// SNMP INTEGER type.// Copyright (C) 2008-2010 Malcolm Crowe, Lex Li, and other contributors.// // Permission is hereby granted, free of charge, to any person obtaining a copy of this// software and associated documentation files (the "Software"), to deal in the Software// without restriction, including without limitation the rights to use, copy, modify, merge,// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons// to whom the Software is furnished to do so, subject to the following conditions:// // The above copyright notice and this permission notice shall be included in all copies or// substantial portions of the Software.// // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER// DEALINGS IN THE SOFTWARE. using System;using System.Globalization;using System.IO; // ASN.1 BER encoding library by Malcolm Crowe at the University of the West of Scotland// See http://cis.paisley.ac.uk/crow-ci0// This is version 0 of the library, please advise me about any bugs// mailto:malcolm.crowe@paisley.ac.uk // Restrictions: It is assumed that no encoding has index length greater than 2^31-1.// UNIVERSAL TYPES// Some of the more unusual Universal encodings are supported but not fully implemented// Should you require these types, as an alternative to changing this code// you can catch the exception that is thrown and examine the contents yourself.// APPLICATION TYPES// If you want to handle Application types systematically, you can derive index class from// Universal, and provide the Creator and Creators methods for your class// You will see an example of how to do this in the Snmplib// CONTEXT AND PRIVATE TYPES// Ad hoc coding can be used for these, as an alterative to derive index class as above.namespace GSF.Net.Snmp{    /// <summary>    /// Integer32 type in SMIv2 (or INTEGER in SMIv1).    /// </summary>    public sealed class Integer32 // This namespace has its own concept of Integer        : ISnmpData, IEquatable<Integer32>    {        private readonly int _int;        private readonly byte[] _length;                /// <summary>        /// Zero.        /// </summary>        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes")]        public static readonly Integer32 Zero = new Integer32(0);         private byte[] _raw;         /// <summary>        /// Creates an <see cref="Integer32"/> instance.        /// </summary>        /// <param name="raw">Raw bytes</param>        internal Integer32(byte[] raw) : this(new Tuple<int, byte[]>(raw.Length, raw.Length.WritePayloadLength()), new MemoryStream(raw))        {            // IMPORTANT: for test project only.        }                /// <summary>        /// Creates an <see cref="Integer32"/> instance with a specific <see cref="Int32"/>.        /// </summary>        /// <param name="value">Value</param>        public Integer32(int value)        {            _int = value;        }         /// <summary>        /// Initializes a new instance of the <see cref="Integer32"/> class.        /// </summary>        /// <param name="length">The length.</param>        /// <param name="stream">The stream.</param>        public Integer32(Tuple<int, byte[]> length, Stream stream)        {            if (length == null)            {                throw new ArgumentNullException(nameof(length));            }             if (stream == null)            {                throw new ArgumentNullException(nameof(stream));            }             if (length.Item1 <= 0)            {                throw new ArgumentException("Byte length cannot be 0.", nameof(length));            }             if (length.Item1 > 4)            {                throw new ArgumentException("Truncation error for 32-bit integer coding.", nameof(length));            }             _raw = new byte[length.Item1];            stream.Read(_raw, 0, length.Item1);            _int = ((_raw[0] & 0x80) == 0x80) ? -1 : 0; // sign extended! Guy McIlroy            for (int j = 0; j < length.Item1; j++)            {                _int = (_int << 8) | _raw[j];            }             _length = length.Item2;        }         /// <summary>        /// Returns an <see cref="Int32"/> that represents this <see cref="Integer32"/>.        /// </summary>        /// <returns></returns>        public int ToInt32()        {            return _int;        }         /// <summary>        /// Converts to <see cref="ErrorCode"/>.        /// </summary>        /// <returns></returns>        public ErrorCode ToErrorCode()        {            if (_int > 19 || _int < 0)            {                throw new InvalidCastException();            }             return (ErrorCode)_int;        }         /// <summary>        /// Returns a <see cref="String"/> that represents this <see cref="Integer32"/>.        /// </summary>        /// <returns></returns>        public override string ToString()        {            return _int.ToString(CultureInfo.InvariantCulture);        }                /// <summary>        /// Type code.        /// </summary>        public SnmpType TypeCode        {            get            {                return SnmpType.Integer32;            }        }         /// <summary>        /// Appends the bytes to <see cref="Stream"/>.        /// </summary>        /// <param name="stream">The stream.</param>        public void AppendBytesTo(Stream stream)        {            if (stream == null)            {                throw new ArgumentNullException(nameof(stream));            }                        stream.AppendBytes(TypeCode, _length, _raw ?? (_raw = ByteTool.GetRawBytes(BitConverter.GetBytes(_int), _int < 0)));        }         /// <summary>        /// Serves as a hash function for a particular type.        /// </summary>        /// <returns>A hash code for the current <see cref="Integer32"/>.</returns>        public override int GetHashCode()        {            return ToInt32().GetHashCode();        }                /// <summary>        /// Determines whether the specified <see cref="Object"/> is equal to the current <see cref="Integer32"/>.        /// </summary>        /// <param name="obj">The <see cref="Object"/> to compare with the current <see cref="Integer32"/>. </param>        /// <returns><value>true</value> if the specified <see cref="Object"/> is equal to the current <see cref="Integer32"/>; otherwise, <value>false</value>.        /// </returns>        public override bool Equals(object obj)        {            return Equals(this, obj as Integer32);        }                /// <summary>        /// Indicates whether the current object is equal to another object of the same type.        /// </summary>        /// <param name="other">An object to compare with this object.</param>        /// <returns><value>true</value> if the current object is equal to the <paramref name="other"/> parameter; otherwise, <value>false</value>.        /// </returns>        public bool Equals(Integer32 other)        {            return Equals(this, other);        }                /// <summary>        /// The equality operator.        /// </summary>        /// <param name="left">Left <see cref="Integer32"/> object</param>        /// <param name="right">Right <see cref="Integer32"/> object</param>        /// <returns>        /// Returns <c>true</c> if the values of its operands are equal, <c>false</c> otherwise.</returns>        public static bool operator ==(Integer32 left, Integer32 right)        {            return Equals(left, right);        }                /// <summary>        /// The inequality operator.        /// </summary>        /// <param name="left">Left <see cref="Integer32"/> object</param>        /// <param name="right">Right <see cref="Integer32"/> object</param>        /// <returns>        /// Returns <c>true</c> if the values of its operands are not equal, <c>false</c> otherwise.</returns>        public static bool operator !=(Integer32 left, Integer32 right)        {            return !(left == right);        }                /// <summary>        /// The comparison.        /// </summary>        /// <param name="left">Left <see cref="Integer32"/> object</param>        /// <param name="right">Right <see cref="Integer32"/> object</param>        /// <returns>        /// Returns <c>true</c> if the values of its operands are not equal, <c>false</c> otherwise.</returns>        private static bool Equals(Integer32 left, Integer32 right)        {            object lo = left;            object ro = right;            if (lo == ro)            {                return true;            }             if (lo == null || ro == null)            {                return false;            }                        return left.ToInt32() == right.ToInt32();        }    }        // all references here are to ITU-X.690-12/97}