From 79cebfadf8703afe9bf28786bc4df1af348c876e Mon Sep 17 00:00:00 2001
From: "Brian S. O'Neill" <bronee@gmail.com>
Date: Thu, 5 Oct 2006 03:54:20 +0000
Subject: Moved raw package out of spi package.

---
 .../java/com/amazon/carbonado/raw/RawUtil.java     | 66 ++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 src/main/java/com/amazon/carbonado/raw/RawUtil.java

(limited to 'src/main/java/com/amazon/carbonado/raw/RawUtil.java')

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;
+    }
+}
-- 
cgit v1.2.3