1324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver/* 2324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * [The "BSD licence"] 3324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Copyright (c) 2005-2008 Terence Parr 4324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * All rights reserved. 5324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 6324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Conversion to C#: 7324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc. 8324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * All rights reserved. 9324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 10324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Redistribution and use in source and binary forms, with or without 11324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * modification, are permitted provided that the following conditions 12324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * are met: 13324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 1. Redistributions of source code must retain the above copyright 14324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * notice, this list of conditions and the following disclaimer. 15324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 2. Redistributions in binary form must reproduce the above copyright 16324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * notice, this list of conditions and the following disclaimer in the 17324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * documentation and/or other materials provided with the distribution. 18324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 3. The name of the author may not be used to endorse or promote products 19324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * derived from this software without specific prior written permission. 20324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 21324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 32324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 33324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruvernamespace Antlr.Runtime.Misc { 34324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver using System.Collections.Generic; 35324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver using ArgumentException = System.ArgumentException; 36324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver using InvalidOperationException = System.InvalidOperationException; 37324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 38324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** A queue that can dequeue and get(i) in O(1) and grow arbitrarily large. 39324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * A linked list is fast at dequeue but slow at get(i). An array is 40324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * the reverse. This is O(1) for both operations. 41324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 42324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * List grows until you dequeue last element at end of buffer. Then 43324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * it resets to start filling at 0 again. If adds/removes are balanced, the 44324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * buffer will not grow too large. 45324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * 46324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * No iterator stuff as that's not how we'll use it. 47324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 48324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public class FastQueue<T> { 49324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary>dynamically-sized buffer of elements</summary> */ 50324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver internal List<T> _data = new List<T>(); 51324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary>index of next element to fill</summary> */ 52324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver internal int _p = 0; 53324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 54324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual int Count { 55324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver get { 56324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return _data.Count - _p; 57324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 58324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 59324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 60324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /// <summary> 61324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /// How deep have we gone? 62324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /// </summary> 63324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual int Range { 64324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver get; 65324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver protected set; 66324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 67324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 68324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary> 69324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * Return element i elements ahead of current element. i==0 gets 70324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * current element. This is not an absolute index into the data list 71324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * since p defines the start of the real list. 72324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver * </summary> 73324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver */ 74324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual T this[int i] { 75324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver get { 76324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver int absIndex = _p + i; 77324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (absIndex >= _data.Count) 78324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver throw new ArgumentException(string.Format("queue index {0} > last index {1}", absIndex, _data.Count - 1)); 79324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (absIndex < 0) 80324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver throw new ArgumentException(string.Format("queue index {0} < 0", absIndex)); 81324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 82324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (absIndex > Range) 83324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Range = absIndex; 84324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 85324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return _data[absIndex]; 86324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 87324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 88324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 89324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary>Get and remove first element in queue</summary> */ 90324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual T Dequeue() { 91324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (Count == 0) 92324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver throw new InvalidOperationException(); 93324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 94324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver T o = this[0]; 95324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver _p++; 96324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // have we hit end of buffer? 97324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if (_p == _data.Count) { 98324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver // if so, it's an opportunity to start filling at index 0 again 99324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver Clear(); // size goes to 0, but retains memory 100324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 101324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return o; 102324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 103324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 104324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual void Enqueue(T o) { 105324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver _data.Add(o); 106324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 107324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 108324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual T Peek() { 109324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return this[0]; 110324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 111324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 112324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public virtual void Clear() { 113324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver _p = 0; 114324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver _data.Clear(); 115324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 116324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver 117324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver /** <summary>Return string of current buffer contents; non-destructive</summary> */ 118324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver public override string ToString() { 119324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver System.Text.StringBuilder buf = new System.Text.StringBuilder(); 120324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver int n = Count; 121324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver for (int i = 0; i < n; i++) { 122324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver buf.Append(this[i]); 123324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver if ((i + 1) < n) 124324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver buf.Append(" "); 125324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 126324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver return buf.ToString(); 127324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 128324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver } 129324c4644fee44b9898524c09511bd33c3f12e2dfBen Gruver} 130