CustomNPC-Plus-API/java/net/minecraft/util/math/IntHashMap.java

package net.minecraft.util.math;

public class IntHashMap<V> {
    private transient IntHashMap.Entry<V>[] slots = new IntHashMap.Entry[16];
    /**
     * The number of items stored in this map
     */
    private transient int count;
    /**
     * The grow threshold
     */
    private int threshold = 12;
    /**
     * The scale factor used to determine when to grow the table
     */
    private final float growFactor = 0.75F;

    /**
     * Makes the passed in integer suitable for hashing by a number of shifts
     */
    private static int computeHash(int integer) {
        integer = integer ^ integer >>> 20 ^ integer >>> 12;
        return integer ^ integer >>> 7 ^ integer >>> 4;
    }

    /**
     * Computes the index of the slot for the hash and slot count passed in.
     */
    private static int getSlotIndex(int hash, int slotCount) {
        return hash & slotCount - 1;
    }

    /**
     * Returns the object associated to a key
     *
     * @param key the integer key to look up
     * @return the value associated with the key, or null if not found
     */
    public V lookup(int key) {
        int i = computeHash(key);

        for (IntHashMap.Entry<V> entry = this.slots[getSlotIndex(i, this.slots.length)]; entry != null; entry = entry.nextEntry) {
            if (entry.hashEntry == key) {
                return entry.valueEntry;
            }
        }

        return (V) null;
    }

    /**
     * Returns true if this hash table contains the specified item.
     *
     * @param key the integer key to check
     * @return true if the map contains this key
     */
    public boolean containsItem(int key) {
        return this.lookupEntry(key) != null;
    }

    final IntHashMap.Entry<V> lookupEntry(int p_76045_1_) {
        int i = computeHash(p_76045_1_);

        for (IntHashMap.Entry<V> entry = this.slots[getSlotIndex(i, this.slots.length)]; entry != null; entry = entry.nextEntry) {
            if (entry.hashEntry == p_76045_1_) {
                return entry;
            }
        }

        return null;
    }

    /**
     * Adds a key and associated value to this map
     *
     * @param key the integer key
     * @param value the value to associate with the key
     */
    public void addKey(int key, V value) {
        int i = computeHash(key);
        int j = getSlotIndex(i, this.slots.length);

        for (IntHashMap.Entry<V> entry = this.slots[j]; entry != null; entry = entry.nextEntry) {
            if (entry.hashEntry == key) {
                entry.valueEntry = value;
                return;
            }
        }

        this.insert(i, key, value, j);
    }

    /**
     * Increases the number of hash slots
     */
    private void grow(int p_76047_1_) {
        IntHashMap.Entry<V>[] entry = this.slots;
        int i = entry.length;

        if (i == 1073741824) {
            this.threshold = Integer.MAX_VALUE;
        } else {
            IntHashMap.Entry<V>[] entry1 = new IntHashMap.Entry[p_76047_1_];
            this.copyTo(entry1);
            this.slots = entry1;
            this.threshold = (int) ((float) p_76047_1_ * this.growFactor);
        }
    }

    /**
     * Copies the hash slots to a new array
     */
    private void copyTo(IntHashMap.Entry<V>[] p_76048_1_) {
        IntHashMap.Entry<V>[] entry = this.slots;
        int i = p_76048_1_.length;

        for (int j = 0; j < entry.length; ++j) {
            IntHashMap.Entry<V> entry1 = entry[j];

            if (entry1 != null) {
                entry[j] = null;

                while (true) {
                    IntHashMap.Entry<V> entry2 = entry1.nextEntry;
                    int k = getSlotIndex(entry1.slotHash, i);
                    entry1.nextEntry = p_76048_1_[k];
                    p_76048_1_[k] = entry1;
                    entry1 = entry2;

                    if (entry2 == null) {
                        break;
                    }
                }
            }
        }
    }

    /**
     * Removes the specified object from the map and returns it
     *
     * @param key the integer key to remove
     */
    public V removeObject(int key) {
        IntHashMap.Entry<V> entry = this.removeEntry(key);
        return (V) (entry == null ? null : entry.valueEntry);
    }

    final IntHashMap.Entry<V> removeEntry(int p_76036_1_) {
        int i = computeHash(p_76036_1_);
        int j = getSlotIndex(i, this.slots.length);
        IntHashMap.Entry<V> entry = this.slots[j];
        IntHashMap.Entry<V> entry1;
        IntHashMap.Entry<V> entry2;

        for (entry1 = entry; entry1 != null; entry1 = entry2) {
            entry2 = entry1.nextEntry;

            if (entry1.hashEntry == p_76036_1_) {
                --this.count;

                if (entry == entry1) {
                    this.slots[j] = entry2;
                } else {
                    entry.nextEntry = entry2;
                }

                return entry1;
            }

            entry = entry1;
        }

        return entry1;
    }

    /**
     * Removes all entries from the map
     */
    public void clearMap() {
        IntHashMap.Entry<V>[] entry = this.slots;

        for (int i = 0; i < entry.length; ++i) {
            entry[i] = null;
        }

        this.count = 0;
    }

    /**
     * Adds an object to a slot
     */
    private void insert(int p_76040_1_, int p_76040_2_, V p_76040_3_, int p_76040_4_) {
        IntHashMap.Entry<V> entry = this.slots[p_76040_4_];
        this.slots[p_76040_4_] = new IntHashMap.Entry(p_76040_1_, p_76040_2_, p_76040_3_, entry);

        if (this.count++ >= this.threshold) {
            this.grow(2 * this.slots.length);
        }
    }

    static class Entry<V> {
        /**
         * The hash code of this entry
         */
        final int hashEntry;
        /**
         * The object stored in this entry
         */
        V valueEntry;
        IntHashMap.Entry<V> nextEntry;
        /**
         * The id of the hash slot computed from the hash
         */
        final int slotHash;

        Entry(int p_i1552_1_, int p_i1552_2_, V p_i1552_3_, IntHashMap.Entry<V> p_i1552_4_) {
            this.valueEntry = p_i1552_3_;
            this.nextEntry = p_i1552_4_;
            this.hashEntry = p_i1552_2_;
            this.slotHash = p_i1552_1_;
        }

        /**
         * Returns the hash code for this entry
         */
        public final int getHash() {
            return this.hashEntry;
        }

        /**
         * Returns the object stored in this entry
         */
        public final V getValue() {
            return this.valueEntry;
        }

        public final boolean equals(Object p_equals_1_) {
            if (!(p_equals_1_ instanceof IntHashMap.Entry)) {
                return false;
            } else {
                IntHashMap.Entry<V> entry = (IntHashMap.Entry) p_equals_1_;
                Object object = Integer.valueOf(this.getHash());
                Object object1 = Integer.valueOf(entry.getHash());

                if (object == object1 || object != null && object.equals(object1)) {
                    Object object2 = this.getValue();
                    Object object3 = entry.getValue();

                    if (object2 == object3 || object2 != null && object2.equals(object3)) {
                        return true;
                    }
                }

                return false;
            }
        }

        public final int hashCode() {
            return IntHashMap.computeHash(this.hashEntry);
        }

        public final String toString() {
            return this.getHash() + "=" + this.getValue();
        }
    }
}