83 lines
2.4 KiB
C#
83 lines
2.4 KiB
C#
//-----------------------------------------------------------------------
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// <copyright file="ColumnValueOfStruct.cs" company="Microsoft Corporation">
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// Copyright (c) Microsoft Corporation.
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// </copyright>
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//-----------------------------------------------------------------------
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namespace Microsoft.Isam.Esent.Interop
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{
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using System;
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/// <summary>
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/// Set a column of a struct type (e.g. Int32/Guid).
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/// </summary>
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/// <typeparam name="T">Type to set.</typeparam>
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public abstract class ColumnValueOfStruct<T> : ColumnValue where T : struct, IEquatable<T>
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{
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/// <summary>
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/// Internal value.
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/// </summary>
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private T? internalValue;
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/// <summary>
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/// Gets the last set or retrieved value of the column. The
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/// value is returned as a generic object.
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/// </summary>
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public override object ValueAsObject
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{
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get
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{
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return BoxedValueCache<T>.GetBoxedValue(this.Value);
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}
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}
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/// <summary>
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/// Gets or sets the value in the struct.
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/// </summary>
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public T? Value
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{
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get
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{
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return this.internalValue;
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}
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set
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{
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this.internalValue = value;
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this.Error = value == null ? JET_wrn.ColumnNull : JET_wrn.Success;
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}
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}
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/// <summary>
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/// Gets the byte length of a column value, which is zero if column is null, otherwise
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/// it matches the Size for this fixed-size column.
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/// </summary>
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public override int Length
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{
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get { return this.Value.HasValue ? this.Size : 0; }
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}
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/// <summary>
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/// Gets a string representation of this object.
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/// </summary>
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/// <returns>A string representation of this object.</returns>
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public override string ToString()
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{
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return this.Value.ToString();
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}
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/// <summary>
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/// Make sure the retrieved data is exactly the size needed for
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/// the structure. An exception is thrown if there is a mismatch.
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/// </summary>
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/// <param name="count">The size of the retrieved data.</param>
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protected void CheckDataCount(int count)
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{
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if (this.Size != count)
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{
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throw new EsentInvalidColumnException();
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}
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}
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}
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}
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