com.google.common.collect.ImmutableRangeSet Maven / Gradle / Ivy
/*
* Copyright (C) 2012 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.SortedLists.KeyAbsentBehavior.NEXT_HIGHER;
import static com.google.common.collect.SortedLists.KeyAbsentBehavior.NEXT_LOWER;
import static com.google.common.collect.SortedLists.KeyPresentBehavior.ANY_PRESENT;
import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.SortedLists.KeyAbsentBehavior;
import com.google.common.collect.SortedLists.KeyPresentBehavior;
import com.google.common.primitives.Ints;
import java.io.Serializable;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.stream.Collector;
/**
* A {@link RangeSet} whose contents will never change, with many other important properties
* detailed at {@link ImmutableCollection}.
*
* @author Louis Wasserman
* @since 14.0
*/
@Beta
@GwtIncompatible
public final class ImmutableRangeSet extends AbstractRangeSet
implements Serializable {
private static final ImmutableRangeSet> EMPTY =
new ImmutableRangeSet<>(ImmutableList.>>of());
private static final ImmutableRangeSet> ALL =
new ImmutableRangeSet<>(ImmutableList.of(Range.>all()));
/**
* Returns a {@code Collector} that accumulates the input elements into a new {@code
* ImmutableRangeSet}. As in {@link Builder}, overlapping ranges are not permitted and adjacent
* ranges will be merged.
*
* @since 23.1
*/
public static >
Collector, ?, ImmutableRangeSet> toImmutableRangeSet() {
return CollectCollectors.toImmutableRangeSet();
}
/** Returns an empty immutable range set. */
@SuppressWarnings("unchecked")
public static ImmutableRangeSet of() {
return (ImmutableRangeSet) EMPTY;
}
/**
* Returns an immutable range set containing the specified single range. If {@link Range#isEmpty()
* range.isEmpty()}, this is equivalent to {@link ImmutableRangeSet#of()}.
*/
public static ImmutableRangeSet of(Range range) {
checkNotNull(range);
if (range.isEmpty()) {
return of();
} else if (range.equals(Range.all())) {
return all();
} else {
return new ImmutableRangeSet(ImmutableList.of(range));
}
}
/** Returns an immutable range set containing the single range {@link Range#all()}. */
@SuppressWarnings("unchecked")
static ImmutableRangeSet all() {
return (ImmutableRangeSet) ALL;
}
/** Returns an immutable copy of the specified {@code RangeSet}. */
public static ImmutableRangeSet copyOf(RangeSet rangeSet) {
checkNotNull(rangeSet);
if (rangeSet.isEmpty()) {
return of();
} else if (rangeSet.encloses(Range.all())) {
return all();
}
if (rangeSet instanceof ImmutableRangeSet) {
ImmutableRangeSet immutableRangeSet = (ImmutableRangeSet) rangeSet;
if (!immutableRangeSet.isPartialView()) {
return immutableRangeSet;
}
}
return new ImmutableRangeSet(ImmutableList.copyOf(rangeSet.asRanges()));
}
/**
* Returns an {@code ImmutableRangeSet} containing each of the specified disjoint ranges.
* Overlapping ranges and empty ranges are forbidden, though adjacent ranges are permitted and
* will be merged.
*
* @throws IllegalArgumentException if any ranges overlap or are empty
* @since 21.0
*/
public static > ImmutableRangeSet copyOf(Iterable> ranges) {
return new ImmutableRangeSet.Builder().addAll(ranges).build();
}
/**
* Returns an {@code ImmutableRangeSet} representing the union of the specified ranges.
*
* This is the smallest {@code RangeSet} which encloses each of the specified ranges. Duplicate
* or connected ranges are permitted, and will be coalesced in the result.
*
* @since 21.0
*/
public static > ImmutableRangeSet unionOf(Iterable> ranges) {
return copyOf(TreeRangeSet.create(ranges));
}
ImmutableRangeSet(ImmutableList> ranges) {
this.ranges = ranges;
}
private ImmutableRangeSet(ImmutableList> ranges, ImmutableRangeSet complement) {
this.ranges = ranges;
this.complement = complement;
}
private final transient ImmutableList> ranges;
@Override
public boolean intersects(Range otherRange) {
int ceilingIndex =
SortedLists.binarySearch(
ranges,
Range.lowerBoundFn(),
otherRange.lowerBound,
Ordering.natural(),
ANY_PRESENT,
NEXT_HIGHER);
if (ceilingIndex < ranges.size()
&& ranges.get(ceilingIndex).isConnected(otherRange)
&& !ranges.get(ceilingIndex).intersection(otherRange).isEmpty()) {
return true;
}
return ceilingIndex > 0
&& ranges.get(ceilingIndex - 1).isConnected(otherRange)
&& !ranges.get(ceilingIndex - 1).intersection(otherRange).isEmpty();
}
@Override
public boolean encloses(Range otherRange) {
int index =
SortedLists.binarySearch(
ranges,
Range.lowerBoundFn(),
otherRange.lowerBound,
Ordering.natural(),
ANY_PRESENT,
NEXT_LOWER);
return index != -1 && ranges.get(index).encloses(otherRange);
}
@Override
public Range rangeContaining(C value) {
int index =
SortedLists.binarySearch(
ranges,
Range.lowerBoundFn(),
Cut.belowValue(value),
Ordering.natural(),
ANY_PRESENT,
NEXT_LOWER);
if (index != -1) {
Range range = ranges.get(index);
return range.contains(value) ? range : null;
}
return null;
}
@Override
public Range span() {
if (ranges.isEmpty()) {
throw new NoSuchElementException();
}
return Range.create(ranges.get(0).lowerBound, ranges.get(ranges.size() - 1).upperBound);
}
@Override
public boolean isEmpty() {
return ranges.isEmpty();
}
/**
* Guaranteed to throw an exception and leave the {@code RangeSet} unmodified.
*
* @throws UnsupportedOperationException always
* @deprecated Unsupported operation.
*/
@Deprecated
@Override
public void add(Range range) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the {@code RangeSet} unmodified.
*
* @throws UnsupportedOperationException always
* @deprecated Unsupported operation.
*/
@Deprecated
@Override
public void addAll(RangeSet other) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the {@code RangeSet} unmodified.
*
* @throws UnsupportedOperationException always
* @deprecated Unsupported operation.
*/
@Deprecated
@Override
public void addAll(Iterable> other) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the {@code RangeSet} unmodified.
*
* @throws UnsupportedOperationException always
* @deprecated Unsupported operation.
*/
@Deprecated
@Override
public void remove(Range range) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the {@code RangeSet} unmodified.
*
* @throws UnsupportedOperationException always
* @deprecated Unsupported operation.
*/
@Deprecated
@Override
public void removeAll(RangeSet other) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the {@code RangeSet} unmodified.
*
* @throws UnsupportedOperationException always
* @deprecated Unsupported operation.
*/
@Deprecated
@Override
public void removeAll(Iterable> other) {
throw new UnsupportedOperationException();
}
@Override
public ImmutableSet> asRanges() {
if (ranges.isEmpty()) {
return ImmutableSet.of();
}
return new RegularImmutableSortedSet<>(ranges, Range.rangeLexOrdering());
}
@Override
public ImmutableSet> asDescendingSetOfRanges() {
if (ranges.isEmpty()) {
return ImmutableSet.of();
}
return new RegularImmutableSortedSet<>(ranges.reverse(), Range.rangeLexOrdering().reverse());
}
private transient ImmutableRangeSet complement;
private final class ComplementRanges extends ImmutableList> {
// True if the "positive" range set is empty or bounded below.
private final boolean positiveBoundedBelow;
// True if the "positive" range set is empty or bounded above.
private final boolean positiveBoundedAbove;
private final int size;
ComplementRanges() {
this.positiveBoundedBelow = ranges.get(0).hasLowerBound();
this.positiveBoundedAbove = Iterables.getLast(ranges).hasUpperBound();
int size = ranges.size() - 1;
if (positiveBoundedBelow) {
size++;
}
if (positiveBoundedAbove) {
size++;
}
this.size = size;
}
@Override
public int size() {
return size;
}
@Override
public Range get(int index) {
checkElementIndex(index, size);
Cut lowerBound;
if (positiveBoundedBelow) {
lowerBound = (index == 0) ? Cut.belowAll() : ranges.get(index - 1).upperBound;
} else {
lowerBound = ranges.get(index).upperBound;
}
Cut upperBound;
if (positiveBoundedAbove && index == size - 1) {
upperBound = Cut.aboveAll();
} else {
upperBound = ranges.get(index + (positiveBoundedBelow ? 0 : 1)).lowerBound;
}
return Range.create(lowerBound, upperBound);
}
@Override
boolean isPartialView() {
return true;
}
}
@Override
public ImmutableRangeSet complement() {
ImmutableRangeSet result = complement;
if (result != null) {
return result;
} else if (ranges.isEmpty()) {
return complement = all();
} else if (ranges.size() == 1 && ranges.get(0).equals(Range.all())) {
return complement = of();
} else {
ImmutableList> complementRanges = new ComplementRanges();
result = complement = new ImmutableRangeSet(complementRanges, this);
}
return result;
}
/**
* Returns a new range set consisting of the union of this range set and {@code other}.
*
* This is essentially the same as {@code TreeRangeSet.create(this).addAll(other)} except it
* returns an {@code ImmutableRangeSet}.
*
* @since 21.0
*/
public ImmutableRangeSet union(RangeSet other) {
return unionOf(Iterables.concat(asRanges(), other.asRanges()));
}
/**
* Returns a new range set consisting of the intersection of this range set and {@code other}.
*
* This is essentially the same as {@code
* TreeRangeSet.create(this).removeAll(other.complement())} except it returns an {@code
* ImmutableRangeSet}.
*
* @since 21.0
*/
public ImmutableRangeSet intersection(RangeSet other) {
RangeSet copy = TreeRangeSet.create(this);
copy.removeAll(other.complement());
return copyOf(copy);
}
/**
* Returns a new range set consisting of the difference of this range set and {@code other}.
*
* This is essentially the same as {@code TreeRangeSet.create(this).removeAll(other)} except it
* returns an {@code ImmutableRangeSet}.
*
* @since 21.0
*/
public ImmutableRangeSet difference(RangeSet other) {
RangeSet copy = TreeRangeSet.create(this);
copy.removeAll(other);
return copyOf(copy);
}
/**
* Returns a list containing the nonempty intersections of {@code range} with the ranges in this
* range set.
*/
private ImmutableList> intersectRanges(final Range range) {
if (ranges.isEmpty() || range.isEmpty()) {
return ImmutableList.of();
} else if (range.encloses(span())) {
return ranges;
}
final int fromIndex;
if (range.hasLowerBound()) {
fromIndex =
SortedLists.binarySearch(
ranges,
Range.upperBoundFn(),
range.lowerBound,
KeyPresentBehavior.FIRST_AFTER,
KeyAbsentBehavior.NEXT_HIGHER);
} else {
fromIndex = 0;
}
int toIndex;
if (range.hasUpperBound()) {
toIndex =
SortedLists.binarySearch(
ranges,
Range.lowerBoundFn(),
range.upperBound,
KeyPresentBehavior.FIRST_PRESENT,
KeyAbsentBehavior.NEXT_HIGHER);
} else {
toIndex = ranges.size();
}
final int length = toIndex - fromIndex;
if (length == 0) {
return ImmutableList.of();
} else {
return new ImmutableList>() {
@Override
public int size() {
return length;
}
@Override
public Range get(int index) {
checkElementIndex(index, length);
if (index == 0 || index == length - 1) {
return ranges.get(index + fromIndex).intersection(range);
} else {
return ranges.get(index + fromIndex);
}
}
@Override
boolean isPartialView() {
return true;
}
};
}
}
/** Returns a view of the intersection of this range set with the given range. */
@Override
public ImmutableRangeSet subRangeSet(Range range) {
if (!isEmpty()) {
Range span = span();
if (range.encloses(span)) {
return this;
} else if (range.isConnected(span)) {
return new ImmutableRangeSet(intersectRanges(range));
}
}
return of();
}
/**
* Returns an {@link ImmutableSortedSet} containing the same values in the given domain
* {@linkplain RangeSet#contains contained} by this range set.
*
* Note: {@code a.asSet(d).equals(b.asSet(d))} does not imply {@code a.equals(b)}! For
* example, {@code a} and {@code b} could be {@code [2..4]} and {@code (1..5)}, or the empty
* ranges {@code [3..3)} and {@code [4..4)}.
*
*
Warning: Be extremely careful what you do with the {@code asSet} view of a large
* range set (such as {@code ImmutableRangeSet.of(Range.greaterThan(0))}). Certain operations on
* such a set can be performed efficiently, but others (such as {@link Set#hashCode} or {@link
* Collections#frequency}) can cause major performance problems.
*
*
The returned set's {@link Object#toString} method returns a short-hand form of the set's
* contents, such as {@code "[1..100]}"}.
*
* @throws IllegalArgumentException if neither this range nor the domain has a lower bound, or if
* neither has an upper bound
*/
public ImmutableSortedSet asSet(DiscreteDomain domain) {
checkNotNull(domain);
if (isEmpty()) {
return ImmutableSortedSet.of();
}
Range span = span().canonical(domain);
if (!span.hasLowerBound()) {
// according to the spec of canonical, neither this ImmutableRangeSet nor
// the range have a lower bound
throw new IllegalArgumentException(
"Neither the DiscreteDomain nor this range set are bounded below");
} else if (!span.hasUpperBound()) {
try {
domain.maxValue();
} catch (NoSuchElementException e) {
throw new IllegalArgumentException(
"Neither the DiscreteDomain nor this range set are bounded above");
}
}
return new AsSet(domain);
}
private final class AsSet extends ImmutableSortedSet {
private final DiscreteDomain domain;
AsSet(DiscreteDomain domain) {
super(Ordering.natural());
this.domain = domain;
}
private transient Integer size;
@Override
public int size() {
// racy single-check idiom
Integer result = size;
if (result == null) {
long total = 0;
for (Range range : ranges) {
total += ContiguousSet.create(range, domain).size();
if (total >= Integer.MAX_VALUE) {
break;
}
}
result = size = Ints.saturatedCast(total);
}
return result.intValue();
}
@Override
public UnmodifiableIterator iterator() {
return new AbstractIterator() {
final Iterator> rangeItr = ranges.iterator();
Iterator elemItr = Iterators.emptyIterator();
@Override
protected C computeNext() {
while (!elemItr.hasNext()) {
if (rangeItr.hasNext()) {
elemItr = ContiguousSet.create(rangeItr.next(), domain).iterator();
} else {
return endOfData();
}
}
return elemItr.next();
}
};
}
@Override
@GwtIncompatible("NavigableSet")
public UnmodifiableIterator descendingIterator() {
return new AbstractIterator() {
final Iterator> rangeItr = ranges.reverse().iterator();
Iterator elemItr = Iterators.emptyIterator();
@Override
protected C computeNext() {
while (!elemItr.hasNext()) {
if (rangeItr.hasNext()) {
elemItr = ContiguousSet.create(rangeItr.next(), domain).descendingIterator();
} else {
return endOfData();
}
}
return elemItr.next();
}
};
}
ImmutableSortedSet subSet(Range range) {
return subRangeSet(range).asSet(domain);
}
@Override
ImmutableSortedSet headSetImpl(C toElement, boolean inclusive) {
return subSet(Range.upTo(toElement, BoundType.forBoolean(inclusive)));
}
@Override
ImmutableSortedSet subSetImpl(
C fromElement, boolean fromInclusive, C toElement, boolean toInclusive) {
if (!fromInclusive && !toInclusive && Range.compareOrThrow(fromElement, toElement) == 0) {
return ImmutableSortedSet.of();
}
return subSet(
Range.range(
fromElement, BoundType.forBoolean(fromInclusive),
toElement, BoundType.forBoolean(toInclusive)));
}
@Override
ImmutableSortedSet tailSetImpl(C fromElement, boolean inclusive) {
return subSet(Range.downTo(fromElement, BoundType.forBoolean(inclusive)));
}
@Override
public boolean contains(Object o) {
if (o == null) {
return false;
}
try {
@SuppressWarnings("unchecked") // we catch CCE's
C c = (C) o;
return ImmutableRangeSet.this.contains(c);
} catch (ClassCastException e) {
return false;
}
}
@Override
int indexOf(Object target) {
if (contains(target)) {
@SuppressWarnings("unchecked") // if it's contained, it's definitely a C
C c = (C) target;
long total = 0;
for (Range range : ranges) {
if (range.contains(c)) {
return Ints.saturatedCast(total + ContiguousSet.create(range, domain).indexOf(c));
} else {
total += ContiguousSet.create(range, domain).size();
}
}
throw new AssertionError("impossible");
}
return -1;
}
@Override
ImmutableSortedSet createDescendingSet() {
return new DescendingImmutableSortedSet(this);
}
@Override
boolean isPartialView() {
return ranges.isPartialView();
}
@Override
public String toString() {
return ranges.toString();
}
@Override
Object writeReplace() {
return new AsSetSerializedForm(ranges, domain);
}
}
private static class AsSetSerializedForm implements Serializable {
private final ImmutableList> ranges;
private final DiscreteDomain domain;
AsSetSerializedForm(ImmutableList> ranges, DiscreteDomain domain) {
this.ranges = ranges;
this.domain = domain;
}
Object readResolve() {
return new ImmutableRangeSet(ranges).asSet(domain);
}
}
/**
* Returns {@code true} if this immutable range set's implementation contains references to
* user-created objects that aren't accessible via this range set's methods. This is generally
* used to determine whether {@code copyOf} implementations should make an explicit copy to avoid
* memory leaks.
*/
boolean isPartialView() {
return ranges.isPartialView();
}
/** Returns a new builder for an immutable range set. */
public static > Builder builder() {
return new Builder();
}
/**
* A builder for immutable range sets.
*
* @since 14.0
*/
public static class Builder> {
private final List> ranges;
public Builder() {
this.ranges = Lists.newArrayList();
}
// TODO(lowasser): consider adding union, in addition to add, that does allow overlap
/**
* Add the specified range to this builder. Adjacent ranges are permitted and will be merged,
* but overlapping ranges will cause an exception when {@link #build()} is called.
*
* @throws IllegalArgumentException if {@code range} is empty
*/
public Builder add(Range range) {
checkArgument(!range.isEmpty(), "range must not be empty, but was %s", range);
ranges.add(range);
return this;
}
/**
* Add all ranges from the specified range set to this builder. Adjacent ranges are permitted
* and will be merged, but overlapping ranges will cause an exception when {@link #build()} is
* called.
*/
public Builder addAll(RangeSet ranges) {
return addAll(ranges.asRanges());
}
/**
* Add all of the specified ranges to this builder. Adjacent ranges are permitted and will be
* merged, but overlapping ranges will cause an exception when {@link #build()} is called.
*
* @throws IllegalArgumentException if any inserted ranges are empty
* @since 21.0
*/
public Builder addAll(Iterable> ranges) {
for (Range range : ranges) {
add(range);
}
return this;
}
Builder combine(Builder builder) {
addAll(builder.ranges);
return this;
}
/**
* Returns an {@code ImmutableRangeSet} containing the ranges added to this builder.
*
* @throws IllegalArgumentException if any input ranges have nonempty overlap
*/
public ImmutableRangeSet build() {
ImmutableList.Builder> mergedRangesBuilder =
new ImmutableList.Builder<>(ranges.size());
Collections.sort(ranges, Range.rangeLexOrdering());
PeekingIterator> peekingItr = Iterators.peekingIterator(ranges.iterator());
while (peekingItr.hasNext()) {
Range range = peekingItr.next();
while (peekingItr.hasNext()) {
Range nextRange = peekingItr.peek();
if (range.isConnected(nextRange)) {
checkArgument(
range.intersection(nextRange).isEmpty(),
"Overlapping ranges not permitted but found %s overlapping %s",
range,
nextRange);
range = range.span(peekingItr.next());
} else {
break;
}
}
mergedRangesBuilder.add(range);
}
ImmutableList> mergedRanges = mergedRangesBuilder.build();
if (mergedRanges.isEmpty()) {
return of();
} else if (mergedRanges.size() == 1
&& Iterables.getOnlyElement(mergedRanges).equals(Range.all())) {
return all();
} else {
return new ImmutableRangeSet(mergedRanges);
}
}
}
private static final class SerializedForm implements Serializable {
private final ImmutableList> ranges;
SerializedForm(ImmutableList> ranges) {
this.ranges = ranges;
}
Object readResolve() {
if (ranges.isEmpty()) {
return of();
} else if (ranges.equals(ImmutableList.of(Range.all()))) {
return all();
} else {
return new ImmutableRangeSet(ranges);
}
}
}
Object writeReplace() {
return new SerializedForm(ranges);
}
}