmp);
 214         return (lastlmp);
 215 }
 216
 217 /*
 218  * mark_insdel --
 219  *      Update the marks based on an insertion or deletion.
 220  *
 221  * PUBLIC: int mark_insdel __P((SCR *, lnop_t, db_recno_t));
 222  */
 223 int
 224 mark_insdel(sp, op, lno)
 225         SCR *sp;
 226         lnop_t op;
 227         db_recno_t lno;
 228 {
 229         LMARK *lmp;
 230         db_recno_t lline;
 231
 232         switch (op) {
 233         case LINE_APPEND:
 234                 /* All insert/append operations are done as inserts. */
 235                 abort();
 236         case LINE_DELETE:
 237                 for (lmp = sp->ep->marks.lh_first;
 238                     lmp != NULL; lmp = lmp->q.le_next)
 239                         if (lmp->lno >= lno)
 240                                 if (lmp->lno == lno) {
 241                                         F_SET(lmp, MARK_DELETED);
 242                                         (void)log_mark(sp, lmp);
 243                                 } else
 244                                         --lmp->lno;
 245                 break;
 246         case LINE_INSERT:
 247                 /*
 248                  * XXX
 249                  * Very nasty special case.  If the file was empty, then we're
 250                  * adding the first line, which is a replacement.  So, we don't
 251                  * modify the marks.  This is a hack to make:
 252                  *
 253                  *      mz:r!echo foo<carriage-return>'z
 254                  *
 255                  * work, i.e. historically you could mark the "line" in an empty
 256                  * file and replace it, and continue to use the mark.  Insane,
 257                  * well, yes, I know, but someone complained.
 258                  *
 259                  * Check for line #2 before going to the end of the file.
 260                  */
 261                 if (!db_exist(sp, 2)) {
 262                         if (db_last(sp, &lline))
 263                                 return (1);
 264                         if (lline == 1)
 265                                 return (0);
 266                 }
 267
 268                 for (lmp = sp->ep->marks.lh_first;
 269                     lmp != NULL; lmp = lmp->q.le_next)
 270                         if (lmp->lno >= lno)
 271                                 ++lmp->lno;
 272                 break;
 273         case LINE_RESET:
 274                 break;
 275         }
 276         return (0);
 277 }