org.kitesdk.data.spi

Class MarkerComparator

java.lang.Object

org.kitesdk.data.spi.MarkerComparator

All Implemented Interfaces:

Comparator<Marker>

@Immutable
public class MarkerComparator
extends Object
implements Comparator<Marker>

Comparison methods for Marker objects with respect to a PartitionStrategy.

Since:

0.9.0

Constructor Summary

Constructors

Constructor and Description
MarkerComparator(PartitionStrategy strategy)

Method Summary

Methods

Modifier and Type	Method and Description
int	compare(Marker m1, Marker m2) Compare two Marker objects under the PartitionStrategy.
boolean	contains(Marker container, Marker test) Returns true if container contains test, false otherwise.
boolean	equals(Object o)
int	hashCode()
int	leftCompare(Marker m1, Marker m2) Compare two Marker objects under the PartitionStrategy.
int	rightCompare(Marker m1, Marker m2) Compare two Marker objects under the PartitionStrategy.

Methods inherited from class java.lang.Object

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

Constructor Detail

MarkerComparator

public MarkerComparator(PartitionStrategy strategy)

Method Detail

contains

public boolean contains(Marker container,
               Marker test)

Returns true if container contains test, false otherwise. Fields for which set has no value (Marker.valueFor(FieldPartitioner) returns null) are treated as wildcards and always match. All fields in the PartitionStrategy are compared.

Parameters:

container - a Marker that defines a set of partitions

test - a Marker that may be a subset of container

Returns:

true if the partitions in test are a subset of container, false otherwise

compare

public int compare(Marker m1,
          Marker m2)

Compare two Marker objects under the PartitionStrategy. All comparisons are with respect to the partition ordering defined by this comparator's PartitionStrategy. Under a PartitionStrategy, a Marker contains a set of one or more partitions. A Marker is strictly less than another if all of the partitions it contains are less than the partitions of the other. Similarly, if all partitions are greater than the partitions of the other, then the Marker is greater. Two Markers are equal if they contain the same set of partitions. This method implements strictly exclusive comparison: if either Marker contains the other, then this throws IllegalStateException. This is because there is at least one partition in the containing Marker that is less than or equal to all partitions in the contained Marker and at least one partition that is greater than or equal to all partitions in the contained Marker. Alternatively, the comparison methods leftCompare(Marker, Marker) and rightCompare(Marker, Marker) consider contained Marker objects to be greater-than and less-than respectively. Note: Because Marker objects are hierarchical, they are either completely disjoint or one marker contains the other. If one contains the other and the two are not equal, this method throws IllegalStateException. TODO: catch wildcard to concrete comparisons and throw an Exception

Specified by:

compare in interface Comparator<Marker>

Parameters:

m1 - a Marker

m2 - a Marker

Returns:

-1 If all partitions in m1 are less than the partitions in m2 0 If m1 and m2 contain the same set of partitions 1 If all partitions of m1 are greater than the partitions in m2

Throws:

IllegalStateException - If either Marker is a proper subset of the other

Since:

0.9.0

See Also:

leftCompare(Marker, Marker), rightCompare(Marker, Marker)

rightCompare

public int rightCompare(Marker m1,
               Marker m2)

Compare two Marker objects under the PartitionStrategy. All comparisons are with respect to the partition ordering defined by this comparator's PartitionStrategy. Under a PartitionStrategy, a Marker contains a set of one or more partitions. A Marker is strictly less than another if all of the partitions it contains are less than the partitions of the other. Similarly, if all partitions are greater than the partitions of the other, then the Marker is greater. Two Markers are equal if they contain the same set of partitions. This method implements right-inclusive comparison: if either Marker contains the other, then it is considered greater. This means that there is at least one partition in the containing Marker that is greater than all of the partitions in the contained Marker. This behavior is for checking an inclusive upper bound for a range. m1 = [ 2013, Oct, * ] m2 = [ 2013, Oct, 12 ] rightCompare(m1, m2) returns 1 rightCompare(m2, m1) returns -1 The comparison method leftCompare(Marker, Marker) implements left-inclusive comparison. Note: Because Marker objects are hierarchical, they are either completely disjoint or one marker contains the other. If one contains the other and the two are not equal, this method considers it to be greater than the other. TODO: catch wildcard to concrete comparisons and throw an Exception

Parameters:

m1 - a Marker

m2 - a Marker

Returns:

-1 If all partitions in m1 are less than the partitions in m2 0 If m1 and m2 contain the same set of partitions 1 If all partitions of m1 are greater than the partitions in m2

Since:

0.9.0

See Also:

compare(Marker, Marker), leftCompare(Marker, Marker)

leftCompare

public int leftCompare(Marker m1,
              Marker m2)

Compare two Marker objects under the PartitionStrategy. All comparisons are with respect to the partition ordering defined by this comparator's PartitionStrategy. Under a PartitionStrategy, a Marker contains a set of one or more partitions. A Marker is strictly less than another if all of the partitions it contains are less than the partitions of the other. Similarly, if all partitions are greater than the partitions of the other, then the Marker is greater. Two Markers are equal if they contain the same set of partitions. This method implements left-inclusive comparison: if either Marker contains the other, then it is considered lesser. This means that there is at least one partition in the containing Marker that is less than all of the partitions in the contained Marker. This behavior is for checking an inclusive lower bound for a range. m1 = [ 2013, Oct, * ] m2 = [ 2013, Oct, 12 ] leftCompare(m1, m2) returns 1 leftCompare(m2, m1) returns -1 The comparison method rightCompare(Marker, Marker) implements right-inclusive comparison. Note: Because Marker objects are hierarchical, they are either completely disjoint or one marker contains the other. If one contains the other and the two are not equal, this method considers it to be less than than the other. TODO: catch wildcard to concrete comparisons and throw an Exception

Parameters:

m1 - a Marker

m2 - a Marker

Returns:

-1 If all partitions in m1 are less than the partitions in m2 0 If m1 and m2 contain the same set of partitions 1 If all partitions of m1 are greater than the partitions in m2

Since:

0.9.0

See Also:

compare(Marker, Marker), rightCompare(Marker, Marker)

equals

public boolean equals(Object o)

Specified by:

equals in interface Comparator<Marker>

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object