Class GTSQLTypeInfoDataSource
- All Implemented Interfaces:
MutableTableDataSource
,TableDataSource
NOTE: This is not designed to be a long kept object. It must not last beyond the lifetime of a transaction.
- Author:
- Tobias Downer
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
Puts this source under a 'root lock'.int
Adds a row to the source.protected static DataTableColumnDef
booleanColumn
(String name) protected TObject
columnValue
(int column, Object ob) Returns a TObject that represents a value for the given column in this table.void
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.protected static DataTableColumnDef
dateColumn
(String name) void
dispose()
Disposes this table data source.void
Flushes all changes made on this MutableTableDataSource to the backing index scheme (IndexSet).getCellContents
(int column, int row) Returns an object that represents the information in the given cell in the table.getColumnScheme
(int column) Returns the SelectableScheme that we use as an index for rows in the given column of this source.Returns a DataTableDef object that defines the layout of the table that this data is in.com.mckoi.database.MasterTableJournal
Returns a journal that details the changes to this data source since it was created.int
Returns the number of rows in this data source.Returns the TransactionSystem object that describes global properties about the data source that generated this object.init()
Initialize the data source.protected static DataTableColumnDef
numericColumn
(String name) void
Removes a root lock from this source.void
removeRow
(int row_index) Completely removes a row from the source.Returns an iterator that is used to sequentually step through all valid rows in this source.protected static DataTableColumnDef
stringColumn
(String name) Convenience methods for constructing a DataTableDef for the dynamically generated table.int
Updates a row in the source.
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Constructor Details
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GTSQLTypeInfoDataSource
Constructor.
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Method Details
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init
Initialize the data source. -
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 interfaceTableDataSource
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getRowCount
public 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 interfaceTableDataSource
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getCellContents
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 interfaceTableDataSource
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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 interfaceMutableTableDataSource
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columnValue
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. -
getSystem
Description copied from interface:TableDataSource
Returns the TransactionSystem object that describes global properties about the data source that generated this object.- Specified by:
getSystem
in interfaceTableDataSource
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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 interfaceTableDataSource
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getColumnScheme
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 interfaceTableDataSource
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addRow
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 interfaceMutableTableDataSource
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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 interfaceMutableTableDataSource
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updateRow
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 interfaceMutableTableDataSource
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getJournal
public com.mckoi.database.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 interfaceMutableTableDataSource
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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 interfaceMutableTableDataSource
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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 interfaceMutableTableDataSource
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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 interfaceMutableTableDataSource
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removeRootLock
public void removeRootLock()Description copied from interface:MutableTableDataSource
Removes a root lock from this source.- Specified by:
removeRootLock
in interfaceMutableTableDataSource
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stringColumn
Convenience methods for constructing a DataTableDef for the dynamically generated table. -
booleanColumn
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numericColumn
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dateColumn
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