src/Lucene.Net.Core/Util/Constants.cs

using Lucene.Net.Support;
using System;

namespace Lucene.Net.Util
{
    /*
     * Licensed to the Apache Software Foundation (ASF) under one or more
     * contributor license agreements.  See the NOTICE file distributed with
     * this work for additional information regarding copyright ownership.
     * The ASF licenses this file to You 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.
     */

    /// <summary>
    /// Some useful constants.
    ///
    /// </summary>

    public sealed class Constants
    {
        private Constants() // can't construct
        {
        }

        /// <summary>
        /// The value of <tt>System.getProperty("java.version")</tt>. * </summary>
        public static readonly string JAVA_VERSION = AppSettings.Get("java.version", "");

        public static readonly string JAVA_VENDOR = AppSettings.Get("java.vendor", "");
        public static readonly string JVM_VENDOR = AppSettings.Get("java.vm.vendor", "");
        public static readonly string JVM_VERSION = AppSettings.Get("java.vm.version", "");
        public static readonly string JVM_NAME = AppSettings.Get("java.vm.name", "");

        /// <summary>
        /// The value of <tt>System.getProperty("os.name")</tt>. * </summary>
        public static readonly string OS_NAME = GetEnvironmentVariable("OS", "Windows_NT") ?? "Linux";

        /// <summary>
        /// True iff running on Linux. </summary>
        public static readonly bool LINUX = OS_NAME.StartsWith("Linux");

        /// <summary>
        /// True iff running on Windows. </summary>
        public static readonly bool WINDOWS = OS_NAME.StartsWith("Windows");

        /// <summary>
        /// True iff running on SunOS. </summary>
        public static readonly bool SUN_OS = OS_NAME.StartsWith("SunOS");

        /// <summary>
        /// True iff running on Mac OS X </summary>
        public static readonly bool MAC_OS_X = OS_NAME.StartsWith("Mac OS X");

        /// <summary>
        /// True iff running on FreeBSD </summary>
        public static readonly bool FREE_BSD = OS_NAME.StartsWith("FreeBSD");

        public static readonly string OS_ARCH = GetEnvironmentVariable("PROCESSOR_ARCHITECTURE", "x86");
        public static readonly string OS_VERSION = GetEnvironmentVariable("OS_VERSION", "?");

        [Obsolete("We are not running on Java for heavens sake")]
        public static readonly bool JRE_IS_MINIMUM_JAVA6 = (bool)new bool?(true); // prevent inlining in foreign class files

        [Obsolete("We are not running on Java for heavens sake")]
        public static readonly bool JRE_IS_MINIMUM_JAVA7 = (bool)new bool?(true); // prevent inlining in foreign class files

        [Obsolete("We are not running on Java for heavens sake")]
        public static readonly bool JRE_IS_MINIMUM_JAVA8;

        [Obsolete("We are not running on Java for heavens sake")]
        public static readonly bool JRE_IS_64BIT;

        static Constants()
        {
            if (IntPtr.Size == 8)
            {
                JRE_IS_64BIT = true;// 64 bit machine
            }
            else if (IntPtr.Size == 4)
            {
                JRE_IS_64BIT = false;// 32 bit machine
            }

            try
            {
                LUCENE_VERSION = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString();
            }
            catch (System.Security.SecurityException) //Ignore in medium trust.
            {
            }
            /* LUCENE TO-DO Well that was all over the top to check architechture
            bool is64Bit = false;
            try
            {
              Type unsafeClass = Type.GetType("sun.misc.Unsafe");
              Field unsafeField = unsafeClass.getDeclaredField("theUnsafe");
              unsafeField.Accessible = true;
              object @unsafe = unsafeField.get(null);
              int addressSize = (int)((Number) unsafeClass.GetMethod("addressSize").invoke(@unsafe));
              is64Bit = addressSize >= 8;
            }
            catch (Exception e)
            {
              string x = System.getProperty("sun.arch.data.model");
              if (x != null)
              {
                is64Bit = x.IndexOf("64") != -1;
              }
              else
              {
                if (OS_ARCH != null && OS_ARCH.IndexOf("64") != -1)
                {
                  is64Bit = true;
                }
                else
                {
                  is64Bit = false;
                }
              }
            }
            JRE_IS_64BIT = is64Bit;

            // this method only exists in Java 8:
            bool v8 = true;
            try
            {
              typeof(Collections).getMethod("emptySortedSet");
            }
            catch (NoSuchMethodException nsme)
            {
              v8 = false;
            }
            JRE_IS_MINIMUM_JAVA8 = v8;
            Package pkg = LucenePackage.Get();
            string v = (pkg == null) ? null : pkg.ImplementationVersion;
            if (v == null)
            {
              v = MainVersionWithoutAlphaBeta() + "-SNAPSHOT";
            }
            LUCENE_VERSION = Ident(v);*/
        }

        // this method prevents inlining the final version constant in compiled classes,
        // see: http://www.javaworld.com/community/node/3400
        private static string Ident(string s)
        {
            return s.ToString();
        }

        // We should never change index format with minor versions, so it should always be x.y or x.y.0.z for alpha/beta versions!
        /// <summary>
        /// this is the internal Lucene version, recorded into each segment.
        /// NOTE: we track per-segment version as a String with the {@code "X.Y"} format
        /// (no minor version), e.g. {@code "4.0", "3.1", "3.0"}.
        /// <p>Alpha and Beta versions will have numbers like {@code "X.Y.0.Z"},
        /// anything else is not allowed. this is done to prevent people from
        /// using indexes created with ALPHA/BETA versions with the released version.
        /// </summary>
        public static readonly string LUCENE_MAIN_VERSION = Ident("4.8");

        /// <summary>
        /// this is the Lucene version for display purposes.
        /// </summary>
        public static readonly string LUCENE_VERSION;

        /// <summary>
        /// Returns a LUCENE_MAIN_VERSION without any ALPHA/BETA qualifier
        /// Used by test only!
        /// </summary>
        public static string MainVersionWithoutAlphaBeta()
        {
            string[] parts = LUCENE_MAIN_VERSION.Split("\\.", true);
            if (parts.Length == 4 && "0".Equals(parts[2]))
            {
                return parts[0] + "." + parts[1];
            }
            return LUCENE_MAIN_VERSION;
        }

        #region MEDIUM-TRUST Support

        private static string GetEnvironmentVariable(string variable, string defaultValueOnSecurityException)
        {
            try
            {
                if (variable == "OS_VERSION") return System.Environment.OSVersion.ToString();

                return System.Environment.GetEnvironmentVariable(variable);
            }
            catch (System.Security.SecurityException)
            {
                return defaultValueOnSecurityException;
            }
        }

        #endregion MEDIUM-TRUST Support
    }
}