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-rw-r--r--core/java/android/util/ContainerHelpers.java63
1 files changed, 63 insertions, 0 deletions
diff --git a/core/java/android/util/ContainerHelpers.java b/core/java/android/util/ContainerHelpers.java
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+/*
+ * 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
+ }
+}