Merge "Add LongSparseLongArray with tests."
This commit is contained in:
Jeff Sharkey
228
core/java/android/util/LongSparseLongArray.java
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228
core/java/android/util/LongSparseLongArray.java
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/*
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* Copyright (C) 2007 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.util;
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import com.android.internal.util.ArrayUtils;
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import java.util.Arrays;
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/**
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* Map of {@code long} to {@code long}. Unlike a normal array of longs, there
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* can be gaps in the indices. It is intended to be more efficient than using a
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* {@code HashMap}.
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*
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* @hide
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*/
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public class LongSparseLongArray implements Cloneable {
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private long[] mKeys;
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private long[] mValues;
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private int mSize;
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/**
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* Creates a new SparseLongArray containing no mappings.
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*/
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public LongSparseLongArray() {
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this(10);
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}
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/**
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* Creates a new SparseLongArray containing no mappings that will not
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* require any additional memory allocation to store the specified
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* number of mappings.
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*/
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public LongSparseLongArray(int initialCapacity) {
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initialCapacity = ArrayUtils.idealLongArraySize(initialCapacity);
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mKeys = new long[initialCapacity];
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mValues = new long[initialCapacity];
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mSize = 0;
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}
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@Override
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public LongSparseLongArray clone() {
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LongSparseLongArray clone = null;
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try {
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clone = (LongSparseLongArray) super.clone();
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clone.mKeys = mKeys.clone();
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clone.mValues = mValues.clone();
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} catch (CloneNotSupportedException cnse) {
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/* ignore */
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}
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return clone;
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}
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/**
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* Gets the long mapped from the specified key, or <code>0</code>
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* if no such mapping has been made.
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*/
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public long get(long key) {
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return get(key, 0);
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}
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/**
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* Gets the long mapped from the specified key, or the specified value
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* if no such mapping has been made.
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*/
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public long get(long key, long valueIfKeyNotFound) {
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int i = Arrays.binarySearch(mKeys, 0, mSize, key);
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if (i < 0) {
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return valueIfKeyNotFound;
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} else {
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return mValues[i];
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}
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}
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/**
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* Removes the mapping from the specified key, if there was any.
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*/
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public void delete(long key) {
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int i = Arrays.binarySearch(mKeys, 0, mSize, key);
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if (i >= 0) {
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removeAt(i);
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}
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}
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/**
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* Removes the mapping at the given index.
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*/
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public void removeAt(int index) {
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System.arraycopy(mKeys, index + 1, mKeys, index, mSize - (index + 1));
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System.arraycopy(mValues, index + 1, mValues, index, mSize - (index + 1));
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mSize--;
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}
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/**
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* Adds a mapping from the specified key to the specified value,
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* replacing the previous mapping from the specified key if there
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* was one.
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*/
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public void put(long key, long value) {
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int i = Arrays.binarySearch(mKeys, 0, mSize, key);
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if (i >= 0) {
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mValues[i] = value;
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} else {
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i = ~i;
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if (mSize >= mKeys.length) {
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growKeyAndValueArrays(mSize + 1);
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}
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if (mSize - i != 0) {
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System.arraycopy(mKeys, i, mKeys, i + 1, mSize - i);
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System.arraycopy(mValues, i, mValues, i + 1, mSize - i);
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}
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mKeys[i] = key;
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mValues[i] = value;
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mSize++;
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}
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}
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/**
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* Returns the number of key-value mappings that this SparseIntArray
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* currently stores.
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*/
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public int size() {
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return mSize;
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}
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/**
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* Given an index in the range <code>0...size()-1</code>, returns
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* the key from the <code>index</code>th key-value mapping that this
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* SparseLongArray stores.
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*/
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public long keyAt(int index) {
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return mKeys[index];
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}
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/**
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* Given an index in the range <code>0...size()-1</code>, returns
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* the value from the <code>index</code>th key-value mapping that this
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* SparseLongArray stores.
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*/
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public long valueAt(int index) {
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return mValues[index];
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}
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/**
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* Returns the index for which {@link #keyAt} would return the
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* specified key, or a negative number if the specified
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* key is not mapped.
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*/
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public int indexOfKey(long key) {
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return Arrays.binarySearch(mKeys, 0, mSize, key);
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}
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/**
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* Returns an index for which {@link #valueAt} would return the
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* specified key, or a negative number if no keys map to the
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* specified value.
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* Beware that this is a linear search, unlike lookups by key,
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* and that multiple keys can map to the same value and this will
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* find only one of them.
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*/
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public int indexOfValue(long value) {
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for (int i = 0; i < mSize; i++)
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if (mValues[i] == value)
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return i;
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return -1;
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}
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/**
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* Removes all key-value mappings from this SparseIntArray.
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*/
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public void clear() {
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mSize = 0;
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}
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/**
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* Puts a key/value pair into the array, optimizing for the case where
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* the key is greater than all existing keys in the array.
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*/
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public void append(long key, long value) {
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if (mSize != 0 && key <= mKeys[mSize - 1]) {
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put(key, value);
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return;
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}
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int pos = mSize;
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if (pos >= mKeys.length) {
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growKeyAndValueArrays(pos + 1);
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}
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mKeys[pos] = key;
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mValues[pos] = value;
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mSize = pos + 1;
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}
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private void growKeyAndValueArrays(int minNeededSize) {
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int n = ArrayUtils.idealLongArraySize(minNeededSize);
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long[] nkeys = new long[n];
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long[] nvalues = new long[n];
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System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
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System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
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mKeys = nkeys;
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mValues = nvalues;
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}
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}
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@@ -0,0 +1,111 @@
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/*
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* Copyright (C) 2007 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.util;
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import junit.framework.TestCase;
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import java.util.HashMap;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.Random;
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/**
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* Tests for {@link LongSparseLongArray}.
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*/
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public class LongSparseLongArrayTest extends TestCase {
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private static final String TAG = "LongSparseLongArrayTest";
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public void testSimplePut() throws Exception {
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final LongSparseLongArray array = new LongSparseLongArray(5);
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for (int i = 0; i < 48; i++) {
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final long value = 1 << i;
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array.put(value, value);
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}
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for (int i = 0; i < 48; i++) {
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final long value = 1 << i;
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assertEquals(value, array.get(value, -1));
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assertEquals(-1, array.get(-value, -1));
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}
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}
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public void testSimplePutBackwards() throws Exception {
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final LongSparseLongArray array = new LongSparseLongArray(5);
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for (int i = 47; i >= 0; i--) {
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final long value = 1 << i;
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array.put(value, value);
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}
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for (int i = 0; i < 48; i++) {
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final long value = 1 << i;
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assertEquals(value, array.get(value, -1));
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assertEquals(-1, array.get(-value, -1));
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}
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}
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public void testMiddleInsert() throws Exception {
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final LongSparseLongArray array = new LongSparseLongArray(5);
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for (int i = 0; i < 48; i++) {
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final long value = 1 << i;
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array.put(value, value);
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}
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final long special = (1 << 24) + 5;
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array.put(special, 1024);
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for (int i = 0; i < 48; i++) {
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final long value = 1 << i;
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assertEquals(value, array.get(value, -1));
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assertEquals(-1, array.get(-value, -1));
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}
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assertEquals(1024, array.get(special, -1));
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}
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public void testFuzz() throws Exception {
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final Random r = new Random();
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final HashMap<Long, Long> map = new HashMap<Long, Long>();
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final LongSparseLongArray array = new LongSparseLongArray(r.nextInt(128));
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for (int i = 0; i < 10240; i++) {
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if (r.nextBoolean()) {
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final long key = r.nextLong();
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final long value = r.nextLong();
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map.put(key, value);
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array.put(key, value);
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}
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if (r.nextBoolean() && map.size() > 0) {
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final int index = r.nextInt(map.size());
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final long key = getKeyAtIndex(map, index);
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map.remove(key);
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array.delete(key);
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}
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}
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Log.d(TAG, "verifying a map with " + map.size() + " entries");
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for (Map.Entry<Long, Long> e : map.entrySet()) {
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final long key = e.getKey();
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final long value = e.getValue();
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assertEquals(value, array.get(key));
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}
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}
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private static <E> E getKeyAtIndex(Map<E, ?> map, int index) {
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final Iterator<E> keys = map.keySet().iterator();
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for (int i = 0; i < index; i++) {
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keys.next();
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}
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return keys.next();
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}
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}
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