From ac765721b6b49c2d0ca957bfbc576b7ad52b04b8 Mon Sep 17 00:00:00 2001
From: Chris Larsen <clarsen@yahoo-inc.com>
Date: Wed, 16 Mar 2016 20:57:50 -0700
Subject: [PATCH] [core] Add byte to double and long conversion methods to
Utils. These will be used for #653 to write timestamps and numeric values to
the ByteIterator maps.
---
core/src/main/java/com/yahoo/ycsb/Utils.java | 63 ++++++++-
.../test/java/com/yahoo/ycsb/TestUtils.java | 129 ++++++++++++++++++
2 files changed, 191 insertions(+), 1 deletion(-)
create mode 100644 core/src/test/java/com/yahoo/ycsb/TestUtils.java
diff --git a/core/src/main/java/com/yahoo/ycsb/Utils.java b/core/src/main/java/com/yahoo/ycsb/Utils.java
index f49bc0f5..5fe699af 100644
--- a/core/src/main/java/com/yahoo/ycsb/Utils.java
+++ b/core/src/main/java/com/yahoo/ycsb/Utils.java
@@ -1,5 +1,5 @@
/**
- * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
+ * Copyright (c) 2010 Yahoo! Inc., 2016 YCSB contributors. 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
@@ -113,4 +113,65 @@ public class Utils
}
return Math.abs(hashval);
}
+
+ /**
+ * Reads a big-endian 8-byte long from an offset in the given array.
+ * @param bytes The array to read from.
+ * @return A long integer.
+ * @throws IndexOutOfBoundsException if the byte array is too small.
+ * @throws NullPointerException if the byte array is null.
+ */
+ public static long bytesToLong(final byte[] bytes) {
+ return (bytes[0] & 0xFFL) << 56
+ | (bytes[1] & 0xFFL) << 48
+ | (bytes[2] & 0xFFL) << 40
+ | (bytes[3] & 0xFFL) << 32
+ | (bytes[4] & 0xFFL) << 24
+ | (bytes[5] & 0xFFL) << 16
+ | (bytes[6] & 0xFFL) << 8
+ | (bytes[7] & 0xFFL) << 0;
+ }
+
+ /**
+ * Writes a big-endian 8-byte long at an offset in the given array.
+ * @param val The value to encode.
+ * @throws IndexOutOfBoundsException if the byte array is too small.
+ */
+ public static byte[] longToBytes(final long val) {
+ final byte[] bytes = new byte[8];
+ bytes[0] = (byte) (val >>> 56);
+ bytes[1] = (byte) (val >>> 48);
+ bytes[2] = (byte) (val >>> 40);
+ bytes[3] = (byte) (val >>> 32);
+ bytes[4] = (byte) (val >>> 24);
+ bytes[5] = (byte) (val >>> 16);
+ bytes[6] = (byte) (val >>> 8);
+ bytes[7] = (byte) (val >>> 0);
+ return bytes;
+ }
+
+ /**
+ * Parses the byte array into a double.
+ * The byte array must be at least 8 bytes long and have been encoded using
+ * {@link #doubleToBytes}. If the array is longer than 8 bytes, only the
+ * first 8 bytes are parsed.
+ * @param bytes The byte array to parse, at least 8 bytes.
+ * @return A double value read from the byte array.
+ * @throws IllegalArgumentException if the byte array is not 8 bytes wide.
+ */
+ public static double bytesToDouble(final byte[] bytes) {
+ if (bytes.length < 8) {
+ throw new IllegalArgumentException("Byte array must be 8 bytes wide.");
+ }
+ return Double.longBitsToDouble(bytesToLong(bytes));
+ }
+
+ /**
+ * Encodes the double value as an 8 byte array.
+ * @param val The double value to encode.
+ * @return A byte array of length 8.
+ */
+ public static byte[] doubleToBytes(final double val) {
+ return longToBytes(Double.doubleToRawLongBits(val));
+ }
}
diff --git a/core/src/test/java/com/yahoo/ycsb/TestUtils.java b/core/src/test/java/com/yahoo/ycsb/TestUtils.java
new file mode 100644
index 00000000..cde51776
--- /dev/null
+++ b/core/src/test/java/com/yahoo/ycsb/TestUtils.java
@@ -0,0 +1,129 @@
+/**
+ * Copyright (c) 2016 YCSB contributors. 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. See accompanying
+ * LICENSE file.
+ */
+
+package com.yahoo.ycsb;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+import java.util.Arrays;
+
+import org.testng.annotations.Test;
+
+public class TestUtils {
+
+ @Test
+ public void bytesToFromLong() throws Exception {
+ byte[] bytes = new byte[8];
+ assertEquals(Utils.bytesToLong(bytes), 0L);
+ assertArrayEquals(Utils.longToBytes(0), bytes);
+
+ bytes[7] = 1;
+ assertEquals(Utils.bytesToLong(bytes), 1L);
+ assertArrayEquals(Utils.longToBytes(1L), bytes);
+
+ bytes = new byte[] { 127, -1, -1, -1, -1, -1, -1, -1 };
+ assertEquals(Utils.bytesToLong(bytes), Long.MAX_VALUE);
+ assertArrayEquals(Utils.longToBytes(Long.MAX_VALUE), bytes);
+
+ bytes = new byte[] { -128, 0, 0, 0, 0, 0, 0, 0 };
+ assertEquals(Utils.bytesToLong(bytes), Long.MIN_VALUE);
+ assertArrayEquals(Utils.longToBytes(Long.MIN_VALUE), bytes);
+
+ bytes = new byte[] { (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
+ (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF };
+ assertEquals(Utils.bytesToLong(bytes), -1L);
+ assertArrayEquals(Utils.longToBytes(-1L), bytes);
+
+ // if the array is too long we just skip the remainder
+ bytes = new byte[] { 0, 0, 0, 0, 0, 0, 0, 1, 42, 42, 42 };
+ assertEquals(Utils.bytesToLong(bytes), 1L);
+ }
+
+ @Test
+ public void bytesToFromDouble() throws Exception {
+ byte[] bytes = new byte[8];
+ assertEquals(Utils.bytesToDouble(bytes), 0, 0.0001);
+ assertArrayEquals(Utils.doubleToBytes(0), bytes);
+
+ bytes = new byte[] { 63, -16, 0, 0, 0, 0, 0, 0 };
+ assertEquals(Utils.bytesToDouble(bytes), 1, 0.0001);
+ assertArrayEquals(Utils.doubleToBytes(1), bytes);
+
+ bytes = new byte[] { -65, -16, 0, 0, 0, 0, 0, 0 };
+ assertEquals(Utils.bytesToDouble(bytes), -1, 0.0001);
+ assertArrayEquals(Utils.doubleToBytes(-1), bytes);
+
+ bytes = new byte[] { 127, -17, -1, -1, -1, -1, -1, -1 };
+ assertEquals(Utils.bytesToDouble(bytes), Double.MAX_VALUE, 0.0001);
+ assertArrayEquals(Utils.doubleToBytes(Double.MAX_VALUE), bytes);
+
+ bytes = new byte[] { 0, 0, 0, 0, 0, 0, 0, 1 };
+ assertEquals(Utils.bytesToDouble(bytes), Double.MIN_VALUE, 0.0001);
+ assertArrayEquals(Utils.doubleToBytes(Double.MIN_VALUE), bytes);
+
+ bytes = new byte[] { 127, -8, 0, 0, 0, 0, 0, 0 };
+ assertTrue(Double.isNaN(Utils.bytesToDouble(bytes)));
+ assertArrayEquals(Utils.doubleToBytes(Double.NaN), bytes);
+
+ bytes = new byte[] { 63, -16, 0, 0, 0, 0, 0, 0, 42, 42, 42 };
+ assertEquals(Utils.bytesToDouble(bytes), 1, 0.0001);
+ }
+
+ @Test (expectedExceptions = NullPointerException.class)
+ public void bytesToLongNull() throws Exception {
+ Utils.bytesToLong(null);
+ }
+
+ @Test (expectedExceptions = IndexOutOfBoundsException.class)
+ public void bytesToLongTooShort() throws Exception {
+ Utils.bytesToLong(new byte[] { 0, 0, 0, 0, 0, 0, 0 });
+ }
+
+ @Test (expectedExceptions = IllegalArgumentException.class)
+ public void bytesToDoubleTooShort() throws Exception {
+ Utils.bytesToDouble(new byte[] { 0, 0, 0, 0, 0, 0, 0 });
+ }
+
+ /**
+ * Since this version of TestNG doesn't appear to have an assertArrayEquals,
+ * this will compare the two to make sure they're the same.
+ * @param actual Actual array to validate
+ * @param expected What the array should contain
+ * @throws AssertionError if the test fails.
+ */
+ public void assertArrayEquals(final byte[] actual, final byte[] expected) {
+ if (actual == null && expected != null) {
+ throw new AssertionError("Expected " + Arrays.toString(expected) +
+ " but found [null]");
+ }
+ if (actual != null && expected == null) {
+ throw new AssertionError("Expected [null] but found " +
+ Arrays.toString(actual));
+ }
+ if (actual.length != expected.length) {
+ throw new AssertionError("Expected length " + expected.length +
+ " but found " + actual.length);
+ }
+ for (int i = 0; i < expected.length; i++) {
+ if (actual[i] != expected[i]) {
+ throw new AssertionError("Expected byte [" + expected[i] +
+ "] at index " + i + " but found [" + actual[i] + "]");
+ }
+ }
+ }
+}
\ No newline at end of file
--
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