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//---------------------------------------------------------------------
// <copyright file="MemberCollection.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//
// @owner Microsoft
// @backupOwner Microsoft
//---------------------------------------------------------------------
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.Common;
using System.Reflection;
using System.Text;
using System.Diagnostics;
using System.Globalization;
namespace System.Data.Metadata.Edm
{
/// <summary>
/// Class representing a collection of member objects
/// </summary>
internal sealed class MemberCollection : MetadataCollection<EdmMember>
{
// This way this collection works is that it has storage for members on the current type and access to
// members in the base types. As of that requirement, MemberCollection has a reference back to the declaring
// type that owns this collection. Whenever MemberCollection is asked to do a look by name, it looks at the
// current collection, if it doesn't find it, then it ask for it from the declaring type's base type's
// MemberCollection. Because of this order, members in derived types hide members in the base type if they
// have the same name. For look up by index, base type members have lower index then current type's members.
// Add/Update/Remove operations on this collection is only allowed for members owned by this MemberCollection
// and not allowed for members owned by MemberCollections in the base types. For example, if the caller tries
// to remove a member by ordinal which is within the base type's member ordinal range, it throws an exception.
// Hence, base type members are in a sense "readonly" to this MemberCollection. When enumerating all the
// members, the enumeration starts from members in the root type in the inheritance chain. With this special
// enumeration requirement, we have a specialized enumerator class for this MemberCollection. See the
// Enumerator class for details on how it works.
#region Constructors
/// <summary>
/// Default constructor for constructing an empty collection
/// </summary>
/// <param name="declaringType">The type that has this member collection</param>
/// <exception cref="System.ArgumentNullException">Thrown if the declaring type is null</exception>
public MemberCollection(StructuralType declaringType)
: this(declaringType, null)
{
}
/// <summary>
/// The constructor for constructing the collection with the given items
/// </summary>
/// <param name="declaringType">The type that has this member collection</param>
/// <param name="items">The items to populate the collection</param>
/// <exception cref="System.ArgumentNullException">Thrown if the declaring type is null</exception>
public MemberCollection(StructuralType declaringType, IEnumerable<EdmMember> items)
: base(items)
{
Debug.Assert(declaringType != null, "This member collection must belong to a declaring type");
_declaringType = declaringType;
}
#endregion
#region Fields
private StructuralType _declaringType;
#endregion
#region Properties
/// <summary>
/// Returns the collection as a readonly collection
/// </summary>
public override System.Collections.ObjectModel.ReadOnlyCollection<EdmMember> AsReadOnly
{
get
{
return new System.Collections.ObjectModel.ReadOnlyCollection<EdmMember>(this);
}
}
/// <summary>
/// Gets the count on the number of items in the collection
/// </summary>
public override int Count
{
get
{
return GetBaseTypeMemberCount() + base.Count;
}
}
/// <summary>
/// Gets an item from the collection with the given index
/// </summary>
/// <param name="index">The index to search for</param>
/// <returns>An item from the collection</returns>
/// <exception cref="System.ArgumentOutOfRangeException">Thrown if the index is out of the range for the Collection</exception>
/// <exception cref="System.InvalidOperationException">Always thrown on setter</exception>
public override EdmMember this[int index]
{
get
{
int relativeIndex = GetRelativeIndex(index);
if (relativeIndex < 0)
{
// This means baseTypeMemberCount must be non-zero, so we can safely cast the base type to StructuralType
return ((StructuralType)_declaringType.BaseType).Members[index];
}
return base[relativeIndex];
}
set
{
throw EntityUtil.OperationOnReadOnlyCollection();
}
}
/// <summary>
/// Gets an item from the collection with the given identity
/// </summary>
/// <param name="identity">The identity of the item to search for</param>
/// <returns>An item from the collection</returns>
/// <exception cref="System.ArgumentNullException">Thrown if identity argument passed in is null</exception>
/// <exception cref="System.ArgumentException">Thrown if the Collection does not have an item with the given identity</exception>
/// <exception cref="System.InvalidOperationException">Always thrown on setter</exception>
public override EdmMember this[string identity]
{
get
{
return GetValue(identity, false);
}
set
{
throw EntityUtil.OperationOnReadOnlyCollection();
}
}
/// <summary>
/// Adds an item to the collection
/// </summary>
/// <param name="member">The item to add to the list</param>
/// <exception cref="System.ArgumentNullException">Thrown if member argument is null</exception>
/// <exception cref="System.InvalidOperationException">Thrown if the member passed in or the collection itself instance is in ReadOnly state</exception>
/// <exception cref="System.ArgumentException">Thrown if the member that is being added already belongs to another MemberCollection</exception>
/// <exception cref="System.ArgumentException">Thrown if the MemberCollection already contains a member with the same identity</exception>
public override void Add(EdmMember member)
{
// Make sure the member is valid for the add operation.
ValidateMemberForAdd(member, "member");
base.Add(member);
// Fix up the declaring type
member.ChangeDeclaringTypeWithoutCollectionFixup(_declaringType);
}
/// <summary>
/// Determines if this collection contains an item of the given identity
/// </summary>
/// <param name="identity">The identity of the item to check for</param>
/// <returns>True if the collection contains the item with the given identity</returns>
public override bool ContainsIdentity(string identity)
{
if (base.ContainsIdentity(identity))
{
return true;
}
// The item is not in this collection, check the base type member collection
EdmType baseType = _declaringType.BaseType;
if (baseType != null && ((StructuralType)baseType).Members.Contains(identity))
{
return true;
}
return false;
}
/// <summary>
/// Find the index of an item
/// </summary>
/// <param name="item">The item whose index is to be looked for</param>
/// <returns>The index of the found item, -1 if not found</returns>
public override int IndexOf(EdmMember item)
{
// Try to get it from this collection, if found, then the relative index needs to be added with the number
// of members in the base type to get the absolute index
int relativeIndex = base.IndexOf(item);
if (relativeIndex != -1)
{
return relativeIndex + GetBaseTypeMemberCount();
}
// Try to find it in the base type
StructuralType baseType = _declaringType.BaseType as StructuralType;
if (baseType != null)
{
return baseType.Members.IndexOf(item);
}
return -1;
}
/// <summary>
/// Copies the items in this collection to an array
/// </summary>
/// <param name="array">The array to copy to</param>
/// <param name="arrayIndex">The index in the array at which to start the copy</param>
/// <exception cref="System.ArgumentNullException">Thrown if array argument is null</exception>
/// <exception cref="System.ArgumentOutOfRangeException">Thrown if the arrayIndex is less than zero</exception>
/// <exception cref="System.ArgumentException">Thrown if the array argument passed in with respect to the arrayIndex passed in not big enough to hold the MemberCollection being copied</exception>
public override void CopyTo(EdmMember[] array, int arrayIndex)
{
// Check on the array index
if (arrayIndex < 0)
{
throw EntityUtil.ArgumentOutOfRange("arrayIndex");
}
// Check if the array together with the array index has enough room to copy
int baseTypeMemberCount = GetBaseTypeMemberCount();
if (base.Count + baseTypeMemberCount > array.Length - arrayIndex)
{
throw EntityUtil.Argument("arrayIndex");
}
// If the base type has any members, copy those first
if (baseTypeMemberCount > 0)
{
((StructuralType)_declaringType.BaseType).Members.CopyTo(array, arrayIndex);
}
base.CopyTo(array, arrayIndex + baseTypeMemberCount);
}
/// <summary>
/// Gets an item from the collection with the given identity
/// </summary>
/// <param name="identity">The identity of the item to search for</param>
/// <param name="ignoreCase">Whether case is ignore in the search</param>
/// <param name="item">An item from the collection, null if the item is not found</param>
/// <returns>True an item is retrieved</returns>
/// <exception cref="System.ArgumentNullException">if identity argument is null</exception>
public override bool TryGetValue(string identity, bool ignoreCase, out EdmMember item)
{
// See if it's in this collection
if (!base.TryGetValue(identity, ignoreCase, out item))
{
// Now go to the parent type to find it
EdmType baseType = _declaringType.BaseType;
if (baseType != null)
{
((StructuralType)baseType).Members.TryGetValue(identity, ignoreCase, out item);
}
}
return item != null;
}
/// <summary>
/// Gets an itme with identity
/// </summary>
/// <param name="identity"></param>
/// <param name="ignoreCase"></param>
/// <returns></returns>
public override EdmMember GetValue(string identity, bool ignoreCase)
{
EdmMember item = null;
if (!TryGetValue(identity, ignoreCase, out item))
{
throw EntityUtil.ItemInvalidIdentity(identity, "identity");
}
return item;
}
/// <summary>
/// Get the declared only members of a particular type
/// </summary>
internal ReadOnlyMetadataCollection<T> GetDeclaredOnlyMembers<T>() where T : EdmMember
{
MetadataCollection<T> newCollection = new MetadataCollection<T>();
for (int i = 0; i < base.Count; i++)
{
T member = base[i] as T;
if (member != null)
{
newCollection.Add(member);
}
}
return newCollection.AsReadOnlyMetadataCollection();
}
/// <summary>
/// Get the number of members the base type has. If the base type is not a structural type or has no
/// members, it returns 0
/// </summary>
/// <returns>The number of members in the base type</returns>
private int GetBaseTypeMemberCount()
{
// The count of members is what in this collection plus base type's member collection
StructuralType baseType = _declaringType.BaseType as StructuralType;
if (baseType != null)
{
return baseType.Members.Count;
}
return 0;
}
/// <summary>
/// Gets the index relative to this collection for the given index. For an index to really refers to something in
/// the base type, the return value is negative relative to this collection. For an index refers to something in this
/// collection, the return value is positive. In both cases, it's simply (index) - (base type member count)
/// </summary>
/// <returns>The relative index</returns>
private int GetRelativeIndex(int index)
{
int baseTypeMemberCount = GetBaseTypeMemberCount();
int thisTypeMemberCount = base.Count;
// Check if the index is in range
if (index < 0 || index >= baseTypeMemberCount + thisTypeMemberCount)
{
throw EntityUtil.ArgumentOutOfRange("index");
}
return index - baseTypeMemberCount;
}
private void ValidateMemberForAdd(EdmMember member, string argumentName)
{
// Check to make sure the given member is not associated with another type
EntityUtil.GenericCheckArgumentNull(member, argumentName);
Debug.Assert(member.DeclaringType == null, string.Format(CultureInfo.CurrentCulture, "The member {0} already has a declaring type, it cannot be added to this collection.", argumentName));
// Validate the item with the declaring type.
_declaringType.ValidateMemberForAdd(member);
}
#endregion
}
}
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