Package org.apache.calcite.rel.externalize

Class RelJsonWriter

java.lang.Object

org.apache.calcite.rel.externalize.RelJsonWriter

All Implemented Interfaces:

RelWriter

public class RelJsonWriter
extends java.lang.Object
implements RelWriter

Callback for a relational expression to dump itself as JSON.

See Also:

RelJsonReader

Field Summary

Fields

Modifier and Type	Field	Description
private JsonBuilder	jsonBuilder
private java.lang.String	previousId
private java.util.Map<RelNode,java.lang.String>	relIdMap
private RelJson	relJson
private java.util.List<java.lang.Object>	relList
private java.util.List<Pair<java.lang.String,java.lang.Object>>	values

Constructor Summary

Constructors

Constructor	Description
RelJsonWriter()

Method Summary

Modifier and Type	Method	Description
java.lang.String	asString()	Returns a JSON string describing the relational expressions that were just explained.
RelWriter	done(RelNode node)	Writes the completed explanation.
void	explain(RelNode rel, java.util.List<Pair<java.lang.String,java.lang.Object>> valueList)	Prints an explanation of a node, with a list of (term, value) pairs.
protected void	explain_(RelNode rel, java.util.List<Pair<java.lang.String,java.lang.Object>> values)
private java.util.List<java.lang.Object>	explainInputs(java.util.List<RelNode> inputs)
SqlExplainLevel	getDetailLevel()
private java.util.List<java.lang.Object>	getList(java.util.List<Pair<java.lang.String,java.lang.Object>> values, java.lang.String tag)
RelWriter	input(java.lang.String term, RelNode input)	Adds an input to the explanation of the current node.
RelWriter	item(java.lang.String term, java.lang.Object value)	Adds an attribute to the explanation of the current node.
RelWriter	itemIf(java.lang.String term, java.lang.Object value, boolean condition)	Adds an input to the explanation of the current node, if a condition holds.
boolean	nest()	Returns whether the writer prefers nested values.
private void	put(java.util.Map<java.lang.String,java.lang.Object> map, java.lang.String name, java.lang.Object value)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

jsonBuilder

private final JsonBuilder jsonBuilder

relJson

private final RelJson relJson

relIdMap

private final java.util.Map<RelNode,java.lang.String> relIdMap

relList

private final java.util.List<java.lang.Object> relList

values

private final java.util.List<Pair<java.lang.String,java.lang.Object>> values

previousId

private java.lang.String previousId

Constructor Detail

RelJsonWriter

public RelJsonWriter()

Method Detail

explain_

protected void explain_(RelNode rel,
                        java.util.List<Pair<java.lang.String,java.lang.Object>> values)

put

private void put(java.util.Map<java.lang.String,java.lang.Object> map,
                 java.lang.String name,
                 java.lang.Object value)

explainInputs

private java.util.List<java.lang.Object> explainInputs(java.util.List<RelNode> inputs)

explain

public final void explain(RelNode rel,
                          java.util.List<Pair<java.lang.String,java.lang.Object>> valueList)

Description copied from interface: RelWriter

Prints an explanation of a node, with a list of (term, value) pairs.

The term-value pairs are generally gathered by calling RelNode.explain(RelWriter). Each sub-class of RelNode calls RelWriter.input(String, org.apache.calcite.rel.RelNode) and RelWriter.item(String, Object) to declare term-value pairs.

Specified by:

explain in interface RelWriter

Parameters:

rel - Relational expression

valueList - List of term-value pairs

getDetailLevel

public SqlExplainLevel getDetailLevel()

Specified by:

getDetailLevel in interface RelWriter

Returns:

detail level at which plan should be generated

input

public RelWriter input(java.lang.String term,
                       RelNode input)

Description copied from interface: RelWriter

Adds an input to the explanation of the current node.

Specified by:

input in interface RelWriter

Parameters:

term - Term for input, e.g. "left" or "input #1".

input - Input relational expression

item

public RelWriter item(java.lang.String term,
                      java.lang.Object value)

Description copied from interface: RelWriter

Adds an attribute to the explanation of the current node.

Specified by:

item in interface RelWriter

Parameters:

term - Term for attribute, e.g. "joinType"

value - Attribute value

getList

private java.util.List<java.lang.Object> getList(java.util.List<Pair<java.lang.String,java.lang.Object>> values,
                                                 java.lang.String tag)

itemIf

public RelWriter itemIf(java.lang.String term,
                        java.lang.Object value,
                        boolean condition)

Description copied from interface: RelWriter

Adds an input to the explanation of the current node, if a condition holds.

Specified by:

itemIf in interface RelWriter

done

public RelWriter done(RelNode node)

Description copied from interface: RelWriter

Writes the completed explanation.

Specified by:

done in interface RelWriter

nest

public boolean nest()

Description copied from interface: RelWriter

Returns whether the writer prefers nested values. Traditional explain writers prefer flattened values.

Specified by:

nest in interface RelWriter

asString

public java.lang.String asString()

Returns a JSON string describing the relational expressions that were just explained.