org.apache.calcite.adapter.cassandra

Class CassandraFilter.Translator

java.lang.Object

org.apache.calcite.adapter.cassandra.CassandraFilter.Translator

Enclosing class:

CassandraFilter

static class CassandraFilter.Translator
extends Object

Translates RexNode expressions into Cassandra expression strings.

Field Summary

Fields

Modifier and Type	Field and Description
private List<String>	clusteringKeys
private List<String>	fieldNames
private List<RelFieldCollation>	implicitFieldCollations
private Set<String>	partitionKeys
private int	restrictedClusteringKeys
private RelDataType	rowType

Constructor Summary

Constructors

Constructor and Description
Translator(RelDataType rowType, List<String> partitionKeys, List<String> clusteringKeys, List<RelFieldCollation> implicitFieldCollations)

Method Summary

Modifier and Type	Method and Description
RelCollation	getImplicitCollation() Infer the implicit correlation from the unrestricted clustering keys.
boolean	isSinglePartition() Check if the query spans only one partition.
private static String	literalValue(RexLiteral literal) Conver the value of a literal to a string.
private String	translateAnd(RexNode condition) Translate a conjunctive predicate to a CQL string.
private String	translateBinary(String op, String rop, RexCall call) Translates a call to a binary operator, reversing arguments if necessary.
private String	translateBinary2(String op, RexNode left, RexNode right) Translates a call to a binary operator.
private String	translateMatch(RexNode condition) Produce the CQL predicate string for the given condition.
private String	translateMatch2(RexNode node) Translate a binary relation.
private String	translateOp2(String op, String name, RexLiteral right) Combines a field name, operator, and literal to produce a predicate string.

Methods inherited from class java.lang.Object

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

Field Detail

rowType

private final RelDataType rowType

fieldNames

private final List<String> fieldNames

partitionKeys

private final Set<String> partitionKeys

clusteringKeys

private final List<String> clusteringKeys

restrictedClusteringKeys

private int restrictedClusteringKeys

implicitFieldCollations

private final List<RelFieldCollation> implicitFieldCollations

Constructor Detail

Translator

Translator(RelDataType rowType,
           List<String> partitionKeys,
           List<String> clusteringKeys,
           List<RelFieldCollation> implicitFieldCollations)

Method Detail

isSinglePartition

public boolean isSinglePartition()

Check if the query spans only one partition.

Returns:

True if the matches translated so far have resulted in a single partition

getImplicitCollation

public RelCollation getImplicitCollation()

Infer the implicit correlation from the unrestricted clustering keys.

Returns:

The collation of the filtered results

translateMatch

private String translateMatch(RexNode condition)

Produce the CQL predicate string for the given condition.

Parameters:

condition - Condition to translate

Returns:

CQL predicate string

literalValue

private static String literalValue(RexLiteral literal)

Conver the value of a literal to a string.

Parameters:

literal - Literal to translate

Returns:

String representation of the literal

translateAnd

private String translateAnd(RexNode condition)

Translate a conjunctive predicate to a CQL string.

Parameters:

condition - A conjunctive predicate

Returns:

CQL string for the predicate

translateMatch2

private String translateMatch2(RexNode node)

Translate a binary relation.

translateBinary

private String translateBinary(String op,
                               String rop,
                               RexCall call)

Translates a call to a binary operator, reversing arguments if necessary.

translateBinary2

private String translateBinary2(String op,
                                RexNode left,
                                RexNode right)

Translates a call to a binary operator. Returns null on failure.

translateOp2

private String translateOp2(String op,
                            String name,
                            RexLiteral right)

Combines a field name, operator, and literal to produce a predicate string.