2 // System.Collections.Generic.Queue
5 // Martin Baulig (martin@ximian.com)
6 // Ben Maurer (bmaurer@ximian.com)
8 // (C) 2003, 2004 Novell, Inc.
12 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
14 // Permission is hereby granted, free of charge, to any person obtaining
15 // a copy of this software and associated documentation files (the
16 // "Software"), to deal in the Software without restriction, including
17 // without limitation the rights to use, copy, modify, merge, publish,
18 // distribute, sublicense, and/or sell copies of the Software, and to
19 // permit persons to whom the Software is furnished to do so, subject to
20 // the following conditions:
22 // The above copyright notice and this permission notice shall be
23 // included in all copies or substantial portions of the Software.
25 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
29 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
30 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
31 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
36 using System.Runtime.InteropServices;
38 namespace System.Collections.Generic
41 public class Queue<T> : IEnumerable <T>, ICollection, IEnumerable
50 private readonly static int INITIAL_SIZE = 16;
54 defaultCapacity = INITIAL_SIZE;
57 public Queue (int count)
60 throw new ArgumentOutOfRangeException ("count");
62 defaultCapacity = count;
66 public Queue (IEnumerable <T> collection)
68 if (collection == null)
69 throw new ArgumentNullException ("collection");
71 foreach (T t in collection)
73 defaultCapacity = size;
79 Array.Clear (data, 0, data.Length);
81 head = tail = size = 0;
84 public bool Contains (T item)
99 public void CopyTo (T [] array, int idx)
102 throw new ArgumentNullException ();
104 if ((uint) idx > (uint) array.Length)
105 throw new ArgumentOutOfRangeException ();
107 if (array.Length - idx < size)
108 throw new ArgumentOutOfRangeException ();
113 int contents_length = data.Length;
114 int length_from_head = contents_length - head;
116 Array.Copy (data, head, array, idx, Math.Min (size, length_from_head));
117 if (size > length_from_head)
118 Array.Copy (data, 0, array,
119 idx + length_from_head,
120 size - length_from_head);
124 void ICollection.CopyTo (Array array, int idx)
127 throw new ArgumentNullException ();
129 if ((uint) idx < (uint) array.Length)
130 throw new ArgumentOutOfRangeException ();
132 if (array.Length - idx < size)
133 throw new ArgumentOutOfRangeException ();
139 int contents_length = data.Length;
140 int length_from_head = contents_length - head;
142 Array.Copy (data, head, array, idx, Math.Min (size, length_from_head));
143 if (size > length_from_head)
144 Array.Copy (data, 0, array,
145 idx + length_from_head,
146 size - length_from_head);
147 } catch (ArrayTypeMismatchException) {
148 throw new ArgumentException ();
156 // clear stuff out to make the GC happy
157 data [head] = default (T);
159 if (++head == data.Length)
170 throw new InvalidOperationException ();
175 public void Enqueue (T item)
177 if (data == null || size == data.Length)
178 SetCapacity (Math.Max (size * 2, 4));
182 if (++tail == data.Length)
189 public T [] ToArray ()
191 T [] t = new T [size];
196 public void TrimExcess ()
198 if (data != null && (size < data.Length * 0.9))
199 Array.Resize <T> (ref data, size == 0 ? defaultCapacity : size);
202 void SetCapacity (int new_size)
204 if (data != null && new_size == data.Length)
208 throw new InvalidOperationException ("shouldnt happen");
210 T [] new_data = new T [new_size];
212 CopyTo (new_data, 0);
224 bool ICollection.IsSynchronized {
225 get { return false; }
228 object ICollection.SyncRoot {
232 public Enumerator GetEnumerator ()
234 return new Enumerator (this);
237 IEnumerator <T> IEnumerable<T>.GetEnumerator ()
239 return GetEnumerator ();
242 IEnumerator IEnumerable.GetEnumerator ()
244 return GetEnumerator ();
247 public struct Enumerator : IEnumerator <T>, IEnumerator, IDisposable {
248 const int NOT_STARTED = -2;
250 // this MUST be -1, because we depend on it in move next.
251 // we just decr the size, so, 0 - 1 == FINISHED
252 const int FINISHED = -1;
258 internal Enumerator (Queue <T> q)
265 // for some fucked up reason, MSFT added a useless dispose to this class
266 // It means that in foreach, we must still do a try/finally. Broken, very
268 public void Dispose ()
273 public bool MoveNext ()
275 if (ver != q.version)
276 throw new InvalidOperationException ();
278 if (idx == NOT_STARTED)
281 return idx != FINISHED && -- idx != FINISHED;
287 throw new InvalidOperationException ();
289 return q.data [(q.size - 1 - idx + q.head) % q.data.Length];
293 void IEnumerator.Reset ()
295 if (ver != q.version)
296 throw new InvalidOperationException ();
301 object IEnumerator.Current {
302 get { return Current; }