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
42 public class Queue<T> : IEnumerable <T>, ICollection, IEnumerable
51 private readonly static int INITIAL_SIZE = 16;
55 defaultCapacity = INITIAL_SIZE;
58 public Queue (int count)
61 throw new ArgumentOutOfRangeException ("count");
63 defaultCapacity = count;
67 public Queue (IEnumerable <T> collection)
69 if (collection == null)
70 throw new ArgumentNullException ("collection");
72 foreach (T t in collection)
74 defaultCapacity = size;
80 Array.Clear (data, 0, data.Length);
82 head = tail = size = 0;
85 public bool Contains (T item)
100 public void CopyTo (T [] array, int idx)
103 throw new ArgumentNullException ();
105 if ((uint) idx > (uint) array.Length)
106 throw new ArgumentOutOfRangeException ();
108 if (array.Length - idx < size)
109 throw new ArgumentOutOfRangeException ();
114 int contents_length = data.Length;
115 int length_from_head = contents_length - head;
117 Array.Copy (data, head, array, idx, Math.Min (size, length_from_head));
118 if (size > length_from_head)
119 Array.Copy (data, 0, array,
120 idx + length_from_head,
121 size - length_from_head);
125 void ICollection.CopyTo (Array array, int idx)
128 throw new ArgumentNullException ();
130 if ((uint) idx < (uint) array.Length)
131 throw new ArgumentOutOfRangeException ();
133 if (array.Length - idx < size)
134 throw new ArgumentOutOfRangeException ();
140 int contents_length = data.Length;
141 int length_from_head = contents_length - head;
143 Array.Copy (data, head, array, idx, Math.Min (size, length_from_head));
144 if (size > length_from_head)
145 Array.Copy (data, 0, array,
146 idx + length_from_head,
147 size - length_from_head);
148 } catch (ArrayTypeMismatchException) {
149 throw new ArgumentException ();
157 // clear stuff out to make the GC happy
158 data [head] = default (T);
160 if (++head == data.Length)
171 throw new InvalidOperationException ();
176 public void Enqueue (T item)
178 if (data == null || size == data.Length)
179 SetCapacity (Math.Max (size * 2, 4));
183 if (++tail == data.Length)
190 public T [] ToArray ()
192 T [] t = new T [size];
197 public void TrimExcess ()
199 if (data != null && (size < data.Length * 0.9))
200 Array.Resize <T> (ref data, size == 0 ? defaultCapacity : size);
203 void SetCapacity (int new_size)
205 if (data != null && new_size == data.Length)
209 throw new InvalidOperationException ("shouldnt happen");
211 T [] new_data = new T [new_size];
213 CopyTo (new_data, 0);
225 bool ICollection.IsSynchronized {
226 get { return false; }
229 object ICollection.SyncRoot {
233 public Enumerator GetEnumerator ()
235 return new Enumerator (this);
238 IEnumerator <T> IEnumerable<T>.GetEnumerator ()
240 return GetEnumerator ();
243 IEnumerator IEnumerable.GetEnumerator ()
245 return GetEnumerator ();
249 public struct Enumerator : IEnumerator <T>, IEnumerator, IDisposable {
250 const int NOT_STARTED = -2;
252 // this MUST be -1, because we depend on it in move next.
253 // we just decr the size, so, 0 - 1 == FINISHED
254 const int FINISHED = -1;
260 internal Enumerator (Queue <T> q)
267 // for some fucked up reason, MSFT added a useless dispose to this class
268 // It means that in foreach, we must still do a try/finally. Broken, very
270 public void Dispose ()
275 public bool MoveNext ()
277 if (ver != q.version)
278 throw new InvalidOperationException ();
280 if (idx == NOT_STARTED)
283 return idx != FINISHED && -- idx != FINISHED;
289 throw new InvalidOperationException ();
291 return q.data [(q.size - 1 - idx + q.head) % q.data.Length];
295 void IEnumerator.Reset ()
297 if (ver != q.version)
298 throw new InvalidOperationException ();
303 object IEnumerator.Current {
304 get { return Current; }