NetBSD-5.0.2/dist/nvi/common/log4.c
/* $NetBSD: log4.c,v 1.1.1.2 2008/05/18 14:29:47 aymeric Exp $ */
/*-
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
* Copyright (c) 1992, 1993, 1994, 1995, 1996
* Keith Bostic. All rights reserved.
*
* See the LICENSE file for redistribution information.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "Id: log4.c,v 10.3 2002/06/08 21:00:33 skimo Exp";
#endif /* not lint */
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <bitstring.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "common.h"
/*
* The log consists of records, each containing a type byte and a variable
* length byte string, as follows:
*
* LOG_CURSOR_INIT MARK
* LOG_CURSOR_END MARK
* LOG_LINE_APPEND_F db_recno_t char *
* LOG_LINE_APPEND_B db_recno_t char *
* LOG_LINE_DELETE_F db_recno_t char *
* LOG_LINE_DELETE_B db_recno_t char *
* LOG_LINE_RESET_F db_recno_t char *
* LOG_LINE_RESET_B db_recno_t char *
* LOG_MARK LMARK
*
* We do before image physical logging. This means that the editor layer
* MAY NOT modify records in place, even if simply deleting or overwriting
* characters. Since the smallest unit of logging is a line, we're using
* up lots of space. This may eventually have to be reduced, probably by
* doing logical logging, which is a much cooler database phrase.
*
* The implementation of the historic vi 'u' command, using roll-forward and
* roll-back, is simple. Each set of changes has a LOG_CURSOR_INIT record,
* followed by a number of other records, followed by a LOG_CURSOR_END record.
* LOG_LINE_RESET records come in pairs. The first is a LOG_LINE_RESET_B
* record, and is the line before the change. The second is LOG_LINE_RESET_F,
* and is the line after the change. Roll-back is done by backing up to the
* first LOG_CURSOR_INIT record before a change. Roll-forward is done in a
* similar fashion.
*
* The 'U' command is implemented by rolling backward to a LOG_CURSOR_END
* record for a line different from the current one. It should be noted that
* this means that a subsequent 'u' command will make a change based on the
* new position of the log's cursor. This is okay, and, in fact, historic vi
* behaved that way.
*/
static int log_cursor1 __P((SCR *, int));
/*
* log_init --
* Initialize the logging subsystem.
*
* PUBLIC: int log_init __P((SCR *, EXF *));
*/
int
log_init(SCR *sp, EXF *ep)
{
DB_LOGC *logc;
DBT data;
size_t nlen;
/*
* !!!
* ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
*
* Initialize the buffer. The logging subsystem has its own
* buffers because the global ones are almost by definition
* going to be in use when the log runs.
*/
sp->wp->l_lp = NULL;
sp->wp->l_len = 0;
ep->l_cursor.lno = 1; /* XXX Any valid recno. */
ep->l_cursor.cno = 0;
ep->l_high = ep->l_cur = 1;
if ((sp->db_error = ep->env->log_cursor(ep->env, &logc, 0))
!= 0) {
msgq(sp, M_DBERR, "env->log_cursor");
F_SET(ep, F_NOLOG);
return (1);
}
nlen = 1024;
retry:
BINC_GOTO(sp, sp->wp->l_lp, sp->wp->l_len, nlen);
memset(&data, 0, sizeof(data));
data.data = sp->wp->l_lp;
data.ulen = sp->wp->l_len;
data.flags = DB_DBT_USERMEM;
switch ((sp->db_error =
logc->get(logc, &ep->lsn_first, &data, DB_LAST))) {
case ENOMEM:
nlen = data.size;
goto retry;
default:
alloc_err:
msgq(sp, M_DBERR, "logc->get");
F_SET(ep, F_NOLOG);
return (1);
case 0:
;
}
MEMCPY(&ep->lsn_cur, &ep->lsn_first, 1);
MEMCPY(&ep->lsn_high, &ep->lsn_first, 1);
logc->close(logc, 0);
ep->l_win = NULL;
/*LOCK_INIT(sp->wp, ep);*/
return (0);
}
/*
* log_end --
* Close the logging subsystem.
*
* PUBLIC: int log_end __P((SCR *, EXF *));
*/
int
log_end(SCR *sp, EXF *ep)
{
/*
* !!!
* ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
*/
/*LOCK_END(sp->wp, ep);*/
if (sp->wp->l_lp != NULL) {
free(sp->wp->l_lp);
sp->wp->l_lp = NULL;
}
sp->wp->l_len = 0;
ep->l_cursor.lno = 1; /* XXX Any valid recno. */
ep->l_cursor.cno = 0;
ep->l_high = ep->l_cur = 1;
return (0);
}
/*
* log_cursor --
* Log the current cursor position, starting an event.
*
* PUBLIC: int log_cursor __P((SCR *));
*/
int
log_cursor(SCR *sp)
{
EXF *ep;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG))
return (0);
/*
* If any changes were made since the last cursor init,
* put out the ending cursor record.
*/
if (ep->l_cursor.lno == OOBLNO) {
if (ep->l_win && ep->l_win != sp->wp)
return 0;
ep->l_cursor.lno = sp->lno;
ep->l_cursor.cno = sp->cno;
ep->l_win = NULL;
return (log_cursor1(sp, LOG_CURSOR_END));
}
ep->l_cursor.lno = sp->lno;
ep->l_cursor.cno = sp->cno;
return (0);
}
/*
* log_cursor1 --
* Actually push a cursor record out.
*/
static int
log_cursor1(SCR *sp, int type)
{
DBT data, key;
EXF *ep;
ep = sp->ep;
/*
if (type == LOG_CURSOR_INIT &&
LOCK_TRY(sp->wp, ep))
return 1;
*/
if (type == LOG_CURSOR_INIT &&
(sp->db_error = __vi_log_truncate(ep)) != 0) {
msgq(sp, M_DBERR, "truncate");
return 1;
}
if ((sp->db_error =
__vi_cursor_log(ep->env, NULL, &ep->lsn_cur, 0, type,
ep->l_cursor.lno, ep->l_cursor.cno)) != 0) {
msgq(sp, M_DBERR, "cursor_log");
return 1;
}
if (type == LOG_CURSOR_END) {
MEMCPY(&ep->lsn_high, &ep->lsn_cur, 1);
/* XXXX should not be needed */
ep->env->log_flush(ep->env, NULL);
}
#if defined(DEBUG) && 0
vtrace(sp, "%lu: %s: %u/%u\n", ep->l_cur,
type == LOG_CURSOR_INIT ? "log_cursor_init" : "log_cursor_end",
sp->lno, sp->cno);
#endif
/* Reset high water mark. */
ep->l_high = ++ep->l_cur;
/*
if (type == LOG_CURSOR_END)
LOCK_UNLOCK(sp->wp, ep);
*/
return (0);
}
/*
* log_line --
* Log a line change.
*
* PUBLIC: int log_line __P((SCR *, db_recno_t, u_int));
*/
int
log_line(SCR *sp, db_recno_t lno, u_int action)
{
DBT data, key;
EXF *ep;
size_t len;
CHAR_T *lp;
db_recno_t lcur;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG))
return (0);
/*
* XXX
*
* Kluge for vi. Clear the EXF undo flag so that the
* next 'u' command does a roll-back, regardless.
*/
F_CLR(ep, F_UNDO);
/* Put out one initial cursor record per set of changes. */
if (ep->l_cursor.lno != OOBLNO) {
if (log_cursor1(sp, LOG_CURSOR_INIT))
return (1);
ep->l_cursor.lno = OOBLNO;
ep->l_win = sp->wp;
} /*else if (ep->l_win != sp->wp) {
printf("log_line own: %p, this: %p\n", ep->l_win, sp->wp);
return 1;
}*/
if ((sp->db_error =
__vi_change_log(ep->env, NULL, &ep->lsn_cur, 0, action,
lno)) != 0) {
msgq(sp, M_DBERR, "change_log");
return 1;
}
#if defined(DEBUG) && 0
switch (action) {
case LOG_LINE_APPEND_F:
vtrace(sp, "%u: log_line: append_f: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_APPEND_B:
vtrace(sp, "%u: log_line: append_b: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_DELETE_F:
vtrace(sp, "%lu: log_line: delete_f: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_DELETE_B:
vtrace(sp, "%lu: log_line: delete_b: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_RESET_F:
vtrace(sp, "%lu: log_line: reset_f: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_RESET_B:
vtrace(sp, "%lu: log_line: reset_b: %lu {%u}\n",
ep->l_cur, lno, len);
break;
}
#endif
/* Reset high water mark. */
ep->l_high = ++ep->l_cur;
return (0);
}
/*
* log_mark --
* Log a mark position. For the log to work, we assume that there
* aren't any operations that just put out a log record -- this
* would mean that undo operations would only reset marks, and not
* cause any other change.
*
* PUBLIC: int log_mark __P((SCR *, LMARK *));
*/
int
log_mark(SCR *sp, LMARK *lmp)
{
DBT data, key;
EXF *ep;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG))
return (0);
/* Put out one initial cursor record per set of changes. */
if (ep->l_cursor.lno != OOBLNO) {
if (log_cursor1(sp, LOG_CURSOR_INIT))
return (1);
ep->l_cursor.lno = OOBLNO;
ep->l_win = sp->wp;
}
if ((sp->db_error =
__vi_mark_log(ep->env, NULL, &ep->lsn_cur, 0,
lmp)) != 0) {
msgq(sp, M_DBERR, "cursor_log");
return 1;
}
#if defined(DEBUG) && 0
vtrace(sp, "%lu: mark %c: %lu/%u\n",
ep->l_cur, lmp->name, lmp->lno, lmp->cno);
#endif
/* Reset high water mark. */
ep->l_high = ++ep->l_cur;
return (0);
}
/*
* Log_backward --
* Roll the log backward one operation.
*
* PUBLIC: int log_backward __P((SCR *, MARK *));
*/
int
log_backward(SCR *sp, MARK *rp)
{
EXF *ep;
LMARK lm;
MARK m;
db_recno_t lno;
int didop;
u_char *p;
size_t size;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG)) {
msgq(sp, M_ERR,
"010|Logging not being performed, undo not possible");
return (1);
}
if (log_compare(&ep->lsn_cur, &ep->lsn_first) <= 0) {
msgq(sp, M_BERR, "011|No changes to undo");
return (1);
}
return __vi_log_traverse(sp, UNDO_BACKWARD, rp);
}
/*
* Log_setline --
* Reset the line to its original appearance.
*
* XXX
* There's a bug in this code due to our not logging cursor movements
* unless a change was made. If you do a change, move off the line,
* then move back on and do a 'U', the line will be restored to the way
* it was before the original change.
*
* PUBLIC: int log_setline __P((SCR *));
*/
int
log_setline(SCR *sp)
{
EXF *ep;
LMARK lm;
MARK m;
db_recno_t lno;
u_char *p;
size_t size;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG)) {
msgq(sp, M_ERR,
"012|Logging not being performed, undo not possible");
return (1);
}
if (log_compare(&ep->lsn_cur, &ep->lsn_first) <= 0) {
msgq(sp, M_BERR, "011|No changes to undo");
return (1);
}
return __vi_log_traverse(sp, UNDO_SETLINE, &m);
}
/*
* Log_forward --
* Roll the log forward one operation.
*
* PUBLIC: int log_forward __P((SCR *, MARK *));
*/
int
log_forward(SCR *sp, MARK *rp)
{
EXF *ep;
LMARK lm;
MARK m;
db_recno_t lno;
int didop;
u_char *p;
size_t size;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG)) {
msgq(sp, M_ERR,
"013|Logging not being performed, roll-forward not possible");
return (1);
}
if (log_compare(&ep->lsn_cur, &ep->lsn_high) >= 0) {
msgq(sp, M_BERR, "014|No changes to re-do");
return (1);
}
return __vi_log_traverse(sp, UNDO_FORWARD, rp);
}