java/src/com/android/inputmethod/latin/StringBuilderPool.java


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/*
 * Copyright (C) 2011 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.android.inputmethod.latin;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * A pool of string builders to be used from anywhere.
 */
public class StringBuilderPool {
    // Singleton
    private static final StringBuilderPool sInstance = new StringBuilderPool();
    private StringBuilderPool() {}
    // TODO: Make this a normal array with a size of 20
    private final List<StringBuilder> mPool =
            Collections.synchronizedList(new ArrayList<StringBuilder>());

    public static StringBuilder getStringBuilder(final int initialSize) {
        final int poolSize = sInstance.mPool.size();
        final StringBuilder sb = poolSize > 0 ? (StringBuilder) sInstance.mPool.remove(poolSize - 1)
                : new StringBuilder(initialSize);
        sb.setLength(0);
        return sb;
    }

    public static void recycle(final StringBuilder garbage) {
        sInstance.mPool.add(garbage);
    }

    public static void ensureCapacity(final int capacity, final int initialSize) {
        for (int i = sInstance.mPool.size(); i < capacity; ++i) {
            final StringBuilder sb = new StringBuilder(initialSize);
            sInstance.mPool.add(sb);
        }
    }

    public static int getSize() {
        return sInstance.mPool.size();
    }
}