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.

Method Summary

Modifier and Type	Method and Description
static void	checkMemoryLimit(long count, QueryLimits settings) Verify the number of in-memory nodes is below the limit.
static void	checkReadLimit(long count, QueryLimits 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, QueryLimits settings)
static <K> org.apache.jackrabbit.oak.query.FilterIterators.DistinctIterator<K>	newDistinct(Iterator<K> it, QueryLimits 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, QueryLimits settings)

Methods inherited from class java.lang.Object

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

Method Detail

checkMemoryLimit

public static void checkMemoryLimit(long count,
                                    QueryLimits 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,
                                  QueryLimits 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,
                                                QueryLimits settings)

newDistinct

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