db_iface.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: db_iface.c,v 12.29 2005/11/08 14:49:44 bostic Exp $
 */

#include "db_config.h"

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

#include <string.h>
#endif

#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc/db_shash.h"
#include "dbinc/btree.h"
#ifndef HAVE_HASH
#include "dbinc/hash.h"                 /* For __db_no_hash_am(). */
#endif
#ifndef HAVE_QUEUE
#include "dbinc/qam.h"                  /* For __db_no_queue_am(). */
#endif
#include "dbinc/lock.h"
#include "dbinc/log.h"
#include "dbinc/mp.h"
#include "dbinc/txn.h"

static int __db_associate_arg __P((DB *, DB *,
               int (*)(DB *, const DBT *, const DBT *, DBT *), u_int32_t));
static int __db_c_del_arg __P((DBC *, u_int32_t));
static int __db_c_get_arg __P((DBC *, DBT *, DBT *, u_int32_t));
static int __db_c_pget_arg __P((DBC *, DBT *, u_int32_t));
static int __db_c_put_arg __P((DBC *, DBT *, DBT *, u_int32_t));
static int __db_curinval __P((const DB_ENV *));
static int __db_cursor_arg __P((DB *, u_int32_t));
static int __db_del_arg __P((DB *, u_int32_t));
static int __db_get_arg __P((const DB *, const DBT *, DBT *, u_int32_t));
static int __db_join_arg __P((DB *, DBC **, u_int32_t));
static int __db_open_arg __P((DB *,
               DB_TXN *, const char *, const char *, DBTYPE, u_int32_t));
static int __db_pget_arg __P((DB *, DBT *, u_int32_t));
static int __db_put_arg __P((DB *, DBT *, DBT *, u_int32_t));
static int __dbt_ferr __P((const DB *, const char *, const DBT *, int));

/*
 * These functions implement the Berkeley DB API.  They are organized in a
 * layered fashion.  The interface functions (XXX_pp) perform all generic
 * error checks (for example, PANIC'd region, replication state change
 * in progress, inconsistent transaction usage), call function-specific
 * check routines (_arg) to check for proper flag usage, etc., do pre-amble
 * processing (incrementing handle counts, handling local transactions),
 * call the function and then do post-amble processing (local transactions,
 * decrement handle counts).
 *
 * The basic structure is:
 *      Check for simple/generic errors (PANIC'd region)
 *      Check if replication is changing state (increment handle count).
 *      Call function-specific argument checking routine
 *      Create internal transaction if necessary
 *      Call underlying worker function
 *      Commit/abort internal transaction if necessary
 *      Decrement handle count
 */

/*
 * __db_associate_pp --
 *      DB->associate pre/post processing.
 *
 * PUBLIC: int __db_associate_pp __P((DB *, DB_TXN *, DB *,
 * PUBLIC:     int (*)(DB *, const DBT *, const DBT *, DBT *), u_int32_t));
 */
int
__db_associate_pp(dbp, txn, sdbp, callback, flags)
        DB *dbp, *sdbp;
        DB_TXN *txn;
        int (*callback) __P((DB *, const DBT *, const DBT *, DBT *));
        u_int32_t flags;
{
        DBC *sdbc;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret, txn_local;

        dbenv = dbp->dbenv;
        txn_local = 0;

        PANIC_CHECK(dbenv);
        STRIP_AUTO_COMMIT(flags);

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
            (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                handle_check = 0;
                goto err;
        }

        /*
         * Secondary cursors may have the primary's lock file ID, so we need
         * to make sure that no older cursors are lying around when we make
         * the transition.
         */
        if (TAILQ_FIRST(&sdbp->active_queue) != NULL ||
            TAILQ_FIRST(&sdbp->join_queue) != NULL) {
                __db_err(dbenv,
    "Databases may not become secondary indices while cursors are open");
                ret = EINVAL;
                goto err;
        }

        if ((ret = __db_associate_arg(dbp, sdbp, callback, flags)) != 0)
                goto err;

        /*
         * Create a local transaction as necessary, check for consistent
         * transaction usage, and, if we have no transaction but do have
         * locking on, acquire a locker id for the handle lock acquisition.
         */
        if (IS_DB_AUTO_COMMIT(dbp, txn)) {
                if ((ret = __txn_begin(dbenv, NULL, &txn, 0)) != 0)
                        goto err;
                txn_local = 1;
        }

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, txn, DB_LOCK_INVALIDID, 0)) != 0)
                goto err;

        while ((sdbc = TAILQ_FIRST(&sdbp->free_queue)) != NULL)
                if ((ret = __db_c_destroy(sdbc)) != 0)
                        goto err;

        ret = __db_associate(dbp, txn, sdbp, callback, flags);

err:    if (txn_local &&
            (t_ret = __db_txn_auto_resolve(dbenv, txn, 0, ret)) && ret == 0)
                ret = t_ret;

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_associate_arg --
 *      Check DB->associate arguments.
 */
static int
__db_associate_arg(dbp, sdbp, callback, flags)
        DB *dbp, *sdbp;
        int (*callback) __P((DB *, const DBT *, const DBT *, DBT *));
        u_int32_t flags;
{
        DB_ENV *dbenv;
        int ret;

        dbenv = dbp->dbenv;

        if (F_ISSET(sdbp, DB_AM_SECONDARY)) {
                __db_err(dbenv,
                    "Secondary index handles may not be re-associated");
                return (EINVAL);
        }
        if (F_ISSET(dbp, DB_AM_SECONDARY)) {
                __db_err(dbenv,
                    "Secondary indices may not be used as primary databases");
                return (EINVAL);
        }
        if (F_ISSET(dbp, DB_AM_DUP)) {
                __db_err(dbenv,
                    "Primary databases may not be configured with duplicates");
                return (EINVAL);
        }
        if (F_ISSET(dbp, DB_AM_RENUMBER)) {
                __db_err(dbenv,
            "Renumbering recno databases may not be used as primary databases");
                return (EINVAL);
        }
        if (dbp->dbenv != sdbp->dbenv &&
            (!F_ISSET(dbp->dbenv, DB_ENV_DBLOCAL) ||
             !F_ISSET(sdbp->dbenv, DB_ENV_DBLOCAL))) {
                __db_err(dbenv,
            "The primary and secondary must be opened in the same environment");
                return (EINVAL);
        }
        if ((DB_IS_THREADED(dbp) && !DB_IS_THREADED(sdbp)) ||
            (!DB_IS_THREADED(dbp) && DB_IS_THREADED(sdbp))) {
                __db_err(dbenv,
            "The DB_THREAD setting must be the same for primary and secondary");
                return (EINVAL);
        }
        if (callback == NULL &&
            (!F_ISSET(dbp, DB_AM_RDONLY) || !F_ISSET(sdbp, DB_AM_RDONLY))) {
                __db_err(dbenv,
    "Callback function may be NULL only when database handles are read-only");
                return (EINVAL);
        }

        if ((ret = __db_fchk(dbenv, "DB->associate", flags, DB_CREATE |
            DB_IMMUTABLE_KEY)) != 0)
                return (ret);

        return (0);
}

/*
 * __db_close_pp --
 *      DB->close pre/post processing.
 *
 * PUBLIC: int __db_close_pp __P((DB *, u_int32_t));
 */
int
__db_close_pp(dbp, flags)
        DB *dbp;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;
        ret = 0;

        PANIC_CHECK(dbenv);

        /*
         * Close a DB handle -- as a handle destructor, we can't fail.
         *
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if (flags != 0 && flags != DB_NOSYNC)
                ret = __db_ferr(dbenv, "DB->close", 0);

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (t_ret = __db_rep_enter(dbp, 0, 0, 0)) != 0) {
                handle_check = 0;
                if (ret == 0)
                        ret = t_ret;
        }

        if ((t_ret = __db_close(dbp, NULL, flags)) != 0 && ret == 0)
                ret = t_ret;

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_cursor_pp --
 *      DB->cursor pre/post processing.
 *
 * PUBLIC: int __db_cursor_pp __P((DB *, DB_TXN *, DBC **, u_int32_t));
 */
int
__db_cursor_pp(dbp, txn, dbcp, flags)
        DB *dbp;
        DB_TXN *txn;
        DBC **dbcp;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret;

        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->cursor");

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        if (txn == NULL) {
                handle_check = IS_ENV_REPLICATED(dbenv) ? 1 : 0;
                if (handle_check && (ret = __op_rep_enter(dbenv)) != 0) {
                        handle_check = 0;
                        goto err;
                }
        } else
                handle_check = 0;
        if ((ret = __db_cursor_arg(dbp, flags)) != 0)
                goto err;

        /*
         * Check for consistent transaction usage.  For now, assume this
         * cursor might be used for read operations only (in which case
         * it may not require a txn).  We'll check more stringently in
         * c_del and c_put.  (Note this means the read-op txn tests have
         * to be a subset of the write-op ones.)
         */
        if ((ret = __db_check_txn(dbp, txn, DB_LOCK_INVALIDID, 1)) != 0)
                goto err;

        ret = __db_cursor(dbp, txn, dbcp, flags);

err:    /* Release replication block on error. */
        if (ret != 0 && handle_check)
                (void)__op_rep_exit(dbenv);

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_cursor --
 *      DB->cursor.
 *
 * PUBLIC: int __db_cursor __P((DB *, DB_TXN *, DBC **, u_int32_t));
 */
int
__db_cursor(dbp, txn, dbcp, flags)
        DB *dbp;
        DB_TXN *txn;
        DBC **dbcp;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DBC *dbc;
        db_lockmode_t mode;
        u_int32_t op;
        int ret;

        dbenv = dbp->dbenv;

        if ((ret = __db_cursor_int(dbp,
            txn, dbp->type, PGNO_INVALID, 0, DB_LOCK_INVALIDID, &dbc)) != 0)
                return (ret);

        /*
         * If this is CDB, do all the locking in the interface, which is
         * right here.
         */
        if (CDB_LOCKING(dbenv)) {
                op = LF_ISSET(DB_OPFLAGS_MASK);
                mode = (op == DB_WRITELOCK) ? DB_LOCK_WRITE :
                    ((op == DB_WRITECURSOR) ? DB_LOCK_IWRITE : DB_LOCK_READ);
                if ((ret = __lock_get(dbenv, dbc->locker, 0,
                    &dbc->lock_dbt, mode, &dbc->mylock)) != 0)
                        goto err;
                if (op == DB_WRITECURSOR)
                        F_SET(dbc, DBC_WRITECURSOR);
                if (op == DB_WRITELOCK)
                        F_SET(dbc, DBC_WRITER);
        }

        if (LF_ISSET(DB_READ_UNCOMMITTED) ||
            (txn != NULL && F_ISSET(txn, TXN_READ_UNCOMMITTED)))
                F_SET(dbc, DBC_READ_UNCOMMITTED);

        if (LF_ISSET(DB_READ_COMMITTED) ||
            (txn != NULL && F_ISSET(txn, TXN_READ_COMMITTED)))
                F_SET(dbc, DBC_READ_COMMITTED);

        *dbcp = dbc;
        return (0);

err:    (void)__db_c_close(dbc);
        return (ret);
}

/*
 * __db_cursor_arg --
 *      Check DB->cursor arguments.
 */
static int
__db_cursor_arg(dbp, flags)
        DB *dbp;
        u_int32_t flags;
{
        DB_ENV *dbenv;

        dbenv = dbp->dbenv;

        /*
         * DB_READ_COMMITTED and DB_READ_UNCOMMITTED are the only valid
         * bit-flags; they require locking.
         */
        if (LF_ISSET(DB_READ_COMMITTED | DB_READ_UNCOMMITTED)) {
                if (!LOCKING_ON(dbenv))
                        return (__db_fnl(dbenv, "DB->cursor"));
                LF_CLR(DB_READ_COMMITTED| DB_READ_UNCOMMITTED);
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        case DB_WRITECURSOR:
                if (DB_IS_READONLY(dbp))
                        return (__db_rdonly(dbenv, "DB->cursor"));
                if (!CDB_LOCKING(dbenv))
                        return (__db_ferr(dbenv, "DB->cursor", 0));
                break;
        case DB_WRITELOCK:
                if (DB_IS_READONLY(dbp))
                        return (__db_rdonly(dbenv, "DB->cursor"));
                break;
        default:
                return (__db_ferr(dbenv, "DB->cursor", 0));
        }

        return (0);
}

/*
 * __db_del_pp --
 *      DB->del pre/post processing.
 *
 * PUBLIC: int __db_del_pp __P((DB *, DB_TXN *, DBT *, u_int32_t));
 */
int
__db_del_pp(dbp, txn, key, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *key;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret, txn_local;

        dbenv = dbp->dbenv;
        txn_local = 0;

        PANIC_CHECK(dbenv);
        STRIP_AUTO_COMMIT(flags);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->del");

#if CONFIG_TEST
        if (IS_REP_MASTER(dbenv))
                DB_TEST_WAIT(dbenv, dbenv->test_check);
#endif
        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
             (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                        handle_check = 0;
                        goto err;
        }

        if ((ret = __db_del_arg(dbp, flags)) != 0)
                goto err;

        /* Create local transaction as necessary. */
        if (IS_DB_AUTO_COMMIT(dbp, txn)) {
                if ((ret = __txn_begin(dbenv, NULL, &txn, 0)) != 0)
                        goto err;
                txn_local = 1;
        }

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, txn, DB_LOCK_INVALIDID, 0)) != 0)
                goto err;

        ret = __db_del(dbp, txn, key, flags);

err:    if (txn_local &&
            (t_ret = __db_txn_auto_resolve(dbenv, txn, 0, ret)) && ret == 0)
                ret = t_ret;

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_del_arg --
 *      Check DB->delete arguments.
 */
static int
__db_del_arg(dbp, flags)
        DB *dbp;
        u_int32_t flags;
{
        DB_ENV *dbenv;

        dbenv = dbp->dbenv;

        /* Check for changes to a read-only tree. */
        if (DB_IS_READONLY(dbp))
                return (__db_rdonly(dbenv, "DB->del"));

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        default:
                return (__db_ferr(dbenv, "DB->del", 0));
        }

        return (0);
}

/*
 * db_fd_pp --
 *      DB->fd pre/post processing.
 *
 * PUBLIC: int __db_fd_pp __P((DB *, int *));
 */
int
__db_fd_pp(dbp, fdp)
        DB *dbp;
        int *fdp;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        DB_FH *fhp;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->fd");

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (ret = __db_rep_enter(dbp, 1, 0, 0)) != 0)
                goto err;

        /*
         * !!!
         * There's no argument checking to be done.
         *
         * !!!
         * The actual method call is simple, do it inline.
         *
         * XXX
         * Truly spectacular layering violation.
         */
        if ((ret = __mp_xxx_fh(dbp->mpf, &fhp)) == 0) {
                if (fhp == NULL) {
                        *fdp = -1;
                        __db_err(dbenv,
                            "Database does not have a valid file handle");
                        ret = ENOENT;
                } else
                        *fdp = fhp->fd;
        }

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

err:    ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_get_pp --
 *      DB->get pre/post processing.
 *
 * PUBLIC: int __db_get_pp __P((DB *, DB_TXN *, DBT *, DBT *, u_int32_t));
 */
int
__db_get_pp(dbp, txn, key, data, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *key, *data;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        u_int32_t mode;
        int handle_check, ret, t_ret, txn_local;

        dbenv = dbp->dbenv;
        mode = 0;
        txn_local = 0;

        PANIC_CHECK(dbenv);
        STRIP_AUTO_COMMIT(flags);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->get");

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
             (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                        handle_check = 0;
                        goto err;
        }

        if ((ret = __db_get_arg(dbp, key, data, flags)) != 0)
                goto err;

        if (LF_ISSET(DB_READ_UNCOMMITTED))
                mode = DB_READ_UNCOMMITTED;
        else if ((flags & DB_OPFLAGS_MASK) == DB_CONSUME ||
            (flags & DB_OPFLAGS_MASK) == DB_CONSUME_WAIT) {
                mode = DB_WRITELOCK;
                if (IS_DB_AUTO_COMMIT(dbp, txn)) {
                        if ((ret = __txn_begin(dbenv, NULL, &txn, 0)) != 0)
                                goto err;
                        txn_local = 1;
                }
        }

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, txn, DB_LOCK_INVALIDID,
            mode == DB_WRITELOCK || LF_ISSET(DB_RMW) ? 0 : 1)) != 0)
                goto err;

        ret = __db_get(dbp, txn, key, data, flags);

err:    if (txn_local &&
            (t_ret = __db_txn_auto_resolve(dbenv, txn, 0, ret)) && ret == 0)
                ret = t_ret;

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_get --
 *      DB->get.
 *
 * PUBLIC: int __db_get __P((DB *, DB_TXN *, DBT *, DBT *, u_int32_t));
 */
int
__db_get(dbp, txn, key, data, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *key, *data;
        u_int32_t flags;
{
        DBC *dbc;
        u_int32_t mode;
        int ret, t_ret;

        mode = 0;
        if (LF_ISSET(DB_READ_UNCOMMITTED)) {
                mode = DB_READ_UNCOMMITTED;
                LF_CLR(DB_READ_UNCOMMITTED);
        } else if (LF_ISSET(DB_READ_COMMITTED)) {
                mode = DB_READ_COMMITTED;
                LF_CLR(DB_READ_COMMITTED);
        } else if ((flags & DB_OPFLAGS_MASK) == DB_CONSUME ||
            (flags & DB_OPFLAGS_MASK) == DB_CONSUME_WAIT)
                mode = DB_WRITELOCK;

        if ((ret = __db_cursor(dbp, txn, &dbc, mode)) != 0)
                return (ret);

        DEBUG_LREAD(dbc, txn, "DB->get", key, NULL, flags);

        /*
         * The DBC_TRANSIENT flag indicates that we're just doing a
         * single operation with this cursor, and that in case of
         * error we don't need to restore it to its old position--we're
         * going to close it right away.  Thus, we can perform the get
         * without duplicating the cursor, saving some cycles in this
         * common case.
         */
        F_SET(dbc, DBC_TRANSIENT);

        /*
         * SET_RET_MEM indicates that if key and/or data have no DBT
         * flags set and DB manages the returned-data memory, that memory
         * will belong to this handle, not to the underlying cursor.
         */
        SET_RET_MEM(dbc, dbp);

        if (LF_ISSET(~(DB_RMW | DB_MULTIPLE)) == 0)
                LF_SET(DB_SET);

        ret = __db_c_get(dbc, key, data, flags);

        if (dbc != NULL && (t_ret = __db_c_close(dbc)) != 0 && ret == 0)
                ret = t_ret;

        return (ret);
}

/*
 * __db_get_arg --
 *      DB->get argument checking, used by both DB->get and DB->pget.
 */
static int
__db_get_arg(dbp, key, data, flags)
        const DB *dbp;
        const DBT *key;
        DBT *data;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        int check_thread, dirty, multi, ret;

        dbenv = dbp->dbenv;

        /*
         * Check for read-modify-write validity.  DB_RMW doesn't make sense
         * with CDB cursors since if you're going to write the cursor, you
         * had to create it with DB_WRITECURSOR.  Regardless, we check for
         * LOCKING_ON and not STD_LOCKING, as we don't want to disallow it.
         * If this changes, confirm that DB does not itself set the DB_RMW
         * flag in a path where CDB may have been configured.
         */
        check_thread = dirty = 0;
        if (LF_ISSET(DB_READ_COMMITTED | DB_READ_UNCOMMITTED | DB_RMW)) {
                if (!LOCKING_ON(dbenv))
                        return (__db_fnl(dbenv, "DB->get"));
                if ((ret = __db_fcchk(dbenv, "DB->get",
                    flags, DB_READ_UNCOMMITTED, DB_READ_COMMITTED)) != 0)
                        return (ret);
                if (LF_ISSET(DB_READ_COMMITTED | DB_READ_UNCOMMITTED))
                        dirty = 1;
                LF_CLR(DB_READ_COMMITTED | DB_READ_UNCOMMITTED | DB_RMW);
        }

        multi = 0;
        if (LF_ISSET(DB_MULTIPLE | DB_MULTIPLE_KEY)) {
                if (LF_ISSET(DB_MULTIPLE_KEY))
                        goto multi_err;
                multi = LF_ISSET(DB_MULTIPLE) ? 1 : 0;
                LF_CLR(DB_MULTIPLE);
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
        case DB_GET_BOTH:
                break;
        case DB_SET_RECNO:
                check_thread = 1;
                if (!F_ISSET(dbp, DB_AM_RECNUM))
                        goto err;
                break;
        case DB_CONSUME:
        case DB_CONSUME_WAIT:
                check_thread = 1;
                if (dirty) {
                        __db_err(dbenv,
                    "%s is not supported with DB_CONSUME or DB_CONSUME_WAIT",
                             LF_ISSET(DB_READ_UNCOMMITTED) ?
                             "DB_READ_UNCOMMITTED" : "DB_READ_COMMITTED");
                        return (EINVAL);
                }
                if (multi)
multi_err:              return (__db_ferr(dbenv, "DB->get", 1));
                if (dbp->type == DB_QUEUE)
                        break;
                /* FALLTHROUGH */
        default:
err:            return (__db_ferr(dbenv, "DB->get", 0));
        }

        /*
         * Check for invalid key/data flags.
         *
         * XXX: Dave Krinsky
         * Remember to modify this when we fix the flag-returning problem.
         */
        if ((ret = __dbt_ferr(dbp, "key", key, check_thread)) != 0)
                return (ret);
        if ((ret = __dbt_ferr(dbp, "data", data, 1)) != 0)
                return (ret);

        if (multi) {
                if (!F_ISSET(data, DB_DBT_USERMEM)) {
                        __db_err(dbenv,
                            "DB_MULTIPLE requires DB_DBT_USERMEM be set");
                        return (EINVAL);
                }
                if (F_ISSET(key, DB_DBT_PARTIAL) ||
                    F_ISSET(data, DB_DBT_PARTIAL)) {
                        __db_err(dbenv,
                            "DB_MULTIPLE does not support DB_DBT_PARTIAL");
                        return (EINVAL);
                }
                if (data->ulen < 1024 ||
                    data->ulen < dbp->pgsize || data->ulen % 1024 != 0) {
                        __db_err(dbenv, "%s%s",
                            "DB_MULTIPLE buffers must be ",
                            "aligned, at least page size and multiples of 1KB");
                        return (EINVAL);
                }
        }

        return (0);
}

/*
 * __db_join_pp --
 *      DB->join pre/post processing.
 *
 * PUBLIC: int __db_join_pp __P((DB *, DBC **, DBC **, u_int32_t));
 */
int
__db_join_pp(primary, curslist, dbcp, flags)
        DB *primary;
        DBC **curslist, **dbcp;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = primary->dbenv;

        PANIC_CHECK(dbenv);

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (ret =
            __db_rep_enter(primary, 1, 0, curslist[0]->txn != NULL)) != 0) {
                handle_check = 0;
                goto err;
        }

        if ((ret = __db_join_arg(primary, curslist, flags)) == 0)
                ret = __db_join(primary, curslist, dbcp, flags);

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

err:    ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_join_arg --
 *      Check DB->join arguments.
 */
static int
__db_join_arg(primary, curslist, flags)
        DB *primary;
        DBC **curslist;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_TXN *txn;
        int i;

        dbenv = primary->dbenv;

        switch (flags) {
        case 0:
        case DB_JOIN_NOSORT:
                break;
        default:
                return (__db_ferr(dbenv, "DB->join", 0));
        }

        if (curslist == NULL || curslist[0] == NULL) {
                __db_err(dbenv,
            "At least one secondary cursor must be specified to DB->join");
                return (EINVAL);
        }

        txn = curslist[0]->txn;
        for (i = 1; curslist[i] != NULL; i++)
                if (curslist[i]->txn != txn) {
                        __db_err(dbenv,
                    "All secondary cursors must share the same transaction");
                        return (EINVAL);
                }

        return (0);
}

/*
 * __db_key_range_pp --
 *      DB->key_range pre/post processing.
 *
 * PUBLIC: int __db_key_range_pp
 * PUBLIC:     __P((DB *, DB_TXN *, DBT *, DB_KEY_RANGE *, u_int32_t));
 */
int
__db_key_range_pp(dbp, txn, key, kr, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *key;
        DB_KEY_RANGE *kr;
        u_int32_t flags;
{
        DBC *dbc;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;

        PANIC_CHECK(dbp->dbenv);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->key_range");

        /*
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if (flags != 0)
                return (__db_ferr(dbenv, "DB->key_range", 0));

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
             (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                handle_check = 0;
                goto err;
        }

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, txn, DB_LOCK_INVALIDID, 1)) != 0)
                goto err;

        /*
         * !!!
         * The actual method call is simple, do it inline.
         */
        switch (dbp->type) {
        case DB_BTREE:
                /* Acquire a cursor. */
                if ((ret = __db_cursor(dbp, txn, &dbc, 0)) != 0)
                        break;

                DEBUG_LWRITE(dbc, NULL, "bam_key_range", NULL, NULL, 0);

                ret = __bam_key_range(dbc, key, kr, flags);

                if ((t_ret = __db_c_close(dbc)) != 0 && ret == 0)
                        ret = t_ret;
                break;
        case DB_HASH:
        case DB_QUEUE:
        case DB_RECNO:
                ret = __dbh_am_chk(dbp, DB_OK_BTREE);
                break;
        case DB_UNKNOWN:
        default:
                ret = __db_unknown_type(dbenv, "DB->key_range", dbp->type);
                break;
        }

err:    /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_open_pp --
 *      DB->open pre/post processing.
 *
 * PUBLIC: int __db_open_pp __P((DB *, DB_TXN *,
 * PUBLIC:     const char *, const char *, DBTYPE, u_int32_t, int));
 */
int
__db_open_pp(dbp, txn, fname, dname, type, flags, mode)
        DB *dbp;
        DB_TXN *txn;
        const char *fname, *dname;
        DBTYPE type;
        u_int32_t flags;
        int mode;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, nosync, remove_me, ret, t_ret, txn_local;

        dbenv = dbp->dbenv;
        nosync = 1;
        remove_me = txn_local = 0;
        handle_check = 0;

        PANIC_CHECK(dbenv);

        ENV_ENTER(dbenv, ip);

        /*
         * Save the file and database names and flags.  We do this here
         * because we don't pass all of the flags down into the actual
         * DB->open method call, we strip DB_AUTO_COMMIT at this layer.
         */
        if ((fname != NULL &&
            (ret = __os_strdup(dbenv, fname, &dbp->fname)) != 0))
                goto err;
        if ((dname != NULL &&
            (ret = __os_strdup(dbenv, dname, &dbp->dname)) != 0))
                goto err;
        dbp->open_flags = flags;

        /* Save the current DB handle flags for refresh. */
        dbp->orig_flags = dbp->flags;

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
            (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                handle_check = 0;
                goto err;
        }

        /*
         * Create local transaction as necessary, check for consistent
         * transaction usage.
         */
        if (IS_ENV_AUTO_COMMIT(dbenv, txn, flags)) {
                if ((ret = __db_txn_auto_init(dbenv, &txn)) != 0)
                        goto err;
                txn_local = 1;
        } else
                if (txn != NULL && !TXN_ON(dbenv)) {
                        ret = __db_not_txn_env(dbenv);
                        goto err;
                }
        LF_CLR(DB_AUTO_COMMIT);

        /*
         * We check arguments after possibly creating a local transaction,
         * which is unusual -- the reason is some flags are illegal if any
         * kind of transaction is in effect.
         */
        if ((ret = __db_open_arg(dbp, txn, fname, dname, type, flags)) == 0)
                if ((ret = __db_open(dbp, txn, fname, dname, type,
                    flags, mode, PGNO_BASE_MD)) != 0)
                        goto txnerr;

        /*
         * You can open the database that describes the subdatabases in the
         * rest of the file read-only.  The content of each key's data is
         * unspecified and applications should never be adding new records
         * or updating existing records.  However, during recovery, we need
         * to open these databases R/W so we can redo/undo changes in them.
         * Likewise, we need to open master databases read/write during
         * rename and remove so we can be sure they're fully sync'ed, so
         * we provide an override flag for the purpose.
         */
        if (dname == NULL && !IS_RECOVERING(dbenv) && !LF_ISSET(DB_RDONLY) &&
            !LF_ISSET(DB_RDWRMASTER) && F_ISSET(dbp, DB_AM_SUBDB)) {
                __db_err(dbenv,
    "files containing multiple databases may only be opened read-only");
                ret = EINVAL;
                goto txnerr;
        }

        /*
         * Success: file creations have to be synchronous, otherwise we don't
         * care.
         */
        if (F_ISSET(dbp, DB_AM_CREATED | DB_AM_CREATED_MSTR))
                nosync = 0;

        /* Success: don't discard the file on close. */
        F_CLR(dbp, DB_AM_DISCARD | DB_AM_CREATED | DB_AM_CREATED_MSTR);

        /*
         * If not transactional, remove the databases/subdatabases.  If we're
         * transactional, the child transaction abort cleans up.
         */
txnerr: if (ret != 0 && txn == NULL) {
                remove_me = F_ISSET(dbp, DB_AM_CREATED);
                if (F_ISSET(dbp, DB_AM_CREATED_MSTR) ||
                    (dname == NULL && remove_me))
                        /* Remove file. */
                        (void)__db_remove_int(dbp, txn, fname, NULL, DB_FORCE);
                else if (remove_me)
                        /* Remove subdatabase. */
                        (void)__db_remove_int(dbp, txn, fname, dname, DB_FORCE);
        }

        if (txn_local && (t_ret =
             __db_txn_auto_resolve(dbenv, txn, nosync, ret)) && ret == 0)
                ret = t_ret;

err:    /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_open_arg --
 *      Check DB->open arguments.
 */
static int
__db_open_arg(dbp, txn, fname, dname, type, flags)
        DB *dbp;
        DB_TXN *txn;
        const char *fname, *dname;
        DBTYPE type;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        u_int32_t ok_flags;
        int ret;

        dbenv = dbp->dbenv;

        /* Validate arguments. */
#undef  OKFLAGS
#define OKFLAGS                                                         \
        (DB_AUTO_COMMIT | DB_CREATE | DB_EXCL | DB_FCNTL_LOCKING |      \
        DB_NOMMAP | DB_NO_AUTO_COMMIT | DB_RDONLY | DB_RDWRMASTER |     \
        DB_READ_UNCOMMITTED | DB_THREAD | DB_TRUNCATE | DB_WRITEOPEN)
        if ((ret = __db_fchk(dbenv, "DB->open", flags, OKFLAGS)) != 0)
                return (ret);
        if (LF_ISSET(DB_EXCL) && !LF_ISSET(DB_CREATE))
                return (__db_ferr(dbenv, "DB->open", 1));
        if (LF_ISSET(DB_RDONLY) && LF_ISSET(DB_CREATE))
                return (__db_ferr(dbenv, "DB->open", 1));

#ifdef  HAVE_VXWORKS
        if (LF_ISSET(DB_TRUNCATE)) {
                __db_err(dbenv, "DB_TRUNCATE not supported on VxWorks");
                return (DB_OPNOTSUP);
        }
#endif
        switch (type) {
        case DB_UNKNOWN:
                if (LF_ISSET(DB_CREATE|DB_TRUNCATE)) {
                        __db_err(dbenv,
            "DB_UNKNOWN type specified with DB_CREATE or DB_TRUNCATE");
                        return (EINVAL);
                }
                ok_flags = 0;
                break;
        case DB_BTREE:
                ok_flags = DB_OK_BTREE;
                break;
        case DB_HASH:
#ifndef HAVE_HASH
                return (__db_no_hash_am(dbenv));
#endif
                ok_flags = DB_OK_HASH;
                break;
        case DB_QUEUE:
#ifndef HAVE_QUEUE
                return (__db_no_queue_am(dbenv));
#endif
                ok_flags = DB_OK_QUEUE;
                break;
        case DB_RECNO:
                ok_flags = DB_OK_RECNO;
                break;
        default:
                __db_err(dbenv, "unknown type: %lu", (u_long)type);
                return (EINVAL);
        }
        if (ok_flags)
                DB_ILLEGAL_METHOD(dbp, ok_flags);

        /* The environment may have been created, but never opened. */
        if (!F_ISSET(dbenv, DB_ENV_DBLOCAL | DB_ENV_OPEN_CALLED)) {
                __db_err(dbenv, "environment not yet opened");
                return (EINVAL);
        }

        /*
         * Historically, you could pass in an environment that didn't have a
         * mpool, and DB would create a private one behind the scenes.  This
         * no longer works.
         */
        if (!F_ISSET(dbenv, DB_ENV_DBLOCAL) && !MPOOL_ON(dbenv)) {
                __db_err(dbenv, "environment did not include a memory pool");
                return (EINVAL);
        }

        /*
         * You can't specify threads during DB->open if subsystems in the
         * environment weren't configured with them.
         */
        if (LF_ISSET(DB_THREAD) &&
            !F_ISSET(dbenv, DB_ENV_DBLOCAL | DB_ENV_THREAD)) {
                __db_err(dbenv, "environment not created using DB_THREAD");
                return (EINVAL);
        }

        /* DB_TRUNCATE is neither transaction recoverable nor lockable. */
        if (LF_ISSET(DB_TRUNCATE) && (LOCKING_ON(dbenv) || txn != NULL)) {
                __db_err(dbenv,
                    "DB_TRUNCATE illegal with %s specified",
                    LOCKING_ON(dbenv) ? "locking" : "transactions");
                return (EINVAL);
        }

        /* Subdatabase checks. */
        if (dname != NULL) {
                /* QAM can only be done on in-memory subdatabases. */
                if (type == DB_QUEUE && fname != NULL) {
                        __db_err(dbenv, "Queue databases must be one-per-file");
                        return (EINVAL);
                }

                /*
                 * Named in-memory databases can't support certain flags,
                 * so check here.
                 */
                if (fname == NULL)
                        F_CLR(dbp, DB_AM_CHKSUM | DB_AM_ENCRYPT);
        }

        return (0);
}

/*
 * __db_pget_pp --
 *      DB->pget pre/post processing.
 *
 * PUBLIC: int __db_pget_pp
 * PUBLIC:     __P((DB *, DB_TXN *, DBT *, DBT *, DBT *, u_int32_t));
 */
int
__db_pget_pp(dbp, txn, skey, pkey, data, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *skey, *pkey, *data;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->pget");

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
            (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                handle_check = 0;
                goto err;
        }

        if ((ret = __db_pget_arg(dbp, pkey, flags)) != 0 ||
            (ret = __db_get_arg(dbp, skey, data, flags)) != 0)
                goto err;

        ret = __db_pget(dbp, txn, skey, pkey, data, flags);

err:    /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_pget --
 *      DB->pget.
 *
 * PUBLIC: int __db_pget
 * PUBLIC:     __P((DB *, DB_TXN *, DBT *, DBT *, DBT *, u_int32_t));
 */
int
__db_pget(dbp, txn, skey, pkey, data, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *skey, *pkey, *data;
        u_int32_t flags;
{
        DBC *dbc;
        u_int32_t mode;
        int ret, t_ret;

        if (LF_ISSET(DB_READ_UNCOMMITTED)) {
                mode = DB_READ_UNCOMMITTED;
                LF_CLR(DB_READ_UNCOMMITTED);
        } else if (LF_ISSET(DB_READ_COMMITTED)) {
                mode = DB_READ_COMMITTED;
                LF_CLR(DB_READ_COMMITTED);
        } else
                mode = 0;

        if ((ret = __db_cursor(dbp, txn, &dbc, mode)) != 0)
                return (ret);

        SET_RET_MEM(dbc, dbp);

        DEBUG_LREAD(dbc, txn, "__db_pget", skey, NULL, flags);

        /*
         * !!!
         * The actual method call is simple, do it inline.
         *
         * The underlying cursor pget will fill in a default DBT for null
         * pkeys, and use the cursor's returned-key memory internally to
         * store any intermediate primary keys.  However, we've just set
         * the returned-key memory to the DB handle's key memory, which
         * is unsafe to use if the DB handle is threaded.  If the pkey
         * argument is NULL, use the DBC-owned returned-key memory
         * instead;  it'll go away when we close the cursor before we
         * return, but in this case that's just fine, as we're not
         * returning the primary key.
         */
        if (pkey == NULL)
                dbc->rkey = &dbc->my_rkey;

        /*
         * The cursor is just a perfectly ordinary secondary database cursor.
         * Call its c_pget() method to do the dirty work.
         */
        if (flags == 0 || flags == DB_RMW)
                flags |= DB_SET;

        ret = __db_c_pget(dbc, skey, pkey, data, flags);

        if ((t_ret = __db_c_close(dbc)) != 0 && ret == 0)
                ret = t_ret;

        return (ret);
}

/*
 * __db_pget_arg --
 *      Check DB->pget arguments.
 */
static int
__db_pget_arg(dbp, pkey, flags)
        DB *dbp;
        DBT *pkey;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        int ret;

        dbenv = dbp->dbenv;

        if (!F_ISSET(dbp, DB_AM_SECONDARY)) {
                __db_err(dbenv,
                    "DB->pget may only be used on secondary indices");
                return (EINVAL);
        }

        if (LF_ISSET(DB_MULTIPLE | DB_MULTIPLE_KEY)) {
                __db_err(dbenv,
        "DB_MULTIPLE and DB_MULTIPLE_KEY may not be used on secondary indices");
                return (EINVAL);
        }

        /* DB_CONSUME makes no sense on a secondary index. */
        LF_CLR(DB_READ_COMMITTED | DB_READ_UNCOMMITTED | DB_RMW);
        switch (flags) {
        case DB_CONSUME:
        case DB_CONSUME_WAIT:
                return (__db_ferr(dbenv, "DB->pget", 0));
        default:
                /* __db_get_arg will catch the rest. */
                break;
        }

        /*
         * We allow the pkey field to be NULL, so that we can make the
         * two-DBT get calls into wrappers for the three-DBT ones.
         */
        if (pkey != NULL &&
            (ret = __dbt_ferr(dbp, "primary key", pkey, 1)) != 0)
                return (ret);

        /* But the pkey field can't be NULL if we're doing a DB_GET_BOTH. */
        if (pkey == NULL && flags == DB_GET_BOTH) {
                __db_err(dbenv,
                    "DB_GET_BOTH on a secondary index requires a primary key");
                return (EINVAL);
        }

        return (0);
}

/*
 * __db_put_pp --
 *      DB->put pre/post processing.
 *
 * PUBLIC: int __db_put_pp __P((DB *, DB_TXN *, DBT *, DBT *, u_int32_t));
 */
int
__db_put_pp(dbp, txn, key, data, flags)
        DB *dbp;
        DB_TXN *txn;
        DBT *key, *data;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, txn_local, t_ret;

        dbenv = dbp->dbenv;
        txn_local = 0;

        PANIC_CHECK(dbenv);
        STRIP_AUTO_COMMIT(flags);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->put");

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check &&
            (ret = __db_rep_enter(dbp, 1, 0, txn != NULL)) != 0) {
                handle_check = 0;
                goto err;
        }

        if ((ret = __db_put_arg(dbp, key, data, flags)) != 0)
                goto err;

        /* Create local transaction as necessary. */
        if (IS_DB_AUTO_COMMIT(dbp, txn)) {
                if ((ret = __txn_begin(dbenv, NULL, &txn, 0)) != 0)
                        goto err;
                txn_local = 1;
        }

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, txn, DB_LOCK_INVALIDID, 0)) != 0)
                goto err;

        ret = __db_put(dbp, txn, key, data, flags);

err:    if (txn_local &&
            (t_ret = __db_txn_auto_resolve(dbenv, txn, 0, ret)) && ret == 0)
                ret = t_ret;

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_put_arg --
 *      Check DB->put arguments.
 */
static int
__db_put_arg(dbp, key, data, flags)
        DB *dbp;
        DBT *key, *data;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        int ret, returnkey;

        dbenv = dbp->dbenv;
        returnkey = 0;

        /* Check for changes to a read-only tree. */
        if (DB_IS_READONLY(dbp))
                return (__db_rdonly(dbenv, "DB->put"));

        /* Check for puts on a secondary. */
        if (F_ISSET(dbp, DB_AM_SECONDARY)) {
                __db_err(dbenv, "DB->put forbidden on secondary indices");
                return (EINVAL);
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
        case DB_NOOVERWRITE:
                break;
        case DB_APPEND:
                if (dbp->type != DB_RECNO && dbp->type != DB_QUEUE)
                        goto err;
                returnkey = 1;
                break;
        case DB_NODUPDATA:
                if (F_ISSET(dbp, DB_AM_DUPSORT))
                        break;
                /* FALLTHROUGH */
        default:
err:            return (__db_ferr(dbenv, "DB->put", 0));
        }

        /* Check for invalid key/data flags. */
        if ((ret = __dbt_ferr(dbp, "key", key, returnkey)) != 0)
                return (ret);
        if ((ret = __dbt_ferr(dbp, "data", data, 0)) != 0)
                return (ret);

        /* Keys shouldn't have partial flags during a put. */
        if (F_ISSET(key, DB_DBT_PARTIAL))
                return (__db_ferr(dbenv, "key DBT", 0));

        /* Check for partial puts in the presence of duplicates. */
        if (F_ISSET(data, DB_DBT_PARTIAL) &&
            (F_ISSET(dbp, DB_AM_DUP) || F_ISSET(key, DB_DBT_DUPOK))) {
                __db_err(dbenv,
"a partial put in the presence of duplicates requires a cursor operation");
                return (EINVAL);
        }

        return (0);
}

/*
 * __db_compact_pp --
 *      DB->compact pre/post processing.
 *
 * PUBLIC: int __db_compact_pp __P((DB *, DB_TXN *,
 * PUBLIC:       DBT *, DBT *, DB_COMPACT *, u_int32_t, DBT *));
 */
int
__db_compact_pp(dbp, txn, start, stop, c_data, flags, end)
        DB *dbp;
        DB_TXN *txn;
        DBT *start, *stop;
        DB_COMPACT *c_data;
        u_int32_t flags;
        DBT *end;
{
        DB_COMPACT *dp, l_data;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->compact");

        /*
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if ((flags & ~DB_COMPACT_FLAGS) != 0)
                return (__db_ferr(dbenv, "DB->compact", 0));

        /* Check for changes to a read-only database. */
        if (DB_IS_READONLY(dbp))
                return (__db_rdonly(dbenv, "DB->compact"));

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (ret = __db_rep_enter(dbp, 1, 0, 0)) != 0) {
                handle_check = 0;
                goto err;
        }

        if (c_data == NULL) {
                dp = &l_data;
                memset(dp, 0, sizeof(*dp));
        } else
                dp = c_data;

        switch (dbp->type) {
        case DB_HASH:
                if (!LF_ISSET(DB_FREELIST_ONLY))
                        goto err;
                /* FALLTHROUGH */
        case DB_BTREE:
        case DB_RECNO:
                ret = __bam_compact(dbp, txn, start, stop, dp, flags, end);
                break;

        default:
err:            ret = __dbh_am_chk(dbp, DB_OK_BTREE);
                break;
        }

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_sync_pp --
 *      DB->sync pre/post processing.
 *
 * PUBLIC: int __db_sync_pp __P((DB *, u_int32_t));
 */
int
__db_sync_pp(dbp, flags)
        DB *dbp;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);
        DB_ILLEGAL_BEFORE_OPEN(dbp, "DB->sync");

        /*
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if (flags != 0)
                return (__db_ferr(dbenv, "DB->sync", 0));

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (ret = __db_rep_enter(dbp, 1, 0, 0)) != 0) {
                handle_check = 0;
                goto err;
        }

        ret = __db_sync(dbp);

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

err:    ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_close_pp --
 *      DBC->c_close pre/post processing.
 *
 * PUBLIC: int __db_c_close_pp __P((DBC *));
 */
int
__db_c_close_pp(dbc)
        DBC *dbc;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        DB *dbp;
        int handle_check, ret, t_ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);
        ENV_ENTER(dbenv, ip);

        /*
         * If the cursor is already closed we have a serious problem, and we
         * assume that the cursor isn't on the active queue.  Don't do any of
         * the remaining cursor close processing.
         */
        if (!F_ISSET(dbc, DBC_ACTIVE)) {
                if (dbp != NULL)
                        __db_err(dbenv, "Closing already-closed cursor");
                DB_ASSERT(0);
                ret = EINVAL;
                goto err;
        }

        /* Check for replication block. */
        handle_check = dbc->txn == NULL && IS_ENV_REPLICATED(dbenv);
        ret = __db_c_close(dbc);

        /* Release replication block. */
        if (handle_check &&
            (t_ret = __op_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

err:    ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_count_pp --
 *      DBC->c_count pre/post processing.
 *
 * PUBLIC: int __db_c_count_pp __P((DBC *, db_recno_t *, u_int32_t));
 */
int
__db_c_count_pp(dbc, recnop, flags)
        DBC *dbc;
        db_recno_t *recnop;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        DB *dbp;
        int ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);

        /*
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         *
         * The cursor must be initialized, return EINVAL for an invalid cursor.
         */
        if (flags != 0)
                return (__db_ferr(dbenv, "DBcursor->count", 0));

        if (!IS_INITIALIZED(dbc))
                return (__db_curinval(dbenv));

        ENV_ENTER(dbenv, ip);

        ret = __db_c_count(dbc, recnop);
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_del_pp --
 *      DBC->c_del pre/post processing.
 *
 * PUBLIC: int __db_c_del_pp __P((DBC *, u_int32_t));
 */
int
__db_c_del_pp(dbc, flags)
        DBC *dbc;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);

        if ((ret = __db_c_del_arg(dbc, flags)) != 0)
                return (ret);

        ENV_ENTER(dbenv, ip);

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, dbc->txn, dbc->locker, 0)) != 0)
                goto err;

        DEBUG_LWRITE(dbc, dbc->txn, "DBcursor->del", NULL, NULL, flags);
        ret = __db_c_del(dbc, flags);
err:
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_del_arg --
 *      Check DBC->c_del arguments.
 */
static int
__db_c_del_arg(dbc, flags)
        DBC *dbc;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        /* Check for changes to a read-only tree. */
        if (DB_IS_READONLY(dbp))
                return (__db_rdonly(dbenv, "DBcursor->del"));

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        case DB_UPDATE_SECONDARY:
                DB_ASSERT(F_ISSET(dbp, DB_AM_SECONDARY));
                break;
        default:
                return (__db_ferr(dbenv, "DBcursor->del", 0));
        }

        /*
         * The cursor must be initialized, return EINVAL for an invalid cursor,
         * otherwise 0.
         */
        if (!IS_INITIALIZED(dbc))
                return (__db_curinval(dbenv));

        return (0);
}

/*
 * __db_c_dup_pp --
 *      DBC->c_dup pre/post processing.
 *
 * PUBLIC: int __db_c_dup_pp __P((DBC *, DBC **, u_int32_t));
 */
int
__db_c_dup_pp(dbc, dbcp, flags)
        DBC *dbc, **dbcp;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);

        /*
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if (flags != 0 && flags != DB_POSITION)
                return (__db_ferr(dbenv, "DBcursor->dup", 0));

        ENV_ENTER(dbenv, ip);

        ret = __db_c_dup(dbc, dbcp, flags);
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_get_pp --
 *      DBC->c_get pre/post processing.
 *
 * PUBLIC: int __db_c_get_pp __P((DBC *, DBT *, DBT *, u_int32_t));
 */
int
__db_c_get_pp(dbc, key, data, flags)
        DBC *dbc;
        DBT *key, *data;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        int ret;
        DB_THREAD_INFO *ip;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);

        if ((ret = __db_c_get_arg(dbc, key, data, flags)) != 0)
                return (ret);

        ENV_ENTER(dbenv, ip);

        DEBUG_LREAD(dbc, dbc->txn, "DBcursor->get",
            flags == DB_SET || flags == DB_SET_RANGE ? key : NULL, NULL, flags);
        ret = __db_c_get(dbc, key, data, flags);

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_get_arg --
 *      Common DBC->get argument checking, used by both DBC->get and DBC->pget.
 */
static int
__db_c_get_arg(dbc, key, data, flags)
        DBC *dbc;
        DBT *key, *data;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        int dirty, multi, ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        /*
         * Typically in checking routines that modify the flags, we have
         * to save them and restore them, because the checking routine
         * calls the work routine.  However, this is a pure-checking
         * routine which returns to a function that calls the work routine,
         * so it's OK that we do not save and restore the flags, even though
         * we modify them.
         *
         * Check for read-modify-write validity.  DB_RMW doesn't make sense
         * with CDB cursors since if you're going to write the cursor, you
         * had to create it with DB_WRITECURSOR.  Regardless, we check for
         * LOCKING_ON and not STD_LOCKING, as we don't want to disallow it.
         * If this changes, confirm that DB does not itself set the DB_RMW
         * flag in a path where CDB may have been configured.
         */
        dirty = 0;
        if (LF_ISSET(DB_READ_UNCOMMITTED | DB_RMW)) {
                if (!LOCKING_ON(dbenv))
                        return (__db_fnl(dbenv, "DBcursor->get"));
                if (LF_ISSET(DB_READ_UNCOMMITTED))
                        dirty = 1;
                LF_CLR(DB_READ_UNCOMMITTED | DB_RMW);
        }

        multi = 0;
        if (LF_ISSET(DB_MULTIPLE | DB_MULTIPLE_KEY)) {
                multi = 1;
                if (LF_ISSET(DB_MULTIPLE) && LF_ISSET(DB_MULTIPLE_KEY))
                        goto multi_err;
                LF_CLR(DB_MULTIPLE | DB_MULTIPLE_KEY);
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case DB_CONSUME:
        case DB_CONSUME_WAIT:
                if (dirty) {
                        __db_err(dbenv,
    "DB_READ_UNCOMMITTED is not supported with DB_CONSUME or DB_CONSUME_WAIT");
                        return (EINVAL);
                }
                if (dbp->type != DB_QUEUE)
                        goto err;
                break;
        case DB_CURRENT:
        case DB_FIRST:
        case DB_GET_BOTH:
        case DB_GET_BOTH_RANGE:
        case DB_NEXT:
        case DB_NEXT_DUP:
        case DB_NEXT_NODUP:
        case DB_SET:
        case DB_SET_RANGE:
                break;
        case DB_LAST:
        case DB_PREV:
        case DB_PREV_NODUP:
                if (multi)
multi_err:              return (__db_ferr(dbenv, "DBcursor->get", 1));
                break;
        case DB_GET_BOTHC:
                if (dbp->type == DB_QUEUE)
                        goto err;
                break;
        case DB_GET_RECNO:
                /*
                 * The one situation in which this might be legal with a
                 * non-RECNUM dbp is if dbp is a secondary and its primary is
                 * DB_AM_RECNUM.
                 */
                if (!F_ISSET(dbp, DB_AM_RECNUM) &&
                    (!F_ISSET(dbp, DB_AM_SECONDARY) ||
                    !F_ISSET(dbp->s_primary, DB_AM_RECNUM)))
                        goto err;
                break;
        case DB_SET_RECNO:
                if (!F_ISSET(dbp, DB_AM_RECNUM))
                        goto err;
                break;
        default:
err:            return (__db_ferr(dbenv, "DBcursor->get", 0));
        }

        /* Check for invalid key/data flags. */
        if ((ret = __dbt_ferr(dbp, "key", key, 0)) != 0)
                return (ret);
        if ((ret = __dbt_ferr(dbp, "data", data, 0)) != 0)
                return (ret);

        if (multi) {
                if (!F_ISSET(data, DB_DBT_USERMEM)) {
                        __db_err(dbenv,
            "DB_MULTIPLE/DB_MULTIPLE_KEY require DB_DBT_USERMEM be set");
                        return (EINVAL);
                }
                if (F_ISSET(key, DB_DBT_PARTIAL) ||
                    F_ISSET(data, DB_DBT_PARTIAL)) {
                        __db_err(dbenv,
            "DB_MULTIPLE/DB_MULTIPLE_KEY do not support DB_DBT_PARTIAL");
                        return (EINVAL);
                }
                if (data->ulen < 1024 ||
                    data->ulen < dbp->pgsize || data->ulen % 1024 != 0) {
                        __db_err(dbenv, "%s%s",
                            "DB_MULTIPLE/DB_MULTIPLE_KEY buffers must be ",
                            "aligned, at least page size and multiples of 1KB");
                        return (EINVAL);
                }
        }

        /*
         * The cursor must be initialized for DB_CURRENT, DB_GET_RECNO and
         * DB_NEXT_DUP.  Return EINVAL for an invalid cursor, otherwise 0.
         */
        if (!IS_INITIALIZED(dbc) && (flags == DB_CURRENT ||
            flags == DB_GET_RECNO || flags == DB_NEXT_DUP))
                return (__db_curinval(dbenv));

        /* Check for consistent transaction usage. */
        if (LF_ISSET(DB_RMW) &&
            (ret = __db_check_txn(dbp, dbc->txn, dbc->locker, 0)) != 0)
                return (ret);

        return (0);
}

/*
 * __db_secondary_close_pp --
 *      DB->close for secondaries
 *
 * PUBLIC: int __db_secondary_close_pp __P((DB *, u_int32_t));
 */
int
__db_secondary_close_pp(dbp, flags)
        DB *dbp;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;
        ret = 0;

        PANIC_CHECK(dbenv);

        /*
         * As a DB handle destructor, we can't fail.
         *
         * !!!
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if (flags != 0 && flags != DB_NOSYNC)
                ret = __db_ferr(dbenv, "DB->close", 0);

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (t_ret = __db_rep_enter(dbp, 0, 0, 0)) != 0) {
                handle_check = 0;
                if (ret == 0)
                        ret = t_ret;
        }

        if ((t_ret = __db_secondary_close(dbp, flags)) != 0 && ret == 0)
                ret = t_ret;

        /* Release replication block. */
        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_pget_pp --
 *      DBC->c_pget pre/post processing.
 *
 * PUBLIC: int __db_c_pget_pp __P((DBC *, DBT *, DBT *, DBT *, u_int32_t));
 */
int
__db_c_pget_pp(dbc, skey, pkey, data, flags)
        DBC *dbc;
        DBT *skey, *pkey, *data;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);

        if ((ret = __db_c_pget_arg(dbc, pkey, flags)) != 0 ||
            (ret = __db_c_get_arg(dbc, skey, data, flags)) != 0)
                return (ret);

        ENV_ENTER(dbenv, ip);

        ret = __db_c_pget(dbc, skey, pkey, data, flags);

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_pget_arg --
 *      Check DBC->pget arguments.
 */
static int
__db_c_pget_arg(dbc, pkey, flags)
        DBC *dbc;
        DBT *pkey;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        int ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        if (!F_ISSET(dbp, DB_AM_SECONDARY)) {
                __db_err(dbenv,
                    "DBcursor->pget may only be used on secondary indices");
                return (EINVAL);
        }

        if (LF_ISSET(DB_MULTIPLE | DB_MULTIPLE_KEY)) {
                __db_err(dbenv,
        "DB_MULTIPLE and DB_MULTIPLE_KEY may not be used on secondary indices");
                return (EINVAL);
        }

        switch (LF_ISSET(~DB_RMW)) {
        case DB_CONSUME:
        case DB_CONSUME_WAIT:
                /* These flags make no sense on a secondary index. */
                return (__db_ferr(dbenv, "DBcursor->pget", 0));
        case DB_GET_BOTH:
                /* DB_GET_BOTH is "get both the primary and the secondary". */
                if (pkey == NULL) {
                        __db_err(dbenv,
                    "DB_GET_BOTH requires both a secondary and a primary key");
                        return (EINVAL);
                }
                break;
        default:
                /* __db_c_get_arg will catch the rest. */
                break;
        }

        /*
         * We allow the pkey field to be NULL, so that we can make the
         * two-DBT get calls into wrappers for the three-DBT ones.
         */
        if (pkey != NULL &&
            (ret = __dbt_ferr(dbp, "primary key", pkey, 0)) != 0)
                return (ret);

        /* But the pkey field can't be NULL if we're doing a DB_GET_BOTH. */
        if (pkey == NULL && (flags & DB_OPFLAGS_MASK) == DB_GET_BOTH) {
                __db_err(dbenv,
                    "DB_GET_BOTH on a secondary index requires a primary key");
                return (EINVAL);
        }
        return (0);
}

/*
 * __db_c_put_pp --
 *      DBC->put pre/post processing.
 *
 * PUBLIC: int __db_c_put_pp __P((DBC *, DBT *, DBT *, u_int32_t));
 */
int
__db_c_put_pp(dbc, key, data, flags)
        DBC *dbc;
        DBT *key, *data;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;

        PANIC_CHECK(dbenv);

        if ((ret = __db_c_put_arg(dbc, key, data, flags)) != 0)
                return (ret);

        ENV_ENTER(dbenv, ip);

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, dbc->txn, dbc->locker, 0)) != 0)
                goto err;

        DEBUG_LWRITE(dbc, dbc->txn, "DBcursor->put",
            flags == DB_KEYFIRST || flags == DB_KEYLAST ||
            flags == DB_NODUPDATA || flags == DB_UPDATE_SECONDARY ?
            key : NULL, data, flags);
        ret =__db_c_put(dbc, key, data, flags);
err:
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_c_put_arg --
 *      Check DBC->put arguments.
 */
static int
__db_c_put_arg(dbc, key, data, flags)
        DBC *dbc;
        DBT *key, *data;
        u_int32_t flags;
{
        DB *dbp;
        DB_ENV *dbenv;
        int key_flags, ret;

        dbp = dbc->dbp;
        dbenv = dbp->dbenv;
        key_flags = 0;

        /* Check for changes to a read-only tree. */
        if (DB_IS_READONLY(dbp))
                return (__db_rdonly(dbenv, "DBcursor->put"));

        /* Check for puts on a secondary. */
        if (F_ISSET(dbp, DB_AM_SECONDARY)) {
                if (flags == DB_UPDATE_SECONDARY)
                        flags = DB_KEYLAST;
                else {
                        __db_err(dbenv,
                    "DBcursor->put forbidden on secondary indices");
                        return (EINVAL);
                }
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case DB_AFTER:
        case DB_BEFORE:
                switch (dbp->type) {
                case DB_BTREE:
                case DB_HASH:           /* Only with unsorted duplicates. */
                        if (!F_ISSET(dbp, DB_AM_DUP))
                                goto err;
                        if (dbp->dup_compare != NULL)
                                goto err;
                        break;
                case DB_QUEUE:          /* Not permitted. */
                        goto err;
                case DB_RECNO:          /* Only with mutable record numbers. */
                        if (!F_ISSET(dbp, DB_AM_RENUMBER))
                                goto err;
                        key_flags = 1;
                        break;
                case DB_UNKNOWN:
                default:
                        goto err;
                }
                break;
        case DB_CURRENT:
                /*
                 * If there is a comparison function, doing a DB_CURRENT
                 * must not change the part of the data item that is used
                 * for the comparison.
                 */
                break;
        case DB_NODUPDATA:
                if (!F_ISSET(dbp, DB_AM_DUPSORT))
                        goto err;
                /* FALLTHROUGH */
        case DB_KEYFIRST:
        case DB_KEYLAST:
                key_flags = 1;
                break;
        default:
err:            return (__db_ferr(dbenv, "DBcursor->put", 0));
        }

        /* Check for invalid key/data flags. */
        if (key_flags && (ret = __dbt_ferr(dbp, "key", key, 0)) != 0)
                return (ret);
        if ((ret = __dbt_ferr(dbp, "data", data, 0)) != 0)
                return (ret);

        /* Keys shouldn't have partial flags during a put. */
        if (F_ISSET(key, DB_DBT_PARTIAL))
                return (__db_ferr(dbenv, "key DBT", 0));

        /*
         * The cursor must be initialized for anything other than DB_KEYFIRST
         * and DB_KEYLAST, return EINVAL for an invalid cursor, otherwise 0.
         */
        if (!IS_INITIALIZED(dbc) && flags != DB_KEYFIRST &&
            flags != DB_KEYLAST && flags != DB_NODUPDATA)
                return (__db_curinval(dbenv));

        return (0);
}

/*
 * __dbt_ferr --
 *      Check a DBT for flag errors.
 */
static int
__dbt_ferr(dbp, name, dbt, check_thread)
        const DB *dbp;
        const char *name;
        const DBT *dbt;
        int check_thread;
{
        DB_ENV *dbenv;
        int ret;

        dbenv = dbp->dbenv;

        /*
         * Check for invalid DBT flags.  We allow any of the flags to be
         * specified to any DB or DBcursor call so that applications can
         * set DB_DBT_MALLOC when retrieving a data item from a secondary
         * database and then specify that same DBT as a key to a primary
         * database, without having to clear flags.
         */
        if ((ret = __db_fchk(dbenv, name, dbt->flags, DB_DBT_APPMALLOC |
            DB_DBT_MALLOC | DB_DBT_DUPOK | DB_DBT_REALLOC | DB_DBT_USERMEM |
            DB_DBT_PARTIAL)) != 0)
                return (ret);
        switch (F_ISSET(dbt, DB_DBT_MALLOC | DB_DBT_REALLOC | DB_DBT_USERMEM)) {
        case 0:
        case DB_DBT_MALLOC:
        case DB_DBT_REALLOC:
        case DB_DBT_USERMEM:
                break;
        default:
                return (__db_ferr(dbenv, name, 1));
        }

        if (check_thread && DB_IS_THREADED(dbp) &&
            !F_ISSET(dbt, DB_DBT_MALLOC | DB_DBT_REALLOC | DB_DBT_USERMEM)) {
                __db_err(dbenv,
                    "DB_THREAD mandates memory allocation flag on DBT %s",
                    name);
                return (EINVAL);
        }
        return (0);
}

/*
 * __db_curinval
 *      Report that a cursor is in an invalid state.
 */
static int
__db_curinval(dbenv)
        const DB_ENV *dbenv;
{
        __db_err(dbenv,
            "Cursor position must be set before performing this operation");
        return (EINVAL);
}

/*
 * __db_txn_auto_init --
 *      Handle DB_AUTO_COMMIT initialization.
 *
 * PUBLIC: int __db_txn_auto_init __P((DB_ENV *, DB_TXN **));
 */
int
__db_txn_auto_init(dbenv, txnidp)
        DB_ENV *dbenv;
        DB_TXN **txnidp;
{
        /*
         * Method calls where applications explicitly specify DB_AUTO_COMMIT
         * require additional validation: the DB_AUTO_COMMIT flag cannot be
         * specified if a transaction cookie is also specified, nor can the
         * flag be specified in a non-transactional environment.
         */
        if (*txnidp != NULL) {
                __db_err(dbenv,
    "DB_AUTO_COMMIT may not be specified along with a transaction handle");
                return (EINVAL);
        }

        if (!TXN_ON(dbenv)) {
                __db_err(dbenv,
    "DB_AUTO_COMMIT may not be specified in non-transactional environment");
                return (EINVAL);
        }

        /*
         * Our caller checked to see if replication is making a state change.
         * Don't call the user-level API (which would repeat that check).
         */
        return (__txn_begin(dbenv, NULL, txnidp, 0));
}

/*
 * __db_txn_auto_resolve --
 *      Resolve local transactions.
 *
 * PUBLIC: int __db_txn_auto_resolve __P((DB_ENV *, DB_TXN *, int, int));
 */
int
__db_txn_auto_resolve(dbenv, txn, nosync, ret)
        DB_ENV *dbenv;
        DB_TXN *txn;
        int nosync, ret;
{
        int t_ret;

        /*
         * We're resolving a transaction for the user, and must decrement the
         * replication handle count.  Call the user-level API.
         */
        if (ret == 0)
                return (__txn_commit(txn, nosync ? DB_TXN_NOSYNC : 0));

        if ((t_ret = __txn_abort(txn)) != 0)
                return (__db_panic(dbenv, t_ret));

        return (ret);
}

---