Update #48 - Added some features from OptiFine

sources/main/java/jdk_internal/icu/util/VersionInfo.java

@@ -0,0 +1,191 @@
+/*
+ * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+/*
+ *******************************************************************************
+ * (C) Copyright IBM Corp. and others, 1996-2009 - All Rights Reserved         *
+ *                                                                             *
+ * The original version of this source code and documentation is copyrighted   *
+ * and owned by IBM, These materials are provided under terms of a License     *
+ * Agreement between IBM and Sun. This technology is protected by multiple     *
+ * US and International patents. This notice and attribution to IBM may not    *
+ * to removed.                                                                 *
+ *******************************************************************************
+ */
+
+package jdk_internal.icu.util;
+
+import java.util.HashMap;
+
+/**
+ * Class to store version numbers of the form major.minor.milli.micro.
+ * 
+ * @author synwee
+ * @stable ICU 2.6
+ */
+public final class VersionInfo {
+	// public data members -------------------------------------------------
+
+	/**
+	 * Data version string for ICU's internal data. Used for appending to data path
+	 * (e.g. icudt43b)
+	 * 
+	 * @internal
+	 * @deprecated This API is ICU internal only.
+	 */
+	@Deprecated
+	public static final String ICU_DATA_VERSION_PATH = "67b";
+
+	// public methods ------------------------------------------------------
+
+	/**
+	 * Returns an instance of VersionInfo with the argument version.
+	 * 
+	 * @param version version String in the format of "major.minor.milli.micro" or
+	 *                "major.minor.milli" or "major.minor" or "major", where major,
+	 *                minor, milli, micro are non-negative numbers {@literal <=}
+	 *                255. If the trailing version numbers are not specified they
+	 *                are taken as 0s. E.g. Version "3.1" is equivalent to
+	 *                "3.1.0.0".
+	 * @return an instance of VersionInfo with the argument version.
+	 * @exception throws an IllegalArgumentException when the argument version is
+	 *                   not in the right format
+	 * @stable ICU 2.6
+	 */
+	public static VersionInfo getInstance(String version) {
+		int length = version.length();
+		int array[] = { 0, 0, 0, 0 };
+		int count = 0;
+		int index = 0;
+
+		while (count < 4 && index < length) {
+			char c = version.charAt(index);
+			if (c == '.') {
+				count++;
+			} else {
+				c -= '0';
+				if (c < 0 || c > 9) {
+					throw new IllegalArgumentException(INVALID_VERSION_NUMBER_);
+				}
+				array[count] *= 10;
+				array[count] += c;
+			}
+			index++;
+		}
+		if (index != length) {
+			throw new IllegalArgumentException(
+					"Invalid version number: String '" + version + "' exceeds version format");
+		}
+		for (int i = 0; i < 4; i++) {
+			if (array[i] < 0 || array[i] > 255) {
+				throw new IllegalArgumentException(INVALID_VERSION_NUMBER_);
+			}
+		}
+
+		return getInstance(array[0], array[1], array[2], array[3]);
+	}
+
+	/**
+	 * Returns an instance of VersionInfo with the argument version.
+	 * 
+	 * @param major major version, non-negative number {@literal <=} 255.
+	 * @param minor minor version, non-negative number {@literal <=} 255.
+	 * @param milli milli version, non-negative number {@literal <=} 255.
+	 * @param micro micro version, non-negative number {@literal <=} 255.
+	 * @exception throws an IllegalArgumentException when either arguments are
+	 *                   negative or {@literal >} 255
+	 * @stable ICU 2.6
+	 */
+	public static VersionInfo getInstance(int major, int minor, int milli, int micro) {
+		// checks if it is in the hashmap
+		// else
+		if (major < 0 || major > 255 || minor < 0 || minor > 255 || milli < 0 || milli > 255 || micro < 0
+				|| micro > 255) {
+			throw new IllegalArgumentException(INVALID_VERSION_NUMBER_);
+		}
+		int version = getInt(major, minor, milli, micro);
+		Integer key = Integer.valueOf(version);
+		Object result = MAP_.get(key);
+		if (result == null) {
+			result = new VersionInfo(version);
+			MAP_.put(key, result);
+		}
+		return (VersionInfo) result;
+	}
+
+	/**
+	 * Compares other with this VersionInfo.
+	 * 
+	 * @param other VersionInfo to be compared
+	 * @return 0 if the argument is a VersionInfo object that has version
+	 *         information equal to this object. Less than 0 if the argument is a
+	 *         VersionInfo object that has version information greater than this
+	 *         object. Greater than 0 if the argument is a VersionInfo object that
+	 *         has version information less than this object.
+	 * @stable ICU 2.6
+	 */
+	public int compareTo(VersionInfo other) {
+		return m_version_ - other.m_version_;
+	}
+
+	// private data members ----------------------------------------------
+
+	/**
+	 * Version number stored as a byte for each of the major, minor, milli and micro
+	 * numbers in the 32 bit int. Most significant for the major and the least
+	 * significant contains the micro numbers.
+	 */
+	private int m_version_;
+	/**
+	 * Map of singletons
+	 */
+	private static final HashMap<Integer, Object> MAP_ = new HashMap<>();
+	/**
+	 * Error statement string
+	 */
+	private static final String INVALID_VERSION_NUMBER_ = "Invalid version number: Version number may be negative or greater than 255";
+
+	// private constructor -----------------------------------------------
+
+	/**
+	 * Constructor with int
+	 * 
+	 * @param compactversion a 32 bit int with each byte representing a number
+	 */
+	private VersionInfo(int compactversion) {
+		m_version_ = compactversion;
+	}
+
+	/**
+	 * Gets the int from the version numbers
+	 * 
+	 * @param major non-negative version number
+	 * @param minor non-negativeversion number
+	 * @param milli non-negativeversion number
+	 * @param micro non-negativeversion number
+	 */
+	private static int getInt(int major, int minor, int milli, int micro) {
+		return (major << 24) | (minor << 16) | (milli << 8) | micro;
+	}
+}