diff options
| author | Brian S. O'Neill <bronee@gmail.com> | 2006-10-05 03:54:20 +0000 |
|---|---|---|
| committer | Brian S. O'Neill <bronee@gmail.com> | 2006-10-05 03:54:20 +0000 |
| commit | 79cebfadf8703afe9bf28786bc4df1af348c876e (patch) | |
| tree | fc9e9ae84e444096eb7dfd0bc5639337a2234b94 /src/main/java/com/amazon/carbonado/raw/RawUtil.java | |
| parent | 1f602d1146ec547a3bf65912a3ba0930dca75eaf (diff) | |
Moved raw package out of spi package.
Diffstat (limited to 'src/main/java/com/amazon/carbonado/raw/RawUtil.java')
| -rw-r--r-- | src/main/java/com/amazon/carbonado/raw/RawUtil.java | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/src/main/java/com/amazon/carbonado/raw/RawUtil.java b/src/main/java/com/amazon/carbonado/raw/RawUtil.java new file mode 100644 index 0000000..f93316a --- /dev/null +++ b/src/main/java/com/amazon/carbonado/raw/RawUtil.java @@ -0,0 +1,66 @@ +/*
+ * Copyright 2006 Amazon Technologies, Inc. or its affiliates.
+ * Amazon, Amazon.com and Carbonado are trademarks or registered trademarks
+ * of Amazon Technologies, Inc. or its affiliates. All rights reserved.
+ *
+ * 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.amazon.carbonado.raw;
+
+/**
+ * Utilities for manipulating binary data.
+ *
+ * @author Brian S O'Neill
+ */
+public class RawUtil {
+ /**
+ * Adds one to an unsigned integer, represented as a byte array. If
+ * overflowed, value in byte array is 0x00, 0x00, 0x00...
+ *
+ * @param value unsigned integer to increment
+ * @return false if overflowed
+ */
+ public static boolean increment(byte[] value) {
+ for (int i=value.length; --i>=0; ) {
+ byte newValue = (byte) ((value[i] & 0xff) + 1);
+ value[i] = newValue;
+ if (newValue != 0) {
+ // No carry bit, so done adding.
+ return true;
+ }
+ }
+ // This point is reached upon overflow.
+ return false;
+ }
+
+ /**
+ * Subtracts one from an unsigned integer, represented as a byte array. If
+ * overflowed, value in byte array is 0xff, 0xff, 0xff...
+ *
+ * @param value unsigned integer to decrement
+ * @return false if overflowed
+ */
+ public static boolean decrement(byte[] value) {
+ for (int i=value.length; --i>=0; ) {
+ byte newValue = (byte) ((value[i] & 0xff) + -1);
+ value[i] = newValue;
+ if (newValue != -1) {
+ // No borrow bit, so done subtracting.
+ return true;
+ }
+ }
+ // This point is reached upon overflow.
+ return false;
+ }
+}
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