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Diffstat (limited to 'core/java/android/util/ContainerHelpers.java')
-rw-r--r-- | core/java/android/util/ContainerHelpers.java | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/core/java/android/util/ContainerHelpers.java b/core/java/android/util/ContainerHelpers.java new file mode 100644 index 0000000..624c4bd --- /dev/null +++ b/core/java/android/util/ContainerHelpers.java @@ -0,0 +1,63 @@ +/* + * 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 android.util; + +class ContainerHelpers { + static final boolean[] EMPTY_BOOLEANS = new boolean[0]; + static final int[] EMPTY_INTS = new int[0]; + static final long[] EMPTY_LONGS = new long[0]; + static final Object[] EMPTY_OBJECTS = new Object[0]; + + // This is Arrays.binarySearch(), but doesn't do any argument validation. + static int binarySearch(int[] array, int size, int value) { + int lo = 0; + int hi = size - 1; + + while (lo <= hi) { + final int mid = (lo + hi) >>> 1; + final 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 + } + + static int binarySearch(long[] array, int size, long value) { + int lo = 0; + int hi = size - 1; + + while (lo <= hi) { + final int mid = (lo + hi) >>> 1; + final long 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 + } +} |