diff options
Diffstat (limited to 'lib/libc/db/mpool/mpool.c')
| -rw-r--r-- | lib/libc/db/mpool/mpool.c | 98 |
1 files changed, 76 insertions, 22 deletions
diff --git a/lib/libc/db/mpool/mpool.c b/lib/libc/db/mpool/mpool.c index 5610eb5..09f888b 100644 --- a/lib/libc/db/mpool/mpool.c +++ b/lib/libc/db/mpool/mpool.c @@ -110,9 +110,7 @@ mpool_filter(MPOOL *mp, void (*pgin) (void *, pgno_t, void *), * Get a new page of memory. */ void * -mpool_new(mp, pgnoaddr) - MPOOL *mp; - pgno_t *pgnoaddr; +mpool_new(MPOOL *mp, pgno_t *pgnoaddr, u_int flags) { struct _hqh *head; BKT *bp; @@ -131,8 +129,13 @@ mpool_new(mp, pgnoaddr) */ if ((bp = mpool_bkt(mp)) == NULL) return (NULL); - *pgnoaddr = bp->pgno = mp->npages++; - bp->flags = MPOOL_PINNED; + if (flags == MPOOL_PAGE_REQUEST) { + mp->npages++; + bp->pgno = *pgnoaddr; + } else + bp->pgno = *pgnoaddr = mp->npages++; + + bp->flags = MPOOL_PINNED | MPOOL_INUSE; head = &mp->hqh[HASHKEY(bp->pgno)]; TAILQ_INSERT_HEAD(head, bp, hq); @@ -140,6 +143,32 @@ mpool_new(mp, pgnoaddr) return (bp->page); } +int +mpool_delete(MPOOL *mp, void *page) +{ + struct _hqh *head; + BKT *bp; + + bp = (BKT *)((char *)page - sizeof(BKT)); + +#ifdef DEBUG + if (!(bp->flags & MPOOL_PINNED)) { + (void)fprintf(stderr, + "mpool_delete: page %d not pinned\n", bp->pgno); + abort(); + } +#endif + + /* Remove from the hash and lru queues. */ + head = &mp->hqh[HASHKEY(bp->pgno)]; + TAILQ_REMOVE(head, bp, hq); + TAILQ_REMOVE(&mp->lqh, bp, q); + + free(bp); + mp->curcache--; + return (RET_SUCCESS); +} + /* * mpool_get * Get a page. @@ -154,12 +183,6 @@ mpool_get(MPOOL *mp, pgno_t pgno, off_t off; int nr; - /* Check for attempt to retrieve a non-existent page. */ - if (pgno >= mp->npages) { - errno = EINVAL; - return (NULL); - } - #ifdef STATISTICS ++mp->pageget; #endif @@ -167,7 +190,7 @@ mpool_get(MPOOL *mp, pgno_t pgno, /* Check for a page that is cached. */ if ((bp = mpool_look(mp, pgno)) != NULL) { #ifdef DEBUG - if (bp->flags & MPOOL_PINNED) { + if (!(flags & MPOOL_IGNOREPIN) && bp->flags & MPOOL_PINNED) { (void)fprintf(stderr, "mpool_get: page %d already pinned\n", bp->pgno); abort(); @@ -193,20 +216,38 @@ mpool_get(MPOOL *mp, pgno_t pgno, return (NULL); /* Read in the contents. */ + off = mp->pagesize * pgno; + if ((nr = pread(mp->fd, bp->page, mp->pagesize, off)) != mp->pagesize) { + switch (nr) { + case -1: + /* errno is set for us by pread(). */ + free(bp); + mp->curcache--; + return (NULL); + case 0: + /* + * A zero-length read means you need to create a + * new page. + */ + memset(bp->page, 0, mp->pagesize); + break; + default: + /* A partial read is definitely bad. */ + free(bp); + mp->curcache--; + errno = EINVAL; + 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); - } /* Set the page number, pin the page. */ bp->pgno = pgno; - bp->flags = MPOOL_PINNED; + if (!(flags & MPOOL_IGNOREPIN)) + bp->flags = MPOOL_PINNED; + bp->flags |= MPOOL_INUSE; /* * Add the page to the head of the hash chain and the tail @@ -245,7 +286,8 @@ mpool_put(MPOOL *mp, void *page, u_int flags) } #endif bp->flags &= ~MPOOL_PINNED; - bp->flags |= flags & MPOOL_DIRTY; + if (flags & MPOOL_DIRTY) + bp->flags |= flags & MPOOL_DIRTY; return (RET_SUCCESS); } @@ -329,6 +371,7 @@ mpool_bkt(MPOOL *mp) bp->page = spage; } #endif + bp->flags = 0; return (bp); } @@ -338,6 +381,7 @@ new: if ((bp = (BKT *)calloc(1, sizeof(BKT) + mp->pagesize)) == NULL) ++mp->pagealloc; #endif bp->page = (char *)bp + sizeof(BKT); + bp->flags = 0; ++mp->curcache; return (bp); } @@ -363,6 +407,15 @@ mpool_write(MPOOL *mp, BKT *bp) if (pwrite(mp->fd, bp->page, mp->pagesize, off) != mp->pagesize) return (RET_ERROR); + /* + * Re-run through the input filter since this page may soon be + * accessed via the cache, and whatever the user's output filter + * did may screw things up if we don't let the input filter + * restore the in-core copy. + */ + if (mp->pgin) + (mp->pgin)(mp->pgcookie, bp->pgno, bp->page); + bp->flags &= ~MPOOL_DIRTY; return (RET_SUCCESS); } @@ -379,7 +432,8 @@ mpool_look(MPOOL *mp, pgno_t pgno) head = &mp->hqh[HASHKEY(pgno)]; TAILQ_FOREACH(bp, head, hq) - if (bp->pgno == pgno) { + if ((bp->pgno == pgno) && + ((bp->flags & MPOOL_INUSE) == MPOOL_INUSE)) { #ifdef STATISTICS ++mp->cachehit; #endif |
