SparseLongArray.java revision f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccda
1021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov/* 2021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Copyright (C) 2011 The Android Open Source Project 3021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * 4021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Licensed under the Apache License, Version 2.0 (the "License"); 5021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * you may not use this file except in compliance with the License. 6021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * You may obtain a copy of the License at 7021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * 8021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * http://www.apache.org/licenses/LICENSE-2.0 9021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * 10021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Unless required by applicable law or agreed to in writing, software 11021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * distributed under the License is distributed on an "AS IS" BASIS, 12021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * See the License for the specific language governing permissions and 14021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * limitations under the License. 15021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 16021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 17021078554b902179442a345a9d080a165c3b5139Svetoslav Ganovpackage android.util; 18021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 19021078554b902179442a345a9d080a165c3b5139Svetoslav Ganovimport com.android.internal.util.ArrayUtils; 20021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 21021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov/** 22021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * SparseLongArrays map integers to longs. Unlike a normal array of longs, 23021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * there can be gaps in the indices. It is intended to be more efficient 24021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * than using a HashMap to map Integers to Longs. 25021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 26021078554b902179442a345a9d080a165c3b5139Svetoslav Ganovpublic class SparseLongArray implements Cloneable { 27f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn static final long[] EMPTY_LONGS = new long[0]; 28021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 29021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov private int[] mKeys; 30021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov private long[] mValues; 31021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov private int mSize; 32021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 33021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 34021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Creates a new SparseLongArray containing no mappings. 35021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 36021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public SparseLongArray() { 37021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov this(10); 38021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 39021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 40021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 41021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Creates a new SparseLongArray containing no mappings that will not 42021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * require any additional memory allocation to store the specified 43f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn * number of mappings. If you supply an initial capacity of 0, the 44f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn * sparse array will be initialized with a light-weight representation 45f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn * not requiring any additional array allocations. 46021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 47021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public SparseLongArray(int initialCapacity) { 48f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn if (initialCapacity == 0) { 49f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn mKeys = SparseArray.EMPTY_INTS; 50f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn mValues = EMPTY_LONGS; 51f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn } else { 52f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn initialCapacity = ArrayUtils.idealLongArraySize(initialCapacity); 53f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn mKeys = new int[initialCapacity]; 54f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn mValues = new long[initialCapacity]; 55f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn } 56021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mSize = 0; 57021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 58021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 59021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov @Override 60021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public SparseLongArray clone() { 61021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov SparseLongArray clone = null; 62021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov try { 63021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov clone = (SparseLongArray) super.clone(); 64021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov clone.mKeys = mKeys.clone(); 65021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov clone.mValues = mValues.clone(); 66021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } catch (CloneNotSupportedException cnse) { 67021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /* ignore */ 68021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 69021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return clone; 70021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 71021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 72021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 73021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Gets the long mapped from the specified key, or <code>0</code> 74021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * if no such mapping has been made. 75021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 76021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public long get(int key) { 77021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return get(key, 0); 78021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 79021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 80021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 81021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Gets the long mapped from the specified key, or the specified value 82021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * if no such mapping has been made. 83021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 84021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public long get(int key, long valueIfKeyNotFound) { 85f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn int i = SparseArray.binarySearch(mKeys, mSize, key); 86021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 87021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (i < 0) { 88021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return valueIfKeyNotFound; 89021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } else { 90021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return mValues[i]; 91021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 92021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 93021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 94021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 95021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Removes the mapping from the specified key, if there was any. 96021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 97021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public void delete(int key) { 98f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn int i = SparseArray.binarySearch(mKeys, mSize, key); 99021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 100021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (i >= 0) { 101021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov removeAt(i); 102021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 103021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 104021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 105021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 106021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Removes the mapping at the given index. 107021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 108021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public void removeAt(int index) { 109021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov System.arraycopy(mKeys, index + 1, mKeys, index, mSize - (index + 1)); 110021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov System.arraycopy(mValues, index + 1, mValues, index, mSize - (index + 1)); 111021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mSize--; 112021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 113021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 114021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 115021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Adds a mapping from the specified key to the specified value, 116021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * replacing the previous mapping from the specified key if there 117021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * was one. 118021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 119021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public void put(int key, long value) { 120f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn int i = SparseArray.binarySearch(mKeys, mSize, key); 121021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 122021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (i >= 0) { 123021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mValues[i] = value; 124021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } else { 125021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov i = ~i; 126021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 127021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (mSize >= mKeys.length) { 128021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov growKeyAndValueArrays(mSize + 1); 129021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 130021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 131021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (mSize - i != 0) { 132021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov System.arraycopy(mKeys, i, mKeys, i + 1, mSize - i); 133021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov System.arraycopy(mValues, i, mValues, i + 1, mSize - i); 134021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 135021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 136021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mKeys[i] = key; 137021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mValues[i] = value; 138021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mSize++; 139021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 140021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 141021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 142021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 143021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Returns the number of key-value mappings that this SparseIntArray 144021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * currently stores. 145021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 146021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public int size() { 147021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return mSize; 148021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 149021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 150021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 151021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Given an index in the range <code>0...size()-1</code>, returns 152021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * the key from the <code>index</code>th key-value mapping that this 153021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * SparseLongArray stores. 154021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 155021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public int keyAt(int index) { 156021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return mKeys[index]; 157021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 158021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 159021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 160021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Given an index in the range <code>0...size()-1</code>, returns 161021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * the value from the <code>index</code>th key-value mapping that this 162021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * SparseLongArray stores. 163021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 164021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public long valueAt(int index) { 165021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return mValues[index]; 166021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 167021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 168021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 169021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Returns the index for which {@link #keyAt} would return the 170021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * specified key, or a negative number if the specified 171021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * key is not mapped. 172021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 173021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public int indexOfKey(int key) { 174f4bf0ae2a7c2d9d92c5c8abdb82baa53b4c9ccdaDianne Hackborn return SparseArray.binarySearch(mKeys, mSize, key); 175021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 176021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 177021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 178021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Returns an index for which {@link #valueAt} would return the 179021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * specified key, or a negative number if no keys map to the 180021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * specified value. 181021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Beware that this is a linear search, unlike lookups by key, 182021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * and that multiple keys can map to the same value and this will 183021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * find only one of them. 184021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 185021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public int indexOfValue(long value) { 186021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov for (int i = 0; i < mSize; i++) 187021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (mValues[i] == value) 188021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return i; 189021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 190021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return -1; 191021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 192021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 193021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 194021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Removes all key-value mappings from this SparseIntArray. 195021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 196021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public void clear() { 197021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mSize = 0; 198021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 199021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 200021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov /** 201021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * Puts a key/value pair into the array, optimizing for the case where 202021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov * the key is greater than all existing keys in the array. 203021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov */ 204021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov public void append(int key, long value) { 205021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (mSize != 0 && key <= mKeys[mSize - 1]) { 206021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov put(key, value); 207021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov return; 208021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 209021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 210021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov int pos = mSize; 211021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov if (pos >= mKeys.length) { 212021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov growKeyAndValueArrays(pos + 1); 213021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 214021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 215021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mKeys[pos] = key; 216021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mValues[pos] = value; 217021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mSize = pos + 1; 218021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 219021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 220021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov private void growKeyAndValueArrays(int minNeededSize) { 221021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov int n = ArrayUtils.idealLongArraySize(minNeededSize); 222021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 223021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov int[] nkeys = new int[n]; 224021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov long[] nvalues = new long[n]; 225021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 226021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length); 227021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov System.arraycopy(mValues, 0, nvalues, 0, mValues.length); 228021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov 229021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mKeys = nkeys; 230021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov mValues = nvalues; 231021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov } 232021078554b902179442a345a9d080a165c3b5139Svetoslav Ganov} 233