Package com.mckoi.database

Class GTDataSource

    • Field Detail

      • system

        private TransactionSystem system
        The TransactionSystem object for this table.

    • Constructor Detail

    • Method Detail

      • columnValue

        protected TObject columnValue​(int column,
                              java.lang.Object ob)
        Returns a TObject that represents a value for the given column in this table. The Object must be of a compatible class to store in the type of the column defined.

      • getDataTableDef

        public abstract DataTableDef getDataTableDef()
        Description copied from interface: TableDataSource
        Returns a DataTableDef object that defines the layout of the table that this data is in.

        This may return 'null' if there is no table definition.

        Specified by:
        getDataTableDef in interface TableDataSource

      • getRowCount

        public abstract int getRowCount()
        Description copied from interface: TableDataSource
        Returns the number of rows in this data source.

        NOTE: Returns 'n' - getCellContents(column, row) is not necessarily valid for row = [0..n]. Use 'rowEnumerator' to generate an iterator for valid row values over this data source.

        Specified by:
        getRowCount in interface TableDataSource

      • rowEnumeration

        public RowEnumeration rowEnumeration()
        Description copied from interface: TableDataSource
        Returns an iterator that is used to sequentually step through all valid rows in this source. The iterator is guarenteed to return exactly 'getRowCount' elements. The row elements returned by this iterator are used in 'getCellContents' in the 'row' parameter.

        Note that this object is only defined if entries in the table are not added/remove during the lifetime of this iterator. If entries are added or removed from the table while this iterator is open, then calls to 'nextRowIndex' will be undefined.

        Specified by:
        rowEnumeration in interface TableDataSource

      • getColumnScheme

        public SelectableScheme getColumnScheme​(int column)
        Description copied from interface: TableDataSource
        Returns the SelectableScheme that we use as an index for rows in the given column of this source. The SelectableScheme is used to determine the relationship between cells in a column.

        ISSUE: The scheme returned here should not have the 'insert' or 'remove' methods called (ie. it should be considered immutable). Perhaps we should make a MutableSelectableScheme interface to guarentee this constraint.

        Specified by:
        getColumnScheme in interface TableDataSource

      • getCellContents

        public abstract TObject getCellContents​(int column,
                                        int row)
        Description copied from interface: TableDataSource
        Returns an object that represents the information in the given cell in the table. This may be an expensive operation, so calls to it should be kept to a minimum. Note that the offset between two rows is not necessarily 1. Use 'rowEnumeration' to create a row iterator.
        Specified by:
        getCellContents in interface TableDataSource

      • addRow

        public int addRow​(RowData row_data)
        Description copied from interface: MutableTableDataSource
        Adds a row to the source. This will add a permanent record into the the underlying data structure. It will also update the indexing schemes as appropriate, and also add the row into the set returned by the 'rowEnumeration' iterator.

        It returns a row index that is used to reference this data in future queries. Throws an exception if the row additional was not possible because of IO reasons.

        Specified by:
        addRow in interface MutableTableDataSource

      • removeRow

        public void removeRow​(int row_index)
        Description copied from interface: MutableTableDataSource
        Completely removes a row from the source. This will permanently remove the record from the underlying data structure. It also updates the indexing schemes and removes the row index from the set returned by the 'rowEnumeration' iterator.

        Throws an exception if the row index does not reference a valid row within the context of this data source.

        Specified by:
        removeRow in interface MutableTableDataSource

      • updateRow

        public int updateRow​(int row_index,
                     RowData row_data)
        Description copied from interface: MutableTableDataSource
        Updates a row in the source. This will make a permanent change to the underlying data structure. It will update the indexing schemes as appropriate, and also add the row into the set returned by the 'rowEnumeration' iterator.

        It returns a row index for the new updated records. Throws an exception if the row update was not possible because of IO reasons or the row index not being a valid reference to a record in this data source.

        Specified by:
        updateRow in interface MutableTableDataSource

      • getJournal

        public MasterTableJournal getJournal()
        Description copied from interface: MutableTableDataSource
        Returns a journal that details the changes to this data source since it was created. This method may return a 'null' object to denote that no logging is being done. If this returns a MasterTableJournal, then all 'addRow' and 'removeRow' method calls and their relative order will be described in this journal.
        Specified by:
        getJournal in interface MutableTableDataSource

      • flushIndexChanges

        public void flushIndexChanges()
        Description copied from interface: MutableTableDataSource
        Flushes all changes made on this MutableTableDataSource to the backing index scheme (IndexSet). This is used during the commit phase of this objects lifetime. The transaction control mechanism has found that there are no clashes and now we need to commit the current table view to the conglomerate. Because this object may not update index information immediately, we call this to flush all the changes to the table to the backing index set.

        When this method returns, the backing IndexSet of this view will be completely up to date.

        Specified by:
        flushIndexChanges in interface MutableTableDataSource

      • constraintIntegrityCheck

        public void constraintIntegrityCheck()
        Description copied from interface: MutableTableDataSource
        Performs all constraint integrity checks and actions to any modifications based on any changes that happened to the table since that last call to this method. It is important that is called after any call to 'addRow', 'removeRow' or 'updateRow'.

        Any constraints that are marked as INITIALLY_IMMEDIATE are checked when this is called, otherwise the constraint is checked at commit time.

        Any referential actions are performed when this method is called. If a referential action causes a modification to another table, this method is recursively called on the table modified.

        If a referential integrity constraint is violated and a referential action is unable to maintain the integrity of the database, any changes made to the table are reverted.

        Specified by:
        constraintIntegrityCheck in interface MutableTableDataSource

      • dispose

        public void dispose()
        Description copied from interface: MutableTableDataSource
        Disposes this table data source. After this method is called, most use of this object is undefined, except for the 'getCellContent' and 'compareCellContent' methods which are valid provided the source is under a root lock.
        Specified by:
        dispose in interface MutableTableDataSource

      • addRootLock

        public void addRootLock()
        Description copied from interface: MutableTableDataSource
        Puts this source under a 'root lock'. A root lock means the root row structure of this object must not change. A root lock is obtained on a table when a ResultSet keeps hold of an object outside the life of the transaction that created the table. It is important that the order of the rows stays constant (committed deleted rows are not really deleted and reused, etc) while a table holds at least 1 root lock.
        Specified by:
        addRootLock in interface MutableTableDataSource

      • stringColumn

        protected static DataTableColumnDef stringColumn​(java.lang.String name)
        Convenience methods for constructing a DataTableDef for the dynamically generated table.

      • booleanColumn

        protected static DataTableColumnDef booleanColumn​(java.lang.String name)

      • numericColumn

        protected static DataTableColumnDef numericColumn​(java.lang.String name)