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/* ****************************************************************************
*
* Copyright (c) Microsoft Corporation.
*
* This source code is subject to terms and conditions of the Apache License, Version 2.0. A
* copy of the license can be found in the License.html file at the root of this distribution. If
* you cannot locate the Apache License, Version 2.0, please send an email to
* dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound
* by the terms of the Apache License, Version 2.0.
*
* You must not remove this notice, or any other, from this software.
*
*
* ***************************************************************************/
#if CLR2
using Microsoft.Scripting.Ast;
#else
using System.Linq.Expressions;
#endif
#if SILVERLIGHT
using System.Core;
#endif
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Dynamic.Utils;
namespace System.Runtime.CompilerServices {
/// <summary>
/// The builder for read only collection.
/// </summary>
/// <typeparam name="T">The type of the collection element.</typeparam>
#if !SILVERLIGHT
[Serializable]
#endif
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
public sealed class ReadOnlyCollectionBuilder<T> : IList<T>, System.Collections.IList {
private const int DefaultCapacity = 4;
private T[] _items;
private int _size;
private int _version;
#if !SILVERLIGHT
[NonSerialized]
#endif
private Object _syncRoot;
static readonly T[] _emptyArray = new T[0];
/// <summary>
/// Constructs a ReadOnlyCollectionBuilder.
/// </summary>
public ReadOnlyCollectionBuilder() {
_items = _emptyArray;
}
/// <summary>
/// Constructs a ReadOnlyCollectionBuilder with a given initial capacity.
/// The contents are empty but builder will have reserved room for the given
/// number of elements before any reallocations are required.
/// </summary>
public ReadOnlyCollectionBuilder(int capacity) {
ContractUtils.Requires(capacity >= 0, "capacity");
_items = new T[capacity];
}
/// <summary>
/// Constructs a ReadOnlyCollectionBuilder, copying contents of the given collection.
/// </summary>
/// <param name="collection"></param>
public ReadOnlyCollectionBuilder(IEnumerable<T> collection) {
ContractUtils.Requires(collection != null, "collection");
ICollection<T> c = collection as ICollection<T>;
if (c != null) {
int count = c.Count;
_items = new T[count];
c.CopyTo(_items, 0);
_size = count;
} else {
_size = 0;
_items = new T[DefaultCapacity];
using (IEnumerator<T> en = collection.GetEnumerator()) {
while (en.MoveNext()) {
Add(en.Current);
}
}
}
}
/// <summary>
/// Gets and sets the capacity of this ReadOnlyCollectionBuilder
/// </summary>
public int Capacity {
get { return _items.Length; }
set {
ContractUtils.Requires(value >= _size, "value");
if (value != _items.Length) {
if (value > 0) {
T[] newItems = new T[value];
if (_size > 0) {
Array.Copy(_items, 0, newItems, 0, _size);
}
_items = newItems;
} else {
_items = _emptyArray;
}
}
}
}
/// <summary>
/// Returns number of elements in the ReadOnlyCollectionBuilder.
/// </summary>
public int Count {
get { return _size; }
}
#region IList<T> Members
/// <summary>
/// Returns the index of the first occurrence of a given value in the builder.
/// </summary>
/// <param name="item">An item to search for.</param>
/// <returns>The index of the first occurrence of an item.</returns>
public int IndexOf(T item) {
return Array.IndexOf(_items, item, 0, _size);
}
/// <summary>
/// Inserts an item to the <see cref="ReadOnlyCollectionBuilder{T}"/> at the specified index.
/// </summary>
/// <param name="index">The zero-based index at which item should be inserted.</param>
/// <param name="item">The object to insert into the <see cref="ReadOnlyCollectionBuilder{T}"/>.</param>
public void Insert(int index, T item) {
ContractUtils.Requires(index <= _size, "index");
if (_size == _items.Length) {
EnsureCapacity(_size + 1);
}
if (index < _size) {
Array.Copy(_items, index, _items, index + 1, _size - index);
}
_items[index] = item;
_size++;
_version++;
}
/// <summary>
/// Removes the <see cref="ReadOnlyCollectionBuilder{T}"/> item at the specified index.
/// </summary>
/// <param name="index">The zero-based index of the item to remove.</param>
public void RemoveAt(int index) {
ContractUtils.Requires(index >= 0 && index < _size, "index");
_size--;
if (index < _size) {
Array.Copy(_items, index + 1, _items, index, _size - index);
}
_items[_size] = default(T);
_version++;
}
/// <summary>
/// Gets or sets the element at the specified index.
/// </summary>
/// <param name="index">The zero-based index of the element to get or set.</param>
/// <returns>The element at the specified index.</returns>
public T this[int index] {
get {
ContractUtils.Requires(index < _size, "index");
return _items[index];
}
set {
ContractUtils.Requires(index < _size, "index");
_items[index] = value;
_version++;
}
}
#endregion
#region ICollection<T> Members
/// <summary>
/// Adds an item to the <see cref="ReadOnlyCollectionBuilder{T}"/>.
/// </summary>
/// <param name="item">The object to add to the <see cref="ReadOnlyCollectionBuilder{T}"/>.</param>
public void Add(T item) {
if (_size == _items.Length) {
EnsureCapacity(_size + 1);
}
_items[_size++] = item;
_version++;
}
/// <summary>
/// Removes all items from the <see cref="ReadOnlyCollectionBuilder{T}"/>.
/// </summary>
public void Clear() {
if (_size > 0) {
Array.Clear(_items, 0, _size);
_size = 0;
}
_version++;
}
/// <summary>
/// Determines whether the <see cref="ReadOnlyCollectionBuilder{T}"/> contains a specific value
/// </summary>
/// <param name="item">the object to locate in the <see cref="ReadOnlyCollectionBuilder{T}"/>.</param>
/// <returns>true if item is found in the <see cref="ReadOnlyCollectionBuilder{T}"/>; otherwise, false.</returns>
public bool Contains(T item) {
if ((Object)item == null) {
for (int i = 0; i < _size; i++) {
if ((Object)_items[i] == null) {
return true;
}
}
return false;
} else {
EqualityComparer<T> c = EqualityComparer<T>.Default;
for (int i = 0; i < _size; i++) {
if (c.Equals(_items[i], item)) {
return true;
}
}
return false;
}
}
/// <summary>
/// Copies the elements of the <see cref="ReadOnlyCollectionBuilder{T}"/> to an <see cref="Array"/>,
/// starting at particular <see cref="Array"/> index.
/// </summary>
/// <param name="array">The one-dimensional <see cref="Array"/> that is the destination of the elements copied from <see cref="ReadOnlyCollectionBuilder{T}"/>.</param>
/// <param name="arrayIndex">The zero-based index in array at which copying begins.</param>
public void CopyTo(T[] array, int arrayIndex) {
Array.Copy(_items, 0, array, arrayIndex, _size);
}
bool ICollection<T>.IsReadOnly {
get { return false; }
}
/// <summary>
/// Removes the first occurrence of a specific object from the <see cref="ReadOnlyCollectionBuilder{T}"/>.
/// </summary>
/// <param name="item">The object to remove from the <see cref="ReadOnlyCollectionBuilder{T}"/>.</param>
/// <returns>true if item was successfully removed from the <see cref="ReadOnlyCollectionBuilder{T}"/>;
/// otherwise, false. This method also returns false if item is not found in the original <see cref="ReadOnlyCollectionBuilder{T}"/>.
/// </returns>
public bool Remove(T item) {
int index = IndexOf(item);
if (index >= 0) {
RemoveAt(index);
return true;
}
return false;
}
#endregion
#region IEnumerable<T> Members
/// <summary>
/// Returns an enumerator that iterates through the collection.
/// </summary>
/// <returns>A <see cref="IEnumerator{T}"/> that can be used to iterate through the collection.</returns>
public IEnumerator<T> GetEnumerator() {
return new Enumerator(this);
}
#endregion
#region IEnumerable Members
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() {
return GetEnumerator();
}
#endregion
#region IList Members
bool System.Collections.IList.IsReadOnly {
get { return false; }
}
int System.Collections.IList.Add(object value) {
ValidateNullValue(value, "value");
try {
Add((T)value);
} catch (InvalidCastException) {
ThrowInvalidTypeException(value, "value");
}
return Count - 1;
}
bool System.Collections.IList.Contains(object value) {
if (IsCompatibleObject(value)) {
return Contains((T)value);
} else return false;
}
int System.Collections.IList.IndexOf(object value) {
if (IsCompatibleObject(value)) {
return IndexOf((T)value);
}
return -1;
}
void System.Collections.IList.Insert(int index, object value) {
ValidateNullValue(value, "value");
try {
Insert(index, (T)value);
} catch (InvalidCastException) {
ThrowInvalidTypeException(value, "value");
}
}
bool System.Collections.IList.IsFixedSize {
get { return false; }
}
void System.Collections.IList.Remove(object value) {
if (IsCompatibleObject(value)) {
Remove((T)value);
}
}
object System.Collections.IList.this[int index] {
get {
return this[index];
}
set {
ValidateNullValue(value, "value");
try {
this[index] = (T)value;
} catch (InvalidCastException) {
ThrowInvalidTypeException(value, "value");
}
}
}
#endregion
#region ICollection Members
void System.Collections.ICollection.CopyTo(Array array, int index) {
ContractUtils.RequiresNotNull(array, "array");
ContractUtils.Requires(array.Rank == 1, "array");
Array.Copy(_items, 0, array, index, _size);
}
bool System.Collections.ICollection.IsSynchronized {
get { return false; }
}
object System.Collections.ICollection.SyncRoot {
get {
if (_syncRoot == null) {
System.Threading.Interlocked.CompareExchange<Object>(ref _syncRoot, new Object(), null);
}
return _syncRoot;
}
}
#endregion
/// <summary>
/// Reverses the order of the elements in the entire <see cref="ReadOnlyCollectionBuilder{T}"/>.
/// </summary>
public void Reverse() {
Reverse(0, Count);
}
/// <summary>
/// Reverses the order of the elements in the specified range.
/// </summary>
/// <param name="index">The zero-based starting index of the range to reverse.</param>
/// <param name="count">The number of elements in the range to reverse.</param>
public void Reverse(int index, int count) {
ContractUtils.Requires(index >= 0, "index");
ContractUtils.Requires(count >= 0, "count");
Array.Reverse(_items, index, count);
_version++;
}
/// <summary>
/// Copies the elements of the <see cref="ReadOnlyCollectionBuilder{T}"/> to a new array.
/// </summary>
/// <returns>An array containing copies of the elements of the <see cref="ReadOnlyCollectionBuilder{T}"/>.</returns>
public T[] ToArray() {
T[] array = new T[_size];
Array.Copy(_items, 0, array, 0, _size);
return array;
}
/// <summary>
/// Creates a <see cref="ReadOnlyCollection{T}"/> containing all of the the elements of the <see cref="ReadOnlyCollectionBuilder{T}"/>,
/// avoiding copying the elements to the new array if possible. Resets the <see cref="ReadOnlyCollectionBuilder{T}"/> after the
/// <see cref="ReadOnlyCollection{T}"/> has been created.
/// </summary>
/// <returns>A new instance of <see cref="ReadOnlyCollection{T}"/>.</returns>
public ReadOnlyCollection<T> ToReadOnlyCollection() {
// Can we use the stored array?
T[] items;
if (_size == _items.Length) {
items = _items;
} else {
items = ToArray();
}
_items = _emptyArray;
_size = 0;
_version++;
return new TrueReadOnlyCollection<T>(items);
}
private void EnsureCapacity(int min) {
if (_items.Length < min) {
int newCapacity = DefaultCapacity;
if (_items.Length > 0) {
newCapacity = _items.Length * 2;
}
if (newCapacity < min) {
newCapacity = min;
}
Capacity = newCapacity;
}
}
private static bool IsCompatibleObject(object value) {
return ((value is T) || (value == null && default(T) == null));
}
private static void ValidateNullValue(object value, string argument) {
if (value == null && !(default(T) == null)) {
throw new ArgumentException(Strings.InvalidNullValue(typeof(T)), argument);
}
}
private static void ThrowInvalidTypeException(object value, string argument) {
throw new ArgumentException(Strings.InvalidObjectType(value != null ? value.GetType() : (object)"null", typeof(T)), argument);
}
#if !SILVERLIGHT
[Serializable]
#endif
private class Enumerator : IEnumerator<T>, System.Collections.IEnumerator {
private readonly ReadOnlyCollectionBuilder<T> _builder;
private readonly int _version;
private int _index;
private T _current;
internal Enumerator(ReadOnlyCollectionBuilder<T> builder) {
_builder = builder;
_version = builder._version;
_index = 0;
_current = default(T);
}
#region IEnumerator<T> Members
public T Current {
get { return _current; }
}
#endregion
#region IDisposable Members
public void Dispose() {
GC.SuppressFinalize(this);
}
#endregion
#region IEnumerator Members
object System.Collections.IEnumerator.Current {
get {
if (_index == 0 || _index > _builder._size) {
throw Error.EnumerationIsDone();
}
return _current;
}
}
public bool MoveNext() {
if (_version == _builder._version) {
if (_index < _builder._size) {
_current = _builder._items[_index++];
return true;
} else {
_index = _builder._size + 1;
_current = default(T);
return false;
}
} else {
throw Error.CollectionModifiedWhileEnumerating();
}
}
#endregion
#region IEnumerator Members
void System.Collections.IEnumerator.Reset() {
if (_version != _builder._version) {
throw Error.CollectionModifiedWhileEnumerating();
}
_index = 0;
_current = default(T);
}
#endregion
}
}
}
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