/**
* Returns true if {@code container} contains {@code test}, false otherwise.
*
* <p>Fields for which {@code set} has no value ({@link Marker#valueFor(FieldPartitioner)} returns
* null) are treated as wildcards and always match.
*
* <p>All fields in the {@link PartitionStrategy} are compared.
*
* @param container a {@code Marker} that defines a set of partitions
* @param test a {@code Marker} that may be a subset of {@code container}
* @return {@code true} if the partitions in {@code test} are a subset of {@code container},
* {@code false} otherwise
*/
@SuppressWarnings("unchecked")
public boolean contains(Marker container, Marker test) {
for (FieldPartitioner field : strategy.getFieldPartitioners()) {
Object containerValue = container.valueFor(field);
if (containerValue != null) {
Object testValue = test.valueFor(field);
if (testValue == null || field.compare(containerValue, testValue) != 0) {
return false;
}
}
/*
* Rather than returning true if containerValue is null, this treats
* null as a wildcard. Everything matches null, so all non-null fields
* will be checked.
*/
}
return true;
}
/**
* Compare two {@link Marker} objects under the {@link PartitionStrategy}.
*
* <p>All comparisons are with respect to the partition ordering defined by this comparator's
* {@code PartitionStrategy}. Under a {@code PartitionStrategy}, a {@code Marker} contains a set
* of one or more partitions. A {@code 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 {@code Marker} is greater. Two {@code
* Markers} are equal if they contain the same set of partitions.
*
* <p>This method implements left-inclusive comparison: if either {@code Marker} contains the
* other, then it is considered lesser. This means that there is at least one partition in the
* containing {@code Marker} that is less than all of the partitions in the contained {@code
* Marker}. This behavior is for checking an inclusive lower bound for a range.
*
* <p>m1 = [ 2013, Oct, * ] m2 = [ 2013, Oct, 12 ] leftCompare(m1, m2) returns 1 leftCompare(m2,
* m1) returns -1
*
* <p>The comparison method {@link #rightCompare(Marker, Marker)} implements right-inclusive
* comparison.
*
* <p>Note: Because {@code 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.
*
* <p>TODO: catch wildcard to concrete comparisons and throw an Exception
*
* @param m1 a {@code Marker}
* @param m2 a {@code Marker}
* @return -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
* @see MarkerComparator#compare(Marker, Marker)
* @see MarkerComparator#rightCompare(Marker, Marker)
* @since 0.9.0
*/
@SuppressWarnings("unchecked")
public int leftCompare(Marker m1, Marker m2) {
for (FieldPartitioner field : strategy.getFieldPartitioners()) {
Object m1Value = m1.valueFor(field);
Object m2Value = m2.valueFor(field);
if (m1Value == null) {
if (m2Value != null) {
// m1 contains m2
return -1;
}
} else if (m2Value == null) {
// m2 contains m1
return 1;
} else {
int cmp = field.compare(m1Value, m2Value);
if (cmp != 0) {
return cmp;
}
}
}
return 0;
}
/**
* Compare two {@link Marker} objects under the {@link PartitionStrategy}.
*
* <p>All comparisons are with respect to the partition ordering defined by this comparator's
* {@code PartitionStrategy}. Under a {@code PartitionStrategy}, a {@code Marker} contains a set
* of one or more partitions. A {@code 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 {@code Marker} is greater. Two {@code
* Markers} are equal if they contain the same set of partitions.
*
* <p>This method implements strictly exclusive comparison: if either {@code Marker} contains the
* other, then this throws {@code IllegalStateException}. This is because there is at least one
* partition in the containing {@code Marker} that is less than or equal to all partitions in the
* contained {@code Marker} and at least one partition that is greater than or equal to all
* partitions in the contained {@code Marker}.
*
* <p>Alternatively, the comparison methods {@link #leftCompare(Marker, Marker)} and {@link
* #rightCompare(Marker, Marker)} consider contained {@code Marker} objects to be greater-than and
* less-than respectively.
*
* <p>Note: Because {@code 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 {@code IllegalStateException}.
*
* <p>TODO: catch wildcard to concrete comparisons and throw an Exception
*
* @param m1 a {@code Marker}
* @param m2 a {@code Marker}
* @return -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 {@code Marker} is a proper subset of the other
* @see MarkerComparator#leftCompare(Marker, Marker)
* @see MarkerComparator#rightCompare(Marker, Marker)
* @since 0.9.0
*/
@Override
@SuppressWarnings("unchecked")
public int compare(Marker m1, Marker m2) {
for (FieldPartitioner field : strategy.getFieldPartitioners()) {
Object m1Value = m1.valueFor(field);
Object m2Value = m2.valueFor(field);
// if either is null, but not both, then they are Incomparable
if (m1Value == null) {
if (m2Value != null) {
// m1 contains m2
throw new IllegalStateException("Incomparable");
}
} else if (m2Value == null) {
// m2 contains m1
throw new IllegalStateException("Incomparable");
} else {
int cmp = field.compare(m1Value, m2Value);
if (cmp != 0) {
return cmp;
}
}
}
return 0;
}
