/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998
* Sleepycat Software. All rights reserved.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)log_put.c 10.44 (Sleepycat) 11/3/98";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#endif
#include "db_int.h"
#include "shqueue.h"
#include "db_page.h"
#include "log.h"
#include "hash.h"
#include "clib_ext.h"
#include "common_ext.h"
static int __log_fill __P((DB_LOG *, DB_LSN *, void *, u_int32_t));
static int __log_flush __P((DB_LOG *, const DB_LSN *));
static int __log_newfd __P((DB_LOG *));
static int __log_putr __P((DB_LOG *, DB_LSN *, const DBT *, u_int32_t));
static int __log_write __P((DB_LOG *, void *, u_int32_t));
/*
* log_put --
* Write a log record.
*/
int
log_put(dblp, lsn, dbt, flags)
DB_LOG *dblp;
DB_LSN *lsn;
const DBT *dbt;
u_int32_t flags;
{
int ret;
LOG_PANIC_CHECK(dblp);
/* Validate arguments. */
if (flags != 0 && flags != DB_CHECKPOINT &&
flags != DB_CURLSN && flags != DB_FLUSH)
return (__db_ferr(dblp->dbenv, "log_put", 0));
LOCK_LOGREGION(dblp);
ret = __log_put(dblp, lsn, dbt, flags);
UNLOCK_LOGREGION(dblp);
return (ret);
}
/*
* __log_put --
* Write a log record; internal version.
*
* PUBLIC: int __log_put __P((DB_LOG *, DB_LSN *, const DBT *, u_int32_t));
*/
int
__log_put(dblp, lsn, dbt, flags)
DB_LOG *dblp;
DB_LSN *lsn;
const DBT *dbt;
u_int32_t flags;
{
DBT fid_dbt, t;
DB_LSN r_unused;
FNAME *fnp;
LOG *lp;
u_int32_t lastoff;
int ret;
lp = dblp->lp;
/*
* If the application just wants to know where we are, fill in
* the information. Currently used by the transaction manager
* to avoid writing TXN_begin records.
*/
if (flags == DB_CURLSN) {
lsn->file = lp->lsn.file;
lsn->offset = lp->lsn.offset;
return (0);
}
/* If this information won't fit in the file, swap files. */
if (lp->lsn.offset + sizeof(HDR) + dbt->size > lp->persist.lg_max) {
if (sizeof(HDR) +
sizeof(LOGP) + dbt->size > lp->persist.lg_max) {
__db_err(dblp->dbenv,
"log_put: record larger than maximum file size");
return (EINVAL);
}
/* Flush the log. */
if ((ret = __log_flush(dblp, NULL)) != 0)
return (ret);
/*
* Save the last known offset from the previous file, we'll
* need it to initialize the persistent header information.
*/
lastoff = lp->lsn.offset;
/* Point the current LSN to the new file. */
++lp->lsn.file;
lp->lsn.offset = 0;
/* Reset the file write offset. */
lp->w_off = 0;
} else
lastoff = 0;
/* Initialize the LSN information returned to the user. */
lsn->file = lp->lsn.file;
lsn->offset = lp->lsn.offset;
/*
* Insert persistent information as the first record in every file.
* Note that the previous length is wrong for the very first record
* of the log, but that's okay, we check for it during retrieval.
*/
if (lp->lsn.offset == 0) {
t.data = &lp->persist;
t.size = sizeof(LOGP);
if ((ret = __log_putr(dblp, lsn,
&t, lastoff == 0 ? 0 : lastoff - lp->len)) != 0)
return (ret);
/* Update the LSN information returned to the user. */
lsn->file = lp->lsn.file;
lsn->offset = lp->lsn.offset;
}
/* Write the application's log record. */
if ((ret = __log_putr(dblp, lsn, dbt, lp->lsn.offset - lp->len)) != 0)
return (ret);
/*
* On a checkpoint, we:
* Put out the checkpoint record (above).
* Save the LSN of the checkpoint in the shared region.
* Append the set of file name information into the log.
*/
if (flags == DB_CHECKPOINT) {
lp->chkpt_lsn = *lsn;
for (fnp = SH_TAILQ_FIRST(&dblp->lp->fq, __fname);
fnp != NULL; fnp = SH_TAILQ_NEXT(fnp, q, __fname)) {
if (fnp->ref == 0) /* Entry not in use. */
continue;
memset(&t, 0, sizeof(t));
t.data = R_ADDR(dblp, fnp->name_off);
t.size = strlen(t.data) + 1;
memset(&fid_dbt, 0, sizeof(fid_dbt));
fid_dbt.data = fnp->ufid;
fid_dbt.size = DB_FILE_ID_LEN;
if ((ret = __log_register_log(dblp, NULL, &r_unused, 0,
LOG_CHECKPOINT, &t, &fid_dbt, fnp->id, fnp->s_type))
!= 0)
return (ret);
}
}
/*
* On a checkpoint or when flush is requested, we:
* Flush the current buffer contents to disk.
* Sync the log to disk.
*/
if (flags == DB_FLUSH || flags == DB_CHECKPOINT)
if ((ret = __log_flush(dblp, NULL)) != 0)
return (ret);
/*
* On a checkpoint, we:
* Save the time the checkpoint was written.
* Reset the bytes written since the last checkpoint.
*/
if (flags == DB_CHECKPOINT) {
(void)time(&lp->chkpt);
lp->stat.st_wc_bytes = lp->stat.st_wc_mbytes = 0;
}
return (0);
}
/*
* __log_putr --
* Actually put a record into the log.
*/
static int
__log_putr(dblp, lsn, dbt, prev)
DB_LOG *dblp;
DB_LSN *lsn;
const DBT *dbt;
u_int32_t prev;
{
HDR hdr;
LOG *lp;
int ret;
lp = dblp->lp;
/*
* Initialize the header. If we just switched files, lsn.offset will
* be 0, and what we really want is the offset of the previous record
* in the previous file. Fortunately, prev holds the value we want.
*/
hdr.prev = prev;
hdr.len = sizeof(HDR) + dbt->size;
hdr.cksum = __ham_func4(dbt->data, dbt->size);
if ((ret = __log_fill(dblp, lsn, &hdr, sizeof(HDR))) != 0)
return (ret);
lp->len = sizeof(HDR);
lp->lsn.offset += sizeof(HDR);
if ((ret = __log_fill(dblp, lsn, dbt->data, dbt->size)) != 0)
return (ret);
lp->len += dbt->size;
lp->lsn.offset += dbt->size;
return (0);
}
/*
* log_flush --
* Write all records less than or equal to the specified LSN.
*/
int
log_flush(dblp, lsn)
DB_LOG *dblp;
const DB_LSN *lsn;
{
int ret;
LOG_PANIC_CHECK(dblp);
LOCK_LOGREGION(dblp);
ret = __log_flush(dblp, lsn);
UNLOCK_LOGREGION(dblp);
return (ret);
}
/*
* __log_flush --
* Write all records less than or equal to the specified LSN; internal
* version.
*/
static int
__log_flush(dblp, lsn)
DB_LOG *dblp;
const DB_LSN *lsn;
{
DB_LSN t_lsn;
LOG *lp;
int current, ret;
ret = 0;
lp = dblp->lp;
/*
* If no LSN specified, flush the entire log by setting the flush LSN
* to the last LSN written in the log. Otherwise, check that the LSN
* isn't a non-existent record for the log.
*/
if (lsn == NULL) {
t_lsn.file = lp->lsn.file;
t_lsn.offset = lp->lsn.offset - lp->len;
lsn = &t_lsn;
} else
if (lsn->file > lp->lsn.file ||
(lsn->file == lp->lsn.file &&
lsn->offset > lp->lsn.offset - lp->len)) {
__db_err(dblp->dbenv,
"log_flush: LSN past current end-of-log");
return (EINVAL);
}
/*
* If the LSN is less than the last-sync'd LSN, we're done. Note,
* the last-sync LSN saved in s_lsn is the LSN of the first byte
* we absolutely know has been written to disk, so the test is <=.
*/
if (lsn->file < lp->s_lsn.file ||
(lsn->file == lp->s_lsn.file && lsn->offset <= lp->s_lsn.offset))
return (0);
/*
* We may need to write the current buffer. We have to write the
* current buffer if the flush LSN is greater than or equal to the
* buffer's starting LSN.
*/
current = 0;
if (lp->b_off != 0 && log_compare(lsn, &lp->f_lsn) >= 0) {
if ((ret = __log_write(dblp, lp->buf, lp->b_off)) != 0)
return (ret);
lp->b_off = 0;
current = 1;
}
/*
* It's possible that this thread may never have written to this log
* file. Acquire a file descriptor if we don't already have one.
*/
if (dblp->lfname != dblp->lp->lsn.file)
if ((ret = __log_newfd(dblp)) != 0)
return (ret);
/* Sync all writes to disk. */
if ((ret = __os_fsync(dblp->lfd)) != 0) {
__db_panic(dblp->dbenv, ret);
return (ret);
}
++lp->stat.st_scount;
/*
* Set the last-synced LSN, using the LSN of the current buffer. If
* the current buffer was flushed, we know the LSN of the first byte
* of the buffer is on disk, otherwise, we only know that the LSN of
* the record before the one beginning the current buffer is on disk.
*
* XXX
* Check to make sure that the saved lsn isn't 0 before we go making
* this change. If DB_CHECKPOINT was called before we actually wrote
* something, you can end up here without ever having written anything
* to a log file, and decrementing either s_lsn.file or s_lsn.offset
* will cause much sadness later on.
*/
lp->s_lsn = lp->f_lsn;
if (!current && lp->s_lsn.file != 0)
if (lp->s_lsn.offset == 0) {
--lp->s_lsn.file;
lp->s_lsn.offset = lp->persist.lg_max;
} else
--lp->s_lsn.offset;
return (0);
}
/*
* __log_fill --
* Write information into the log.
*/
static int
__log_fill(dblp, lsn, addr, len)
DB_LOG *dblp;
DB_LSN *lsn;
void *addr;
u_int32_t len;
{
LOG *lp;
u_int32_t nrec;
size_t nw, remain;
int ret;
/* Copy out the data. */
for (lp = dblp->lp; len > 0;) {
/*
* If we're beginning a new buffer, note the user LSN to which
* the first byte of the buffer belongs. We have to know this
* when flushing the buffer so that we know if the in-memory
* buffer needs to be flushed.
*/
if (lp->b_off == 0)
lp->f_lsn = *lsn;
/*
* If we're on a buffer boundary and the data is big enough,
* copy as many records as we can directly from the data.
*/
if (lp->b_off == 0 && len >= sizeof(lp->buf)) {
nrec = len / sizeof(lp->buf);
if ((ret = __log_write(dblp,
addr, nrec * sizeof(lp->buf))) != 0)
return (ret);
addr = (u_int8_t *)addr + nrec * sizeof(lp->buf);
len -= nrec * sizeof(lp->buf);
continue;
}
/* Figure out how many bytes we can copy this time. */
remain = sizeof(lp->buf) - lp->b_off;
nw = remain > len ? len : remain;
memcpy(lp->buf + lp->b_off, addr, nw);
addr = (u_int8_t *)addr + nw;
len -= nw;
lp->b_off += nw;
/* If we fill the buffer, flush it. */
if (lp->b_off == sizeof(lp->buf)) {
if ((ret =
__log_write(dblp, lp->buf, sizeof(lp->buf))) != 0)
return (ret);
lp->b_off = 0;
}
}
return (0);
}
/*
* __log_write --
* Write the log buffer to disk.
*/
static int
__log_write(dblp, addr, len)
DB_LOG *dblp;
void *addr;
u_int32_t len;
{
LOG *lp;
ssize_t nw;
int ret;
/*
* If we haven't opened the log file yet or the current one
* has changed, acquire a new log file.
*/
lp = dblp->lp;
if (dblp->lfd == -1 || dblp->lfname != lp->lsn.file)
if ((ret = __log_newfd(dblp)) != 0)
return (ret);
/*
* Seek to the offset in the file (someone may have written it
* since we last did).
*/
if ((ret = __os_seek(dblp->lfd, 0, 0, lp->w_off, 0, SEEK_SET)) != 0 ||
(ret = __os_write(dblp->lfd, addr, len, &nw)) != 0) {
__db_panic(dblp->dbenv, ret);
return (ret);
}
if (nw != (int32_t)len)
return (EIO);
/* Reset the buffer offset and update the seek offset. */
lp->w_off += len;
/* Update written statistics. */
if ((lp->stat.st_w_bytes += len) >= MEGABYTE) {
lp->stat.st_w_bytes -= MEGABYTE;
++lp->stat.st_w_mbytes;
}
if ((lp->stat.st_wc_bytes += len) >= MEGABYTE) {
lp->stat.st_wc_bytes -= MEGABYTE;
++lp->stat.st_wc_mbytes;
}
++lp->stat.st_wcount;
return (0);
}
/*
* log_file --
* Map a DB_LSN to a file name.
*/
int
log_file(dblp, lsn, namep, len)
DB_LOG *dblp;
const DB_LSN *lsn;
char *namep;
size_t len;
{
int ret;
char *name;
LOG_PANIC_CHECK(dblp);
LOCK_LOGREGION(dblp);
ret = __log_name(dblp, lsn->file, &name, NULL, 0);
UNLOCK_LOGREGION(dblp);
if (ret != 0)
return (ret);
/* Check to make sure there's enough room and copy the name. */
if (len < strlen(name) + 1) {
*namep = '\0';
return (ENOMEM);
}
(void)strcpy(namep, name);
__os_freestr(name);
return (0);
}
/*
* __log_newfd --
* Acquire a file descriptor for the current log file.
*/
static int
__log_newfd(dblp)
DB_LOG *dblp;
{
int ret;
char *name;
/* Close any previous file descriptor. */
if (dblp->lfd != -1) {
(void)__os_close(dblp->lfd);
dblp->lfd = -1;
}
/* Get the path of the new file and open it. */
dblp->lfname = dblp->lp->lsn.file;
if ((ret = __log_name(dblp,
dblp->lfname, &name, &dblp->lfd, DB_CREATE | DB_SEQUENTIAL)) != 0)
__db_err(dblp->dbenv, "log_put: %s: %s", name, strerror(ret));
__os_freestr(name);
return (ret);
}
/*
* __log_name --
* Return the log name for a particular file, and optionally open it.
*
* PUBLIC: int __log_name __P((DB_LOG *, u_int32_t, char **, int *, u_int32_t));
*/
int
__log_name(dblp, filenumber, namep, fdp, flags)
DB_LOG *dblp;
u_int32_t filenumber, flags;
char **namep;
int *fdp;
{
int ret;
char *oname;
char old[sizeof(LFPREFIX) + 5 + 20], new[sizeof(LFPREFIX) + 10 + 20];
/*
* !!!
* The semantics of this routine are bizarre.
*
* The reason for all of this is that we need a place where we can
* intercept requests for log files, and, if appropriate, check for
* both the old-style and new-style log file names. The trick is
* that all callers of this routine that are opening the log file
* read-only want to use an old-style file name if they can't find
* a match using a new-style name. The only down-side is that some
* callers may check for the old-style when they really don't need
* to, but that shouldn't mess up anything, and we only check for
* the old-style name when we've already failed to find a new-style
* one.
*
* Create a new-style file name, and if we're not going to open the
* file, return regardless.
*/
(void)snprintf(new, sizeof(new), LFNAME, filenumber);
if ((ret = __db_appname(dblp->dbenv,
DB_APP_LOG, dblp->dir, new, 0, NULL, namep)) != 0 || fdp == NULL)
return (ret);
/* Open the new-style file -- if we succeed, we're done. */
if ((ret = __db_open(*namep,
flags, flags, dblp->lp->persist.mode, fdp)) == 0)
return (0);
/*
* The open failed... if the DB_RDONLY flag isn't set, we're done,
* the caller isn't interested in old-style files.
*/
if (!LF_ISSET(DB_RDONLY))
return (ret);
/* Create an old-style file name. */
(void)snprintf(old, sizeof(old), LFNAME_V1, filenumber);
if ((ret = __db_appname(dblp->dbenv,
DB_APP_LOG, dblp->dir, old, 0, NULL, &oname)) != 0)
goto err;
/*
* Open the old-style file -- if we succeed, we're done. Free the
* space allocated for the new-style name and return the old-style
* name to the caller.
*/
if ((ret = __db_open(oname,
flags, flags, dblp->lp->persist.mode, fdp)) == 0) {
__os_freestr(*namep);
*namep = oname;
return (0);
}
/*
* Couldn't find either style of name -- return the new-style name
* for the caller's error message. If it's an old-style name that's
* actually missing we're going to confuse the user with the error
* message, but that implies that not only were we looking for an
* old-style name, but we expected it to exist and we weren't just
* looking for any log file. That's not a likely error.
*/
err: __os_freestr(oname);
return (ret);
}