com.netflix.hollow.tools.query

Class HollowFieldMatchQuery

java.lang.Object

com.netflix.hollow.tools.query.HollowFieldMatchQuery

public class HollowFieldMatchQuery
extends java.lang.Object

A HollowFieldMatchQuery can be used to scan through all records in a dataset to match specific field name/value combinations.

Results are returned in the form of a Map<String, BitSet>. Each type for which any records matched will have an entry in the returned Map, keyed by type name. The corresponding value is a BitSet which is set at the positions of the ordinals of the matched records.

Hint: The returned Map<String, BitSet> may be in turn passed to the TransitiveSetTraverser to be augmented with any records which reference matched records. For example, we can imagine a data model for which the following code would provide a selection which includes the Actor record for "Tom Hanks", plus any Movie records in which he stars:

 
 HollowFieldMatchQuery query = new HollowFieldMatchQuery(myStateEngine);
 Map<String, BitSet> selection = query.findMatchingRecords("actorName", "Tom Hanks");
  
 TransitiveSetTraverser.addReferencingOutsideClosure(myStateEngine, selection);
 
 

Constructor Summary

Constructors

Constructor and Description
HollowFieldMatchQuery(HollowReadStateEngine readEngine)

Method Summary

Modifier and Type	Method and Description
java.util.Map<java.lang.String,java.util.BitSet>	findMatchingRecords(java.lang.String fieldName, java.lang.String fieldValue) Match any records which include a field with the provided fieldName and value.
java.util.Map<java.lang.String,java.util.BitSet>	findMatchingRecords(java.lang.String typeName, java.lang.String fieldName, java.lang.String fieldValue) Match any records of the specified type, which have the specified field set to the specified value.

Methods inherited from class java.lang.Object

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

Constructor Detail

HollowFieldMatchQuery

public HollowFieldMatchQuery(HollowReadStateEngine readEngine)

Method Detail

findMatchingRecords

public java.util.Map<java.lang.String,java.util.BitSet> findMatchingRecords(java.lang.String fieldName,
                                                                            java.lang.String fieldValue)

Match any records which include a field with the provided fieldName and value.

Parameters:

fieldName - the field name

fieldValue - the field value as a string that will be parsed as the type of the field to match.

Returns:

the matching records

findMatchingRecords

public java.util.Map<java.lang.String,java.util.BitSet> findMatchingRecords(java.lang.String typeName,
                                                                            java.lang.String fieldName,
                                                                            java.lang.String fieldValue)

Match any records of the specified type, which have the specified field set to the specified value.

Parameters:

typeName - the type name

fieldName - the field name

fieldValue - the field value as a string that will be parsed as the type of the field to match.

Returns:

the matching records