db_iface.c

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/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998, 1999, 2000
 *      Sleepycat Software.  All rights reserved.
 */

#include "config.h"

#ifndef lint
static const char revid[] = "$Id: db__iface_8c-source.html,v 1.1 2008/06/08 10:17:40 sebdiaz Exp $";
#endif /* not lint */

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

#include <errno.h>
#endif

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

static int __db_curinval __P((const DB_ENV *));
static int __db_rdonly __P((const DB_ENV *, const char *));
static int __dbt_ferr __P((const DB *, const char *, const DBT *, int));

/*
 * CDB___db_cursorchk --
 *      Common cursor argument checking routine.
 *
 * PUBLIC: int CDB___db_cursorchk __P((const DB *, u_int32_t, int));
 */
int
CDB___db_cursorchk(dbp, flags, isrdonly)
        const DB *dbp;
        u_int32_t flags;
        int isrdonly;
{
        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        case DB_WRITECURSOR:
                if (isrdonly)
                        return (__db_rdonly(dbp->dbenv, "DB->cursor"));
                if (!LOCKING(dbp->dbenv))
                        return (CDB___db_ferr(dbp->dbenv, "DB->cursor", 0));
                break;
        case DB_WRITELOCK:
                if (isrdonly)
                        return (__db_rdonly(dbp->dbenv, "DB->cursor"));
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DB->cursor", 0));
        }

        return (0);
}

/*
 * CDB___db_ccountchk --
 *      Common cursor count argument checking routine.
 *
 * PUBLIC: int CDB___db_ccountchk __P((const DB *, u_int32_t, int));
 */
int
CDB___db_ccountchk(dbp, flags, isvalid)
        const DB *dbp;
        u_int32_t flags;
        int isvalid;
{
        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DBcursor->c_count", 0));
        }

        /*
         * The cursor must be initialized, return EINVAL for an invalid cursor,
         * otherwise 0.
         */
        return (isvalid ? 0 : __db_curinval(dbp->dbenv));
}

/*
 * CDB___db_cdelchk --
 *      Common cursor delete argument checking routine.
 *
 * PUBLIC: int CDB___db_cdelchk __P((const DB *, u_int32_t, int, int));
 */
int
CDB___db_cdelchk(dbp, flags, isrdonly, isvalid)
        const DB *dbp;
        u_int32_t flags;
        int isrdonly, isvalid;
{
        /* Check for changes to a read-only tree. */
        if (isrdonly)
                return (__db_rdonly(dbp->dbenv, "c_del"));

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DBcursor->c_del", 0));
        }

        /*
         * The cursor must be initialized, return EINVAL for an invalid cursor,
         * otherwise 0.
         */
        return (isvalid ? 0 : __db_curinval(dbp->dbenv));
}

/*
 * CDB___db_cgetchk --
 *      Common cursor get argument checking routine.
 *
 * PUBLIC: int CDB___db_cgetchk __P((const DB *, DBT *, DBT *, u_int32_t, int));
 */
int
CDB___db_cgetchk(dbp, key, data, flags, isvalid)
        const DB *dbp;
        DBT *key, *data;
        u_int32_t flags;
        int isvalid;
{
        int key_einval, ret;

        key_einval = 0;

        /*
         * 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.
         */
        if (LF_ISSET(DB_RMW)) {
                if (!LOCKING_ON(dbp->dbenv)) {
                        CDB___db_err(dbp->dbenv,
                            "the DB_RMW flag requires locking");
                        return (EINVAL);
                }
                LF_CLR(DB_RMW);
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case DB_CONSUME:
                if (dbp->type != DB_QUEUE)
                        goto err;
                break;
        case DB_CURRENT:
        case DB_FIRST:
        case DB_LAST:
        case DB_NEXT:
        case DB_NEXT_DUP:
        case DB_NEXT_NODUP:
        case DB_PREV:
        case DB_PREV_NODUP:
                break;
        case DB_GET_BOTHC:
                if (dbp->type == DB_QUEUE)
                        goto err;
                /* FALLTHROUGH */
        case DB_GET_BOTH:
        case DB_SET:
        case DB_SET_RANGE:
                key_einval = 1;
                break;
        case DB_GET_RECNO:
                if (!F_ISSET(dbp, DB_BT_RECNUM))
                        goto err;
                break;
        case DB_SET_RECNO:
                if (!F_ISSET(dbp, DB_BT_RECNUM))
                        goto err;
                key_einval = 1;
                break;
        default:
err:            return (CDB___db_ferr(dbp->dbenv, "DBcursor->c_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);

        /*
         * The cursor must be initialized for DB_CURRENT or DB_NEXT_DUP,
         * return EINVAL for an invalid cursor, otherwise 0.
         */
        if (isvalid || (flags != DB_CURRENT && flags != DB_NEXT_DUP))
                return (0);

        return(__db_curinval(dbp->dbenv));
}

/*
 * CDB___db_cputchk --
 *      Common cursor put argument checking routine.
 *
 * PUBLIC: int CDB___db_cputchk __P((const DB *,
 * PUBLIC:    const DBT *, DBT *, u_int32_t, int, int));
 */
int
CDB___db_cputchk(dbp, key, data, flags, isrdonly, isvalid)
        const DB *dbp;
        const DBT *key;
        DBT *data;
        u_int32_t flags;
        int isrdonly, isvalid;
{
        int key_einval, key_flags, ret;

        key_einval = key_flags = 0;

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

        /* 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_RE_RENUMBER))
                                goto err;
                        key_flags = 1;
                        break;
                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:
                if (dbp->type == DB_QUEUE || dbp->type == DB_RECNO)
                        goto err;
                key_einval = key_flags = 1;
                break;
        default:
err:            return (CDB___db_ferr(dbp->dbenv, "DBcursor->c_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);

        /*
         * The cursor must be initialized for anything other than DB_KEYFIRST
         * and DB_KEYLAST, return EINVAL for an invalid cursor, otherwise 0.
         */
        if (isvalid || flags == DB_KEYFIRST ||
            flags == DB_KEYLAST || flags == DB_NODUPDATA)
                return (0);

        return (__db_curinval(dbp->dbenv));
}

/*
 * CDB___db_closechk --
 *      DB->close flag check.
 *
 * PUBLIC: int CDB___db_closechk __P((const DB *, u_int32_t));
 */
int
CDB___db_closechk(dbp, flags)
        const DB *dbp;
        u_int32_t flags;
{
        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
        case DB_NOSYNC:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DB->close", 0));
        }

        return (0);
}

/*
 * CDB___db_delchk --
 *      Common delete argument checking routine.
 *
 * PUBLIC: int CDB___db_delchk __P((const DB *, DBT *, u_int32_t, int));
 */
int
CDB___db_delchk(dbp, key, flags, isrdonly)
        const DB *dbp;
        DBT *key;
        u_int32_t flags;
        int isrdonly;
{
        COMPQUIET(key, NULL);

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

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

        return (0);
}

/*
 * CDB___db_getchk --
 *      Common get argument checking routine.
 *
 * PUBLIC: int CDB___db_getchk __P((const DB *, const DBT *, DBT *, u_int32_t));
 */
int
CDB___db_getchk(dbp, key, data, flags)
        const DB *dbp;
        const DBT *key;
        DBT *data;
        u_int32_t flags;
{
        int ret;

        /*
         * 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.
         */
        if (LF_ISSET(DB_RMW)) {
                if (!LOCKING_ON(dbp->dbenv)) {
                        CDB___db_err(dbp->dbenv,
                            "the DB_RMW flag requires locking");
                        return (EINVAL);
                }
                LF_CLR(DB_RMW);
        }

        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
        case DB_GET_BOTH:
                break;
        case DB_SET_RECNO:
                if (!F_ISSET(dbp, DB_BT_RECNUM))
                        goto err;
                break;
        default:
err:            return (CDB___db_ferr(dbp->dbenv, "DB->get", 0));
        }

        /* Check for invalid key/data flags. */
        if ((ret = __dbt_ferr(dbp, "key", key, flags == DB_SET_RECNO)) != 0)
                return (ret);
        if ((ret = __dbt_ferr(dbp, "data", data, 1)) != 0)
                return (ret);

        return (0);
}

/*
 * CDB___db_joinchk --
 *      Common join argument checking routine.
 *
 * PUBLIC: int CDB___db_joinchk __P((const DB *, u_int32_t));
 */
int
CDB___db_joinchk(dbp, flags)
        const DB *dbp;
        u_int32_t flags;
{
        switch (flags) {
        case 0:
        case DB_JOIN_NOSORT:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DB->join", 0));
        }

        return (0);
}

/*
 * CDB___db_joingetchk --
 *      Common join_get argument checking routine.
 *
 * PUBLIC: int CDB___db_joingetchk __P((const DB *, DBT *, u_int32_t));
 */
int
CDB___db_joingetchk(dbp, key, flags)
        const DB *dbp;
        DBT *key;
        u_int32_t flags;
{

        if (LF_ISSET(DB_RMW)) {
                if (!LOCKING_ON(dbp->dbenv)) {
                        CDB___db_err(dbp->dbenv,
                            "the DB_RMW flag requires locking");
                        return (EINVAL);
                }
                LF_CLR(DB_RMW);
        }

        switch (flags) {
        case 0:
        case DB_JOIN_ITEM:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DBcursor->c_get", 0));
        }

        /*
         * A partial get of the key of a join cursor don't make much sense;
         * the entire key is necessary to query the primary database
         * and find the datum, and so regardless of the size of the key
         * it would not be a performance improvement.  Since it would require
         * special handling, we simply disallow it.
         *
         * A partial get of the data, however, potentially makes sense (if
         * all possible data are a predictable large structure, for instance)
         * and causes us no headaches, so we permit it.
         */
        if (F_ISSET(key, DB_DBT_PARTIAL)) {
                CDB___db_err(dbp->dbenv,
                    "DB_DBT_PARTIAL may not be set on key during join_get");
                return (EINVAL);
        }

        return (0);
}

/*
 * CDB___db_putchk --
 *      Common put argument checking routine.
 *
 * PUBLIC: int CDB___db_putchk
 * PUBLIC:    __P((const DB *, DBT *, const DBT *, u_int32_t, int, int));
 */
int
CDB___db_putchk(dbp, key, data, flags, isrdonly, isdup)
        const DB *dbp;
        DBT *key;
        const DBT *data;
        u_int32_t flags;
        int isrdonly, isdup;
{
        int key_einval, key_flags, ret;

        key_einval = key_flags = 0;

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

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

        /* Check for partial puts in the presence of duplicates. */
        if (isdup && F_ISSET(data, DB_DBT_PARTIAL)) {
                CDB___db_err(dbp->dbenv,
"a partial put in the presence of duplicates requires a cursor operation");
                return (EINVAL);
        }

        return (0);
}

/*
 * CDB___db_removechk --
 *      DB->remove flag check.
 *
 * PUBLIC: int CDB___db_removechk __P((const DB *, u_int32_t));
 */
int
CDB___db_removechk(dbp, flags)
        const DB *dbp;
        u_int32_t flags;
{
        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DB->remove", 0));
        }

        return (0);
}

/*
 * CDB___db_statchk --
 *      Common stat argument checking routine.
 *
 * PUBLIC: int CDB___db_statchk __P((const DB *, u_int32_t));
 */
int
CDB___db_statchk(dbp, flags)
        const DB *dbp;
        u_int32_t flags;
{
        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
        case DB_CACHED_COUNTS:
                break;
        case DB_RECORDCOUNT:
                if (dbp->type == DB_RECNO)
                        break;
                if (dbp->type == DB_BTREE && F_ISSET(dbp, DB_BT_RECNUM))
                        break;
                goto err;
        default:
err:            return (CDB___db_ferr(dbp->dbenv, "DB->stat", 0));
        }

        return (0);
}

/*
 * CDB___db_syncchk --
 *      Common sync argument checking routine.
 *
 * PUBLIC: int CDB___db_syncchk __P((const DB *, u_int32_t));
 */
int
CDB___db_syncchk(dbp, flags)
        const DB *dbp;
        u_int32_t flags;
{
        /* Check for invalid function flags. */
        switch (flags) {
        case 0:
                break;
        default:
                return (CDB___db_ferr(dbp->dbenv, "DB->sync", 0));
        }

        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 = CDB___db_fchk(dbenv, name, dbt->flags,
            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 (CDB___db_ferr(dbenv, name, 1));
        }

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

/*
 * __db_rdonly --
 *      Common readonly message.
 */
static int
__db_rdonly(dbenv, name)
        const DB_ENV *dbenv;
        const char *name;
{
        CDB___db_err(dbenv, "%s: attempt to modify a read-only tree", name);
        return (EACCES);
}

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

---