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Sourcecode: db4.1 version File versions

bt_open.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2002
 *    Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994, 1995, 1996
 *    Keith Bostic.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994, 1995
 *    The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Olson.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "db_config.h"

#ifndef lint
static const char revid[] = "$Id: bt_open.c,v 11.76 2002/09/04 19:06:42 margo Exp $";
#endif /* not lint */

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

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

#include "db_int.h"
#include "dbinc/crypto.h"
#include "dbinc/db_page.h"
#include "dbinc/db_swap.h"
#include "dbinc/btree.h"
#include "dbinc/db_shash.h"
#include "dbinc/lock.h"
#include "dbinc/log.h"
#include "dbinc/fop.h"

static void __bam_init_meta __P((DB *, BTMETA *, db_pgno_t, DB_LSN *));

/*
 * __bam_open --
 *    Open a btree.
 *
 * PUBLIC: int __bam_open __P((DB *,
 * PUBLIC:      DB_TXN *, const char *, db_pgno_t, u_int32_t));
 */
int
__bam_open(dbp, txn, name, base_pgno, flags)
      DB *dbp;
      DB_TXN *txn;
      const char *name;
      db_pgno_t base_pgno;
      u_int32_t flags;
{
      BTREE *t;

      COMPQUIET(name, NULL);
      t = dbp->bt_internal;

      /* Initialize the remaining fields/methods of the DB. */
      dbp->key_range = __bam_key_range;
      dbp->stat = __bam_stat;

      /*
       * We don't permit the user to specify a prefix routine if they didn't
       * also specify a comparison routine, they can't know enough about our
       * comparison routine to get it right.
       */
      if (t->bt_compare == __bam_defcmp && t->bt_prefix != __bam_defpfx) {
            __db_err(dbp->dbenv,
"prefix comparison may not be specified for default comparison routine");
            return (EINVAL);
      }

      /*
       * Verify that the bt_minkey value specified won't cause the
       * calculation of ovflsize to underflow [#2406] for this pagesize.
       */
      if (B_MINKEY_TO_OVFLSIZE(dbp, t->bt_minkey, dbp->pgsize) >
          B_MINKEY_TO_OVFLSIZE(dbp, DEFMINKEYPAGE, dbp->pgsize)) {
            __db_err(dbp->dbenv,
                "bt_minkey value of %lu too high for page size of %lu",
                (u_long)t->bt_minkey, (u_long)dbp->pgsize);
            return (EINVAL);
      }

      /* Start up the tree. */
      return (__bam_read_root(dbp, txn, base_pgno, flags));
}

/*
 * __bam_metachk --
 *
 * PUBLIC: int __bam_metachk __P((DB *, const char *, BTMETA *));
 */
int
__bam_metachk(dbp, name, btm)
      DB *dbp;
      const char *name;
      BTMETA *btm;
{
      DB_ENV *dbenv;
      u_int32_t vers;
      int ret;

      dbenv = dbp->dbenv;

      /*
       * At this point, all we know is that the magic number is for a Btree.
       * Check the version, the database may be out of date.
       */
      vers = btm->dbmeta.version;
      if (F_ISSET(dbp, DB_AM_SWAP))
            M_32_SWAP(vers);
      switch (vers) {
      case 6:
      case 7:
            __db_err(dbenv,
                "%s: btree version %lu requires a version upgrade",
                name, (u_long)vers);
            return (DB_OLD_VERSION);
      case 8:
      case 9:
            break;
      default:
            __db_err(dbenv,
                "%s: unsupported btree version: %lu", name, (u_long)vers);
            return (EINVAL);
      }

      /* Swap the page if we need to. */
      if (F_ISSET(dbp, DB_AM_SWAP) && (ret = __bam_mswap((PAGE *)btm)) != 0)
            return (ret);

      /*
       * Check application info against metadata info, and set info, flags,
       * and type based on metadata info.
       */
      if ((ret =
          __db_fchk(dbenv, "DB->open", btm->dbmeta.flags, BTM_MASK)) != 0)
            return (ret);

      if (F_ISSET(&btm->dbmeta, BTM_RECNO)) {
            if (dbp->type == DB_BTREE)
                  goto wrong_type;
            dbp->type = DB_RECNO;
            DB_ILLEGAL_METHOD(dbp, DB_OK_RECNO);
      } else {
            if (dbp->type == DB_RECNO)
                  goto wrong_type;
            dbp->type = DB_BTREE;
            DB_ILLEGAL_METHOD(dbp, DB_OK_BTREE);
      }

      if (F_ISSET(&btm->dbmeta, BTM_DUP))
            F_SET(dbp, DB_AM_DUP);
      else
            if (F_ISSET(dbp, DB_AM_DUP)) {
                  __db_err(dbenv,
            "%s: DB_DUP specified to open method but not set in database",
                      name);
                  return (EINVAL);
            }

      if (F_ISSET(&btm->dbmeta, BTM_RECNUM)) {
            if (dbp->type != DB_BTREE)
                  goto wrong_type;
            F_SET(dbp, DB_AM_RECNUM);

            if ((ret = __db_fcchk(dbenv,
                "DB->open", dbp->flags, DB_AM_DUP, DB_AM_RECNUM)) != 0)
                  return (ret);
      } else
            if (F_ISSET(dbp, DB_AM_RECNUM)) {
                  __db_err(dbenv,
          "%s: DB_RECNUM specified to open method but not set in database",
                      name);
                  return (EINVAL);
            }

      if (F_ISSET(&btm->dbmeta, BTM_FIXEDLEN)) {
            if (dbp->type != DB_RECNO)
                  goto wrong_type;
            F_SET(dbp, DB_AM_FIXEDLEN);
      } else
            if (F_ISSET(dbp, DB_AM_FIXEDLEN)) {
                  __db_err(dbenv,
      "%s: DB_FIXEDLEN specified to open method but not set in database",
                      name);
                  return (EINVAL);
            }

      if (F_ISSET(&btm->dbmeta, BTM_RENUMBER)) {
            if (dbp->type != DB_RECNO)
                  goto wrong_type;
            F_SET(dbp, DB_AM_RENUMBER);
      } else
            if (F_ISSET(dbp, DB_AM_RENUMBER)) {
                  __db_err(dbenv,
          "%s: DB_RENUMBER specified to open method but not set in database",
                      name);
                  return (EINVAL);
            }

      if (F_ISSET(&btm->dbmeta, BTM_SUBDB))
            F_SET(dbp, DB_AM_SUBDB);
      else
            if (F_ISSET(dbp, DB_AM_SUBDB)) {
                  __db_err(dbenv,
          "%s: multiple databases specified but not supported by file",
                      name);
                  return (EINVAL);
            }

      if (F_ISSET(&btm->dbmeta, BTM_DUPSORT)) {
            if (dbp->dup_compare == NULL)
                  dbp->dup_compare = __bam_defcmp;
            F_SET(dbp, DB_AM_DUPSORT);
      } else
            if (dbp->dup_compare != NULL) {
                  __db_err(dbenv,
            "%s: duplicate sort specified but not supported in database",
                      name);
                  return (EINVAL);
            }

      /* Set the page size. */
      dbp->pgsize = btm->dbmeta.pagesize;

      /* Copy the file's ID. */
      memcpy(dbp->fileid, btm->dbmeta.uid, DB_FILE_ID_LEN);

      return (0);

wrong_type:
      if (dbp->type == DB_BTREE)
            __db_err(dbenv,
                "open method type is Btree, database type is Recno");
      else
            __db_err(dbenv,
                "open method type is Recno, database type is Btree");
      return (EINVAL);
}

/*
 * __bam_read_root --
 *    Read the root page and check a tree.
 *
 * PUBLIC: int __bam_read_root __P((DB *, DB_TXN *, db_pgno_t, u_int32_t));
 */
int
__bam_read_root(dbp, txn, base_pgno, flags)
      DB *dbp;
      DB_TXN *txn;
      db_pgno_t base_pgno;
      u_int32_t flags;
{
      BTMETA *meta;
      BTREE *t;
      DBC *dbc;
      DB_LOCK metalock;
      DB_MPOOLFILE *mpf;
      int ret, t_ret;

      meta = NULL;
      t = dbp->bt_internal;
      LOCK_INIT(metalock);
      mpf = dbp->mpf;
      ret = 0;

      /* Get a cursor.  */
      if ((ret = dbp->cursor(dbp, txn, &dbc, 0)) != 0)
            return (ret);

      /* Get the metadata page. */
      if ((ret =
          __db_lget(dbc, 0, base_pgno, DB_LOCK_READ, 0, &metalock)) != 0)
            goto err;
      if ((ret = mpf->get(mpf, &base_pgno, 0, (PAGE **)&meta)) != 0)
            goto err;

      /*
       * If the magic number is set, the tree has been created.  Correct
       * any fields that may not be right.  Note, all of the local flags
       * were set by DB->open.
       *
       * Otherwise, we'd better be in recovery or abort, in which case the
       * metadata page will be created/initialized elsewhere.
       */
      DB_ASSERT(meta->dbmeta.magic != 0 ||
          IS_RECOVERING(dbp->dbenv) || F_ISSET(dbp, DB_AM_RECOVER));

      t->bt_maxkey = meta->maxkey;
      t->bt_minkey = meta->minkey;
      t->re_pad = meta->re_pad;
      t->re_len = meta->re_len;

      t->bt_meta = base_pgno;
      t->bt_root = meta->root;

      /*
       * !!!
       * If creating a subdatabase, we've already done an insert when
       * we put the subdatabase's entry into the master database, so
       * our last-page-inserted value is wrongly initialized for the
       * master database, not the subdatabase we're creating.  I'm not
       * sure where the *right* place to clear this value is, it's not
       * intuitively obvious that it belongs here.
       */
      t->bt_lpgno = PGNO_INVALID;

      /* We must initialize last_pgno, it could be stale. */
      if (!LF_ISSET(DB_RDONLY) && dbp->meta_pgno == PGNO_BASE_MD) {
            mpf->last_pgno(mpf, &meta->dbmeta.last_pgno);
            ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY);
      } else
            ret = mpf->put(mpf, meta, 0);
      meta = NULL;

err:  /* Put the metadata page back. */
      if (meta != NULL && (t_ret = mpf->put(mpf, meta, 0)) != 0 && ret == 0)
            ret = t_ret;
      if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
            ret = t_ret;

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

/*
 * __bam_init_meta --
 *
 * Initialize a btree meta-data page.  The following fields may need
 * to be updated later: last_pgno, root.
 */
static void
__bam_init_meta(dbp, meta, pgno, lsnp)
      DB *dbp;
      BTMETA *meta;
      db_pgno_t pgno;
      DB_LSN *lsnp;
{
      BTREE *t;

      memset(meta, 0, sizeof(BTMETA));
      meta->dbmeta.lsn = *lsnp;
      meta->dbmeta.pgno = pgno;
      meta->dbmeta.magic = DB_BTREEMAGIC;
      meta->dbmeta.version = DB_BTREEVERSION;
      meta->dbmeta.pagesize = dbp->pgsize;
      if (F_ISSET(dbp, DB_AM_CHKSUM))
            FLD_SET(meta->dbmeta.metaflags, DBMETA_CHKSUM);
      if (F_ISSET(dbp, DB_AM_ENCRYPT)) {
            meta->dbmeta.encrypt_alg =
                ((DB_CIPHER *)dbp->dbenv->crypto_handle)->alg;
            DB_ASSERT(meta->dbmeta.encrypt_alg != 0);
            meta->crypto_magic = meta->dbmeta.magic;
      }
      meta->dbmeta.type = P_BTREEMETA;
      meta->dbmeta.free = PGNO_INVALID;
      meta->dbmeta.last_pgno = pgno;
      if (F_ISSET(dbp, DB_AM_DUP))
            F_SET(&meta->dbmeta, BTM_DUP);
      if (F_ISSET(dbp, DB_AM_FIXEDLEN))
            F_SET(&meta->dbmeta, BTM_FIXEDLEN);
      if (F_ISSET(dbp, DB_AM_RECNUM))
            F_SET(&meta->dbmeta, BTM_RECNUM);
      if (F_ISSET(dbp, DB_AM_RENUMBER))
            F_SET(&meta->dbmeta, BTM_RENUMBER);
      if (F_ISSET(dbp, DB_AM_SUBDB))
            F_SET(&meta->dbmeta, BTM_SUBDB);
      if (dbp->dup_compare != NULL)
            F_SET(&meta->dbmeta, BTM_DUPSORT);
      if (dbp->type == DB_RECNO)
            F_SET(&meta->dbmeta, BTM_RECNO);
      memcpy(meta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN);

      t = dbp->bt_internal;
      meta->maxkey = t->bt_maxkey;
      meta->minkey = t->bt_minkey;
      meta->re_len = t->re_len;
      meta->re_pad = t->re_pad;
}

/*
 * __bam_new_file --
 * Create the necessary pages to begin a new database file.
 *
 * This code appears more complex than it is because of the two cases (named
 * and unnamed).  The way to read the code is that for each page being created,
 * there are three parts: 1) a "get page" chunk (which either uses malloc'd
 * memory or calls mpf->get), 2) the initialization, and 3) the "put page"
 * chunk which either does a fop write or an mpf->put.
 *
 * PUBLIC: int __bam_new_file __P((DB *, DB_TXN *, DB_FH *, const char *));
 */
int
__bam_new_file(dbp, txn, fhp, name)
      DB *dbp;
      DB_TXN *txn;
      DB_FH *fhp;
      const char *name;
{
      BTMETA *meta;
      DB_ENV *dbenv;
      DB_LSN lsn;
      DB_MPOOLFILE *mpf;
      DB_PGINFO pginfo;
      DBT pdbt;
      PAGE *root;
      db_pgno_t pgno;
      int ret;
      void *buf;

      dbenv = dbp->dbenv;
      mpf = dbp->mpf;
      root = NULL;
      meta = NULL;
      memset(&pdbt, 0, sizeof(pdbt));

      /* Build meta-data page. */

      if (name == NULL) {
            pgno = PGNO_BASE_MD;
            ret = mpf->get(mpf, &pgno, DB_MPOOL_CREATE, &meta);
      } else {
            pginfo.db_pagesize = dbp->pgsize;
            pginfo.flags =
                F_ISSET(dbp, (DB_AM_CHKSUM | DB_AM_ENCRYPT | DB_AM_SWAP));
            pginfo.type = dbp->type;
            pdbt.data = &pginfo;
            pdbt.size = sizeof(pginfo);
            ret = __os_calloc(dbp->dbenv, 1, dbp->pgsize, &buf);
            meta = (BTMETA *)buf;
      }
      if (ret != 0)
            return (ret);

      LSN_NOT_LOGGED(lsn);
      __bam_init_meta(dbp, meta, PGNO_BASE_MD, &lsn);
      meta->root = 1;
      meta->dbmeta.last_pgno = 1;

      if (name == NULL)
            ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY);
      else {
            if ((ret = __db_pgout(dbenv, PGNO_BASE_MD, meta, &pdbt)) != 0)
                  goto err;
            ret = __fop_write(dbenv,
                txn, name, DB_APP_DATA, fhp, 0, buf, dbp->pgsize, 1);
      }
      if (ret != 0)
            goto err;
      meta = NULL;

      /* Now build root page. */
      if (name == NULL) {
            pgno = 1;
            if ((ret = mpf->get(mpf, &pgno, DB_MPOOL_CREATE, &root)) != 0)
                  goto err;
      } else {
#ifdef DIAGNOSTIC
            memset(buf, dbp->pgsize, 0);
#endif
            root = (PAGE *)buf;
      }

      P_INIT(root, dbp->pgsize, 1, PGNO_INVALID, PGNO_INVALID,
          LEAFLEVEL, dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE);
      LSN_NOT_LOGGED(root->lsn);

      if (name == NULL)
            ret = mpf->put(mpf, root, DB_MPOOL_DIRTY);
      else {
            if ((ret = __db_pgout(dbenv, root->pgno, root, &pdbt)) != 0)
                  goto err;
            ret = __fop_write(dbenv, txn,
                name, DB_APP_DATA, fhp, dbp->pgsize, buf, dbp->pgsize, 1);
      }
      if (ret != 0)
            goto err;
      root = NULL;

err:  if (name != NULL)
            __os_free(dbenv, buf);
      else {
            if (meta != NULL)
                  (void)mpf->put(mpf, meta, 0);
            if (root != NULL)
                  (void)mpf->put(mpf, root, 0);
      }
      return (ret);
}

/*
 * __bam_new_subdb --
 *    Create a metadata page and a root page for a new btree.
 *
 * PUBLIC: int __bam_new_subdb __P((DB *, DB *, DB_TXN *));
 */
int
__bam_new_subdb(mdbp, dbp, txn)
      DB *mdbp, *dbp;
      DB_TXN *txn;
{
      BTMETA *meta;
      DBC *dbc;
      DB_ENV *dbenv;
      DB_LOCK metalock;
      DB_LSN lsn;
      DB_MPOOLFILE *mpf;
      PAGE *root;
      int ret, t_ret;

      dbenv = mdbp->dbenv;
      mpf = mdbp->mpf;
      dbc = NULL;
      meta = NULL;
      root = NULL;

      if ((ret = mdbp->cursor(mdbp, txn,
          &dbc, CDB_LOCKING(dbenv) ?  DB_WRITECURSOR : 0)) != 0)
            return (ret);

      /* Get, and optionally create the metadata page. */
      if ((ret = __db_lget(dbc,
          0, dbp->meta_pgno, DB_LOCK_WRITE, 0, &metalock)) != 0)
            goto err;
      if ((ret = mpf->get(mpf, &dbp->meta_pgno, DB_MPOOL_CREATE, &meta)) != 0)
            goto err;

      /* Build meta-data page. */
      lsn = meta->dbmeta.lsn;
      __bam_init_meta(dbp, meta, dbp->meta_pgno, &lsn);
      if ((ret = __db_log_page(mdbp,
          txn, &meta->dbmeta.lsn, dbp->meta_pgno, (PAGE *)meta)) != 0)
            goto err;

      /* Create and initialize a root page. */
      if ((ret = __db_new(dbc,
          dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE, &root)) != 0)
            goto err;
      root->level = LEAFLEVEL;

      if (DBENV_LOGGING(dbenv) &&
          (ret = __bam_root_log(mdbp, txn, &meta->dbmeta.lsn, 0,
          meta->dbmeta.pgno, root->pgno, &meta->dbmeta.lsn)) != 0)
            goto err;

      meta->root = root->pgno;
      if ((ret =
          __db_log_page(mdbp, txn, &root->lsn, root->pgno, root)) != 0)
            goto err;

      /* Release the metadata and root pages. */
      if ((ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY)) != 0)
            goto err;
      meta = NULL;
      if ((ret = mpf->put(mpf, root, DB_MPOOL_DIRTY)) != 0)
            goto err;
      root = NULL;
err:
      if (meta != NULL)
            if ((t_ret = mpf->put(mpf, meta, 0)) != 0 && ret == 0)
                  ret = t_ret;
      if (root != NULL)
            if ((t_ret = mpf->put(mpf, root, 0)) != 0 && ret == 0)
                  ret = t_ret;
      if (LOCK_ISSET(metalock))
            if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
                  ret = t_ret;
      if (dbc != NULL)
            if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
                  ret = t_ret;
      return (ret);
}

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