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NetBSD/usr.bin/vi/common/log.c

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/* $NetBSD: log.c,v 1.2 1998/01/09 08:06:45 perry 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[] = "@(#)log.c 10.8 (Berkeley) 3/6/96";
#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 recno_t char *
* LOG_LINE_DELETE recno_t char *
* LOG_LINE_INSERT recno_t char *
* LOG_LINE_RESET_F recno_t char *
* LOG_LINE_RESET_B 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));
static void log_err __P((SCR *, char *, int));
#if defined(DEBUG) && 0
static void log_trace __P((SCR *, char *, recno_t, u_char *));
#endif
/* Try and restart the log on failure, i.e. if we run out of memory. */
#define LOG_ERR { \
log_err(sp, __FILE__, __LINE__); \
return (1); \
}
/*
* log_init --
* Initialize the logging subsystem.
*
* PUBLIC: int log_init __P((SCR *, EXF *));
*/
int
log_init(sp, ep)
SCR *sp;
EXF *ep;
{
/*
* !!!
* 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.
*/
ep->l_lp = NULL;
ep->l_len = 0;
ep->l_cursor.lno = 1; /* XXX Any valid recno. */
ep->l_cursor.cno = 0;
ep->l_high = ep->l_cur = 1;
ep->log = dbopen(NULL, O_CREAT | O_NONBLOCK | O_RDWR,
S_IRUSR | S_IWUSR, DB_RECNO, NULL);
if (ep->log == NULL) {
msgq(sp, M_SYSERR, "009|Log file");
F_SET(ep, F_NOLOG);
return (1);
}
return (0);
}
/*
* log_end --
* Close the logging subsystem.
*
* PUBLIC: int log_end __P((SCR *, EXF *));
*/
int
log_end(sp, ep)
SCR *sp;
EXF *ep;
{
/*
* !!!
* ep MAY NOT BE THE SAME AS sp->ep, DON'T USE THE LATTER.
*/
if (ep->log != NULL) {
(void)(ep->log->close)(ep->log);
ep->log = NULL;
}
if (ep->l_lp != NULL) {
free(ep->l_lp);
ep->l_lp = NULL;
}
ep->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(sp)
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) {
ep->l_cursor.lno = sp->lno;
ep->l_cursor.cno = sp->cno;
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(sp, type)
SCR *sp;
int type;
{
DBT data, key;
EXF *ep;
ep = sp->ep;
BINC_RET(sp, ep->l_lp, ep->l_len, sizeof(u_char) + sizeof(MARK));
ep->l_lp[0] = type;
memmove(ep->l_lp + sizeof(u_char), &ep->l_cursor, sizeof(MARK));
key.data = &ep->l_cur;
key.size = sizeof(recno_t);
data.data = ep->l_lp;
data.size = sizeof(u_char) + sizeof(MARK);
if (ep->log->put(ep->log, &key, &data, 0) == -1)
LOG_ERR;
#if defined(DEBUG) && 0
TRACE(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;
return (0);
}
/*
* log_line --
* Log a line change.
*
* PUBLIC: int log_line __P((SCR *, recno_t, u_int));
*/
int
log_line(sp, lno, action)
SCR *sp;
recno_t lno;
u_int action;
{
DBT data, key;
EXF *ep;
size_t len;
char *lp;
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;
}
/*
* Put out the changes. If it's a LOG_LINE_RESET_B call, it's a
* special case, avoid the caches. Also, if it fails and it's
* line 1, it just means that the user started with an empty file,
* so fake an empty length line.
*/
if (action == LOG_LINE_RESET_B) {
if (db_get(sp, lno, DBG_NOCACHE, &lp, &len)) {
if (lno != 1) {
db_err(sp, lno);
return (1);
}
len = 0;
lp = "";
}
} else
if (db_get(sp, lno, DBG_FATAL, &lp, &len))
return (1);
BINC_RET(sp,
ep->l_lp, ep->l_len, len + sizeof(u_char) + sizeof(recno_t));
ep->l_lp[0] = action;
memmove(ep->l_lp + sizeof(u_char), &lno, sizeof(recno_t));
memmove(ep->l_lp + sizeof(u_char) + sizeof(recno_t), lp, len);
key.data = &ep->l_cur;
key.size = sizeof(recno_t);
data.data = ep->l_lp;
data.size = len + sizeof(u_char) + sizeof(recno_t);
if (ep->log->put(ep->log, &key, &data, 0) == -1)
LOG_ERR;
#if defined(DEBUG) && 0
switch (action) {
case LOG_LINE_APPEND:
TRACE(sp, "%u: log_line: append: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_DELETE:
TRACE(sp, "%lu: log_line: delete: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_INSERT:
TRACE(sp, "%lu: log_line: insert: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_RESET_F:
TRACE(sp, "%lu: log_line: reset_f: %lu {%u}\n",
ep->l_cur, lno, len);
break;
case LOG_LINE_RESET_B:
TRACE(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(sp, lmp)
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;
}
BINC_RET(sp, ep->l_lp,
ep->l_len, sizeof(u_char) + sizeof(LMARK));
ep->l_lp[0] = LOG_MARK;
memmove(ep->l_lp + sizeof(u_char), lmp, sizeof(LMARK));
key.data = &ep->l_cur;
key.size = sizeof(recno_t);
data.data = ep->l_lp;
data.size = sizeof(u_char) + sizeof(LMARK);
if (ep->log->put(ep->log, &key, &data, 0) == -1)
LOG_ERR;
#if defined(DEBUG) && 0
TRACE(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(sp, rp)
SCR *sp;
MARK *rp;
{
DBT key, data;
EXF *ep;
LMARK lm;
MARK m;
recno_t lno;
int didop;
u_char *p;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG)) {
msgq(sp, M_ERR,
"010|Logging not being performed, undo not possible");
return (1);
}
if (ep->l_cur == 1) {
msgq(sp, M_BERR, "011|No changes to undo");
return (1);
}
F_SET(ep, F_NOLOG); /* Turn off logging. */
key.data = &ep->l_cur; /* Initialize db request. */
key.size = sizeof(recno_t);
for (didop = 0;;) {
--ep->l_cur;
if (ep->log->get(ep->log, &key, &data, 0))
LOG_ERR;
#if defined(DEBUG) && 0
log_trace(sp, "log_backward", ep->l_cur, data.data);
#endif
switch (*(p = (u_char *)data.data)) {
case LOG_CURSOR_INIT:
if (didop) {
memmove(rp, p + sizeof(u_char), sizeof(MARK));
F_CLR(ep, F_NOLOG);
return (0);
}
break;
case LOG_CURSOR_END:
break;
case LOG_LINE_APPEND:
case LOG_LINE_INSERT:
didop = 1;
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (db_delete(sp, lno))
goto err;
++sp->rptlines[L_DELETED];
break;
case LOG_LINE_DELETE:
didop = 1;
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (db_insert(sp, lno, p + sizeof(u_char) +
sizeof(recno_t), data.size - sizeof(u_char) -
sizeof(recno_t)))
goto err;
++sp->rptlines[L_ADDED];
break;
case LOG_LINE_RESET_F:
break;
case LOG_LINE_RESET_B:
didop = 1;
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (db_set(sp, lno, p + sizeof(u_char) +
sizeof(recno_t), data.size - sizeof(u_char) -
sizeof(recno_t)))
goto err;
if (sp->rptlchange != lno) {
sp->rptlchange = lno;
++sp->rptlines[L_CHANGED];
}
break;
case LOG_MARK:
didop = 1;
memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
m.lno = lm.lno;
m.cno = lm.cno;
if (mark_set(sp, lm.name, &m, 0))
goto err;
break;
default:
abort();
}
}
err: F_CLR(ep, F_NOLOG);
return (1);
}
/*
* 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(sp)
SCR *sp;
{
DBT key, data;
EXF *ep;
LMARK lm;
MARK m;
recno_t lno;
u_char *p;
ep = sp->ep;
if (F_ISSET(ep, F_NOLOG)) {
msgq(sp, M_ERR,
"012|Logging not being performed, undo not possible");
return (1);
}
if (ep->l_cur == 1)
return (1);
F_SET(ep, F_NOLOG); /* Turn off logging. */
key.data = &ep->l_cur; /* Initialize db request. */
key.size = sizeof(recno_t);
for (;;) {
--ep->l_cur;
if (ep->log->get(ep->log, &key, &data, 0))
LOG_ERR;
#if defined(DEBUG) && 0
log_trace(sp, "log_setline", ep->l_cur, data.data);
#endif
switch (*(p = (u_char *)data.data)) {
case LOG_CURSOR_INIT:
memmove(&m, p + sizeof(u_char), sizeof(MARK));
if (m.lno != sp->lno || ep->l_cur == 1) {
F_CLR(ep, F_NOLOG);
return (0);
}
break;
case LOG_CURSOR_END:
memmove(&m, p + sizeof(u_char), sizeof(MARK));
if (m.lno != sp->lno) {
++ep->l_cur;
F_CLR(ep, F_NOLOG);
return (0);
}
break;
case LOG_LINE_APPEND:
case LOG_LINE_INSERT:
case LOG_LINE_DELETE:
case LOG_LINE_RESET_F:
break;
case LOG_LINE_RESET_B:
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (lno == sp->lno &&
db_set(sp, lno, p + sizeof(u_char) +
sizeof(recno_t), data.size - sizeof(u_char) -
sizeof(recno_t)))
goto err;
if (sp->rptlchange != lno) {
sp->rptlchange = lno;
++sp->rptlines[L_CHANGED];
}
case LOG_MARK:
memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
m.lno = lm.lno;
m.cno = lm.cno;
if (mark_set(sp, lm.name, &m, 0))
goto err;
break;
default:
abort();
}
}
err: F_CLR(ep, F_NOLOG);
return (1);
}
/*
* Log_forward --
* Roll the log forward one operation.
*
* PUBLIC: int log_forward __P((SCR *, MARK *));
*/
int
log_forward(sp, rp)
SCR *sp;
MARK *rp;
{
DBT key, data;
EXF *ep;
LMARK lm;
MARK m;
recno_t lno;
int didop;
u_char *p;
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 (ep->l_cur == ep->l_high) {
msgq(sp, M_BERR, "014|No changes to re-do");
return (1);
}
F_SET(ep, F_NOLOG); /* Turn off logging. */
key.data = &ep->l_cur; /* Initialize db request. */
key.size = sizeof(recno_t);
for (didop = 0;;) {
++ep->l_cur;
if (ep->log->get(ep->log, &key, &data, 0))
LOG_ERR;
#if defined(DEBUG) && 0
log_trace(sp, "log_forward", ep->l_cur, data.data);
#endif
switch (*(p = (u_char *)data.data)) {
case LOG_CURSOR_END:
if (didop) {
++ep->l_cur;
memmove(rp, p + sizeof(u_char), sizeof(MARK));
F_CLR(ep, F_NOLOG);
return (0);
}
break;
case LOG_CURSOR_INIT:
break;
case LOG_LINE_APPEND:
case LOG_LINE_INSERT:
didop = 1;
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (db_insert(sp, lno, p + sizeof(u_char) +
sizeof(recno_t), data.size - sizeof(u_char) -
sizeof(recno_t)))
goto err;
++sp->rptlines[L_ADDED];
break;
case LOG_LINE_DELETE:
didop = 1;
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (db_delete(sp, lno))
goto err;
++sp->rptlines[L_DELETED];
break;
case LOG_LINE_RESET_B:
break;
case LOG_LINE_RESET_F:
didop = 1;
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
if (db_set(sp, lno, p + sizeof(u_char) +
sizeof(recno_t), data.size - sizeof(u_char) -
sizeof(recno_t)))
goto err;
if (sp->rptlchange != lno) {
sp->rptlchange = lno;
++sp->rptlines[L_CHANGED];
}
break;
case LOG_MARK:
didop = 1;
memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
m.lno = lm.lno;
m.cno = lm.cno;
if (mark_set(sp, lm.name, &m, 0))
goto err;
break;
default:
abort();
}
}
err: F_CLR(ep, F_NOLOG);
return (1);
}
/*
* log_err --
* Try and restart the log on failure, i.e. if we run out of memory.
*/
static void
log_err(sp, file, line)
SCR *sp;
char *file;
int line;
{
EXF *ep;
msgq(sp, M_SYSERR, "015|%s/%d: log put error", tail(file), line);
ep = sp->ep;
(void)ep->log->close(ep->log);
if (!log_init(sp, ep))
msgq(sp, M_ERR, "267|Log restarted");
}
#if defined(DEBUG) && 0
static void
log_trace(sp, msg, rno, p)
SCR *sp;
char *msg;
recno_t rno;
u_char *p;
{
LMARK lm;
MARK m;
recno_t lno;
switch (*p) {
case LOG_CURSOR_INIT:
memmove(&m, p + sizeof(u_char), sizeof(MARK));
TRACE(sp, "%lu: %s: C_INIT: %u/%u\n", rno, msg, m.lno, m.cno);
break;
case LOG_CURSOR_END:
memmove(&m, p + sizeof(u_char), sizeof(MARK));
TRACE(sp, "%lu: %s: C_END: %u/%u\n", rno, msg, m.lno, m.cno);
break;
case LOG_LINE_APPEND:
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
TRACE(sp, "%lu: %s: APPEND: %lu\n", rno, msg, lno);
break;
case LOG_LINE_INSERT:
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
TRACE(sp, "%lu: %s: INSERT: %lu\n", rno, msg, lno);
break;
case LOG_LINE_DELETE:
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
TRACE(sp, "%lu: %s: DELETE: %lu\n", rno, msg, lno);
break;
case LOG_LINE_RESET_F:
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
TRACE(sp, "%lu: %s: RESET_F: %lu\n", rno, msg, lno);
break;
case LOG_LINE_RESET_B:
memmove(&lno, p + sizeof(u_char), sizeof(recno_t));
TRACE(sp, "%lu: %s: RESET_B: %lu\n", rno, msg, lno);
break;
case LOG_MARK:
memmove(&lm, p + sizeof(u_char), sizeof(LMARK));
TRACE(sp,
"%lu: %s: MARK: %u/%u\n", rno, msg, lm.lno, lm.cno);
break;
default:
abort();
}
}
#endif
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