Package org.eclipse.rdf4j.federated.algebra

## Class PassThroughTupleExpr

- java.lang.Object
- - org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode
  - - org.eclipse.rdf4j.federated.algebra.PassThroughTupleExpr

- All Implemented Interfaces:
    `Serializable`, `Cloneable`, `FedXTupleExpr`, `QueryRef`, `VariableExpr`, `GraphPatternGroupable`, `QueryModelNode`, `TupleExpr`, `VariableScopeChange`

      public class PassThroughTupleExpr
      extends AbstractQueryModelNode
      implements FedXTupleExpr

  Marker `TupleExpr` that is used from `FedXTupleQuery.evaluate(TupleQueryResultHandler)` to allow for passing through of results to the handler.

  Passing through of results to the handler is supported for `SingleSourceQuery`s, i.e. if the original query is sent as is to the single relevant source. In this case no materialization and in-memory handling through FedX is done, if a `TupleQueryResultHandler` is supplied.

  Author:
    Andreas Schwarte
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `PassThroughTupleExpr​(TupleExpr parsedQuery, TupleQueryResultHandler resultHandler)` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `PassThroughTupleExpr` | `clone()` | Returns a (deep) clone of this query model node.
    `Set<String>` | `getAssuredBindingNames()` | Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
    `Set<String>` | `getBindingNames()` | Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
    `TupleExpr` | `getExpr()` |
    `List<String>` | `getFreeVars()` |
    `QueryInfo` | `getQueryInfo()` | Retrieve the attached query information of the tuple expression
    `TupleQueryResultHandler` | `getResultHandler()` |
    `boolean` | `isPassedThrough()` |
    `void` | `setPassedThrough​(boolean flag)` |
    `<X extends Exception> void` | `visit​(QueryModelVisitor<X> visitor)` | Visits this node.
    `<X extends Exception> void` | `visitChildren​(QueryModelVisitor<X> visitor)` | Dummy implementation of `QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>)` that does nothing.

    - ### Methods inherited from class org.eclipse.rdf4j.query.algebra.AbstractQueryModelNode

      `getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, isGraphPatternGroup, isVariableScopeChange, nullEquals, replaceChildNode, replaceNodeInList, replaceWith, setCostEstimate, setGraphPatternGroup, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, setVariableScopeChange, toString`

    - ### Methods inherited from class java.lang.Object

      `equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface org.eclipse.rdf4j.federated.algebra.FedXTupleExpr

      `getFreeVarCount`

    - ### Methods inherited from interface org.eclipse.rdf4j.query.algebra.QueryModelNode

      `equals, getCostEstimate, getParentNode, getResultSizeActual, getResultSizeEstimate, getSignature, getTotalTimeNanosActual, replaceChildNode, replaceWith, setCostEstimate, setParentNode, setResultSizeActual, setResultSizeEstimate, setTotalTimeNanosActual, toString`

- - ### Constructor Detail

    - #### PassThroughTupleExpr

          public PassThroughTupleExpr​(TupleExpr parsedQuery,
                                      TupleQueryResultHandler resultHandler)

  - ### Method Detail

    - #### visitChildren

          public <X extends Exception> void visitChildren​(QueryModelVisitor<X> visitor)
                                                   throws X extends Exception

      Description copied from class: `AbstractQueryModelNode`
      Dummy implementation of `QueryModelNode.visitChildren(org.eclipse.rdf4j.query.algebra.QueryModelVisitor<X>)` that does nothing. Subclasses should override this method when they have child nodes.
      Specified by:
        `visitChildren` in interface `QueryModelNode`
      Overrides:
        `visitChildren` in class `AbstractQueryModelNode`
      Throws:
        `X extends Exception`

    - #### getResultHandler

          public TupleQueryResultHandler getResultHandler()

    - #### getExpr

          public TupleExpr getExpr()

    - #### isPassedThrough

          public boolean isPassedThrough()

      Returns:
        if the query result has already been passed through to the supplied `TupleQueryResultHandler`

    - #### setPassedThrough

          public void setPassedThrough​(boolean flag)

    - #### getBindingNames

          public Set<String> getBindingNames()

      Description copied from interface: `TupleExpr`
      Gets the names of the bindings that are, or can be, returned by this tuple expression when it is evaluated.
      Specified by:
        `getBindingNames` in interface `TupleExpr`
      Returns:
        A set of binding names.

    - #### getAssuredBindingNames

          public Set<String> getAssuredBindingNames()

      Description copied from interface: `TupleExpr`
      Gets the names of the bindings that are guaranteed to be present in the results produced by this tuple expression.
      Specified by:
        `getAssuredBindingNames` in interface `TupleExpr`
      Returns:
        A set of binding names.

    - #### clone

          public PassThroughTupleExpr clone()

      Description copied from interface: `QueryModelNode`
      Returns a (deep) clone of this query model node. This method recursively clones the entire node tree, starting from this nodes.
      Specified by:
        `clone` in interface `QueryModelNode`
      Specified by:
        `clone` in interface `TupleExpr`
      Overrides:
        `clone` in class `AbstractQueryModelNode`
      Returns:
        A deep clone of this query model node.

    - #### visit

          public <X extends Exception> void visit​(QueryModelVisitor<X> visitor)
                                           throws X extends Exception

      Description copied from interface: `QueryModelNode`
      Visits this node. The node reports itself to the visitor with the proper runtime type.
      Specified by:
        `visit` in interface `QueryModelNode`
      Throws:
        `X extends Exception`

    - #### getFreeVars

          public List<String> getFreeVars()

      Specified by:
        `getFreeVars` in interface `VariableExpr`
      Returns:
        a list of free (i.e. unbound) variables in this expression

    - #### getQueryInfo

          public QueryInfo getQueryInfo()

      Description copied from interface: `QueryRef`
      Retrieve the attached query information of the tuple expression
      Specified by:
        `getQueryInfo` in interface `QueryRef`
      Returns:
        the `QueryInfo`