com.github.tommyettinger.ds.ObjectObjectMap Maven / Gradle / Ivy
Show all versions of jdkgdxds Show documentation
/*
* Copyright (c) 2022-2025 See AUTHORS file.
*
* 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.github.tommyettinger.ds;
import com.github.tommyettinger.digital.BitConversion;
import com.github.tommyettinger.ds.support.util.Appender;
import com.github.tommyettinger.function.ObjObjToObjBiFunction;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
import java.util.AbstractCollection;
import java.util.AbstractSet;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.Set;
import static com.github.tommyettinger.ds.Utilities.neverIdentical;
import static com.github.tommyettinger.ds.Utilities.tableSize;
/**
* An unordered map where the keys and values are objects. Null keys are not allowed. No allocation is done except when growing
* the table size.
*
* This class performs fast contains and remove (typically O(1), worst case O(n) but that is rare in practice). Add may be
* slightly slower, depending on hash collisions. Hashcodes are rehashed to reduce collisions and the need to resize. Load factors
* greater than 0.91 greatly increase the chances to resize to the next higher POT size.
*
* Unordered sets and maps are not designed to provide especially fast iteration. Iteration is faster with {@link Ordered} types like
* ObjectOrderedSet and ObjectObjectOrderedMap.
*
* You can customize most behavior of this map by extending it. {@link #place(Object)} can be overridden to change how hashCodes
* are calculated (which can be useful for types like {@link StringBuilder} that don't implement hashCode()), and
* {@link #equate(Object, Object)} can be overridden to change how equality is calculated.
*
* This implementation uses linear probing with the backward shift algorithm for removal.
* It tries different hashes from a simple family, with the hash changing on resize.
* Linear probing continues to work even when all hashCodes collide; it just works more slowly in that case.
*
* @author Nathan Sweet
* @author Tommy Ettinger
*/
public class ObjectObjectMap implements Map, Iterable> {
protected int size;
protected @Nullable K[] keyTable;
protected @Nullable V[] valueTable;
/**
* Between 0f (exclusive) and 1f (inclusive, if you're careful), this determines how full the backing tables
* can get before this increases their size. Larger values use less memory but make the data structure slower.
*/
protected float loadFactor;
/**
* Precalculated value of {@code (int)(keyTable.length * loadFactor)}, used to determine when to resize.
*/
protected int threshold;
/**
* Used by {@link #place(Object)} typically, this should always equal {@code BitConversion.countLeadingZeros(mask)}.
* For a table that could hold 2 items (with 1 bit indices), this would be {@code 64 - 1 == 63}. For a table that
* could hold 256 items (with 8 bit indices), this would be {@code 64 - 8 == 56}.
*/
protected int shift;
/**
* A bitmask used to confine hashcodes to the size of the table. Must be all 1-bits in its low positions, ie a power of two
* minus 1. If {@link #place(Object)} is overridden, this can be used instead of {@link #shift} to isolate usable bits of a
* hash.
*/
protected int mask;
@Nullable protected transient Entries entries1;
@Nullable protected transient Entries entries2;
@Nullable protected transient Values values1;
@Nullable protected transient Values values2;
@Nullable protected transient Keys keys1;
@Nullable protected transient Keys keys2;
/**
* Returned by {@link #get(Object)} when no value exists for the given key, as well as some other methods to indicate that
* no value in the Map could be returned.
*/
@Nullable public V defaultValue = null;
/**
* Creates a new map with an initial capacity of 51 and a load factor of {@link Utilities#getDefaultLoadFactor()}.
*/
public ObjectObjectMap () {
this(51, Utilities.getDefaultLoadFactor());
}
/**
* Creates a new map with the given starting capacity and a load factor of {@link Utilities#getDefaultLoadFactor()}.
*
* @param initialCapacity If not a power of two, it is increased to the next nearest power of two.
*/
public ObjectObjectMap (int initialCapacity) {
this(initialCapacity, Utilities.getDefaultLoadFactor());
}
/**
* Creates a new map with the specified initial capacity and load factor. This map will hold initialCapacity items before
* growing the backing table.
*
* @param initialCapacity If not a power of two, it is increased to the next nearest power of two.
* @param loadFactor what fraction of the capacity can be filled before this has to resize; 0 < loadFactor <= 1
*/
public ObjectObjectMap (int initialCapacity, float loadFactor) {
if (loadFactor <= 0f || loadFactor > 1f) {throw new IllegalArgumentException("loadFactor must be > 0 and <= 1: " + loadFactor);}
this.loadFactor = loadFactor;
int tableSize = tableSize(initialCapacity, loadFactor);
threshold = (int)(tableSize * loadFactor);
mask = tableSize - 1;
shift = BitConversion.countLeadingZeros(mask) + 32;
keyTable = (K[])new Object[tableSize];
valueTable = (V[])new Object[tableSize];
}
/**
* Creates a new map identical to the specified map.
*
* @param map an ObjectObjectMap to copy
*/
public ObjectObjectMap (ObjectObjectMap map) {
this.loadFactor = map.loadFactor;
this.threshold = map.threshold;
this.mask = map.mask;
this.shift = map.shift;
keyTable = Arrays.copyOf(map.keyTable, map.keyTable.length);
valueTable = Arrays.copyOf(map.valueTable, map.valueTable.length);
size = map.size;
defaultValue = map.defaultValue;
}
/**
* Creates a new map identical to the specified map.
*
* @param map a Map to copy; ObjectObjectMap or its subclasses will be faster
*/
public ObjectObjectMap (Map map) {
this(map.size());
putAll(map);
}
/**
* Given two side-by-side arrays, one of keys, one of values, this constructs a map and inserts each pair of key and value into it.
* If keys and values have different lengths, this only uses the length of the smaller array.
*
* @param keys an array of keys
* @param values an array of values
*/
public ObjectObjectMap (K[] keys, V[] values) {
this(Math.min(keys.length, values.length));
putAll(keys, values);
}
/**
* Given two side-by-side collections, one of keys, one of values, this constructs a map and inserts each pair of key and value into it.
* If keys and values have different lengths, this only uses the length of the smaller collection.
*
* @param keys a Collection of keys
* @param values a Collection of values
*/
public ObjectObjectMap (Collection keys, Collection values) {
this(Math.min(keys.size(), values.size()));
putAll(keys, values);
}
/**
* Returns an index >= 0 and <= {@link #mask} for the specified {@code item}, mixed.
*
* @param item a non-null Object; its hashCode() method should be used by most implementations
* @return an index between 0 and {@link #mask} (both inclusive)
*/
protected int place (@NonNull Object item) {
final int h = item.hashCode();
return (h ^ (h << 9 | h >>> 23) ^ (h << 21 | h >>> 11)) & mask;
// This can be used if you know hashCode() has few collisions normally, and won't be maliciously manipulated.
// return item.hashCode() & mask;
}
/**
* Compares the objects left and right, which are usually keys, for equality, returning true if they are considered
* equal. This is used by the rest of this class to determine whether two keys are considered equal. Normally, this
* returns {@code left.equals(right)}, but subclasses can override it to use reference equality, fuzzy equality, deep
* array equality, or any other custom definition of equality. Usually, {@link #place(Object)} is also overridden if
* this method is.
*
* @param left must be non-null; typically a key being compared, but not necessarily
* @param right may be null; typically a key being compared, but can often be null for an empty key slot, or some other type
* @return true if left and right are considered equal for the purposes of this class
*/
protected boolean equate (Object left, @Nullable Object right) {
return left.equals(right);
}
/**
* Returns the index of the key if already present, else {@code ~index} for the next empty index. This calls
* {@link #equate(Object, Object)} to determine if two keys are equivalent.
*
* @param key a non-null K key
* @return a negative index if the key was not found, or the non-negative index of the existing key if found
*/
protected int locateKey (Object key) {
K[] keyTable = this.keyTable;
for (int i = place(key); ; i = i + 1 & mask) {
K other = keyTable[i];
if (equate(key, other))
return i; // Same key was found.
if (other == null)
return ~i; // Always negative; means empty space is available at i.
}
}
/**
* Returns the old value associated with the specified key, or this map's {@link #defaultValue} if there was no prior value.
*/
@Override
@Nullable
public V put (K key, @Nullable V value) {
int i = locateKey(key);
if (i >= 0) { // Existing key was found.
V oldValue = valueTable[i];
valueTable[i] = value;
return oldValue;
}
i = ~i; // Empty space was found.
keyTable[i] = key;
valueTable[i] = value;
if (++size >= threshold) {resize(keyTable.length << 1);}
return defaultValue;
}
@Nullable
public V putOrDefault (K key, @Nullable V value, @Nullable V defaultValue) {
int i = locateKey(key);
if (i >= 0) { // Existing key was found.
V oldValue = valueTable[i];
valueTable[i] = value;
return oldValue;
}
i = ~i; // Empty space was found.
keyTable[i] = key;
valueTable[i] = value;
if (++size >= threshold) {resize(keyTable.length << 1);}
return defaultValue;
}
/**
* Copies all the mappings from the specified map to this map
* (optional operation). The effect of this call is equivalent to that
* of calling {@link #put(Object, Object) put(k, v)} on this map once
* for each mapping from key {@code k} to value {@code v} in the
* specified map. The behavior of this operation is undefined if the
* specified map is modified while the operation is in progress.
*
* Note that {@link #putAll(ObjectObjectMap)} is more specific and can be
* more efficient by using the internal details of this class.
*
* @param m mappings to be stored in this map
* @throws UnsupportedOperationException if the {@code putAll} operation
* is not supported by this map
* @throws ClassCastException if the class of a key or value in the
* specified map prevents it from being stored in this map
* @throws NullPointerException if the specified map is null, or if
* this map does not permit null keys or values, and the
* specified map contains null keys or values
* @throws IllegalArgumentException if some property of a key or value in
* the specified map prevents it from being stored in this map
*/
@Override
public void putAll (Map m) {
ensureCapacity(m.size());
for (Map.Entry kv : m.entrySet()) {put(kv.getKey(), kv.getValue());}
}
/**
* Puts every key-value pair in the given map into this, with the values from the given map
* overwriting the previous values if two keys are identical.
*
* @param map a map with compatible key and value types; will not be modified
*/
public void putAll (ObjectObjectMap map) {
ensureCapacity(map.size);
K[] keyTable = map.keyTable;
V[] valueTable = map.valueTable;
K key;
for (int i = 0, n = keyTable.length; i < n; i++) {
key = keyTable[i];
if (key != null) {put(key, valueTable[i]);}
}
}
/**
* Given two side-by-side collections, one of keys, one of values, this inserts each pair of key and value into this map with put().
*
* @param keys a Collection of keys
* @param values a Collection of values
*/
public void putAll (Collection keys, Collection values) {
int length = Math.min(keys.size(), values.size());
ensureCapacity(length);
K key;
Iterator ki = keys.iterator();
Iterator vi = values.iterator();
while (ki.hasNext() && vi.hasNext()) {
key = ki.next();
if (key != null) {
put(key, vi.next());
}
}
}
/**
* Given two side-by-side arrays, one of keys, one of values, this inserts each pair of key and value into this map with put().
*
* @param keys an array of keys
* @param values an array of values
*/
public void putAll (K[] keys, V[] values) {
putAll(keys, 0, values, 0, Math.min(keys.length, values.length));
}
/**
* Given two side-by-side arrays, one of keys, one of values, this inserts each pair of key and value into this map with put().
*
* @param keys an array of keys
* @param values an array of values
* @param length how many items from keys and values to insert, at-most
*/
public void putAll (K[] keys, V[] values, int length) {
putAll(keys, 0, values, 0, length);
}
/**
* Given two side-by-side arrays, one of keys, one of values, this inserts each pair of key and value into this map with put().
*
* @param keys an array of keys
* @param keyOffset the first index in keys to insert
* @param values an array of values
* @param valueOffset the first index in values to insert
* @param length how many items from keys and values to insert, at-most
*/
public void putAll (K[] keys, int keyOffset, V[] values, int valueOffset, int length) {
length = Math.min(length, Math.min(keys.length - keyOffset, values.length - valueOffset));
ensureCapacity(length);
K key;
for (int k = keyOffset, v = valueOffset, i = 0, n = length; i < n; i++, k++, v++) {
key = keys[k];
if (key != null) {put(key, values[v]);}
}
}
/**
* Skips checks for existing keys, doesn't increment size.
*/
protected void putResize (K key, @Nullable V value) {
K[] keyTable = this.keyTable;
for (int i = place(key); ; i = i + 1 & mask) {
if (keyTable[i] == null) {
keyTable[i] = key;
valueTable[i] = value;
return;
}
}
}
/**
* Returns the value for the specified key, or {@link #defaultValue} if the key is not in the map.
* Note that {@link #defaultValue} is often null, which is also a valid value that can be assigned to a
* legitimate key. Checking that the result of this method is null does not guarantee that the
* {@code key} is not present.
*
* @param key a non-null Object that should almost always be a {@code K} (or an instance of a subclass of {@code K})
*/
@Override
@Nullable
public V get (Object key) {
K[] keyTable = this.keyTable;
for (int i = place(key); ; i = i + 1 & mask) {
K other = keyTable[i];
if (equate(key, other))
return valueTable[i];
if (other == null)
return defaultValue;
}
}
/**
* Returns the value for the specified key, or the given default value if the key is not in the map.
*/
@Nullable
public V getOrDefault (Object key, @Nullable V defaultValue) {
K[] keyTable = this.keyTable;
for (int i = place(key); ; i = i + 1 & mask) {
K other = keyTable[i];
if (equate(key, other))
return valueTable[i];
if (other == null)
return defaultValue;
}
}
@Override
@Nullable
public V remove (Object key) {
int pos = locateKey(key);
if (pos < 0) return defaultValue;
K rem;
@Nullable K[] keyTable = this.keyTable;
@Nullable V[] valueTable = this.valueTable;
@Nullable V oldValue = valueTable[pos];
int mask = this.mask, last, slot;
size--;
for (;;) {
pos = ((last = pos) + 1) & mask;
for (;;) {
if ((rem = keyTable[pos]) == null) {
keyTable[last] = null;
valueTable[last] = null;
return oldValue;
}
slot = place(rem);
if (last <= pos ? last >= slot || slot > pos : last >= slot && slot > pos) break;
pos = (pos + 1) & mask;
}
keyTable[last] = rem;
valueTable[last] = valueTable[pos];
}
}
/**
* Returns true if the map has one or more items.
*/
public boolean notEmpty () {
return size != 0;
}
/**
* Returns the number of key-value mappings in this map. If the
* map contains more than {@code Integer.MAX_VALUE} elements, returns
* {@code Integer.MAX_VALUE}.
*
* @return the number of key-value mappings in this map
*/
@Override
public int size () {
return size;
}
/**
* Returns true if the map is empty.
*/
@Override
public boolean isEmpty () {
return size == 0;
}
/**
* Gets the default value, a {@code V} which is returned by {@link #get(Object)} if the key is not found.
* If not changed, the default value is null.
*
* @return the current default value
*/
@Nullable
public V getDefaultValue () {
return defaultValue;
}
/**
* Sets the default value, a {@code V} which is returned by {@link #get(Object)} if the key is not found.
* If not changed, the default value is null. Note that {@link #getOrDefault(Object, Object)} is also available,
* which allows specifying a "not-found" value per-call.
*
* @param defaultValue may be any V object or null; should usually be one that doesn't occur as a typical value
*/
public void setDefaultValue (@Nullable V defaultValue) {
this.defaultValue = defaultValue;
}
/**
* Reduces the size of the backing arrays to be the specified capacity / loadFactor, or less. If the capacity is already less,
* nothing is done. If the map contains more items than the specified capacity, the next highest power of two capacity is used
* instead.
*/
public void shrink (int maximumCapacity) {
if (maximumCapacity < 0) {throw new IllegalArgumentException("maximumCapacity must be >= 0: " + maximumCapacity);}
int tableSize = tableSize(Math.max(maximumCapacity, size), loadFactor);
if (keyTable.length > tableSize) {resize(tableSize);}
}
/**
* Clears the map and reduces the size of the backing arrays to be the specified capacity / loadFactor, if they are larger.
*/
public void clear (int maximumCapacity) {
int tableSize = tableSize(maximumCapacity, loadFactor);
if (keyTable.length <= tableSize) {
clear();
return;
}
size = 0;
resize(tableSize);
}
@Override
public void clear () {
if (size == 0) {return;}
size = 0;
Utilities.clear(keyTable);
Utilities.clear(valueTable);
}
/**
* Returns true if the specified value is in the map. Note this traverses the entire map and compares every value, which may
* be an expensive operation.
*
* @param identity If true, uses == to compare the specified value with values in the map. If false, uses
* {@link #equals(Object)}.
*/
public boolean containsValue (@Nullable Object value, boolean identity) {
V[] valueTable = this.valueTable;
if (value == null) {
K[] keyTable = this.keyTable;
for (int i = valueTable.length - 1; i >= 0; i--) {if (keyTable[i] != null && valueTable[i] == null) {return true;}}
} else if (identity) {
for (int i = valueTable.length - 1; i >= 0; i--) {if (valueTable[i] == value) {return true;}}
} else {
for (int i = valueTable.length - 1; i >= 0; i--) {if (value.equals(valueTable[i])) {return true;}}
}
return false;
}
@Override
public boolean containsKey (Object key) {
K[] keyTable = this.keyTable;
for (int i = place(key); ; i = i + 1 & mask) {
K other = keyTable[i];
if (equate(key, other))
return true;
if (other == null)
return false;
}
}
/**
* Returns {@code true} if this map maps one or more keys to the
* specified value. More formally, returns {@code true} if and only if
* this map contains at least one mapping to a value {@code v} such that
* {@code (value==null ? v==null : value.equals(v))}. This operation
* will probably require time linear in the map size for most
* implementations of the {@code Map} interface.
*
* @param value value whose presence in this map is to be tested
* @return {@code true} if this map maps one or more keys to the
* specified value
* @throws ClassCastException if the value is of an inappropriate type for
* this map
* (optional)
* @throws NullPointerException if the specified value is null and this
* map does not permit null values
* (optional)
*/
@Override
public boolean containsValue (Object value) {
return containsValue(value, false);
}
/**
* Returns a key that maps to the specified value, or null if value is not in the map.
* Note, this traverses the entire map and compares
* every value using {@link Object#equals(Object)}, which may be an expensive operation.
* This is the same as calling {@code findKey(value, false)}.
* @param value the value to search for
* @return a key that maps to value, if present, or null if value cannot be found
*/
@Nullable
public K findKey (@Nullable Object value) {
return findKey(value, false);
}
/**
* Returns the key for the specified value, or null if it is not in the map. Note this traverses the entire map and compares
* every value, which may be an expensive operation.
*
* @param value the value to search for
* @param identity If true, uses == to compare the specified value with values in the map. If false, uses
* {@link #equals(Object)}.
* @return a key that maps to value, if present, or null if value cannot be found
*/
@Nullable
public K findKey (@Nullable Object value, boolean identity) {
V[] valueTable = this.valueTable;
if (value == null) {
K[] keyTable = this.keyTable;
for (int i = valueTable.length - 1; i >= 0; i--) {if (keyTable[i] != null && valueTable[i] == null) {return keyTable[i];}}
} else if (identity) {
for (int i = valueTable.length - 1; i >= 0; i--) {if (valueTable[i] == value) {return keyTable[i];}}
} else {
for (int i = valueTable.length - 1; i >= 0; i--) {if (value.equals(valueTable[i])) {return keyTable[i];}}
}
return null;
}
/**
* Increases the size of the backing array to accommodate the specified number of additional items / loadFactor. Useful before
* adding many items to avoid multiple backing array resizes.
*
* @param additionalCapacity how many additional items this should be able to hold without resizing (probably)
*/
public void ensureCapacity (int additionalCapacity) {
int tableSize = tableSize(size + additionalCapacity, loadFactor);
if (keyTable.length < tableSize) {resize(tableSize);}
}
protected void resize (int newSize) {
int oldCapacity = keyTable.length;
threshold = (int)(newSize * loadFactor);
mask = newSize - 1;
shift = BitConversion.countLeadingZeros(mask) + 32;
K[] oldKeyTable = keyTable;
V[] oldValueTable = valueTable;
keyTable = (K[])new Object[newSize];
valueTable = (V[])new Object[newSize];
if (size > 0) {
for (int i = 0; i < oldCapacity; i++) {
K key = oldKeyTable[i];
if (key != null) {putResize(key, oldValueTable[i]);}
}
}
}
/**
* Effectively does nothing here because the hashMultiplier is no longer stored or used.
* Subclasses can use this as some kind of identifier or user data, though.
*
* @return any int; the value isn't used internally, but may be used by subclasses to identify something
*/
public int getHashMultiplier() {
return 0;
}
/**
* Effectively does nothing here because the hashMultiplier is no longer stored or used.
* Subclasses can use this to set some kind of identifier or user data, though.
*
* @param unused any int; will not be used as-is
*/
public void setHashMultiplier(int unused) {
}
/**
* Gets the length of the internal array used to store all keys, as well as empty space awaiting more items to be
* entered. This length is equal to the length of the array used to store all values, and empty space for values,
* here. This is also called the capacity.
* @return the length of the internal array that holds all keys
*/
public int getTableSize() {
return keyTable.length;
}
public float getLoadFactor () {
return loadFactor;
}
public void setLoadFactor (float loadFactor) {
if (loadFactor <= 0f || loadFactor > 1f) {throw new IllegalArgumentException("loadFactor must be > 0 and <= 1: " + loadFactor);}
this.loadFactor = loadFactor;
int tableSize = tableSize(size, loadFactor);
if (tableSize - 1 != mask) {
resize(tableSize);
}
}
@Override
public int hashCode () {
int h = size;
K[] keyTable = this.keyTable;
V[] valueTable = this.valueTable;
for (int i = 0, n = keyTable.length; i < n; i++) {
K key = keyTable[i];
if (key != null) {
h ^= key.hashCode();
V value = valueTable[i];
if (value != null) {h ^= value.hashCode();}
}
}
return h;
}
@SuppressWarnings({"rawtypes", "unchecked"})
@Override
public boolean equals (Object obj) {
if (obj == this) {return true;}
if (!(obj instanceof Map)) {return false;}
Map other = (Map)obj;
if (other.size() != size) {return false;}
K[] keyTable = this.keyTable;
V[] valueTable = this.valueTable;
try {
for (int i = 0, n = keyTable.length; i < n; i++) {
K key = keyTable[i];
if (key != null) {
V value = valueTable[i];
if (value == null) {
if (other.getOrDefault(key, neverIdentical) != null) {return false;}
} else {
if (!value.equals(other.get(key))) {return false;}
}
}
}
}catch (ClassCastException | NullPointerException unused) {
return false;
}
return true;
}
/**
* Uses == for comparison of each value.
*/
public boolean equalsIdentity (@Nullable Object obj) {
if (obj == this) {return true;}
if (!(obj instanceof ObjectObjectMap)) {return false;}
ObjectObjectMap other = (ObjectObjectMap)obj;
if (other.size != size) {return false;}
K[] keyTable = this.keyTable;
V[] valueTable = this.valueTable;
for (int i = 0, n = keyTable.length; i < n; i++) {
K key = keyTable[i];
if (key != null && valueTable[i] != other.getOrDefault(key, neverIdentical)) {return false;}
}
return true;
}
@Override
public String toString () {
return toString(", ", true);
}
/**
* Delegates to {@link #toString(String, boolean)} with the given entrySeparator and without braces.
* This is different from {@link #toString()}, which includes braces by default.
*
* @param entrySeparator how to separate entries, such as {@code ", "}
* @return a new String representing this map
*/
public String toString (String entrySeparator) {
return toString(entrySeparator, false);
}
public String toString (String entrySeparator, boolean braces) {
return appendTo(new StringBuilder(32), entrySeparator, braces).toString();
}
/**
* Makes a String from the contents of this ObjectObjectMap, but uses the given {@link Appender} and
* {@link Appender} to convert each key and each value to a customizable representation and append them
* to a temporary StringBuilder. To use
* the default String representation, you can use {@code StringBuilder::append} as an appender.
*
* @param entrySeparator how to separate entries, such as {@code ", "}
* @param keyValueSeparator how to separate each key from its value, such as {@code "="} or {@code ":"}
* @param braces true to wrap the output in curly braces, or false to omit them
* @param keyAppender a function that takes a StringBuilder and a K, and returns the modified StringBuilder
* @param valueAppender a function that takes a StringBuilder and a V, and returns the modified StringBuilder
* @return a new String representing this map
*/
public String toString (String entrySeparator, String keyValueSeparator, boolean braces,
Appender keyAppender, Appender valueAppender){
return appendTo(new StringBuilder(), entrySeparator, keyValueSeparator, braces, keyAppender, valueAppender).toString();
}
public StringBuilder appendTo (StringBuilder sb, String entrySeparator, boolean braces) {
return appendTo(sb, entrySeparator, "=", braces, StringBuilder::append, StringBuilder::append);
}
/**
* Appends to a StringBuilder from the contents of this ObjectObjectMap, but uses the given {@link Appender} and
* {@link Appender} to convert each key and each value to a customizable representation and append them
* to a StringBuilder. To use
* the default String representation, you can use {@code StringBuilder::append} as an appender.
*
* @param sb a StringBuilder that this can append to
* @param entrySeparator how to separate entries, such as {@code ", "}
* @param keyValueSeparator how to separate each key from its value, such as {@code "="} or {@code ":"}
* @param braces true to wrap the output in curly braces, or false to omit them
* @param keyAppender a function that takes a StringBuilder and a K, and returns the modified StringBuilder
* @param valueAppender a function that takes a StringBuilder and a V, and returns the modified StringBuilder
* @return {@code sb}, with the appended keys and values of this map
*/
public StringBuilder appendTo (StringBuilder sb, String entrySeparator, String keyValueSeparator, boolean braces,
Appender keyAppender, Appender valueAppender) {
if (size == 0) {return braces ? sb.append("{}") : sb;}
if (braces) {sb.append('{');}
K[] keyTable = this.keyTable;
V[] valueTable = this.valueTable;
int i = keyTable.length;
while (i-- > 0) {
K key = keyTable[i];
if (key == null) {continue;}
if(key == this) sb.append("(this)");
else keyAppender.apply(sb, key);
sb.append(keyValueSeparator);
V value = valueTable[i];
if(value == this) sb.append("(this)");
else valueAppender.apply(sb, value);
break;
}
while (i-- > 0) {
K key = keyTable[i];
if (key == null) {continue;}
sb.append(entrySeparator);
if(key == this) sb.append("(this)");
else keyAppender.apply(sb, key);
sb.append(keyValueSeparator);
V value = valueTable[i];
if(value == this) sb.append("(this)");
else valueAppender.apply(sb, value);
}
if (braces) {sb.append('}');}
return sb;
}
/**
* Reduces the size of the map to the specified size. If the map is already smaller than the specified
* size, no action is taken. This indiscriminately removes items from the backing array until the
* requested newSize is reached, or until the full backing array has had its elements removed.
*
* This tries to remove from the end of the iteration order, but because the iteration order is not
* guaranteed by an unordered map, this can remove essentially any item(s) from the map if it is larger
* than newSize.
*
* @param newSize the target size to try to reach by removing items, if smaller than the current size
*/
public void truncate (int newSize) {
@Nullable K[] keyTable = this.keyTable;
@Nullable V[] valTable = this.valueTable;
newSize = Math.max(0, newSize);
for (int i = keyTable.length - 1; i >= 0 && size > newSize; i--) {
if (keyTable[i] != null) {
keyTable[i] = null;
valTable[i] = null;
--size;
}
}
}
@Override
@Nullable
public V replace (K key, V value) {
int i = locateKey(key);
if (i >= 0) {
V oldValue = valueTable[i];
valueTable[i] = value;
return oldValue;
}
return defaultValue;
}
/**
* Just like Map's merge() default method, but this doesn't use Java 8 APIs (so it should work on RoboVM), and this
* won't remove entries if the remappingFunction returns null (in that case, it will call {@code put(key, null)}).
* This also uses a functional interface from Funderby instead of the JDK, for RoboVM support.
* @param key key with which the resulting value is to be associated
* @param value the value to be merged with the existing value
* associated with the key or, if no existing value
* is associated with the key, to be associated with the key
* @param remappingFunction given a V from this and the V {@code value}, this should return what V to use
* @return the value now associated with key
*/
@Nullable
public V combine (K key, V value, ObjObjToObjBiFunction remappingFunction) {
int i = locateKey(key);
V next = (i < 0) ? value : remappingFunction.apply(valueTable[i], value);
put(key, next);
return next;
}
/**
* Simply calls {@link #combine(Object, Object, ObjObjToObjBiFunction)} on this map using every
* key-value pair in {@code other}. If {@code other} isn't empty, calling this will probably modify
* this map, though this depends on the {@code remappingFunction}.
* @param other a non-null Map (or subclass) with compatible key and value types
* @param remappingFunction given a V value from this and a value from other, this should return what V to use
*/
public void combine (Map other, ObjObjToObjBiFunction remappingFunction) {
for (Map.Entry e : other.entrySet()) {
combine(e.getKey(), e.getValue(), remappingFunction);
}
}
/**
* Reuses the iterator of the reused {@link Entries} produced by {@link #entrySet()};
* does not permit nested iteration. Iterate over {@link Entries#Entries(ObjectObjectMap)} if you
* need nested or multithreaded iteration. You can remove an Entry from this ObjectObjectMap
* using this Iterator.
*
* @return an {@link Iterator} over {@link Map.Entry} key-value pairs; remove is supported.
*/
@Override
public @NonNull MapIterator> iterator () {
return entrySet().iterator();
}
/**
* Returns a {@link Set} view of the keys contained in this map.
* The set is backed by the map, so changes to the map are
* reflected in the set, and vice versa. If the map is modified
* while an iteration over the set is in progress (except through
* the iterator's own {@code remove} operation), the results of
* the iteration are undefined. The set supports element removal,
* which removes the corresponding mapping from the map, via the
* {@code Iterator.remove}, {@code Set.remove},
* {@code removeAll}, {@code retainAll}, and {@code clear}
* operations. It does not support the {@code add} or {@code addAll}
* operations.
*
* Note that the same Collection instance is returned each time this
* method is called. Use the {@link Keys} constructor for nested or
* multithreaded iteration.
*
* @return a set view of the keys contained in this map
*/
@Override
public @NonNull Keys keySet () {
if (keys1 == null || keys2 == null) {
keys1 = new Keys<>(this);
keys2 = new Keys<>(this);
}
if (!keys1.iter.valid) {
keys1.iter.reset();
keys1.iter.valid = true;
keys2.iter.valid = false;
return keys1;
}
keys2.iter.reset();
keys2.iter.valid = true;
keys1.iter.valid = false;
return keys2;
}
/**
* Returns a Collection of the values in the map. Remove is supported. Note that the same Collection instance is returned each
* time this method is called. Use the {@link Values} constructor for nested or multithreaded iteration.
*
* @return a {@link Collection} of V values
*/
@Override
public @NonNull Values values () {
if (values1 == null || values2 == null) {
values1 = new Values<>(this);
values2 = new Values<>(this);
}
if (!values1.iter.valid) {
values1.iter.reset();
values1.iter.valid = true;
values2.iter.valid = false;
return values1;
}
values2.iter.reset();
values2.iter.valid = true;
values1.iter.valid = false;
return values2;
}
/**
* Returns a Set of Map.Entry, containing the entries in the map. Remove is supported by the Set's iterator.
* Note that the same iterator instance is returned each time this method is called.
* Use the {@link Entries} constructor for nested or multithreaded iteration.
*
* @return a {@link Set} of {@link Map.Entry} key-value pairs
*/
@Override
public @NonNull Entries entrySet () {
if (entries1 == null || entries2 == null) {
entries1 = new Entries<>(this);
entries2 = new Entries<>(this);
}
if (!entries1.iter.valid) {
entries1.iter.reset();
entries1.iter.valid = true;
entries2.iter.valid = false;
return entries1;
}
entries2.iter.reset();
entries2.iter.valid = true;
entries1.iter.valid = false;
return entries2;
}
public static class Entry implements Map.Entry {
@Nullable public K key;
@Nullable public V value;
public Entry () {
}
public Entry (@Nullable K key, @Nullable V value) {
this.key = key;
this.value = value;
}
public Entry (Map.Entry entry) {
key = entry.getKey();
value = entry.getValue();
}
@Override
@Nullable
public String toString () {
return key + "=" + value;
}
/**
* Returns the key corresponding to this entry.
*
* @return the key corresponding to this entry
* @throws IllegalStateException implementations may, but are not
* required to, throw this exception if the entry has been
* removed from the backing map.
*/
@Override
public K getKey () {
Objects.requireNonNull(key);
return key;
}
/**
* Returns the value corresponding to this entry. If the mapping
* has been removed from the backing map (by the iterator's
* {@code remove} operation), the results of this call are undefined.
*
* @return the value corresponding to this entry
* @throws IllegalStateException implementations may, but are not
* required to, throw this exception if the entry has been
* removed from the backing map.
*/
@Override
@Nullable
public V getValue () {
return value;
}
/**
* Replaces the value corresponding to this entry with the specified
* value (optional operation). (Writes through to the map.) The
* behavior of this call is undefined if the mapping has already been
* removed from the map (by the iterator's {@code remove} operation).
*
* @param value new value to be stored in this entry
* @return old value corresponding to the entry
* @throws UnsupportedOperationException if the {@code put} operation
* is not supported by the backing map
* @throws ClassCastException if the class of the specified value
* prevents it from being stored in the backing map
* @throws NullPointerException if the backing map does not permit
* null values, and the specified value is null
* @throws IllegalArgumentException if some property of this value
* prevents it from being stored in the backing map
* @throws IllegalStateException implementations may, but are not
* required to, throw this exception if the entry has been
* removed from the backing map.
*/
@Override
@Nullable
public V setValue (V value) {
V old = this.value;
this.value = value;
return old;
}
@Override
public boolean equals (@Nullable Object o) {
if (this == o) {return true;}
if (o == null || getClass() != o.getClass()) {return false;}
Entry entry = (Entry)o;
if (!Objects.equals(key, entry.key)) {return false;}
return Objects.equals(value, entry.value);
}
@Override
public int hashCode () {
int result = key != null ? key.hashCode() : 0;
result = 31 * result + (value != null ? value.hashCode() : 0);
return result;
}
}
public static abstract class MapIterator implements Iterable, Iterator {
public boolean hasNext;
protected final ObjectObjectMap map;
protected int nextIndex, currentIndex;
public boolean valid = true;
public MapIterator (ObjectObjectMap map) {
this.map = map;
reset();
}
public void reset () {
currentIndex = -1;
nextIndex = -1;
findNextIndex();
}
protected void findNextIndex () {
K[] keyTable = map.keyTable;
for (int n = keyTable.length; ++nextIndex < n; ) {
if (keyTable[nextIndex] != null) {
hasNext = true;
return;
}
}
hasNext = false;
}
@Override
public void remove () {
int i = currentIndex;
if (i < 0) {throw new IllegalStateException("next must be called before remove.");}
K[] keyTable = map.keyTable;
V[] valueTable = map.valueTable;
int mask = map.mask, next = i + 1 & mask;
K key;
while ((key = keyTable[next]) != null) {
int placement = map.place(key);
if ((next - placement & mask) > (i - placement & mask)) {
keyTable[i] = key;
valueTable[i] = valueTable[next];
i = next;
}
next = next + 1 & mask;
}
keyTable[i] = null;
valueTable[i] = null;
map.size--;
if (i != currentIndex) {--nextIndex;}
currentIndex = -1;
}
}
public static class Entries extends AbstractSet> implements EnhancedCollection> {
protected Entry entry = new Entry<>();
protected MapIterator> iter;
public Entries (ObjectObjectMap map) {
iter = new MapIterator>(map) {
@Override
public @NonNull MapIterator> iterator () {
return this;
}
/**
* Note: the same entry instance is returned each time this method is called.
*
* @return a reused Entry that will have its key and value set to the next pair
*/
@Override
public Map.Entry next () {
if (!hasNext) {throw new NoSuchElementException();}
if (!valid) {throw new RuntimeException("#iterator() cannot be used nested.");}
K[] keyTable = map.keyTable;
entry.key = keyTable[nextIndex];
entry.value = map.valueTable[nextIndex];
currentIndex = nextIndex;
findNextIndex();
return entry;
}
@Override
public boolean hasNext () {
if (!valid) {throw new RuntimeException("#iterator() cannot be used nested.");}
return hasNext;
}
};
}
@Override
public boolean contains (Object o) {
return iter.map.containsKey(o);
}
/**
* Returns an iterator over the elements contained in this collection.
*
* @return an iterator over the elements contained in this collection
*/
@Override
public @NonNull MapIterator> iterator () {
return iter;
}
@Override
public int size () {
return iter.map.size;
}
@Override
public int hashCode () {
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
iter.reset();
int hc = super.hashCode();
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return hc;
}
@Override
public String toString () {
return toString(", ", true);
}
/**
* The iterator is reused by this data structure, and you can reset it
* back to the start of the iteration order using this.
*/
public void resetIterator () {
iter.reset();
}
/**
* Returns a new {@link ObjectList} containing the remaining items.
* Does not change the position of this iterator.
*/
public ObjectList> toList () {
ObjectList> list = new ObjectList<>(iter.map.size);
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {list.add(new Entry<>(iter.next()));}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return list;
}
/**
* Append the remaining items that this can iterate through into the given Collection.
* Does not change the position of this iterator.
* @param coll any modifiable Collection; may have items appended into it
* @return the given collection
*/
public Collection> appendInto(Collection> coll) {
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {coll.add(new Entry<>(iter.next()));}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return coll;
}
/**
* Append the remaining items that this can iterate through into the given Map.
* Does not change the position of this iterator. Note that a Map is not a Collection.
* @param coll any modifiable Map; may have items appended into it
* @return the given map
*/
public Map appendInto(Map coll) {
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {
iter.next();
coll.put(entry.key, entry.value);
}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return coll;
}
}
public static class Values extends AbstractCollection implements EnhancedCollection {
protected MapIterator iter;
public Values (ObjectObjectMap map) {
iter = new MapIterator(map) {
@Override
public @NonNull MapIterator iterator () {
return this;
}
@Override
public boolean hasNext () {
if (!valid) {throw new RuntimeException("#iterator() cannot be used nested.");}
return hasNext;
}
@Override
public V next () {
if (!hasNext) {throw new NoSuchElementException();}
if (!valid) {throw new RuntimeException("#iterator() cannot be used nested.");}
V value = map.valueTable[nextIndex];
currentIndex = nextIndex;
findNextIndex();
return value;
}
};
}
/**
* Returns an iterator over the elements contained in this collection.
*
* @return an iterator over the elements contained in this collection
*/
@Override
public @NonNull MapIterator iterator () {
return iter;
}
/**
* The iterator is reused by this data structure, and you can reset it
* back to the start of the iteration order using this.
*/
public void resetIterator () {
iter.reset();
}
@Override
public int size () {
return iter.map.size;
}
@Override
public String toString () {
return toString(", ", true);
}
/**
* Returns a new {@link ObjectList} containing the remaining items.
* Does not change the position of this iterator.
*/
public ObjectList toList () {
ObjectList list = new ObjectList<>(iter.map.size);
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {list.add(iter.next());}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return list;
}
/**
* Append the remaining items that this can iterate through into the given Collection.
* Does not change the position of this iterator.
* @param coll any modifiable Collection; may have items appended into it
* @return the given collection
*/
public Collection appendInto(Collection coll) {
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {coll.add(iter.next());}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return coll;
}
}
public static class Keys extends AbstractSet implements EnhancedCollection {
protected MapIterator iter;
public Keys (ObjectObjectMap map) {
iter = new MapIterator(map) {
@Override
public @NonNull MapIterator iterator () {
return this;
}
@Override
public boolean hasNext () {
if (!valid) {throw new RuntimeException("#iterator() cannot be used nested.");}
return hasNext;
}
@Override
public K next () {
if (!hasNext) {throw new NoSuchElementException();}
if (!valid) {throw new RuntimeException("#iterator() cannot be used nested.");}
K key = map.keyTable[nextIndex];
currentIndex = nextIndex;
findNextIndex();
return key;
}
};
}
@Override
public boolean contains (Object o) {
return iter.map.containsKey(o);
}
/**
* Returns an iterator over the elements contained in this collection.
*
* @return an iterator over the elements contained in this collection
*/
@Override
public @NonNull MapIterator iterator () {
return iter;
}
@Override
public int size () {
return iter.map.size;
}
@Override
public int hashCode () {
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
iter.reset();
int hc = super.hashCode();
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return hc;
}
@Override
public String toString () {
return toString(", ", true);
}
/**
* The iterator is reused by this data structure, and you can reset it
* back to the start of the iteration order using this.
*/
public void resetIterator () {
iter.reset();
}
/**
* Returns a new {@link ObjectList} containing the remaining items.
* Does not change the position of this iterator.
*/
public ObjectList toList () {
ObjectList list = new ObjectList<>(iter.map.size);
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {list.add(iter.next());}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return list;
}
/**
* Append the remaining items that this can iterate through into the given Collection.
* Does not change the position of this iterator.
* @param coll any modifiable Collection; may have items appended into it
* @return the given collection
*/
public Collection appendInto(Collection coll) {
int currentIdx = iter.currentIndex, nextIdx = iter.nextIndex;
boolean hn = iter.hasNext;
while (iter.hasNext) {coll.add(iter.next());}
iter.currentIndex = currentIdx;
iter.nextIndex = nextIdx;
iter.hasNext = hn;
return coll;
}
}
/**
* Constructs an empty map given the types as generic type arguments.
* This is usually less useful than just using the constructor, but can be handy
* in some code-generation scenarios when you don't know how many arguments you will have.
*
* @param the type of keys
* @param the type of values
* @return a new map containing nothing
*/
public static ObjectObjectMap with () {
return new ObjectObjectMap<>(0);
}
/**
* Constructs a single-entry map given one key and one value.
* This is mostly useful as an optimization for {@link #with(Object, Object, Object...)}
* when there's no "rest" of the keys or values.
*
* @param key0 the first and only key
* @param value0 the first and only value
* @param the type of key0
* @param the type of value0
* @return a new map containing just the entry mapping key0 to value0
*/
public static ObjectObjectMap with (K key0, V value0) {
ObjectObjectMap map = new ObjectObjectMap<>(1);
map.put(key0, value0);
return map;
}
/**
* Constructs a single-entry map given two key-value pairs.
* This is mostly useful as an optimization for {@link #with(Object, Object, Object...)}
* when there's no "rest" of the keys or values.
*
* @param key0 a K key
* @param value0 a V value
* @param key1 a K key
* @param value1 a V value
* @param the type of key0
* @param the type of value0
* @return a new map containing entries mapping each key to the following value
*/
public static ObjectObjectMap with (K key0, V value0, K key1, V value1) {
ObjectObjectMap map = new ObjectObjectMap<>(2);
map.put(key0, value0);
map.put(key1, value1);
return map;
}
/**
* Constructs a single-entry map given three key-value pairs.
* This is mostly useful as an optimization for {@link #with(Object, Object, Object...)}
* when there's no "rest" of the keys or values.
*
* @param key0 a K key
* @param value0 a V value
* @param key1 a K key
* @param value1 a V value
* @param key2 a K key
* @param value2 a V value
* @param the type of key0
* @param the type of value0
* @return a new map containing entries mapping each key to the following value
*/
public static ObjectObjectMap with (K key0, V value0, K key1, V value1, K key2, V value2) {
ObjectObjectMap map = new ObjectObjectMap<>(3);
map.put(key0, value0);
map.put(key1, value1);
map.put(key2, value2);
return map;
}
/**
* Constructs a single-entry map given four key-value pairs.
* This is mostly useful as an optimization for {@link #with(Object, Object, Object...)}
* when there's no "rest" of the keys or values.
*
* @param key0 a K key
* @param value0 a V value
* @param key1 a K key
* @param value1 a V value
* @param key2 a K key
* @param value2 a V value
* @param key3 a K key
* @param value3 a V value
* @param the type of key0
* @param the type of value0
* @return a new map containing entries mapping each key to the following value
*/
public static ObjectObjectMap with (K key0, V value0, K key1, V value1, K key2, V value2, K key3, V value3) {
ObjectObjectMap map = new ObjectObjectMap<>(4);
map.put(key0, value0);
map.put(key1, value1);
map.put(key2, value2);
map.put(key3, value3);
return map;
}
/**
* Constructs a map given alternating keys and values.
* This can be useful in some code-generation scenarios, or when you want to make a
* map conveniently by-hand and have it populated at the start. You can also use
* {@link #ObjectObjectMap(Object[], Object[])}, which takes all keys and then all values.
* This needs all keys to have the same type and all values to have the same type, because
* it gets those types from the first key parameter and first value parameter. Any keys that don't
* have K as their type or values that don't have V as their type have that entry skipped.
*
* @param key0 the first key; will be used to determine the type of all keys
* @param value0 the first value; will be used to determine the type of all values
* @param rest an array or varargs of alternating K, V, K, V... elements
* @param the type of keys, inferred from key0
* @param the type of values, inferred from value0
* @return a new map containing the given keys and values
*/
@SuppressWarnings("unchecked")
public static ObjectObjectMap with (K key0, V value0, Object... rest) {
ObjectObjectMap map = new ObjectObjectMap<>(1 + (rest.length >>> 1));
map.put(key0, value0);
for (int i = 1; i < rest.length; i += 2) {
try {
map.put((K)rest[i - 1], (V)rest[i]);
} catch (ClassCastException ignored) {
}
}
return map;
}
}