SQLBinary.cs source code in C# .NET

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/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / SQLTypes / SQLBinary.cs / 1 / SQLBinary.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// junfang 
// [....]
// [....] 
//----------------------------------------------------------------------------- 

//************************************************************************* 
// @File: SqlBinary.cs
//
// Create by:    JunFang
// 
// Purpose: Implementation of SqlBinary which is corresponding to
//            data type "binary/varbinary" in SQL Server 
// 
// Notes:
// 
// History:
//
//   1/30/2000  JunFang        Created and implemented as first drop.
// 
// @EndHeader@
//************************************************************************* 
 
using System;
using System.Data.Common; 
using System.Globalization;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization; 

namespace System.Data.SqlTypes { 
 
    [Serializable]
    [XmlSchemaProvider("GetXsdType")] 
    public struct SqlBinary : INullable, IComparable, IXmlSerializable {
        private byte[] m_value; // null if m_value is null

        // constructor 
        // construct a Null
        private SqlBinary(bool fNull) { 
            m_value = null; 
    }
 
        /// 
        ///    
        ///       Initializes a new instance of the  class with a binary object to be stored.
        ///     
        /// 
        public SqlBinary(byte[] value) { 
            // if value is null, this generates a SqlBinary.Null 
            if (value == null)
                m_value = null; 
            else {
                m_value = new byte[value.Length];
                value.CopyTo(m_value, 0);
            } 
        }
 
        ///  
        ///    
        ///       Initializes a new instance of the  class with a binary object to be stored.  This constructor will not copy the value. 
        ///    
        /// 
        internal SqlBinary(byte[] value, bool ignored) {
            // if value is null, this generates a SqlBinary.Null 
            if (value == null)
                m_value = null; 
            else { 
                m_value = value;
            } 
        }

        // INullable
        ///  
        ///    
        ///       Gets whether or not  is null. 
        ///     
        /// 
        public bool IsNull { 
            get { return(m_value == null);}
        }

        // property: Value 
        /// 
        ///     
        ///       Gets 
        ///       or sets the
        ///       value of the SQL binary object retrieved. 
        ///    
        /// 
        public byte[] Value {
            get { 
                if (IsNull)
                    throw new SqlNullValueException(); 
                else { 
                    byte[] value = new byte[m_value.Length];
                    m_value.CopyTo(value, 0); 
                    return value;
                }
            }
        } 

 		// class indexer 
		public byte this[int index] { 
			get {
				if (IsNull) 
                    throw new SqlNullValueException();
 				else
					return m_value[index];
 			} 
 		}
 
        // property: Length 
        /// 
        ///     
        ///       Gets the length in bytes of .
        ///    
        /// 
        public int Length { 
            get {
                if (!IsNull) 
                    return m_value.Length; 
                else
                    throw new SqlNullValueException(); 
            }
        }

        // Implicit conversion from byte[] to SqlBinary 
		// Alternative: constructor SqlBinary(bytep[])
        ///  
        ///     
        ///       Converts a binary object to a .
        ///     
        /// 
        public static implicit operator SqlBinary(byte[] x) {
            return new SqlBinary(x);
        } 

        // Explicit conversion from SqlBinary to byte[]. Throw exception if x is Null. 
 		// Alternative: Value property 
        /// 
        ///     
        ///       Converts a  to a binary object.
        ///    
        /// 
        public static explicit operator byte[](SqlBinary x) { 
            return x.Value;
        } 
 
        /// 
        ///     
        ///       Returns a string describing a  object.
        ///    
        /// 
        public override String ToString() { 
            return IsNull ? SQLResource.NullString : "SqlBinary(" + m_value.Length.ToString(CultureInfo.InvariantCulture) + ")";
        } 
 

        // Unary operators 

        // Binary operators

        // Arithmetic operators 
        /// 
        ///     
        ///       Adds two instances of  together. 
        ///    
        ///  
        // Alternative method: SqlBinary.Concat
        public static SqlBinary operator +(SqlBinary x, SqlBinary y) {
            if (x.IsNull || y.IsNull)
                return Null; 

            byte[] rgbResult = new byte[x.Value.Length + y.Value.Length]; 
            x.Value.CopyTo(rgbResult, 0); 
            y.Value.CopyTo(rgbResult, x.Value.Length);
 
            return new SqlBinary(rgbResult);
        }

 
        // Comparisons
 
        private static EComparison PerformCompareByte(byte[] x, byte[] y) { 
            // the smaller length of two arrays
            int len = (x.Length < y.Length) ? x.Length : y.Length; 
            int i;

            for (i = 0; i < len; ++i) {
                if (x[i] != y[i]) { 
                    if (x[i] < y[i])
                        return EComparison.LT; 
                    else 
                        return EComparison.GT;
                } 
            }

            if (x.Length == y.Length)
                return EComparison.EQ; 
            else {
                // if the remaining bytes are all zeroes, they are still equal. 
 
                byte bZero = (byte)0;
 
                if (x.Length < y.Length) {
                    // array X is shorter
                    for (i = len; i < y.Length; ++i) {
                        if (y[i] != bZero) 
                            return EComparison.LT;
                    } 
                } 
                else {
                    // array Y is shorter 
                    for (i = len; i < x.Length; ++i) {
                        if (x[i] != bZero)
                            return EComparison.GT;
                    } 
                }
 
                return EComparison.EQ; 
            }
        } 


        // Implicit conversions
 
        // Explicit conversions
 
        // Explicit conversion from SqlGuid to SqlBinary 
        /// 
        ///     
        ///       Converts a  to a 
        ///       .
        ///    
        ///  
        // Alternative method: SqlGuid.ToSqlBinary
        public static explicit operator SqlBinary(SqlGuid x) { 
            return x.IsNull ? SqlBinary.Null : new SqlBinary(x.ToByteArray()); 
        }
 
        // Builtin functions

        // Overloading comparison operators
        ///  
        ///    
        ///       Compares two instances of  for 
        ///       equality. 
        ///    
        ///  
        public static SqlBoolean operator==(SqlBinary x, SqlBinary y) {
            if (x.IsNull || y.IsNull)
                return SqlBoolean.Null;
 
            return new SqlBoolean(PerformCompareByte(x.Value, y.Value) == EComparison.EQ);
        } 
 
        /// 
        ///     
        ///       Compares two instances of 
        ///       for equality.
        ///    
        ///  
        public static SqlBoolean operator!=(SqlBinary x, SqlBinary y) {
            return ! (x == y); 
        } 

        ///  
        ///    
        ///       Compares the first  for being less than the
        ///       second .
        ///     
        /// 
        public static SqlBoolean operator<(SqlBinary x, SqlBinary y) { 
            if (x.IsNull || y.IsNull) 
                return SqlBoolean.Null;
 
            return new SqlBoolean(PerformCompareByte(x.Value, y.Value) == EComparison.LT);
        }

        ///  
        ///    
        ///       Compares the first  for being greater than the second . 
        ///     
        /// 
        public static SqlBoolean operator>(SqlBinary x, SqlBinary y) { 
            if (x.IsNull || y.IsNull)
                return SqlBoolean.Null;

            return new SqlBoolean(PerformCompareByte(x.Value, y.Value) == EComparison.GT); 
        }
 
        ///  
        ///    
        ///       Compares the first  for being less than or equal to the second . 
        ///    
        /// 
        public static SqlBoolean operator<=(SqlBinary x, SqlBinary y) {
            if (x.IsNull || y.IsNull) 
                return SqlBoolean.Null;
 
            EComparison cmpResult = PerformCompareByte(x.Value, y.Value); 
            return new SqlBoolean(cmpResult == EComparison.LT || cmpResult == EComparison.EQ);
        } 

        /// 
        ///    
        ///       Compares the first  for being greater than or equal the second . 
        ///    
        ///  
        public static SqlBoolean operator>=(SqlBinary x, SqlBinary y) { 
            if (x.IsNull || y.IsNull)
                return SqlBoolean.Null; 

            EComparison cmpResult = PerformCompareByte(x.Value, y.Value);
            return new SqlBoolean(cmpResult == EComparison.GT || cmpResult == EComparison.EQ);
        } 

        //-------------------------------------------------- 
        // Alternative methods for overloaded operators 
        //--------------------------------------------------
 
        // Alternative method for operator +
        public static SqlBinary Add(SqlBinary x, SqlBinary y) {
                return x + y;
        } 

         public static SqlBinary Concat(SqlBinary x, SqlBinary y) { 
                return x + y; 
        }
 
        // Alternative method for operator ==
        public static SqlBoolean Equals(SqlBinary x, SqlBinary y) {
            return (x == y);
        } 

        // Alternative method for operator != 
        public static SqlBoolean NotEquals(SqlBinary x, SqlBinary y) { 
            return (x != y);
        } 

        // Alternative method for operator <
        public static SqlBoolean LessThan(SqlBinary x, SqlBinary y) {
            return (x < y); 
        }
 
        // Alternative method for operator > 
        public static SqlBoolean GreaterThan(SqlBinary x, SqlBinary y) {
            return (x > y); 
        }

        // Alternative method for operator <=
        public static SqlBoolean LessThanOrEqual(SqlBinary x, SqlBinary y) { 
            return (x <= y);
        } 
 
        // Alternative method for operator >=
        public static SqlBoolean GreaterThanOrEqual(SqlBinary x, SqlBinary y) { 
            return (x >= y);
        }

        // Alternative method for conversions. 
        public SqlGuid ToSqlGuid() {
            return (SqlGuid)this; 
        } 

        // IComparable 
        // Compares this object to another object, returning an integer that
        // indicates the relationship.
        // Returns a value less than zero if this < object, zero if this = object,
        // or a value greater than zero if this > object. 
        // null is considered to be less than any instance.
        // If object is not of same type, this method throws an ArgumentException. 
        ///  
        ///    [To be supplied.]
        ///  
        public int CompareTo(Object value) {
            if (value is SqlBinary) {
                SqlBinary i = (SqlBinary)value;
 
                return CompareTo(i);
            } 
            throw ADP.WrongType(value.GetType(), typeof(SqlBinary)); 
        }
 
        public int CompareTo(SqlBinary value) {
            // If both Null, consider them equal.
            // Otherwise, Null is less than anything.
            if (IsNull) 
                return value.IsNull ? 0  : -1;
            else if (value.IsNull) 
                return 1; 

            if (this < value) return -1; 
            if (this > value) return 1;
            return 0;
        }
 
        // Compares this instance with a specified object
        ///  
        ///    [To be supplied.] 
        /// 
        public override bool Equals(Object value) { 
            if (!(value is SqlBinary)) {
                return false;
            }
 
            SqlBinary i = (SqlBinary)value;
 
            if (i.IsNull || IsNull) 
                return (i.IsNull && IsNull);
            else 
                return (this == i).Value;
        }

        // Hash a byte array. 
        // Trailing zeroes/spaces would affect the hash value, so caller needs to
        // perform trimming as necessary. 
        internal static int HashByteArray(byte[] rgbValue, int length) 
        {
            SQLDebug.Check(length >= 0); 

            if (length <= 0)
                return 0;
 
            SQLDebug.Check(rgbValue.Length >= length);
 
            int ulValue = 0; 
            int ulHi;
 
            // Size of CRC window (hashing bytes, ssstr, sswstr, numeric)
            const int x_cbCrcWindow = 4;
            // const int iShiftVal = (sizeof ulValue) * (8*sizeof(char)) - x_cbCrcWindow;
            const int iShiftVal = 4 * 8 - x_cbCrcWindow; 

            for(int i = 0; i < length; i++) 
                { 
                ulHi = (ulValue >> iShiftVal) & 0xff;
                ulValue <<= x_cbCrcWindow; 
                ulValue = ulValue ^ rgbValue[i] ^ ulHi;
                }

            return ulValue; 
        }
        // For hashing purpose 
        ///  
        ///    [To be supplied.]
        ///  
        public override int GetHashCode()
        {
                    if (IsNull)
                        return 0; 

                    //First trim off extra '\0's 
                    int cbLen = m_value.Length; 
                    while (cbLen > 0 && m_value[cbLen - 1] == 0)
                        --cbLen; 

                    return HashByteArray(m_value, cbLen);
        }
 
        /// 
        ///    [To be supplied.] 
        ///  
        XmlSchema IXmlSerializable.GetSchema() { return null; }
 
        /// 
        ///    [To be supplied.]
        /// 
        void IXmlSerializable.ReadXml(XmlReader reader) { 
            string isNull = reader.GetAttribute("nil", XmlSchema.InstanceNamespace);
            if (isNull != null && XmlConvert.ToBoolean(isNull)) { 
                m_value = null; 
            }
            else { 
                string base64 = reader.ReadElementString();
                if (base64 == null) {
                    m_value = new byte[0];
                } 
                else {
                    base64 = base64.Trim(); 
 
                    if (base64.Length == 0) {
                        m_value = new byte[0]; 
                    }
                    else {
                        m_value = Convert.FromBase64String(base64);
                    } 
                }
            } 
        } 

        ///  
        ///    [To be supplied.]
        /// 
        void IXmlSerializable.WriteXml(XmlWriter writer) {
            if (IsNull) { 
                writer.WriteAttributeString("xsi", "nil", XmlSchema.InstanceNamespace, "true");
            } 
            else { 
                writer.WriteString(Convert.ToBase64String(m_value));
            } 
        }

        /// 
        ///    [To be supplied.] 
        /// 
        public static XmlQualifiedName GetXsdType(XmlSchemaSet schemaSet) { 
            return new XmlQualifiedName("base64Binary", XmlSchema.Namespace); 
        }
 
        /// 
        ///    
        ///       Represents a null value that can be assigned to
        ///       the  property of an 
        ///       instance of the  class.
        ///     
        ///  
        public static readonly SqlBinary Null       = new SqlBinary(true);
 
    } // SqlBinary

} // namespace System.Data.SqlTypes

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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