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/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * 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.ppiech.auto.value.jackson.util;

import java.util.Map;

/**
 * Base implementation of ArrayMap that doesn't include any standard Java
 * container API interoperability.  These features are generally heavier-weight ways
 * to interact with the container, so discouraged, but they can be useful to make it
 * easier to use as a drop-in replacement for HashMap.  If you don't need them, this
 * class can be preferrable since it doesn't bring in any of the implementation of those
 * APIs, allowing that code to be stripped by ProGuard.
 */
public class SimpleArrayMap {

    static final int[] EMPTY_INTS = new int[0];
    static final Object[] EMPTY_OBJECTS = new Object[0];

    /**
     * The minimum amount by which the capacity of a ArrayMap will increase.
     * This is tuned to be relatively space-efficient.
     */
    private static final int BASE_SIZE = 4;

    /**
     * Maximum number of entries to have in array caches.
     */
    private static final int CACHE_SIZE = 10;

    /**
     * Caches of small array objects to avoid spamming garbage.  The cache
     * Object[] variable is a pointer to a linked list of array objects.
     * The first entry in the array is a pointer to the next array in the
     * list; the second entry is a pointer to the int[] hash code array for it.
     */
    static Object[] mBaseCache;
    static int mBaseCacheSize;
    static Object[] mTwiceBaseCache;
    static int mTwiceBaseCacheSize;

    int[] mHashes;
    Object[] mArray;
    int mSize;

    int indexOf(Object key, int hash) {
        final int N = mSize;

        // Important fast case: if nothing is in here, nothing to look for.
        if (N == 0) {
            return ~0;
        }

        int index = binarySearch(mHashes, N, hash);

        // If the hash code wasn't found, then we have no entry for this key.
        if (index < 0) {
            return index;
        }

        // If the key at the returned index matches, that's what we want.
        if (key.equals(mArray[index<<1])) {
            return index;
        }

        // Search for a matching key after the index.
        int end;
        for (end = index + 1; end < N && mHashes[end] == hash; end++) {
            if (key.equals(mArray[end << 1])) return end;
        }

        // Search for a matching key before the index.
        for (int i = index - 1; i >= 0 && mHashes[i] == hash; i--) {
            if (key.equals(mArray[i << 1])) return i;
        }

        // Key not found -- return negative value indicating where a
        // new entry for this key should go.  We use the end of the
        // hash chain to reduce the number of array entries that will
        // need to be copied when inserting.
        return ~end;
    }

    int indexOfNull() {
        final int N = mSize;

        // Important fast case: if nothing is in here, nothing to look for.
        if (N == 0) {
            return ~0;
        }

        int index = binarySearch(mHashes, N, 0);

        // If the hash code wasn't found, then we have no entry for this key.
        if (index < 0) {
            return index;
        }

        // If the key at the returned index matches, that's what we want.
        if (null == mArray[index<<1]) {
            return index;
        }

        // Search for a matching key after the index.
        int end;
        for (end = index + 1; end < N && mHashes[end] == 0; end++) {
            if (null == mArray[end << 1]) return end;
        }

        // Search for a matching key before the index.
        for (int i = index - 1; i >= 0 && mHashes[i] == 0; i--) {
            if (null == mArray[i << 1]) return i;
        }

        // Key not found -- return negative value indicating where a
        // new entry for this key should go.  We use the end of the
        // hash chain to reduce the number of array entries that will
        // need to be copied when inserting.
        return ~end;
    }

    private void allocArrays(final int size) {
        if (size == (BASE_SIZE*2)) {
            synchronized (SimpleArrayMap.class) {
                if (mTwiceBaseCache != null) {
                    final Object[] array = mTwiceBaseCache;
                    mArray = array;
                    mTwiceBaseCache = (Object[])array[0];
                    mHashes = (int[])array[1];
                    array[0] = array[1] = null;
                    mTwiceBaseCacheSize--;
                    return;
                }
            }
        } else if (size == BASE_SIZE) {
            synchronized (SimpleArrayMap.class) {
                if (mBaseCache != null) {
                    final Object[] array = mBaseCache;
                    mArray = array;
                    mBaseCache = (Object[])array[0];
                    mHashes = (int[])array[1];
                    array[0] = array[1] = null;
                    mBaseCacheSize--;
                    return;
                }
            }
        }

        mHashes = new int[size];
        mArray = new Object[size<<1];
    }

    private static void freeArrays(final int[] hashes, final Object[] array, final int size) {
        if (hashes.length == (BASE_SIZE*2)) {
            synchronized (SimpleArrayMap.class) {
                if (mTwiceBaseCacheSize < CACHE_SIZE) {
                    array[0] = mTwiceBaseCache;
                    array[1] = hashes;
                    for (int i=(size<<1)-1; i>=2; i--) {
                        array[i] = null;
                    }
                    mTwiceBaseCache = array;
                    mTwiceBaseCacheSize++;
                }
            }
        } else if (hashes.length == BASE_SIZE) {
            synchronized (SimpleArrayMap.class) {
                if (mBaseCacheSize < CACHE_SIZE) {
                    array[0] = mBaseCache;
                    array[1] = hashes;
                    for (int i=(size<<1)-1; i>=2; i--) {
                        array[i] = null;
                    }
                    mBaseCache = array;
                    mBaseCacheSize++;
                }
            }
        }
    }

    /**
     * Create a new empty ArrayMap.  The default capacity of an array map is 0, and
     * will grow once items are added to it.
     */
    public SimpleArrayMap() {
        mHashes = EMPTY_INTS;
        mArray = EMPTY_OBJECTS;
        mSize = 0;
    }

    /**
     * Create a new ArrayMap with a given initial capacity.
     */
    public SimpleArrayMap(int capacity) {
        if (capacity == 0) {
            mHashes = EMPTY_INTS;
            mArray = EMPTY_OBJECTS;
        } else {
            allocArrays(capacity);
        }
        mSize = 0;
    }

    /**
     * Create a new ArrayMap with the mappings from the given ArrayMap.
     */
    public SimpleArrayMap(SimpleArrayMap map) {
        this();
        if (map != null) {
            putAll(map);
        }
    }

    /**
     * Make the array map empty.  All storage is released.
     */
    public void clear() {
        if (mSize != 0) {
            freeArrays(mHashes, mArray, mSize);
            mHashes = EMPTY_INTS;
            mArray = EMPTY_OBJECTS;
            mSize = 0;
        }
    }

    /**
     * Ensure the array map can hold at least minimumCapacity
     * items.
     */
    public void ensureCapacity(int minimumCapacity) {
        if (mHashes.length < minimumCapacity) {
            final int[] ohashes = mHashes;
            final Object[] oarray = mArray;
            allocArrays(minimumCapacity);
            if (mSize > 0) {
                System.arraycopy(ohashes, 0, mHashes, 0, mSize);
                System.arraycopy(oarray, 0, mArray, 0, mSize<<1);
            }
            freeArrays(ohashes, oarray, mSize);
        }
    }

    /**
     * Check whether a key exists in the array.
     *
     * @param key The key to search for.
     * @return Returns true if the key exists, else false.
     */
    public boolean containsKey(Object key) {
        return indexOfKey(key) >= 0;
    }

    /**
     * Returns the index of a key in the set.
     *
     * @param key The key to search for.
     * @return Returns the index of the key if it exists, else a negative integer.
     */
    public int indexOfKey(Object key) {
        return key == null ? indexOfNull() : indexOf(key, key.hashCode());
    }

    int indexOfValue(Object value) {
        final int N = mSize*2;
        final Object[] array = mArray;
        if (value == null) {
            for (int i=1; i>1;
                }
            }
        } else {
            for (int i=1; i>1;
                }
            }
        }
        return -1;
    }

    /**
     * Check whether a value exists in the array.  This requires a linear search
     * through the entire array.
     *
     * @param value The value to search for.
     * @return Returns true if the value exists, else false.
     */
    public boolean containsValue(Object value) {
        return indexOfValue(value) >= 0;
    }

    /**
     * Retrieve a value from the array.
     * @param key The key of the value to retrieve.
     * @return Returns the value associated with the given key,
     * or null if there is no such key.
     */
    public V get(Object key) {
        final int index = indexOfKey(key);
        return index >= 0 ? (V)mArray[(index<<1)+1] : null;
    }

    /**
     * Return the key at the given index in the array.
     * @param index The desired index, must be between 0 and {@link #size()}-1.
     * @return Returns the key stored at the given index.
     */
    public K keyAt(int index) {
        return (K)mArray[index << 1];
    }

    /**
     * Return the value at the given index in the array.
     * @param index The desired index, must be between 0 and {@link #size()}-1.
     * @return Returns the value stored at the given index.
     */
    public V valueAt(int index) {
        return (V)mArray[(index << 1) + 1];
    }

    /**
     * Set the value at a given index in the array.
     * @param index The desired index, must be between 0 and {@link #size()}-1.
     * @param value The new value to store at this index.
     * @return Returns the previous value at the given index.
     */
    public V setValueAt(int index, V value) {
        index = (index << 1) + 1;
        V old = (V)mArray[index];
        mArray[index] = value;
        return old;
    }

    /**
     * Return true if the array map contains no items.
     */
    public boolean isEmpty() {
        return mSize <= 0;
    }

    /**
     * Add a new value to the array map.
     * @param key The key under which to store the value.  Must not be null.  If
     * this key already exists in the array, its value will be replaced.
     * @param value The value to store for the given key.
     * @return Returns the old value that was stored for the given key, or null if there
     * was no such key.
     */
    public V put(K key, V value) {
        final int hash;
        int index;
        if (key == null) {
            hash = 0;
            index = indexOfNull();
        } else {
            hash = key.hashCode();
            index = indexOf(key, hash);
        }
        if (index >= 0) {
            index = (index<<1) + 1;
            final V old = (V)mArray[index];
            mArray[index] = value;
            return old;
        }

        index = ~index;
        if (mSize >= mHashes.length) {
            final int n = mSize >= (BASE_SIZE*2) ? (mSize+(mSize>>1))
                    : (mSize >= BASE_SIZE ? (BASE_SIZE*2) : BASE_SIZE);

            final int[] ohashes = mHashes;
            final Object[] oarray = mArray;
            allocArrays(n);

            if (mHashes.length > 0) {
                System.arraycopy(ohashes, 0, mHashes, 0, ohashes.length);
                System.arraycopy(oarray, 0, mArray, 0, oarray.length);
            }

            freeArrays(ohashes, oarray, mSize);
        }

        if (index < mSize) {
            System.arraycopy(mHashes, index, mHashes, index + 1, mSize - index);
            System.arraycopy(mArray, index << 1, mArray, (index + 1) << 1, (mSize - index) << 1);
        }

        mHashes[index] = hash;
        mArray[index<<1] = key;
        mArray[(index<<1)+1] = value;
        mSize++;
        return null;
    }

    /**
     * Perform a {@link #put(Object, Object)} of all key/value pairs in array
     * @param array The array whose contents are to be retrieved.
     */
    public void putAll(SimpleArrayMap array) {
        final int N = array.mSize;
        ensureCapacity(mSize + N);
        if (mSize == 0) {
            if (N > 0) {
                System.arraycopy(array.mHashes, 0, mHashes, 0, N);
                System.arraycopy(array.mArray, 0, mArray, 0, N<<1);
                mSize = N;
            }
        } else {
            for (int i=0; i= 0) {
            return removeAt(index);
        }

        return null;
    }

    /**
     * Remove the key/value mapping at the given index.
     * @param index The desired index, must be between 0 and {@link #size()}-1.
     * @return Returns the value that was stored at this index.
     */
    public V removeAt(int index) {
        final Object old = mArray[(index << 1) + 1];
        if (mSize <= 1) {
            // Now empty.
            freeArrays(mHashes, mArray, mSize);
            mHashes = EMPTY_INTS;
            mArray = EMPTY_OBJECTS;
            mSize = 0;
        } else {
            if (mHashes.length > (BASE_SIZE*2) && mSize < mHashes.length/3) {
                // Shrunk enough to reduce size of arrays.  We don't allow it to
                // shrink smaller than (BASE_SIZE*2) to avoid flapping between
                // that and BASE_SIZE.
                final int n = mSize > (BASE_SIZE*2) ? (mSize + (mSize>>1)) : (BASE_SIZE*2);

                final int[] ohashes = mHashes;
                final Object[] oarray = mArray;
                allocArrays(n);

                mSize--;
                if (index > 0) {
                    System.arraycopy(ohashes, 0, mHashes, 0, index);
                    System.arraycopy(oarray, 0, mArray, 0, index << 1);
                }
                if (index < mSize) {
                    System.arraycopy(ohashes, index + 1, mHashes, index, mSize - index);
                    System.arraycopy(oarray, (index + 1) << 1, mArray, index << 1,
                            (mSize - index) << 1);
                }
            } else {
                mSize--;
                if (index < mSize) {
                    System.arraycopy(mHashes, index + 1, mHashes, index, mSize - index);
                    System.arraycopy(mArray, (index + 1) << 1, mArray, index << 1,
                            (mSize - index) << 1);
                }
                mArray[mSize << 1] = null;
                mArray[(mSize << 1) + 1] = null;
            }
        }
        return (V)old;
    }

    /**
     * Return the number of items in this array map.
     */
    public int size() {
        return mSize;
    }

    /**
     * {@inheritDoc}
     *
     * 

This implementation returns false if the object is not a map, or * if the maps have different sizes. Otherwise, for each key in this map, * values of both maps are compared. If the values for any key are not * equal, the method returns false, otherwise it returns true. */ @Override public boolean equals(Object object) { if (this == object) { return true; } if (object instanceof Map) { Map map = (Map) object; if (size() != map.size()) { return false; } try { for (int i=0; iThis implementation composes a string by iterating over its mappings. If * this map contains itself as a key or a value, the string "(this Map)" * will appear in its place. */ @Override public String toString() { if (isEmpty()) { return "{}"; } StringBuilder buffer = new StringBuilder(mSize * 28); buffer.append('{'); for (int i=0; i 0) { buffer.append(", "); } Object key = keyAt(i); if (key != this) { buffer.append(key); } else { buffer.append("(this Map)"); } buffer.append('='); Object value = valueAt(i); if (value != this) { buffer.append(value); } else { buffer.append("(this Map)"); } } buffer.append('}'); return buffer.toString(); } static int binarySearch(int[] array, int size, int value) { int lo = 0; int hi = size - 1; while (lo <= hi) { int mid = (lo + hi) >>> 1; int midVal = array[mid]; if (midVal < value) { lo = mid + 1; } else if (midVal > value) { hi = mid - 1; } else { return mid; // value found } } return ~lo; // value not present } }





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