where.c

winNT技术操作系统,国外开放的原代码和LIUX一样

                value = 0;
            else
            {
                r = msi_string2idW(wv->db->strings, val_cond->u.sval, &value);
                if (r != ERROR_SUCCESS)
                {
                    TRACE("no id for %s, assuming it doesn't exist in the table\n", debugstr_w(wv->cond->u.expr.right->u.sval));
                    return ERROR_SUCCESS;
                }
            }

            do
            {
                r = table->ops->find_matching_rows(table, col, value, &row, &handle);
                if (r == ERROR_SUCCESS)
                    wv->reorder[ wv->row_count ++ ] = row;
            } while (r == ERROR_SUCCESS);

            if (r == ERROR_NO_MORE_ITEMS)
                return ERROR_SUCCESS;
            else
                return r;
        }
        /* else fallback to slow case */
    }

    for( i=0; i<count; i++ )
    {
        val = 0;
        r = WHERE_evaluate( wv->db, table, i, wv->cond, &val, record );
        if( r != ERROR_SUCCESS )
            return r;
        if( val )
            wv->reorder[ wv->row_count ++ ] = i;
    }

    return ERROR_SUCCESS;
}

static UINT WHERE_close( struct tagMSIVIEW *view )
{
    MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;

    TRACE("%p\n", wv );

    if( !wv->table )
         return ERROR_FUNCTION_FAILED;

    msi_free( wv->reorder );
    wv->reorder = NULL;

    return wv->table->ops->close( wv->table );
}

static UINT WHERE_get_dimensions( struct tagMSIVIEW *view, UINT *rows, UINT *cols )
{
    MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;

    TRACE("%p %p %p\n", wv, rows, cols );

    if( !wv->table )
         return ERROR_FUNCTION_FAILED;

    if( rows )
    {
        if( !wv->reorder )
            return ERROR_FUNCTION_FAILED;
        *rows = wv->row_count;
    }

    return wv->table->ops->get_dimensions( wv->table, NULL, cols );
}

static UINT WHERE_get_column_info( struct tagMSIVIEW *view,
                UINT n, LPWSTR *name, UINT *type )
{
    MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;

    TRACE("%p %d %p %p\n", wv, n, name, type );

    if( !wv->table )
         return ERROR_FUNCTION_FAILED;

    return wv->table->ops->get_column_info( wv->table, n, name, type );
}

static UINT WHERE_modify( struct tagMSIVIEW *view, MSIMODIFY eModifyMode,
                MSIRECORD *rec )
{
    MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;

    TRACE("%p %d %p\n", wv, eModifyMode, rec );

    if( !wv->table )
         return ERROR_FUNCTION_FAILED;

    return wv->table->ops->modify( wv->table, eModifyMode, rec );
}

static UINT WHERE_delete( struct tagMSIVIEW *view )
{
    MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;

    TRACE("%p\n", wv );

    if( wv->table )
        wv->table->ops->delete( wv->table );
    wv->table = 0;

    msi_free( wv->reorder );
    wv->reorder = NULL;
    wv->row_count = 0;

    msiobj_release( &wv->db->hdr );
    msi_free( wv );

    return ERROR_SUCCESS;
}

static UINT WHERE_find_matching_rows( struct tagMSIVIEW *view, UINT col,
    UINT val, UINT *row, MSIITERHANDLE *handle )
{
    MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
    UINT r;

    TRACE("%p, %d, %u, %p\n", view, col, val, *handle);

    if( !wv->table )
         return ERROR_FUNCTION_FAILED;

    r = wv->table->ops->find_matching_rows( wv->table, col, val, row, handle );

    if( *row > wv->row_count )
        return ERROR_NO_MORE_ITEMS;

    *row = wv->reorder[ *row ];

    return r;
}


static const MSIVIEWOPS where_ops =
{
    WHERE_fetch_int,
    WHERE_fetch_stream,
    WHERE_set_row,
    NULL,
    WHERE_execute,
    WHERE_close,
    WHERE_get_dimensions,
    WHERE_get_column_info,
    WHERE_modify,
    WHERE_delete,
    WHERE_find_matching_rows
};

static UINT WHERE_VerifyCondition( MSIDATABASE *db, MSIVIEW *table, struct expr *cond,
                                   UINT *valid )
{
    UINT r, val = 0;

    switch( cond->type )
    {
    case EXPR_COLUMN:
        r = VIEW_find_column( table, cond->u.column, &val );
        if( r == ERROR_SUCCESS )
        {
            UINT type = 0;
            r = table->ops->get_column_info( table, val, NULL, &type );
            if( r == ERROR_SUCCESS )
            {
                if (type&MSITYPE_STRING)
                    cond->type = EXPR_COL_NUMBER_STRING;
                else if ((type&0xff) == 4)
                    cond->type = EXPR_COL_NUMBER32;
                else
                    cond->type = EXPR_COL_NUMBER;
                cond->u.col_number = val;
                *valid = 1;
            }
            else
                *valid = 0;
        }
        else
        {
            *valid = 0;
            ERR("Couldn't find column %s\n", debugstr_w( cond->u.column ) );
        }
        break;
    case EXPR_COMPLEX:
        r = WHERE_VerifyCondition( db, table, cond->u.expr.left, valid );
        if( r != ERROR_SUCCESS )
            return r;
        if( !*valid )
            return ERROR_SUCCESS;
        r = WHERE_VerifyCondition( db, table, cond->u.expr.right, valid );
        if( r != ERROR_SUCCESS )
            return r;

        /* check the type of the comparison */
        if( ( cond->u.expr.left->type == EXPR_SVAL ) ||
            ( cond->u.expr.left->type == EXPR_COL_NUMBER_STRING ) ||
            ( cond->u.expr.right->type == EXPR_SVAL ) ||
            ( cond->u.expr.right->type == EXPR_COL_NUMBER_STRING ) )
        {
            switch( cond->u.expr.op )
            {
            case OP_EQ:
            case OP_GT:
            case OP_LT:
                break;
            default:
                *valid = FALSE;
                return ERROR_INVALID_PARAMETER;
            }

            /* FIXME: check we're comparing a string to a column */

            cond->type = EXPR_STRCMP;
        }

        break;
    case EXPR_UNARY:
        if ( cond->u.expr.left->type != EXPR_COLUMN )
        {
            *valid = FALSE;
            return ERROR_INVALID_PARAMETER;
        }
        r = WHERE_VerifyCondition( db, table, cond->u.expr.left, valid );
        if( r != ERROR_SUCCESS )
            return r;
        break;
    case EXPR_IVAL:
        *valid = 1;
        cond->type = EXPR_UVAL;
        cond->u.uval = cond->u.ival;
        break;
    case EXPR_WILDCARD:
        *valid = 1;
        break;
    case EXPR_SVAL:
        *valid = 1;
        break;
    default:
        ERR("Invalid expression type\n");
        *valid = 0;
        break;
    }

    return ERROR_SUCCESS;
}

UINT WHERE_CreateView( MSIDATABASE *db, MSIVIEW **view, MSIVIEW *table,
                       struct expr *cond )
{
    MSIWHEREVIEW *wv = NULL;
    UINT count = 0, r, valid = 0;

    TRACE("%p\n", table );

    r = table->ops->get_dimensions( table, NULL, &count );
    if( r != ERROR_SUCCESS )
    {
        ERR("can't get table dimensions\n");
        return r;
    }

    if( cond )
    {
        r = WHERE_VerifyCondition( db, table, cond, &valid );
        if( r != ERROR_SUCCESS )
            return r;
        if( !valid )
            return ERROR_FUNCTION_FAILED;
    }

    wv = msi_alloc_zero( sizeof *wv );
    if( !wv )
        return ERROR_FUNCTION_FAILED;
    
    /* fill the structure */
    wv->view.ops = &where_ops;
    msiobj_addref( &db->hdr );
    wv->db = db;
    wv->table = table;
    wv->row_count = 0;
    wv->reorder = NULL;
    wv->cond = cond;
    *view = (MSIVIEW*) wv;

    return ERROR_SUCCESS;
}