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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.compat;
import android.util.Log;
import java.lang.reflect.Method;
import java.util.Arrays;
public class ArraysCompatUtils {
private static final String TAG = ArraysCompatUtils.class.getSimpleName();
private static final Method METHOD_Arrays_binarySearch = CompatUtils
.getMethod(Arrays.class, "binarySearch", int[].class, int.class, int.class, int.class);
public static int binarySearch(int[] array, int startIndex, int endIndex, int value) {
if (METHOD_Arrays_binarySearch != null) {
final Object index = CompatUtils.invoke(null, 0, METHOD_Arrays_binarySearch,
array, startIndex, endIndex, value);
return (Integer)index;
} else {
return compatBinarySearch(array, startIndex, endIndex, value);
}
}
// TODO: Implement fast binary search
/* package for testing */
static int compatBinarySearch(int[] array, int startIndex, int endIndex, int value) {
// Output error log because this method has strict performance penalty.
// Note that this method has been called only from spell checker and spell checker exists
// only from IceCreamSandwich and after, so that there is no chance on pre-ICS device to
// invoke this method.
Log.e(TAG, "Invoked expensive binarySearch");
if (startIndex > endIndex) throw new IllegalArgumentException();
if (startIndex < 0 || endIndex > array.length) throw new ArrayIndexOutOfBoundsException();
final int work[] = new int[endIndex - startIndex];
System.arraycopy(array, startIndex, work, 0, work.length);
final int index = Arrays.binarySearch(work, value);
if (index >= 0) {
return index + startIndex;
} else {
return ~(~index + startIndex);
}
}
}
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