#region Apache License
//
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to you under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion
using System;
using System.Collections;
namespace log4net.Appender
{
///
/// A strongly-typed collection of objects.
///
/// Nicko Cadell
public class AppenderCollection : ICollection, IList, IEnumerable
#if !NETSTANDARD1_3
, ICloneable
#endif
{
#region Interfaces
///
/// Supports type-safe iteration over a .
///
///
public interface IAppenderCollectionEnumerator
{
///
/// Gets the current element in the collection.
///
IAppender Current { get; }
///
/// Advances the enumerator to the next element in the collection.
///
///
/// true if the enumerator was successfully advanced to the next element;
/// false if the enumerator has passed the end of the collection.
///
///
/// The collection was modified after the enumerator was created.
///
bool MoveNext();
///
/// Sets the enumerator to its initial position, before the first element in the collection.
///
void Reset();
}
#endregion
private const int DEFAULT_CAPACITY = 16;
#region Implementation (data)
private IAppender[] m_array;
private int m_count = 0;
private int m_version = 0;
#endregion
#region Static Wrappers
///
/// Creates a read-only wrapper for a AppenderCollection instance.
///
/// list to create a readonly wrapper arround
///
/// An AppenderCollection wrapper that is read-only.
///
public static AppenderCollection ReadOnly(AppenderCollection list)
{
if(list==null) throw new ArgumentNullException("list");
return new ReadOnlyAppenderCollection(list);
}
#endregion
#region Static Fields
///
/// An empty readonly static AppenderCollection
///
public static readonly AppenderCollection EmptyCollection = ReadOnly(new AppenderCollection(0));
#endregion
#region Constructors
///
/// Initializes a new instance of the AppenderCollection class
/// that is empty and has the default initial capacity.
///
public AppenderCollection()
{
m_array = new IAppender[DEFAULT_CAPACITY];
}
///
/// Initializes a new instance of the AppenderCollection class
/// that has the specified initial capacity.
///
///
/// The number of elements that the new AppenderCollection is initially capable of storing.
///
public AppenderCollection(int capacity)
{
m_array = new IAppender[capacity];
}
///
/// Initializes a new instance of the AppenderCollection class
/// that contains elements copied from the specified AppenderCollection.
///
/// The AppenderCollection whose elements are copied to the new collection.
public AppenderCollection(AppenderCollection c)
{
m_array = new IAppender[c.Count];
AddRange(c);
}
///
/// Initializes a new instance of the AppenderCollection class
/// that contains elements copied from the specified array.
///
/// The array whose elements are copied to the new list.
public AppenderCollection(IAppender[] a)
{
m_array = new IAppender[a.Length];
AddRange(a);
}
///
/// Initializes a new instance of the AppenderCollection class
/// that contains elements copied from the specified collection.
///
/// The collection whose elements are copied to the new list.
public AppenderCollection(ICollection col)
{
m_array = new IAppender[col.Count];
AddRange(col);
}
///
/// Type visible only to our subclasses
/// Used to access protected constructor
///
///
internal protected enum Tag
{
///
/// A value
///
Default
}
///
/// Allow subclasses to avoid our default constructors
///
///
///
internal protected AppenderCollection(Tag tag)
{
m_array = null;
}
#endregion
#region Operations (type-safe ICollection)
///
/// Gets the number of elements actually contained in the AppenderCollection.
///
public virtual int Count
{
get { return m_count; }
}
///
/// Copies the entire AppenderCollection to a one-dimensional
/// array.
///
/// The one-dimensional array to copy to.
public virtual void CopyTo(IAppender[] array)
{
this.CopyTo(array, 0);
}
///
/// Copies the entire AppenderCollection to a one-dimensional
/// array, starting at the specified index of the target array.
///
/// The one-dimensional array to copy to.
/// The zero-based index in at which copying begins.
public virtual void CopyTo(IAppender[] array, int start)
{
if (m_count > array.GetUpperBound(0) + 1 - start)
{
throw new System.ArgumentException("Destination array was not long enough.");
}
Array.Copy(m_array, 0, array, start, m_count);
}
///
/// Gets a value indicating whether access to the collection is synchronized (thread-safe).
///
/// false, because the backing type is an array, which is never thread-safe.
public virtual bool IsSynchronized
{
get { return false; }
}
///
/// Gets an object that can be used to synchronize access to the collection.
///
public virtual object SyncRoot
{
get { return m_array; }
}
#endregion
#region Operations (type-safe IList)
///
/// Gets or sets the at the specified index.
///
/// The zero-based index of the element to get or set.
///
/// is less than zero
/// -or-
/// is equal to or greater than .
///
public virtual IAppender this[int index]
{
get
{
ValidateIndex(index); // throws
return m_array[index];
}
set
{
ValidateIndex(index); // throws
++m_version;
m_array[index] = value;
}
}
///
/// Adds a to the end of the AppenderCollection.
///
/// The to be added to the end of the AppenderCollection.
/// The index at which the value has been added.
public virtual int Add(IAppender item)
{
if (m_count == m_array.Length)
{
EnsureCapacity(m_count + 1);
}
m_array[m_count] = item;
m_version++;
return m_count++;
}
///
/// Removes all elements from the AppenderCollection.
///
public virtual void Clear()
{
++m_version;
m_array = new IAppender[DEFAULT_CAPACITY];
m_count = 0;
}
///
/// Creates a shallow copy of the .
///
/// A new with a shallow copy of the collection data.
public virtual object Clone()
{
AppenderCollection newCol = new AppenderCollection(m_count);
Array.Copy(m_array, 0, newCol.m_array, 0, m_count);
newCol.m_count = m_count;
newCol.m_version = m_version;
return newCol;
}
///
/// Determines whether a given is in the AppenderCollection.
///
/// The to check for.
/// true if is found in the AppenderCollection; otherwise, false.
public virtual bool Contains(IAppender item)
{
for (int i=0; i != m_count; ++i)
{
if (m_array[i].Equals(item))
{
return true;
}
}
return false;
}
///
/// Returns the zero-based index of the first occurrence of a
/// in the AppenderCollection.
///
/// The to locate in the AppenderCollection.
///
/// The zero-based index of the first occurrence of
/// in the entire AppenderCollection, if found; otherwise, -1.
///
public virtual int IndexOf(IAppender item)
{
for (int i=0; i != m_count; ++i)
{
if (m_array[i].Equals(item))
{
return i;
}
}
return -1;
}
///
/// Inserts an element into the AppenderCollection at the specified index.
///
/// The zero-based index at which should be inserted.
/// The to insert.
///
/// is less than zero
/// -or-
/// is equal to or greater than .
///
public virtual void Insert(int index, IAppender item)
{
ValidateIndex(index, true); // throws
if (m_count == m_array.Length)
{
EnsureCapacity(m_count + 1);
}
if (index < m_count)
{
Array.Copy(m_array, index, m_array, index + 1, m_count - index);
}
m_array[index] = item;
m_count++;
m_version++;
}
///
/// Removes the first occurrence of a specific from the AppenderCollection.
///
/// The to remove from the AppenderCollection.
///
/// The specified was not found in the AppenderCollection.
///
public virtual void Remove(IAppender item)
{
int i = IndexOf(item);
if (i < 0)
{
throw new System.ArgumentException("Cannot remove the specified item because it was not found in the specified Collection.");
}
++m_version;
RemoveAt(i);
}
///
/// Removes the element at the specified index of the AppenderCollection.
///
/// The zero-based index of the element to remove.
///
/// is less than zero
/// -or-
/// is equal to or greater than .
///
public virtual void RemoveAt(int index)
{
ValidateIndex(index); // throws
m_count--;
if (index < m_count)
{
Array.Copy(m_array, index + 1, m_array, index, m_count - index);
}
// We can't set the deleted entry equal to null, because it might be a value type.
// Instead, we'll create an empty single-element array of the right type and copy it
// over the entry we want to erase.
IAppender[] temp = new IAppender[1];
Array.Copy(temp, 0, m_array, m_count, 1);
m_version++;
}
///
/// Gets a value indicating whether the collection has a fixed size.
///
/// true if the collection has a fixed size; otherwise, false. The default is false
public virtual bool IsFixedSize
{
get { return false; }
}
///
/// Gets a value indicating whether the IList is read-only.
///
/// true if the collection is read-only; otherwise, false. The default is false
public virtual bool IsReadOnly
{
get { return false; }
}
#endregion
#region Operations (type-safe IEnumerable)
///
/// Returns an enumerator that can iterate through the AppenderCollection.
///
/// An for the entire AppenderCollection.
public virtual IAppenderCollectionEnumerator GetEnumerator()
{
return new Enumerator(this);
}
#endregion
#region Public helpers (just to mimic some nice features of ArrayList)
///
/// Gets or sets the number of elements the AppenderCollection can contain.
///
public virtual int Capacity
{
get
{
return m_array.Length;
}
set
{
if (value < m_count)
{
value = m_count;
}
if (value != m_array.Length)
{
if (value > 0)
{
IAppender[] temp = new IAppender[value];
Array.Copy(m_array, 0, temp, 0, m_count);
m_array = temp;
}
else
{
m_array = new IAppender[DEFAULT_CAPACITY];
}
}
}
}
///
/// Adds the elements of another AppenderCollection to the current AppenderCollection.
///
/// The AppenderCollection whose elements should be added to the end of the current AppenderCollection.
/// The new of the AppenderCollection.
public virtual int AddRange(AppenderCollection x)
{
if (m_count + x.Count >= m_array.Length)
{
EnsureCapacity(m_count + x.Count);
}
Array.Copy(x.m_array, 0, m_array, m_count, x.Count);
m_count += x.Count;
m_version++;
return m_count;
}
///
/// Adds the elements of a array to the current AppenderCollection.
///
/// The array whose elements should be added to the end of the AppenderCollection.
/// The new of the AppenderCollection.
public virtual int AddRange(IAppender[] x)
{
if (m_count + x.Length >= m_array.Length)
{
EnsureCapacity(m_count + x.Length);
}
Array.Copy(x, 0, m_array, m_count, x.Length);
m_count += x.Length;
m_version++;
return m_count;
}
///
/// Adds the elements of a collection to the current AppenderCollection.
///
/// The collection whose elements should be added to the end of the AppenderCollection.
/// The new of the AppenderCollection.
public virtual int AddRange(ICollection col)
{
if (m_count + col.Count >= m_array.Length)
{
EnsureCapacity(m_count + col.Count);
}
foreach(object item in col)
{
Add((IAppender)item);
}
return m_count;
}
///
/// Sets the capacity to the actual number of elements.
///
public virtual void TrimToSize()
{
this.Capacity = m_count;
}
///
/// Return the collection elements as an array
///
/// the array
public virtual IAppender[] ToArray()
{
IAppender[] resultArray = new IAppender[m_count];
if (m_count > 0)
{
Array.Copy(m_array, 0, resultArray, 0, m_count);
}
return resultArray;
}
#endregion
#region Implementation (helpers)
///
/// is less than zero
/// -or-
/// is equal to or greater than .
///
private void ValidateIndex(int i)
{
ValidateIndex(i, false);
}
///
/// is less than zero
/// -or-
/// is equal to or greater than .
///
private void ValidateIndex(int i, bool allowEqualEnd)
{
int max = (allowEqualEnd) ? (m_count) : (m_count-1);
if (i < 0 || i > max)
{
throw log4net.Util.SystemInfo.CreateArgumentOutOfRangeException("i", (object)i, "Index was out of range. Must be non-negative and less than the size of the collection. [" + (object)i + "] Specified argument was out of the range of valid values.");
}
}
private void EnsureCapacity(int min)
{
int newCapacity = ((m_array.Length == 0) ? DEFAULT_CAPACITY : m_array.Length * 2);
if (newCapacity < min)
{
newCapacity = min;
}
this.Capacity = newCapacity;
}
#endregion
#region Implementation (ICollection)
void ICollection.CopyTo(Array array, int start)
{
if (m_count > 0)
{
Array.Copy(m_array, 0, array, start, m_count);
}
}
#endregion
#region Implementation (IList)
object IList.this[int i]
{
get { return (object)this[i]; }
set { this[i] = (IAppender)value; }
}
int IList.Add(object x)
{
return this.Add((IAppender)x);
}
bool IList.Contains(object x)
{
return this.Contains((IAppender)x);
}
int IList.IndexOf(object x)
{
return this.IndexOf((IAppender)x);
}
void IList.Insert(int pos, object x)
{
this.Insert(pos, (IAppender)x);
}
void IList.Remove(object x)
{
this.Remove((IAppender)x);
}
void IList.RemoveAt(int pos)
{
this.RemoveAt(pos);
}
#endregion
#region Implementation (IEnumerable)
IEnumerator IEnumerable.GetEnumerator()
{
return (IEnumerator)(this.GetEnumerator());
}
#endregion
#region Nested enumerator class
///
/// Supports simple iteration over a .
///
///
private sealed class Enumerator : IEnumerator, IAppenderCollectionEnumerator
{
#region Implementation (data)
private readonly AppenderCollection m_collection;
private int m_index;
private int m_version;
#endregion
#region Construction
///
/// Initializes a new instance of the Enumerator class.
///
///
internal Enumerator(AppenderCollection tc)
{
m_collection = tc;
m_index = -1;
m_version = tc.m_version;
}
#endregion
#region Operations (type-safe IEnumerator)
///
/// Gets the current element in the collection.
///
public IAppender Current
{
get { return m_collection[m_index]; }
}
///
/// Advances the enumerator to the next element in the collection.
///
///
/// true if the enumerator was successfully advanced to the next element;
/// false if the enumerator has passed the end of the collection.
///
///
/// The collection was modified after the enumerator was created.
///
public bool MoveNext()
{
if (m_version != m_collection.m_version)
{
throw new System.InvalidOperationException("Collection was modified; enumeration operation may not execute.");
}
++m_index;
return (m_index < m_collection.Count);
}
///
/// Sets the enumerator to its initial position, before the first element in the collection.
///
public void Reset()
{
m_index = -1;
}
#endregion
#region Implementation (IEnumerator)
object IEnumerator.Current
{
get { return this.Current; }
}
#endregion
}
#endregion
#region Nested Read Only Wrapper class
///
private sealed class ReadOnlyAppenderCollection : AppenderCollection, ICollection
{
#region Implementation (data)
private readonly AppenderCollection m_collection;
#endregion
#region Construction
internal ReadOnlyAppenderCollection(AppenderCollection list) : base(Tag.Default)
{
m_collection = list;
}
#endregion
#region Type-safe ICollection
public override void CopyTo(IAppender[] array)
{
m_collection.CopyTo(array);
}
public override void CopyTo(IAppender[] array, int start)
{
m_collection.CopyTo(array,start);
}
void ICollection.CopyTo(Array array, int start)
{
((ICollection)m_collection).CopyTo(array, start);
}
public override int Count
{
get { return m_collection.Count; }
}
public override bool IsSynchronized
{
get { return m_collection.IsSynchronized; }
}
public override object SyncRoot
{
get { return this.m_collection.SyncRoot; }
}
#endregion
#region Type-safe IList
public override IAppender this[int i]
{
get { return m_collection[i]; }
set { throw new NotSupportedException("This is a Read Only Collection and can not be modified"); }
}
public override int Add(IAppender x)
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override void Clear()
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override bool Contains(IAppender x)
{
return m_collection.Contains(x);
}
public override int IndexOf(IAppender x)
{
return m_collection.IndexOf(x);
}
public override void Insert(int pos, IAppender x)
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override void Remove(IAppender x)
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override void RemoveAt(int pos)
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override bool IsFixedSize
{
get { return true; }
}
public override bool IsReadOnly
{
get { return true; }
}
#endregion
#region Type-safe IEnumerable
public override IAppenderCollectionEnumerator GetEnumerator()
{
return m_collection.GetEnumerator();
}
#endregion
#region Public Helpers
// (just to mimic some nice features of ArrayList)
public override int Capacity
{
get { return m_collection.Capacity; }
set { throw new NotSupportedException("This is a Read Only Collection and can not be modified"); }
}
public override int AddRange(AppenderCollection x)
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override int AddRange(IAppender[] x)
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
public override IAppender[] ToArray()
{
return m_collection.ToArray();
}
public override void TrimToSize()
{
throw new NotSupportedException("This is a Read Only Collection and can not be modified");
}
#endregion
}
#endregion
}
}