com.pervasive.datarush.tokens.record

Class RecordMap.RecordMapIterator

java.lang.Object

com.pervasive.datarush.tokens.record.RecordMap.RecordMapIterator

All Implemented Interfaces:

RecordValuedIterator, TokenValuedIterator, RecordValued, TokenValued, RecordTyped, TokenTyped

Enclosing class:

RecordMap

public class RecordMap.RecordMapIterator
extends Object
implements RecordValuedIterator

An iterator capable of providing access to a subset of records within the record map's cache. The subset is defined by an invocation of the seek method. Once a seek is successful, the iterator can be used to step through the records matching the seek criteria.

Method Summary

Modifier and Type	Method and Description
boolean	containsNull() Determines if any field in the record is null valued.
int	getAbsoluteIndex() Returns the dense value index for the current value.
ScalarValued	getField(int index) Get the field at the given index within the list of fields.
ScalarValued	getField(String fieldName) Gets the value of the field with the given name.
ScalarValued[]	getFields() Gets the values of all fields in the record
RecordTokenType	getType() Gets the data type of the token.
boolean	isNull() Indicates whether the token is null valued.
ScalarValuedIterator	newFieldIterator(FieldIteratorProperties properties) Create a new iterator for visiting the fields in this RecordValued object.
ScalarValuedIterator	newFieldIterator(ScalarTokenType type) Create a new iterator for visiting the fields in this RecordValued object.
ScalarValuedIterator	newFieldIterator(ScalarTokenType type, String[] selectedFieldNames) Create a new iterator for visiting the fields in this RecordValued object.
void	resetIteration() Resets the iteration to the beginning.
boolean	seek() Seek to the records in the cache that have the same key value as the current record of the input data source tied to this iterator.
int	size() Gets the number of fields in the record schema.
boolean	stepNext() Advances to the next value not equal to "zero".

Methods inherited from class java.lang.Object

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

Method Detail

seek

public boolean seek()

Seek to the records in the cache that have the same key value as the current record of the input data source tied to this iterator.

Returns:

true if the seek worked; false otherwise. If false is returned, the iterator is not positioned on a valid record and will fail if data access methods are utilized.

getAbsoluteIndex

public int getAbsoluteIndex()

Description copied from interface: TokenValuedIterator

Returns the dense value index for the current value. Dense value index is the index of the value in the "dense" representation; If this represents an iterator over fields in a record, RecordTokenType.get(denseIndex) will return the associated field.

NOTE: Iteration order is unspecified on this interface. Some implementations guarantee sort order whereas others do not. Please refer to the documentation on the factory method from which this iterator was constructed for ordering information.

Specified by:

getAbsoluteIndex in interface TokenValuedIterator

Returns:

The dense index.

resetIteration

public void resetIteration()

Description copied from interface: TokenValuedIterator

Resets the iteration to the beginning.

Specified by:

resetIteration in interface TokenValuedIterator

stepNext

public boolean stepNext()

Description copied from interface: TokenValuedIterator

Advances to the next value not equal to "zero".

Specified by:

stepNext in interface TokenValuedIterator

Returns:

true if position is beyond the end.

getType

public RecordTokenType getType()

Description copied from interface: TokenValued

Gets the data type of the token. This type will dictate the valid values that can be contained.

Specified by:

getType in interface RecordValued

Specified by:

getType in interface TokenValued

Specified by:

getType in interface RecordTyped

Specified by:

getType in interface TokenTyped

Returns:

the token type.

isNull

public boolean isNull()

Description copied from interface: TokenValued

Indicates whether the token is null valued. Tokens support null values analogous to SQL. Before accessing the value of the container, it is usually best to ensure it is not null valued using this method.

Specified by:

isNull in interface TokenValued

Returns:

true if the token is null valued, false otherwise

containsNull

public boolean containsNull()

Description copied from interface: RecordValued

Determines if any field in the record is null valued.

Specified by:

containsNull in interface RecordValued

Returns:

true if at least one field is null valued, false if none are

getField

public ScalarValued getField(String fieldName)

Description copied from interface: RecordValued

Gets the value of the field with the given name.

Specified by:

getField in interface RecordValued

Parameters:

fieldName - the field name

Returns:

the field's value

getField

public ScalarValued getField(int index)

Description copied from interface: RecordValued

Get the field at the given index within the list of fields.

Specified by:

getField in interface RecordValued

Parameters:

index - zero-based index into the field list

Returns:

the field's value

getFields

public ScalarValued[] getFields()

Description copied from interface: RecordValued

Gets the values of all fields in the record

Specified by:

getFields in interface RecordValued

Returns:

an array containing the values of the record's fields

newFieldIterator

public ScalarValuedIterator newFieldIterator(ScalarTokenType type)

Description copied from interface: RecordValued

Create a new iterator for visiting the fields in this RecordValued object. Visitation order will be sorted by the field's index.

Specified by:

newFieldIterator in interface RecordValued

Parameters:

type - the type of fields over which to iterate

Returns:

an iterator over fields of the specified type

newFieldIterator

public ScalarValuedIterator newFieldIterator(ScalarTokenType type,
                                             String[] selectedFieldNames)

Description copied from interface: RecordValued

Create a new iterator for visiting the fields in this RecordValued object. Visitation order will be sorted by the field's index.

Specified by:

newFieldIterator in interface RecordValued

Parameters:

type - the type of fields over which to iterate

selectedFieldNames - the fields over which to iterate

Returns:

an iterator over the specified fields

newFieldIterator

public ScalarValuedIterator newFieldIterator(FieldIteratorProperties properties)

Description copied from interface: RecordValued

Create a new iterator for visiting the fields in this RecordValued object. Visitation order will optionally be sorted by the field's index, depending on the value of FieldIteratorProperties.isSorted().

Specified by:

newFieldIterator in interface RecordValued

Parameters:

properties - properties for the iterator

Returns:

an iterator over the fields

size

public int size()

Description copied from interface: RecordValued

Gets the number of fields in the record schema.

Specified by:

size in interface RecordValued

Returns:

the number of fields