/**
* Returns an immutable map containing the same entries as the provided sorted map, with the same
* ordering.
*
* <p>Despite the method name, this method attempts to avoid actually copying the data when it is
* safe to do so. The exact circumstances under which a copy will or will not be performed are
* undocumented and subject to change.
*
* @throws NullPointerException if any key or value in {@code map} is null
*/
@SuppressWarnings("unchecked")
public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(SortedMap<K, ? extends V> map) {
Comparator<? super K> comparator = map.comparator();
if (comparator == null) {
// If map has a null comparator, the keys should have a natural ordering,
// even though K doesn't explicitly implement Comparable.
comparator = (Comparator<? super K>) NATURAL_ORDER;
}
if (map instanceof ImmutableSortedMap) {
// TODO(kevinb): Prove that this cast is safe, even though
// Collections.unmodifiableSortedMap requires the same key type.
@SuppressWarnings("unchecked")
ImmutableSortedMap<K, V> kvMap = (ImmutableSortedMap<K, V>) map;
if (!kvMap.isPartialView()) {
return kvMap;
}
}
return fromEntries(comparator, true, map.entrySet());
}
private static <K, V> ImmutableSortedMap<K, V> copyOfInternal(
Map<? extends K, ? extends V> map, Comparator<? super K> comparator) {
boolean sameComparator = false;
if (map instanceof SortedMap) {
SortedMap<?, ?> sortedMap = (SortedMap<?, ?>) map;
Comparator<?> comparator2 = sortedMap.comparator();
sameComparator =
(comparator2 == null) ? comparator == NATURAL_ORDER : comparator.equals(comparator2);
}
if (sameComparator && (map instanceof ImmutableSortedMap)) {
// TODO(kevinb): Prove that this cast is safe, even though
// Collections.unmodifiableSortedMap requires the same key type.
@SuppressWarnings("unchecked")
ImmutableSortedMap<K, V> kvMap = (ImmutableSortedMap<K, V>) map;
if (!kvMap.isPartialView()) {
return kvMap;
}
}
return fromEntries(comparator, sameComparator, map.entrySet());
}
public Comparator<? super byte[]> comparator() {
return map.comparator();
}
public Comparator<? super K> comparator() {
checkInit();
return delegate.comparator();
}
@Override
public void doInitialize(SortedMap<K, V> sortedMap, boolean empty) {
init(empty ? new TreeMap<K, V>(sortedMap.comparator()) : sortedMap, null, false);
}
private <K, V> void verify(
SortedMap<K, V> immutableMap, SortedMap<K, V> mutableMap, K key1, K key2, V value) {
try {
immutableMap.clear();
Assert.assertTrue(mutableMap.isEmpty());
} catch (UnsupportedOperationException e) {
Assert.assertFalse(mutableMap.isEmpty());
}
Assert.assertEquals(immutableMap.containsKey(key1), mutableMap.containsKey(key1));
Assert.assertEquals(immutableMap.containsKey(key2), mutableMap.containsKey(key2));
Assert.assertEquals(immutableMap.containsValue(value), mutableMap.containsValue(value));
Assert.assertEquals(immutableMap.containsValue(null), mutableMap.containsValue(null));
Assert.assertEquals(immutableMap.entrySet(), mutableMap.entrySet());
Assert.assertEquals(immutableMap.get(key1), mutableMap.get(key1));
Assert.assertEquals(immutableMap.get(key2), mutableMap.get(key2));
Assert.assertEquals(immutableMap.isEmpty(), mutableMap.isEmpty());
Assert.assertEquals(immutableMap.keySet(), mutableMap.keySet());
try {
immutableMap.put(key1, value);
Assert.fail();
} catch (UnsupportedOperationException e) {
}
try {
immutableMap.putAll(java.util.Collections.singletonMap(key1, value));
Assert.fail();
} catch (UnsupportedOperationException e) {
}
try {
immutableMap.remove(key1);
} catch (UnsupportedOperationException e) {
}
Assert.assertEquals(immutableMap.size(), mutableMap.size());
// Is it OK that this fails?
// Assert.assertEquals(immutableMap.values(), mutableMap.values());
Assert.assertEquals(immutableMap.values().size(), mutableMap.values().size());
if (!mutableMap.isEmpty()) {
Assert.assertEquals(
immutableMap.values().iterator().next(), mutableMap.values().iterator().next());
}
Assert.assertSame(immutableMap.comparator(), mutableMap.comparator());
if (!mutableMap.isEmpty()) {
Assert.assertEquals(immutableMap.firstKey(), mutableMap.firstKey());
Assert.assertEquals(immutableMap.lastKey(), mutableMap.lastKey());
} else {
try {
immutableMap.firstKey();
Assert.fail();
} catch (NoSuchElementException e) {
}
try {
immutableMap.lastKey();
Assert.fail();
} catch (NoSuchElementException e) {
}
}
Assert.assertEquals(immutableMap.headMap(key1), mutableMap.headMap(key1));
Assert.assertEquals(immutableMap.headMap(key2), mutableMap.headMap(key2));
Assert.assertEquals(immutableMap.subMap(key1, key2), mutableMap.subMap(key1, key2));
Assert.assertEquals(immutableMap.tailMap(key1), mutableMap.tailMap(key1));
Assert.assertEquals(immutableMap.tailMap(key2), mutableMap.tailMap(key2));
}
/** Switches row and column qualifier. Use same comparator as the given map. Returns TreeMap. */
public static <V> SortedMap<Key, V> transposeMap(SortedMap<Key, V> mapOrig) {
SortedMap<Key, V> m = new TreeMap<>(mapOrig.comparator());
return transposeMapHelp(mapOrig, m);
}