#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)mpool.c 8.5 (Berkeley) 7/26/94";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/db/mpool/mpool.c,v 1.16 2009/03/28 04:00:46 delphij Exp $");
#include "namespace.h"
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "un-namespace.h"
#include <db.h>
#define __MPOOLINTERFACE_PRIVATE
#include <mpool.h>
static BKT *mpool_bkt(MPOOL *);
static BKT *mpool_look(MPOOL *, pgno_t);
static int mpool_write(MPOOL *, BKT *);
MPOOL *
mpool_open(void *key, int fd, pgno_t pagesize, pgno_t maxcache)
{
struct stat sb;
MPOOL *mp;
int entry;
if (_fstat(fd, &sb))
return (NULL);
if (!S_ISREG(sb.st_mode)) {
errno = ESPIPE;
return (NULL);
}
if ((mp = (MPOOL *)calloc(1, sizeof(MPOOL))) == NULL)
return (NULL);
TAILQ_INIT(&mp->lqh);
for (entry = 0; entry < HASHSIZE; ++entry)
TAILQ_INIT(&mp->hqh[entry]);
mp->maxcache = maxcache;
mp->npages = sb.st_size / pagesize;
mp->pagesize = pagesize;
mp->fd = fd;
return (mp);
}
void
mpool_filter(MPOOL *mp, void (*pgin) (void *, pgno_t, void *),
void (*pgout) (void *, pgno_t, void *), void *pgcookie)
{
mp->pgin = pgin;
mp->pgout = pgout;
mp->pgcookie = pgcookie;
}
void *
mpool_new(mp, pgnoaddr)
MPOOL *mp;
pgno_t *pgnoaddr;
{
struct _hqh *head;
BKT *bp;
if (mp->npages == MAX_PAGE_NUMBER) {
(void)fprintf(stderr, "mpool_new: page allocation overflow.\n");
LIBC_ABORT("page allocation overflow");
}
#ifdef STATISTICS
++mp->pagenew;
#endif
if ((bp = mpool_bkt(mp)) == NULL)
return (NULL);
*pgnoaddr = bp->pgno = mp->npages++;
bp->flags = MPOOL_PINNED;
head = &mp->hqh[HASHKEY(bp->pgno)];
TAILQ_INSERT_HEAD(head, bp, hq);
TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
return (bp->page);
}
void *
mpool_get(MPOOL *mp, pgno_t pgno,
u_int flags)
{
struct _hqh *head;
BKT *bp;
off_t off;
int nr;
if (pgno >= mp->npages) {
errno = EINVAL;
return (NULL);
}
#ifdef STATISTICS
++mp->pageget;
#endif
if ((bp = mpool_look(mp, pgno)) != NULL) {
#ifdef DEBUG
if (bp->flags & MPOOL_PINNED) {
(void)fprintf(stderr,
"mpool_get: page %d already pinned\n", bp->pgno);
LIBC_ABORT("page %d already pinned", bp->pgno);
}
#endif
head = &mp->hqh[HASHKEY(bp->pgno)];
TAILQ_REMOVE(head, bp, hq);
TAILQ_INSERT_HEAD(head, bp, hq);
TAILQ_REMOVE(&mp->lqh, bp, q);
TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
bp->flags |= MPOOL_PINNED;
return (bp->page);
}
if ((bp = mpool_bkt(mp)) == NULL)
return (NULL);
#ifdef STATISTICS
++mp->pageread;
#endif
off = mp->pagesize * pgno;
nr = pread(mp->fd, bp->page, mp->pagesize, off);
if (nr != mp->pagesize) {
if (nr >= 0)
errno = EFTYPE;
return (NULL);
}
bp->pgno = pgno;
bp->flags = MPOOL_PINNED;
head = &mp->hqh[HASHKEY(bp->pgno)];
TAILQ_INSERT_HEAD(head, bp, hq);
TAILQ_INSERT_TAIL(&mp->lqh, bp, q);
if (mp->pgin != NULL)
(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
return (bp->page);
}
int
mpool_put(MPOOL *mp, void *page, u_int flags)
{
BKT *bp;
#ifdef STATISTICS
++mp->pageput;
#endif
bp = (BKT *)((char *)page - sizeof(BKT));
#ifdef DEBUG
if (!(bp->flags & MPOOL_PINNED)) {
(void)fprintf(stderr,
"mpool_put: page %d not pinned\n", bp->pgno);
LIBC_ABORT("page %d not pinned", bp->pgno);
}
#endif
bp->flags &= ~MPOOL_PINNED;
bp->flags |= flags & MPOOL_DIRTY;
return (RET_SUCCESS);
}
int
mpool_close(MPOOL *mp)
{
BKT *bp;
while (!TAILQ_EMPTY(&mp->lqh)) {
bp = TAILQ_FIRST(&mp->lqh);
TAILQ_REMOVE(&mp->lqh, bp, q);
free(bp);
}
free(mp);
return (RET_SUCCESS);
}
int
mpool_sync(MPOOL *mp)
{
BKT *bp;
TAILQ_FOREACH(bp, &mp->lqh, q) {
if (bp->flags & MPOOL_DIRTY) {
if (mpool_write(mp, bp) == RET_ERROR) {
return (RET_ERROR);
} else {
if (mp->pgin != NULL)
(mp->pgin)(mp->pgcookie, bp->pgno, bp->page);
}
}
}
return (_fsync(mp->fd) ? RET_ERROR : RET_SUCCESS);
}
static BKT *
mpool_bkt(MPOOL *mp)
{
struct _hqh *head;
BKT *bp;
if (mp->curcache < mp->maxcache)
goto new;
TAILQ_FOREACH(bp, &mp->lqh, q)
if (!(bp->flags & MPOOL_PINNED)) {
if (bp->flags & MPOOL_DIRTY &&
mpool_write(mp, bp) == RET_ERROR)
return (NULL);
#ifdef STATISTICS
++mp->pageflush;
#endif
head = &mp->hqh[HASHKEY(bp->pgno)];
TAILQ_REMOVE(head, bp, hq);
TAILQ_REMOVE(&mp->lqh, bp, q);
#ifdef DEBUG
{ void *spage;
spage = bp->page;
memset(bp, 0xff, sizeof(BKT) + mp->pagesize);
bp->page = spage;
}
#endif
return (bp);
}
new: if ((bp = (BKT *)calloc(1, sizeof(BKT) + mp->pagesize)) == NULL)
return (NULL);
#ifdef STATISTICS
++mp->pagealloc;
#endif
bp->page = (char *)bp + sizeof(BKT);
++mp->curcache;
return (bp);
}
static int
mpool_write(MPOOL *mp, BKT *bp)
{
off_t off;
#ifdef STATISTICS
++mp->pagewrite;
#endif
if (mp->pgout)
(mp->pgout)(mp->pgcookie, bp->pgno, bp->page);
off = mp->pagesize * bp->pgno;
if (pwrite(mp->fd, bp->page, mp->pagesize, off) != mp->pagesize)
return (RET_ERROR);
bp->flags &= ~MPOOL_DIRTY;
return (RET_SUCCESS);
}
static BKT *
mpool_look(MPOOL *mp, pgno_t pgno)
{
struct _hqh *head;
BKT *bp;
head = &mp->hqh[HASHKEY(pgno)];
TAILQ_FOREACH(bp, head, hq)
if (bp->pgno == pgno) {
#ifdef STATISTICS
++mp->cachehit;
#endif
return (bp);
}
#ifdef STATISTICS
++mp->cachemiss;
#endif
return (NULL);
}
#ifdef STATISTICS
void
mpool_stat(MPOOL *mp)
{
BKT *bp;
int cnt;
char *sep;
(void)fprintf(stderr, "%lu pages in the file\n", mp->npages);
(void)fprintf(stderr,
"page size %lu, cacheing %lu pages of %lu page max cache\n",
mp->pagesize, mp->curcache, mp->maxcache);
(void)fprintf(stderr, "%lu page puts, %lu page gets, %lu page new\n",
mp->pageput, mp->pageget, mp->pagenew);
(void)fprintf(stderr, "%lu page allocs, %lu page flushes\n",
mp->pagealloc, mp->pageflush);
if (mp->cachehit + mp->cachemiss)
(void)fprintf(stderr,
"%.0f%% cache hit rate (%lu hits, %lu misses)\n",
((double)mp->cachehit / (mp->cachehit + mp->cachemiss))
* 100, mp->cachehit, mp->cachemiss);
(void)fprintf(stderr, "%lu page reads, %lu page writes\n",
mp->pageread, mp->pagewrite);
sep = "";
cnt = 0;
TAILQ_FOREACH(bp, &mp->lqh, q) {
(void)fprintf(stderr, "%s%d", sep, bp->pgno);
if (bp->flags & MPOOL_DIRTY)
(void)fprintf(stderr, "d");
if (bp->flags & MPOOL_PINNED)
(void)fprintf(stderr, "P");
if (++cnt == 10) {
sep = "\n";
cnt = 0;
} else
sep = ", ";
}
(void)fprintf(stderr, "\n");
}
#endif