org.apache.jackrabbit.oak.query

Class FilterIterators

java.lang.Object

org.apache.jackrabbit.oak.query.FilterIterators

public class FilterIterators
extends Object

Filtering iterators that are useful for queries with limit, offset, order by, or distinct.

Constructor Summary

Constructors

Constructor and Description
FilterIterators()

Method Summary

Modifier and Type	Method and Description
static void	checkMemoryLimit(long count, QueryEngineSettings settings) Verify the number of in-memory nodes is below the limit.
static void	checkReadLimit(long count, QueryEngineSettings settings) Verify the number of node read operations is below the limit.
static <K> Iterator<K>	newCombinedFilter(Iterator<K> it, boolean distinct, long limit, long offset, Comparator<K> orderBy, QueryEngineSettings settings)
static <K> org.apache.jackrabbit.oak.query.FilterIterators.DistinctIterator<K>	newDistinct(Iterator<K> it, QueryEngineSettings settings)
static <K> Iterator<K>	newLimit(Iterator<K> it, long limit)
static <K> Iterator<K>	newOffset(Iterator<K> it, long offset)
static <K> Iterator<K>	newSort(Iterator<K> it, Comparator<K> orderBy, int max, QueryEngineSettings settings)

Methods inherited from class java.lang.Object

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

Constructor Detail

FilterIterators

public FilterIterators()

Method Detail

checkMemoryLimit

public static void checkMemoryLimit(long count,
                                    QueryEngineSettings settings)

Verify the number of in-memory nodes is below the limit.

Parameters:

count - the number of nodes

settings - the query engine settings

Throws:

UnsupportedOperationException - if the limit was exceeded

checkReadLimit

public static void checkReadLimit(long count,
                                  QueryEngineSettings settings)

Verify the number of node read operations is below the limit.

Parameters:

count - the number of read operations

settings - the query engine settings

Throws:

UnsupportedOperationException - if the limit was exceeded

newCombinedFilter

public static <K> Iterator<K> newCombinedFilter(Iterator<K> it,
                                                boolean distinct,
                                                long limit,
                                                long offset,
                                                Comparator<K> orderBy,
                                                QueryEngineSettings settings)

newDistinct

public static <K> org.apache.jackrabbit.oak.query.FilterIterators.DistinctIterator<K> newDistinct(Iterator<K> it,
                                                                                                  QueryEngineSettings settings)

newLimit

public static <K> Iterator<K> newLimit(Iterator<K> it,
                                       long limit)

newOffset

public static <K> Iterator<K> newOffset(Iterator<K> it,
                                        long offset)

newSort

public static <K> Iterator<K> newSort(Iterator<K> it,
                                      Comparator<K> orderBy,
                                      int max,
                                      QueryEngineSettings settings)