/*-
 * 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[] = "@(#)bt_stat.c     10.27 (Sleepycat) 11/25/98";
#endif /* not lint */

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <errno.h>
#include <string.h>
#endif

#include "db_int.h"
#include "db_page.h"
#include "btree.h"

/*
 * __bam_stat --
 *      Gather/print the btree statistics
 *
 * PUBLIC: int __bam_stat __P((DB *, void *, void *(*)(size_t), u_int32_t));
 */
int
__bam_stat(dbp, spp, db_malloc, flags)
        DB *dbp;
        void *spp;
        void *(*db_malloc) __P((size_t));
        u_int32_t flags;
{
        BTMETA *meta;
        BTREE *t;
        DBC *dbc;
        DB_BTREE_STAT *sp;
        DB_LOCK lock;
        PAGE *h;
        db_pgno_t lastpgno, pgno;
        int ret, t_ret;

        DB_PANIC_CHECK(dbp);

        /* Check for invalid flags. */
        if ((ret = __db_statchk(dbp, flags)) != 0)
                return (ret);

        if ((ret = dbp->cursor(dbp, NULL, &dbc, 0)) != 0)
                return (ret);

        DEBUG_LWRITE(dbc, NULL, "bam_stat", NULL, NULL, flags);

        t = dbp->internal;

        if (spp == NULL)
                return (0);

        /* Allocate and clear the structure. */
        if ((ret = __os_malloc(sizeof(*sp), db_malloc, &sp)) != 0)
                goto err;
        memset(sp, 0, sizeof(*sp));

        /* If the app just wants the record count, make it fast. */
        if (flags == DB_RECORDCOUNT) {
                pgno = PGNO_ROOT;
                if ((ret = __bam_lget(dbc, 0, pgno, DB_LOCK_READ, &lock)) != 0)
                        goto err;
                if ((ret = memp_fget(dbp->mpf, &pgno, 0, (PAGE **)&h)) != 0)
                        goto err;

                sp->bt_nrecs = RE_NREC(h);

                (void)memp_fput(dbp->mpf, h, 0);
                (void)__BT_LPUT(dbc, lock);
                goto done;
        }

        /* Get the meta-data page. */
        pgno = PGNO_METADATA;
        if ((ret = __bam_lget(dbc, 0, pgno, DB_LOCK_READ, &lock)) != 0)
                goto err;
        if ((ret = memp_fget(dbp->mpf, &pgno, 0, (PAGE **)&meta)) != 0)
                goto err;

        /* Translate the metadata flags. */
        if (F_ISSET(meta, BTM_DUP))
                sp->bt_flags |= DB_DUP;
        if (F_ISSET(meta, BTM_FIXEDLEN))
                sp->bt_flags |= DB_FIXEDLEN;
        if (F_ISSET(meta, BTM_RECNUM))
                sp->bt_flags |= DB_RECNUM;
        if (F_ISSET(meta, BTM_RENUMBER))
                sp->bt_flags |= DB_RENUMBER;

        /* Get the remaining metadata fields. */
        sp->bt_minkey = meta->minkey;
        sp->bt_maxkey = meta->maxkey;
        sp->bt_re_len = meta->re_len;
        sp->bt_re_pad = meta->re_pad;
        sp->bt_magic = meta->magic;
        sp->bt_version = meta->version;

        /* Get the page size from the DB. */
        sp->bt_pagesize = dbp->pgsize;

        /* Walk the free list, counting pages. */
        for (sp->bt_free = 0, pgno = meta->free; pgno != PGNO_INVALID;) {
                ++sp->bt_free;

                if ((ret = memp_fget(dbp->mpf, &pgno, 0, &h)) != 0) {
                        (void)memp_fput(dbp->mpf, meta, 0);
                        (void)__BT_TLPUT(dbc, lock);
                        goto err;
                }
                pgno = h->next_pgno;
                (void)memp_fput(dbp->mpf, h, 0);
        }

        /* Discard the meta-data page. */
        (void)memp_fput(dbp->mpf, meta, 0);
        (void)__BT_TLPUT(dbc, lock);

        /* Determine the last page of the database. */
        if ((ret = memp_fget(dbp->mpf, &lastpgno, DB_MPOOL_LAST, &h)) != 0)
                goto err;
        (void)memp_fput(dbp->mpf, h, 0);

        /* Get the root page. */
        pgno = PGNO_ROOT;
        if ((ret = __bam_lget(dbc, 0, PGNO_ROOT, DB_LOCK_READ, &lock)) != 0)
                goto err;
        if ((ret = memp_fget(dbp->mpf, &pgno, 0, &h)) != 0) {
                (void)__BT_LPUT(dbc, lock);
                goto err;
        }

        /* Get the levels from the root page. */
        sp->bt_levels = h->level;

        /* Walk the page list, counting things. */
        for (;;) {
                switch (TYPE(h)) {
                case P_INVALID:
                        break;
                case P_IBTREE:
                case P_IRECNO:
                        ++sp->bt_int_pg;
                        sp->bt_int_pgfree += HOFFSET(h) - LOFFSET(h);
                        break;
                case P_LBTREE:
                        ++sp->bt_leaf_pg;
                        sp->bt_leaf_pgfree += HOFFSET(h) - LOFFSET(h);
                        sp->bt_nrecs += NUM_ENT(h) / P_INDX;
                        break;
                case P_LRECNO:
                        ++sp->bt_leaf_pg;
                        sp->bt_leaf_pgfree += HOFFSET(h) - LOFFSET(h);
                        sp->bt_nrecs += NUM_ENT(h);
                        break;
                case P_DUPLICATE:
                        ++sp->bt_dup_pg;
                        /* XXX MARGO: sp->bt_dup_pgfree; */
                        break;
                case P_OVERFLOW:
                        ++sp->bt_over_pg;
                        /* XXX MARGO: sp->bt_over_pgfree; */
                        break;
                default:
                        (void)memp_fput(dbp->mpf, h, 0);
                        (void)__BT_LPUT(dbc, lock);
                        return (__db_pgfmt(dbp, pgno));
                }

                (void)memp_fput(dbp->mpf, h, 0);
                (void)__BT_LPUT(dbc, lock);

                if (++pgno > lastpgno)
                        break;
                if (__bam_lget(dbc, 0, pgno, DB_LOCK_READ, &lock))
                        break;
                if (memp_fget(dbp->mpf, &pgno, 0, &h) != 0) {
                        (void)__BT_LPUT(dbc, lock);
                        break;
                }
        }

done:   *(DB_BTREE_STAT **)spp = sp;
        ret = 0;

err:    if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
                ret = t_ret;
        return (ret);
}