Class BaseTransactionalDataset
Abstract Base Class for Mutable Datasets that support Transactions.
Inherited Members
Namespace: VDS.RDF.Query.Datasets
Assembly: dotNetRdf.dll
Syntax
public abstract class BaseTransactionalDataset : BaseDataset, ISparqlDataset, ITripleIndexRemarks
The Transaction implementation of dotNetRDF is based upon a MRSW concurrency model, since only one writer may be active changes are immediately pushed to the dataset and visible within the transaction and they are committed or rolled back when Flush() or Discard() are called.
So in practical terms it is perfectly OK for the storage to be updated during a transaction because if the transaction fails the changes will be rolled back because all changes are stored in-memory until the end of the transaction. This may not be an ideal transaction model for all scenarios so you may wish to implement your own version of transactions or code your implementations of the abstract methods accordingly to limit actual persistence to the end of a transaction.
Constructors
| Edit this page View SourceBaseTransactionalDataset()
Creates a new Transactional Dataset.
Declaration
public BaseTransactionalDataset()BaseTransactionalDataset(bool)
Creates a new Transactional Dataset with the given Union Default Graph setting.
Declaration
public BaseTransactionalDataset(bool unionDefaultGraph)Parameters
| Type | Name | Description |
|---|---|---|
| bool | unionDefaultGraph | Whether to use a Union Default Graph. |
BaseTransactionalDataset(Uri)
Creates a new Transactional Dataset with a fixed Default Graph and no Union Default Graph.
Declaration
[Obsolete("Replaced by BaseTransactionalDataset(IRefNode)")]
public BaseTransactionalDataset(Uri defaultGraphUri)Parameters
| Type | Name | Description |
|---|---|---|
| Uri | defaultGraphUri | Default Graph URI. |
BaseTransactionalDataset(IRefNode)
Creates a new transactional dataset with a fixed default graph and no union default graph.
Declaration
public BaseTransactionalDataset(IRefNode defaultGraphName)Parameters
| Type | Name | Description |
|---|---|---|
| IRefNode | defaultGraphName | Default graph name. |
Properties
| Edit this page View Sourcethis[Uri]
Gets a Graph from the Dataset.
Declaration
[Obsolete("Replaced by this[IRefNode]")]
public override sealed IGraph this[Uri graphUri] { get; }Parameters
| Type | Name | Description |
|---|---|---|
| Uri | graphUri | Graph URI. |
Property Value
| Type | Description |
|---|---|
| IGraph |
Overrides
Remarks
If the Graph has been modified during the active Transaction the modified version is returned rather than the original version.
this[IRefNode]
Gets the graph with the given name from the dataset.
Declaration
public override sealed IGraph this[IRefNode graphName] { get; }Parameters
| Type | Name | Description |
|---|---|---|
| IRefNode | graphName | Graph name. |
Property Value
| Type | Description |
|---|---|
| IGraph |
Overrides
Remarks
This property need only return a read-only view of the Graph, code which wishes to modify Graphs should use the GetModifiableGraph() method to guarantee a Graph they can modify and will be persisted to the underlying storage.
Methods
| Edit this page View SourceAddGraph(IGraph)
Adds a Graph to the Dataset.
Declaration
public override sealed bool AddGraph(IGraph g)Parameters
| Type | Name | Description |
|---|---|---|
| IGraph | g | Graph to add. |
Returns
| Type | Description |
|---|---|
| bool |
Overrides
| Edit this page View SourceAddGraphInternal(IGraph)
Adds a Graph to the Dataset.
Declaration
protected abstract bool AddGraphInternal(IGraph g)Parameters
| Type | Name | Description |
|---|---|---|
| IGraph | g | Graph to add. |
Returns
| Type | Description |
|---|---|
| bool |
Discard()
Ensures that any changes to the Dataset (if any) are discarded.
Declaration
public override sealed void Discard()Overrides
Remarks
Rollback the Active Transaction.
DiscardInternal()
Allows the derived dataset to take any post-Discard() actions required.
Declaration
protected virtual void DiscardInternal()Flush()
Ensures that any changes to the Dataset (if any) are flushed to the underlying Storage.
Declaration
public override sealed void Flush()Overrides
Remarks
Commits the Active Transaction.
FlushInternal()
Allows the derived dataset to take any post-Flush() actions required.
Declaration
protected virtual void FlushInternal()GetModifiableGraph(IRefNode)
Gets the Graph with the given URI from the Dataset.
Declaration
public override sealed IGraph GetModifiableGraph(IRefNode graphName)Parameters
| Type | Name | Description |
|---|---|---|
| IRefNode | graphName | Graph URI. |
Returns
| Type | Description |
|---|---|
| IGraph |
Overrides
Remarks
Graphs returned from this method must be modifiable and the Dataset must guarantee that when it is Flushed or Disposed of that any changes to the Graph are persisted.
GetModifiableGraphInternal(IRefNode)
Gets a Graph from the Dataset that can be modified transactionally.
Declaration
protected abstract ITransactionalGraph GetModifiableGraphInternal(IRefNode graphName)Parameters
| Type | Name | Description |
|---|---|---|
| IRefNode | graphName | Graph URI. |
Returns
| Type | Description |
|---|---|
| ITransactionalGraph |
RemoveGraph(Uri)
Removes a Graph from the Dataset.
Declaration
[Obsolete("Replaced by RemoveGraph(IRefNode)")]
public override sealed bool RemoveGraph(Uri graphUri)Parameters
| Type | Name | Description |
|---|---|---|
| Uri | graphUri | Graph URI. |
Returns
| Type | Description |
|---|---|
| bool |
Overrides
| Edit this page View SourceRemoveGraph(IRefNode)
Removes a Graph from the Dataset.
Declaration
public override bool RemoveGraph(IRefNode graphName)Parameters
| Type | Name | Description |
|---|---|---|
| IRefNode | graphName | Graph name. |
Returns
| Type | Description |
|---|---|
| bool |
Overrides
Exceptions
| Type | Condition |
|---|---|
| NotSupportedException | May be thrown if the Dataset is immutable i.e. Updates not supported. |