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log.c revision 1.1.1.1
      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: log.c,v 10.26 2002/03/02 23:12:13 skimo Exp  (Berkeley) Date: 2002/03/02 23:12:13 ";
     14 #endif /* not lint */
     15 
     16 #include <sys/types.h>
     17 #include <sys/queue.h>
     18 #include <sys/stat.h>
     19 
     20 #include <bitstring.h>
     21 #include <errno.h>
     22 #include <fcntl.h>
     23 #include <limits.h>
     24 #include <stdio.h>
     25 #include <stdlib.h>
     26 #include <string.h>
     27 
     28 #include "common.h"
     29 
     30 /*
     31  * The log consists of records, each containing a type byte and a variable
     32  * length byte string, as follows:
     33  *
     34  *	LOG_CURSOR_INIT		MARK
     35  *	LOG_CURSOR_END		MARK
     36  *	LOG_LINE_APPEND_F 	db_recno_t		char *
     37  *	LOG_LINE_APPEND_B 	db_recno_t		char *
     38  *	LOG_LINE_DELETE_F	db_recno_t		char *
     39  *	LOG_LINE_DELETE_B	db_recno_t		char *
     40  *	LOG_LINE_RESET_F	db_recno_t		char *
     41  *	LOG_LINE_RESET_B	db_recno_t		char *
     42  *	LOG_MARK		LMARK
     43  *
     44  * We do before image physical logging.  This means that the editor layer
     45  * MAY NOT modify records in place, even if simply deleting or overwriting
     46  * characters.  Since the smallest unit of logging is a line, we're using
     47  * up lots of space.  This may eventually have to be reduced, probably by
     48  * doing logical logging, which is a much cooler database phrase.
     49  *
     50  * The implementation of the historic vi 'u' command, using roll-forward and
     51  * roll-back, is simple.  Each set of changes has a LOG_CURSOR_INIT record,
     52  * followed by a number of other records, followed by a LOG_CURSOR_END record.
     53  * LOG_LINE_RESET records come in pairs.  The first is a LOG_LINE_RESET_B
     54  * record, and is the line before the change.  The second is LOG_LINE_RESET_F,
     55  * and is the line after the change.  Roll-back is done by backing up to the
     56  * first LOG_CURSOR_INIT record before a change.  Roll-forward is done in a
     57  * similar fashion.
     58  *
     59  * The 'U' command is implemented by rolling backward to a LOG_CURSOR_END
     60  * record for a line different from the current one.  It should be noted that
     61  * this means that a subsequent 'u' command will make a change based on the
     62  * new position of the log's cursor.  This is okay, and, in fact, historic vi
     63  * behaved that way.
     64  */
     65 
     66 static int	vi_log_get __P((SCR *sp, db_recno_t *lnop, size_t *size));
     67 static int	log_cursor1 __P((SCR *, int));
     68 static void	log_err __P((SCR *, char *, int));
     69 #if defined(DEBUG) && 0
     70 static void	log_trace __P((SCR *, char *, db_recno_t, u_char *));
     71 #endif
     72 
     73 /* Try and restart the log on failure, i.e. if we run out of memory. */
     74 #define	LOG_ERR {							\
     75 	log_err(sp, __FILE__, __LINE__);				\
     76 	return (1);							\
     77 }
     78 
     79 /* offset of CHAR_T string in log needs to be aligned on some systems
     80  * because it is passed to db_set as a string
     81  */
     82 typedef struct {
     83     char    data[sizeof(u_char) /* type */ + sizeof(db_recno_t)];
     84     CHAR_T  str[1];
     85 } log_t;
     86 #define CHAR_T_OFFSET ((char *)(((log_t*)0)->str) - (char *)0)
     87 
     88 /*
     89  * log_init --
     90  *	Initialize the logging subsystem.
     91  *
     92  * PUBLIC: int log_init __P((SCR *, EXF *));
     93  */
     94 int
     95 log_init(SCR *sp, EXF *ep)
     96 {
     97 	/*
     98 	 * !!!
     99 	 * ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
    100 	 *
    101 	 * Initialize the buffer.  The logging subsystem has its own
    102 	 * buffers because the global ones are almost by definition
    103 	 * going to be in use when the log runs.
    104 	 */
    105 	sp->wp->l_lp = NULL;
    106 	sp->wp->l_len = 0;
    107 	ep->l_cursor.lno = 1;		/* XXX Any valid recno. */
    108 	ep->l_cursor.cno = 0;
    109 	ep->l_high = ep->l_cur = 1;
    110 
    111 	if (db_create(&ep->log, 0, 0) != 0 ||
    112 	    db_open(ep->log, NULL, DB_RECNO,
    113 			  DB_CREATE | VI_DB_THREAD, S_IRUSR | S_IWUSR) != 0) {
    114 		msgq(sp, M_SYSERR, "009|Log file");
    115 		F_SET(ep, F_NOLOG);
    116 		return (1);
    117 	}
    118 
    119 	ep->l_win = NULL;
    120 	/*LOCK_INIT(sp->wp, ep);*/
    121 
    122 	return (0);
    123 }
    124 
    125 /*
    126  * log_end --
    127  *	Close the logging subsystem.
    128  *
    129  * PUBLIC: int log_end __P((SCR *, EXF *));
    130  */
    131 int
    132 log_end(SCR *sp, EXF *ep)
    133 {
    134 	/*
    135 	 * !!!
    136 	 * ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
    137 	 */
    138 	/*LOCK_END(sp->wp, ep);*/
    139 	if (ep->log != NULL) {
    140 		(void)(ep->log->close)(ep->log, DB_NOSYNC);
    141 		ep->log = NULL;
    142 	}
    143 	if (sp->wp->l_lp != NULL) {
    144 		free(sp->wp->l_lp);
    145 		sp->wp->l_lp = NULL;
    146 	}
    147 	sp->wp->l_len = 0;
    148 	ep->l_cursor.lno = 1;		/* XXX Any valid recno. */
    149 	ep->l_cursor.cno = 0;
    150 	ep->l_high = ep->l_cur = 1;
    151 	return (0);
    152 }
    153 
    154 /*
    155  * log_cursor --
    156  *	Log the current cursor position, starting an event.
    157  *
    158  * PUBLIC: int log_cursor __P((SCR *));
    159  */
    160 int
    161 log_cursor(SCR *sp)
    162 {
    163 	EXF *ep;
    164 
    165 	ep = sp->ep;
    166 	if (F_ISSET(ep, F_NOLOG))
    167 		return (0);
    168 
    169 	/*
    170 	 * If any changes were made since the last cursor init,
    171 	 * put out the ending cursor record.
    172 	 */
    173 	if (ep->l_cursor.lno == OOBLNO) {
    174 		if (ep->l_win && ep->l_win != sp->wp)
    175 			return 0;
    176 		ep->l_cursor.lno = sp->lno;
    177 		ep->l_cursor.cno = sp->cno;
    178 		ep->l_win = NULL;
    179 		return (log_cursor1(sp, LOG_CURSOR_END));
    180 	}
    181 	ep->l_cursor.lno = sp->lno;
    182 	ep->l_cursor.cno = sp->cno;
    183 	return (0);
    184 }
    185 
    186 /*
    187  * log_cursor1 --
    188  *	Actually push a cursor record out.
    189  */
    190 static int
    191 log_cursor1(SCR *sp, int type)
    192 {
    193 	DBT data, key;
    194 	EXF *ep;
    195 
    196 	ep = sp->ep;
    197 
    198 	/*
    199 	if (type == LOG_CURSOR_INIT &&
    200 	    LOCK_TRY(sp->wp, ep))
    201 		return 1;
    202 	*/
    203 
    204 	BINC_RETC(sp, sp->wp->l_lp, sp->wp->l_len, sizeof(u_char) + sizeof(MARK));
    205 	sp->wp->l_lp[0] = type;
    206 	memmove(sp->wp->l_lp + sizeof(u_char), &ep->l_cursor, sizeof(MARK));
    207 
    208 	memset(&key, 0, sizeof(key));
    209 	key.data = &ep->l_cur;
    210 	key.size = sizeof(db_recno_t);
    211 	memset(&data, 0, sizeof(data));
    212 	data.data = sp->wp->l_lp;
    213 	data.size = sizeof(u_char) + sizeof(MARK);
    214 	if (ep->log->put(ep->log, NULL, &key, &data, 0) == -1)
    215 		LOG_ERR;
    216 
    217 #if defined(DEBUG) && 0
    218 	vtrace(sp, "%lu: %s: %u/%u\n", ep->l_cur,
    219 	    type == LOG_CURSOR_INIT ? "log_cursor_init" : "log_cursor_end",
    220 	    sp->lno, sp->cno);
    221 #endif
    222 	/* Reset high water mark. */
    223 	ep->l_high = ++ep->l_cur;
    224 
    225 	/*
    226 	if (type == LOG_CURSOR_END)
    227 		LOCK_UNLOCK(sp->wp, ep);
    228 	*/
    229 	return (0);
    230 }
    231 
    232 /*
    233  * log_line --
    234  *	Log a line change.
    235  *
    236  * PUBLIC: int log_line __P((SCR *, db_recno_t, u_int));
    237  */
    238 int
    239 log_line(SCR *sp, db_recno_t lno, u_int action)
    240 {
    241 	DBT data, key;
    242 	EXF *ep;
    243 	size_t len;
    244 	CHAR_T *lp;
    245 	db_recno_t lcur;
    246 
    247 	ep = sp->ep;
    248 	if (F_ISSET(ep, F_NOLOG))
    249 		return (0);
    250 
    251 	/*
    252 	 * XXX
    253 	 *
    254 	 * Kluge for vi.  Clear the EXF undo flag so that the
    255 	 * next 'u' command does a roll-back, regardless.
    256 	 */
    257 	F_CLR(ep, F_UNDO);
    258 
    259 	/* Put out one initial cursor record per set of changes. */
    260 	if (ep->l_cursor.lno != OOBLNO) {
    261 		if (log_cursor1(sp, LOG_CURSOR_INIT))
    262 			return (1);
    263 		ep->l_cursor.lno = OOBLNO;
    264 		ep->l_win = sp->wp;
    265 	} /*else if (ep->l_win != sp->wp) {
    266 		printf("log_line own: %p, this: %p\n", ep->l_win, sp->wp);
    267 		return 1;
    268 	}*/
    269 
    270 	switch (action) {
    271 	/* newly added for DB4 logging */
    272 	case LOG_LINE_APPEND_B:
    273 	case LOG_LINE_DELETE_F:
    274 		return 0;
    275 	}
    276 
    277 	/*
    278 	 * Put out the changes.  If it's a LOG_LINE_RESET_B call, it's a
    279 	 * special case, avoid the caches.  Also, if it fails and it's
    280 	 * line 1, it just means that the user started with an empty file,
    281 	 * so fake an empty length line.
    282 	 */
    283 	if (action == LOG_LINE_RESET_B) {
    284 		if (db_get(sp, lno, DBG_NOCACHE, &lp, &len)) {
    285 			static CHAR_T nul = 0;
    286 			if (lno != 1) {
    287 				db_err(sp, lno);
    288 				return (1);
    289 			}
    290 			len = 0;
    291 			lp = &nul;
    292 		}
    293 	} else
    294 		if (db_get(sp, lno, DBG_FATAL, &lp, &len))
    295 			return (1);
    296 	BINC_RETC(sp,
    297 	    sp->wp->l_lp, sp->wp->l_len,
    298 	    len * sizeof(CHAR_T) + CHAR_T_OFFSET);
    299 	sp->wp->l_lp[0] = action;
    300 	memmove(sp->wp->l_lp + sizeof(u_char), &lno, sizeof(db_recno_t));
    301 	MEMMOVEW(sp->wp->l_lp + CHAR_T_OFFSET, lp, len);
    302 
    303 	lcur = ep->l_cur;
    304 	memset(&key, 0, sizeof(key));
    305 	key.data = &lcur;
    306 	key.size = sizeof(db_recno_t);
    307 	memset(&data, 0, sizeof(data));
    308 	data.data = sp->wp->l_lp;
    309 	data.size = len * sizeof(CHAR_T) + CHAR_T_OFFSET;
    310 	if (ep->log->put(ep->log, NULL, &key, &data, 0) == -1)
    311 		LOG_ERR;
    312 
    313 #if defined(DEBUG) && 0
    314 	switch (action) {
    315 	case LOG_LINE_APPEND_F:
    316 		vtrace(sp, "%u: log_line: append_f: %lu {%u}\n",
    317 		    ep->l_cur, lno, len);
    318 		break;
    319 	case LOG_LINE_APPEND_B:
    320 		vtrace(sp, "%u: log_line: append_b: %lu {%u}\n",
    321 		    ep->l_cur, lno, len);
    322 		break;
    323 	case LOG_LINE_DELETE_F:
    324 		vtrace(sp, "%lu: log_line: delete_f: %lu {%u}\n",
    325 		    ep->l_cur, lno, len);
    326 		break;
    327 	case LOG_LINE_DELETE_B:
    328 		vtrace(sp, "%lu: log_line: delete_b: %lu {%u}\n",
    329 		    ep->l_cur, lno, len);
    330 		break;
    331 	case LOG_LINE_RESET_F:
    332 		vtrace(sp, "%lu: log_line: reset_f: %lu {%u}\n",
    333 		    ep->l_cur, lno, len);
    334 		break;
    335 	case LOG_LINE_RESET_B:
    336 		vtrace(sp, "%lu: log_line: reset_b: %lu {%u}\n",
    337 		    ep->l_cur, lno, len);
    338 		break;
    339 	}
    340 #endif
    341 	/* Reset high water mark. */
    342 	ep->l_high = ++ep->l_cur;
    343 
    344 	return (0);
    345 }
    346 
    347 /*
    348  * log_mark --
    349  *	Log a mark position.  For the log to work, we assume that there
    350  *	aren't any operations that just put out a log record -- this
    351  *	would mean that undo operations would only reset marks, and not
    352  *	cause any other change.
    353  *
    354  * PUBLIC: int log_mark __P((SCR *, LMARK *));
    355  */
    356 int
    357 log_mark(SCR *sp, LMARK *lmp)
    358 {
    359 	DBT data, key;
    360 	EXF *ep;
    361 
    362 	ep = sp->ep;
    363 	if (F_ISSET(ep, F_NOLOG))
    364 		return (0);
    365 
    366 	/* Put out one initial cursor record per set of changes. */
    367 	if (ep->l_cursor.lno != OOBLNO) {
    368 		if (log_cursor1(sp, LOG_CURSOR_INIT))
    369 			return (1);
    370 		ep->l_cursor.lno = OOBLNO;
    371 		ep->l_win = sp->wp;
    372 	}
    373 
    374 	BINC_RETC(sp, sp->wp->l_lp,
    375 	    sp->wp->l_len, sizeof(u_char) + sizeof(LMARK));
    376 	sp->wp->l_lp[0] = LOG_MARK;
    377 	memmove(sp->wp->l_lp + sizeof(u_char), lmp, sizeof(LMARK));
    378 
    379 	memset(&key, 0, sizeof(key));
    380 	key.data = &ep->l_cur;
    381 	key.size = sizeof(db_recno_t);
    382 	memset(&data, 0, sizeof(data));
    383 	data.data = sp->wp->l_lp;
    384 	data.size = sizeof(u_char) + sizeof(LMARK);
    385 	if (ep->log->put(ep->log, NULL, &key, &data, 0) == -1)
    386 		LOG_ERR;
    387 
    388 #if defined(DEBUG) && 0
    389 	vtrace(sp, "%lu: mark %c: %lu/%u\n",
    390 	    ep->l_cur, lmp->name, lmp->lno, lmp->cno);
    391 #endif
    392 	/* Reset high water mark. */
    393 	ep->l_high = ++ep->l_cur;
    394 	return (0);
    395 }
    396 
    397 /*
    398  * vi_log_get --
    399  *	Get a line from the log in log buffer.
    400  */
    401 static int
    402 vi_log_get(SCR *sp, db_recno_t *lnop, size_t *size)
    403 {
    404 	DBT key, data;
    405 	size_t nlen;
    406 	EXF *ep;
    407 
    408 	ep = sp->ep;
    409 
    410 	nlen = 1024;
    411 retry:
    412 	BINC_RETC(sp, sp->wp->l_lp, sp->wp->l_len, nlen);
    413 
    414 	memset(&key, 0, sizeof(key));
    415 	key.data = lnop;		/* Initialize db request. */
    416 	key.size = sizeof(db_recno_t);
    417 	memset(&data, 0, sizeof(data));
    418 	data.data = sp->wp->l_lp;
    419 	data.ulen = sp->wp->l_len;
    420 	data.flags = DB_DBT_USERMEM;
    421 	switch (ep->log->get(ep->log, NULL, &key, &data, 0)) {
    422 	case ENOMEM:
    423 		nlen = data.size;
    424 		goto retry;
    425 	case 0:
    426 		*size = data.size;
    427 		return 0;
    428 	default:
    429 		return 1;
    430 	}
    431 }
    432 
    433 /*
    434  * Log_backward --
    435  *	Roll the log backward one operation.
    436  *
    437  * PUBLIC: int log_backward __P((SCR *, MARK *));
    438  */
    439 int
    440 log_backward(SCR *sp, MARK *rp)
    441 {
    442 	EXF *ep;
    443 	LMARK lm;
    444 	MARK m;
    445 	db_recno_t lno;
    446 	int didop;
    447 	u_char *p;
    448 	size_t size;
    449 
    450 	ep = sp->ep;
    451 	if (F_ISSET(ep, F_NOLOG)) {
    452 		msgq(sp, M_ERR,
    453 		    "010|Logging not being performed, undo not possible");
    454 		return (1);
    455 	}
    456 
    457 	if (ep->l_cur == 1) {
    458 		msgq(sp, M_BERR, "011|No changes to undo");
    459 		return (1);
    460 	}
    461 
    462 	if (ep->l_win && ep->l_win != sp->wp) {
    463 		ex_emsg(sp, NULL, EXM_LOCKED);
    464 		return 1;
    465 	}
    466 	ep->l_win = sp->wp;
    467 
    468 
    469 	F_SET(ep, F_NOLOG);		/* Turn off logging. */
    470 
    471 	for (didop = 0;;) {
    472 		--ep->l_cur;
    473 		if (vi_log_get(sp, &ep->l_cur, &size))
    474 			LOG_ERR;
    475 #if defined(DEBUG) && 0
    476 		log_trace(sp, "log_backward", ep->l_cur, data.data);
    477 #endif
    478 		switch (*(p = (u_char *)sp->wp->l_lp)) {
    479 		case LOG_CURSOR_INIT:
    480 			if (didop) {
    481 				memmove(rp, p + sizeof(u_char), sizeof(MARK));
    482 				F_CLR(ep, F_NOLOG);
    483 				ep->l_win = NULL;
    484 				return (0);
    485 			}
    486 			break;
    487 		case LOG_CURSOR_END:
    488 			break;
    489 		case LOG_LINE_APPEND_F:
    490 			didop = 1;
    491 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    492 			if (db_delete(sp, lno))
    493 				goto err;
    494 			++sp->rptlines[L_DELETED];
    495 			break;
    496 		case LOG_LINE_DELETE_B:
    497 			didop = 1;
    498 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    499 			if (db_insert(sp, lno,
    500 			    (CHAR_T *)(p + CHAR_T_OFFSET),
    501 			    (size - CHAR_T_OFFSET) / sizeof(CHAR_T)))
    502 				goto err;
    503 			++sp->rptlines[L_ADDED];
    504 			break;
    505 		case LOG_LINE_RESET_F:
    506 			break;
    507 		case LOG_LINE_RESET_B:
    508 			didop = 1;
    509 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    510 			if (db_set(sp, lno,
    511 			    (CHAR_T *)(p + CHAR_T_OFFSET),
    512 			    (size - CHAR_T_OFFSET) / sizeof(CHAR_T)))
    513 				goto err;
    514 			if (sp->rptlchange != lno) {
    515 				sp->rptlchange = lno;
    516 				++sp->rptlines[L_CHANGED];
    517 			}
    518 			break;
    519 		case LOG_MARK:
    520 			didop = 1;
    521 			memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
    522 			m.lno = lm.lno;
    523 			m.cno = lm.cno;
    524 			if (mark_set(sp, lm.name, &m, 0))
    525 				goto err;
    526 			break;
    527 		default:
    528 			abort();
    529 		}
    530 	}
    531 
    532 err:	F_CLR(ep, F_NOLOG);
    533 	ep->l_win = NULL;
    534 	return (1);
    535 }
    536 
    537 /*
    538  * Log_setline --
    539  *	Reset the line to its original appearance.
    540  *
    541  * XXX
    542  * There's a bug in this code due to our not logging cursor movements
    543  * unless a change was made.  If you do a change, move off the line,
    544  * then move back on and do a 'U', the line will be restored to the way
    545  * it was before the original change.
    546  *
    547  * PUBLIC: int log_setline __P((SCR *));
    548  */
    549 int
    550 log_setline(SCR *sp)
    551 {
    552 	EXF *ep;
    553 	LMARK lm;
    554 	MARK m;
    555 	db_recno_t lno;
    556 	u_char *p;
    557 	size_t size;
    558 
    559 	ep = sp->ep;
    560 	if (F_ISSET(ep, F_NOLOG)) {
    561 		msgq(sp, M_ERR,
    562 		    "012|Logging not being performed, undo not possible");
    563 		return (1);
    564 	}
    565 
    566 	if (ep->l_cur == 1)
    567 		return (1);
    568 
    569 	if (ep->l_win && ep->l_win != sp->wp) {
    570 		ex_emsg(sp, NULL, EXM_LOCKED);
    571 		return 1;
    572 	}
    573 	ep->l_win = sp->wp;
    574 
    575 	F_SET(ep, F_NOLOG);		/* Turn off logging. */
    576 
    577 	for (;;) {
    578 		--ep->l_cur;
    579 		if (vi_log_get(sp, &ep->l_cur, &size))
    580 			LOG_ERR;
    581 #if defined(DEBUG) && 0
    582 		log_trace(sp, "log_setline", ep->l_cur, data.data);
    583 #endif
    584 		switch (*(p = (u_char *)sp->wp->l_lp)) {
    585 		case LOG_CURSOR_INIT:
    586 			memmove(&m, p + sizeof(u_char), sizeof(MARK));
    587 			if (m.lno != sp->lno || ep->l_cur == 1) {
    588 				F_CLR(ep, F_NOLOG);
    589 				ep->l_win = NULL;
    590 				return (0);
    591 			}
    592 			break;
    593 		case LOG_CURSOR_END:
    594 			memmove(&m, p + sizeof(u_char), sizeof(MARK));
    595 			if (m.lno != sp->lno) {
    596 				++ep->l_cur;
    597 				F_CLR(ep, F_NOLOG);
    598 				ep->l_win = NULL;
    599 				return (0);
    600 			}
    601 			break;
    602 		case LOG_LINE_APPEND_F:
    603 		case LOG_LINE_DELETE_B:
    604 		case LOG_LINE_RESET_F:
    605 			break;
    606 		case LOG_LINE_RESET_B:
    607 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    608 			if (lno == sp->lno &&
    609 			    db_set(sp, lno, (CHAR_T *)(p + CHAR_T_OFFSET),
    610 				(size - CHAR_T_OFFSET) / sizeof(CHAR_T)))
    611 				goto err;
    612 			if (sp->rptlchange != lno) {
    613 				sp->rptlchange = lno;
    614 				++sp->rptlines[L_CHANGED];
    615 			}
    616 		case LOG_MARK:
    617 			memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
    618 			m.lno = lm.lno;
    619 			m.cno = lm.cno;
    620 			if (mark_set(sp, lm.name, &m, 0))
    621 				goto err;
    622 			break;
    623 		default:
    624 			abort();
    625 		}
    626 	}
    627 
    628 err:	F_CLR(ep, F_NOLOG);
    629 	ep->l_win = NULL;
    630 	return (1);
    631 }
    632 
    633 /*
    634  * Log_forward --
    635  *	Roll the log forward one operation.
    636  *
    637  * PUBLIC: int log_forward __P((SCR *, MARK *));
    638  */
    639 int
    640 log_forward(SCR *sp, MARK *rp)
    641 {
    642 	EXF *ep;
    643 	LMARK lm;
    644 	MARK m;
    645 	db_recno_t lno;
    646 	int didop;
    647 	u_char *p;
    648 	size_t size;
    649 
    650 	ep = sp->ep;
    651 	if (F_ISSET(ep, F_NOLOG)) {
    652 		msgq(sp, M_ERR,
    653 	    "013|Logging not being performed, roll-forward not possible");
    654 		return (1);
    655 	}
    656 
    657 	if (ep->l_cur == ep->l_high) {
    658 		msgq(sp, M_BERR, "014|No changes to re-do");
    659 		return (1);
    660 	}
    661 
    662 	if (ep->l_win && ep->l_win != sp->wp) {
    663 		ex_emsg(sp, NULL, EXM_LOCKED);
    664 		return 1;
    665 	}
    666 	ep->l_win = sp->wp;
    667 
    668 	F_SET(ep, F_NOLOG);		/* Turn off logging. */
    669 
    670 	for (didop = 0;;) {
    671 		++ep->l_cur;
    672 		if (vi_log_get(sp, &ep->l_cur, &size))
    673 			LOG_ERR;
    674 #if defined(DEBUG) && 0
    675 		log_trace(sp, "log_forward", ep->l_cur, data.data);
    676 #endif
    677 		switch (*(p = (u_char *)sp->wp->l_lp)) {
    678 		case LOG_CURSOR_END:
    679 			if (didop) {
    680 				++ep->l_cur;
    681 				memmove(rp, p + sizeof(u_char), sizeof(MARK));
    682 				F_CLR(ep, F_NOLOG);
    683 				ep->l_win = NULL;
    684 				return (0);
    685 			}
    686 			break;
    687 		case LOG_CURSOR_INIT:
    688 			break;
    689 		case LOG_LINE_APPEND_F:
    690 			didop = 1;
    691 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    692 			if (db_insert(sp, lno,
    693 			    (CHAR_T *)(p + CHAR_T_OFFSET),
    694 			    (size - CHAR_T_OFFSET) / sizeof(CHAR_T)))
    695 				goto err;
    696 			++sp->rptlines[L_ADDED];
    697 			break;
    698 		case LOG_LINE_DELETE_B:
    699 			didop = 1;
    700 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    701 			if (db_delete(sp, lno))
    702 				goto err;
    703 			++sp->rptlines[L_DELETED];
    704 			break;
    705 		case LOG_LINE_RESET_B:
    706 			break;
    707 		case LOG_LINE_RESET_F:
    708 			didop = 1;
    709 			memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    710 			if (db_set(sp, lno,
    711 			    (CHAR_T *)(p + CHAR_T_OFFSET),
    712 			    (size - CHAR_T_OFFSET) / sizeof(CHAR_T)))
    713 				goto err;
    714 			if (sp->rptlchange != lno) {
    715 				sp->rptlchange = lno;
    716 				++sp->rptlines[L_CHANGED];
    717 			}
    718 			break;
    719 		case LOG_MARK:
    720 			didop = 1;
    721 			memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
    722 			m.lno = lm.lno;
    723 			m.cno = lm.cno;
    724 			if (mark_set(sp, lm.name, &m, 0))
    725 				goto err;
    726 			break;
    727 		default:
    728 			abort();
    729 		}
    730 	}
    731 
    732 err:	F_CLR(ep, F_NOLOG);
    733 	ep->l_win = NULL;
    734 	return (1);
    735 }
    736 
    737 /*
    738  * log_err --
    739  *	Try and restart the log on failure, i.e. if we run out of memory.
    740  */
    741 static void
    742 log_err(SCR *sp, char *file, int line)
    743 {
    744 	EXF *ep;
    745 
    746 	msgq(sp, M_SYSERR, "015|%s/%d: log put error", tail(file), line);
    747 	ep = sp->ep;
    748 	(void)ep->log->close(ep->log, DB_NOSYNC);
    749 	if (!log_init(sp, ep))
    750 		msgq(sp, M_ERR, "267|Log restarted");
    751 }
    752 
    753 #if defined(DEBUG) && 0
    754 static void
    755 log_trace(sp, msg, rno, p)
    756 	SCR *sp;
    757 	char *msg;
    758 	db_recno_t rno;
    759 	u_char *p;
    760 {
    761 	LMARK lm;
    762 	MARK m;
    763 	db_recno_t lno;
    764 
    765 	switch (*p) {
    766 	case LOG_CURSOR_INIT:
    767 		memmove(&m, p + sizeof(u_char), sizeof(MARK));
    768 		vtrace(sp, "%lu: %s:  C_INIT: %u/%u\n", rno, msg, m.lno, m.cno);
    769 		break;
    770 	case LOG_CURSOR_END:
    771 		memmove(&m, p + sizeof(u_char), sizeof(MARK));
    772 		vtrace(sp, "%lu: %s:   C_END: %u/%u\n", rno, msg, m.lno, m.cno);
    773 		break;
    774 	case LOG_LINE_APPEND_F:
    775 		memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    776 		vtrace(sp, "%lu: %s:  APPEND_F: %lu\n", rno, msg, lno);
    777 		break;
    778 	case LOG_LINE_APPEND_B:
    779 		memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    780 		vtrace(sp, "%lu: %s:  APPEND_B: %lu\n", rno, msg, lno);
    781 		break;
    782 	case LOG_LINE_DELETE_F:
    783 		memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    784 		vtrace(sp, "%lu: %s:  DELETE_F: %lu\n", rno, msg, lno);
    785 		break;
    786 	case LOG_LINE_DELETE_B:
    787 		memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    788 		vtrace(sp, "%lu: %s:  DELETE_B: %lu\n", rno, msg, lno);
    789 		break;
    790 	case LOG_LINE_RESET_F:
    791 		memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    792 		vtrace(sp, "%lu: %s: RESET_F: %lu\n", rno, msg, lno);
    793 		break;
    794 	case LOG_LINE_RESET_B:
    795 		memmove(&lno, p + sizeof(u_char), sizeof(db_recno_t));
    796 		vtrace(sp, "%lu: %s: RESET_B: %lu\n", rno, msg, lno);
    797 		break;
    798 	case LOG_MARK:
    799 		memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
    800 		vtrace(sp,
    801 		    "%lu: %s:    MARK: %u/%u\n", rno, msg, lm.lno, lm.cno);
    802 		break;
    803 	default:
    804 		abort();
    805 	}
    806 }
    807 #endif
    808