feat: #954 - TryDequeue and TryPeek Queue extension methods

Directory.Build.targets

@@ -67,6 +67,7 @@
     <DefineConstants>$(DefineConstants);FEATURE_NUMBER_PARSE_READONLYSPAN</DefineConstants>
     <DefineConstants>$(DefineConstants);FEATURE_STREAM_READ_SPAN</DefineConstants>
     <DefineConstants>$(DefineConstants);FEATURE_STRINGBUILDER_APPEND_READONLYSPAN</DefineConstants>
+    <DefineConstants>$(DefineConstants);FEATURE_QUEUE_TRYDEQUEUE_TRYPEEK</DefineConstants>
 
   </PropertyGroup>
 

src/Lucene.Net.Analysis.Common/Analysis/Compound/CompoundWordTokenFilterBase.cs

@@ -4,6 +4,7 @@
 using Lucene.Net.Analysis.Util;
 using Lucene.Net.Diagnostics;
 using Lucene.Net.Util;
+using Lucene.Net.Support;
 using System;
 using System.Collections.Generic;
 
@@ -109,10 +110,9 @@ protected CompoundWordTokenFilterBase(LuceneVersion matchVersion, TokenStream in
 
         public override sealed bool IncrementToken()
         {
-            if (m_tokens.Count > 0)
+            if (m_tokens.TryDequeue(out CompoundToken token))
             {
                 if (Debugging.AssertsEnabled) Debugging.Assert(current != null);
-                CompoundToken token = m_tokens.Dequeue();
                 RestoreState(current); // keep all other attributes untouched
                 m_termAtt.SetEmpty().Append(token.Text);
                 m_offsetAtt.SetOffset(token.StartOffset, token.EndOffset);
@@ -197,4 +197,4 @@ public CompoundToken(CompoundWordTokenFilterBase compoundWordTokenFilterBase, in
             }
         }
     }
-}
+}

src/Lucene.Net.Analysis.Common/Analysis/Shingle/ShingleFilter.cs

@@ -1,6 +1,7 @@
 // Lucene version compatibility level 4.8.1
 using Lucene.Net.Analysis.TokenAttributes;
 using Lucene.Net.Util;
+using Lucene.Net.Support;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -508,11 +509,7 @@ public override void End()
         /// <exception cref="IOException"> if there's a problem getting the next token </exception>
         private void ShiftInputWindow()
         {
-            InputWindowToken firstToken = null;
-            if (inputWindow.Count > 0)
-            {
-                firstToken = inputWindow.Dequeue();
-            }
+            inputWindow.TryDequeue(out InputWindowToken firstToken); // LUCENENET: firstToken will be null if the queue is empty
             while (inputWindow.Count < maxShingleSize)
             {
                 if (null != firstToken) // recycle the firstToken, if available

src/Lucene.Net.Analysis.Common/Analysis/Th/ThaiTokenizer.cs

@@ -5,6 +5,7 @@
 using J2N;
 using Lucene.Net.Analysis.TokenAttributes;
 using Lucene.Net.Analysis.Util;
+using Lucene.Net.Support;
 using Lucene.Net.Support.Threading;
 using Lucene.Net.Util;
 using System;
@@ -236,20 +237,21 @@ public int Current
         {
             get
             {
-                if (transitions.Count > 0)
-                    return transitions.Peek();
+                if (transitions.TryPeek(out int current))
+                {
+                    return current;
+                }
 
                 return wordBreaker.Current;
             }
         }
 
         public int Next()
         {
-            if (transitions.Count > 0)
-                transitions.Dequeue();
-
-            if (transitions.Count > 0)
-                return transitions.Peek();
+            if (transitions.TryDequeue(out _) && transitions.TryPeek(out int next))
+            {
+                return next;
+            }
 
             return GetNext();
         }
@@ -297,15 +299,15 @@ private int GetNext()
                     prevWasNonThai = isNonThai;
                 }
 
-                if (transitions.Count > 0)
+                if (transitions.TryPeek(out int transition))
                 {
                     transitions.Enqueue(current);
-                    return transitions.Peek();
+                    return transition;
                 }
             }
 
             return current;
         }
     }
 }
-#endif
+#endif

src/Lucene.Net.Analysis.Phonetic/DoubleMetaphoneFilter.cs

@@ -1,6 +1,7 @@
 // lucene version compatibility level: 4.8.1
 using Lucene.Net.Analysis.Phonetic.Language;
 using Lucene.Net.Analysis.TokenAttributes;
+using Lucene.Net.Support;
 using System;
 using System.Collections.Generic;
 
@@ -37,7 +38,7 @@ public sealed class DoubleMetaphoneFilter : TokenFilter
         private readonly IPositionIncrementAttribute posAtt;
 
         /// <summary>
-        /// Creates a <see cref="DoubleMetaphoneFilter"/> with the specified maximum code length, 
+        /// Creates a <see cref="DoubleMetaphoneFilter"/> with the specified maximum code length,
         /// and either adding encoded forms as synonyms (<c>inject=true</c>) or
         /// replacing them.
         /// </summary>
@@ -54,10 +55,9 @@ public override bool IncrementToken()
         {
             for (;;)
             {
-                if (!(remainingTokens.Count == 0))
+                if (remainingTokens.TryDequeue(out State first))
                 {
                     // clearAttributes();  // not currently necessary
-                    var first = remainingTokens.Dequeue();
                     RestoreState(first);
                     return true;
                 }

src/Lucene.Net.Join/Support/ToParentBlockJoinCollector.cs

@@ -351,11 +351,10 @@ public virtual void SetScorer(Scorer scorer)
             var queue = new Queue<Scorer>();
             //System.out.println("\nqueue: add top scorer=" + value);
             queue.Enqueue(scorer);
-            while (queue.Count > 0)
+            // LUCENENET NOTE: This reuses the scorer argument variable, which
+            // differs from this.scorer.
+            while (queue.TryDequeue(out scorer))
             {
-                // LUCENENET NOTE: This reuses the scorer argument variable, which
-                // differs from this.scorer.
-                scorer = queue.Dequeue();
                 //System.out.println("  poll: " + value + "; " + value.getWeight().getQuery());
                 if (scorer is ToParentBlockJoinQuery.BlockJoinScorer blockJoinScorer)
                 {

src/Lucene.Net.Join/ToParentBlockJoinCollector.cs

@@ -349,11 +349,10 @@ public virtual void SetScorer(Scorer scorer)
             var queue = new Queue<Scorer>();
             //System.out.println("\nqueue: add top scorer=" + value);
             queue.Enqueue(scorer);
-            while (queue.Count > 0)
+            // LUCENENET NOTE: This reuses the scorer argument variable, which
+            // differs from this.scorer.
+            while (queue.TryDequeue(out scorer))
             {
-                // LUCENENET NOTE: This reuses the scorer argument variable, which
-                // differs from this.scorer.
-                scorer = queue.Dequeue();
                 //System.out.println("  poll: " + value + "; " + value.getWeight().getQuery());
                 if (scorer is ToParentBlockJoinQuery.BlockJoinScorer blockJoinScorer)
                 {

src/Lucene.Net.Suggest/Suggest/Tst/TSTAutocomplete.cs

@@ -203,4 +203,4 @@ public virtual IList<TernaryTreeNode> PrefixCompletion(TernaryTreeNode root, str
             return suggest;
         }
     }
-}
+}

src/Lucene.Net.TestFramework/Util/Automaton/AutomatonTestUtil.cs

@@ -1,5 +1,6 @@
 using J2N;
 using J2N.Runtime.CompilerServices;
+using Lucene.Net.Support;
 using Lucene.Net.Diagnostics;
 using RandomizedTesting.Generators;
 using System;
@@ -305,9 +306,8 @@ public static void DeterminizeSimple(Automaton a, ISet<State> initialset)
             worklist.Enqueue(initialset);
             a.initial = new State();
             newstate[initialset] = a.initial;
-            while (worklist.Count > 0)
+            while (worklist.TryDequeue(out ISet<State> s))
             {
-                ISet<State> s = worklist.Dequeue();
                 State r = newstate[s];
                 foreach (State q in s)
                 {
@@ -466,9 +466,8 @@ public RandomAcceptedStrings(Automaton a)
 
             // Breadth-first search, from accept states,
             // backwards:
-            while (q.Count > 0)
+            while (q.TryDequeue(out State s))
             {
-                State s = q.Dequeue();
                 if (allArriving.TryGetValue(s, out IList<ArrivingTransition> arriving) && arriving != null)
                 {
                     foreach (ArrivingTransition at in arriving)
@@ -566,4 +565,4 @@ public int[] GetRandomAcceptedString(Random r)
             return soFar.ToArray(); // LUCENENET: ArrayUtil.ToIntArray() call unnecessary
         }
     }
-}
+}

src/Lucene.Net.Tests/Support/QueueExtensionsTests.cs

@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using NUnit.Framework;
+
+using Lucene.Net.Attributes;
+using Lucene.Net.Util;
+using Lucene.Net.Support;
+using System;
+
+using Assert = Lucene.Net.TestFramework.Assert;
+
+
+namespace Lucene.Net
+{
+    /*
+     * 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.
+     */
+
+    public class QueueExtensionsTests : LuceneTestCase
+    {
+#if !FEATURE_QUEUE_TRYDEQUEUE_TRYPEEK
+        [Test, LuceneNetSpecific]
+        public void TryDequeue_ThrowsWhenQueueNull()
+        {
+            Queue<int> queue = null;
+            Assert.Throws<ArgumentNullException>(() => queue.TryDequeue(out int _));
+        }
+
+        [Test, LuceneNetSpecific]
+        public void TryDequeue_QueueEmpty()
+        {
+            Queue<int> queue = new Queue<int>();
+            bool found = queue.TryDequeue(out int result);
+            Assert.AreEqual(found, false);
+            Assert.AreEqual(result, default(int));
+        }
+
+        [Test, LuceneNetSpecific]
+        public void TryDequeue_QueueNotEmpty()
+        {
+            Queue<int> queue = new Queue<int>();
+            int item = 1;
+            queue.Enqueue(item);
+            int countBefore = queue.Count;
+            bool found = queue.TryDequeue(out int result);
+            Assert.AreEqual(found, true);
+            Assert.AreEqual(result, item);
+            Assert.AreEqual(queue.Count, countBefore - 1);
+        }
+
+        [Test, LuceneNetSpecific]
+        public void TryPeek_ThrowsWhenQueueNull()
+        {
+            Queue<int> queue = null;
+            Assert.Throws<ArgumentNullException>(() => queue.TryPeek(out int _));
+        }
+
+        [Test, LuceneNetSpecific]
+        public void TryPeek_QueueEmpty()
+        {
+            Queue<int> queue = new Queue<int>();
+            bool found = queue.TryPeek(out int result);
+            Assert.AreEqual(found, false);
+            Assert.AreEqual(result, default(int));
+        }
+
+        [Test, LuceneNetSpecific]
+        public void TryPeek_QueueNotEmpty()
+        {
+            Queue<int> queue = new Queue<int>();
+            int item = 1;
+            queue.Enqueue(item);
+            int countBefore = queue.Count;
+            bool found = queue.TryPeek(out int result);
+            Assert.AreEqual(found, true);
+            Assert.AreEqual(result, item);
+            Assert.AreEqual(queue.Count, countBefore);
+        }
+#endif
+    }
+}

src/Lucene.Net/Index/DocumentsWriterFlushControl.cs

@@ -1,6 +1,7 @@
 using J2N.Runtime.CompilerServices;
 using J2N.Threading.Atomic;
 using Lucene.Net.Diagnostics;
+using Lucene.Net.Support;
 using Lucene.Net.Support.Threading;
 using Lucene.Net.Util;
 using System;
@@ -501,8 +502,7 @@ internal DocumentsWriterPerThread NextPendingFlush()
             UninterruptableMonitor.Enter(this);
             try
             {
-                DocumentsWriterPerThread poll;
-                if (flushQueue.Count > 0 && (poll = flushQueue.Dequeue()) != null)
+                if (flushQueue.TryDequeue(out DocumentsWriterPerThread poll))
                 {
                     UpdateStallState();
                     return poll;
@@ -641,7 +641,7 @@ internal int NumFlushingDWPT
             }
         }
 
-        public bool GetAndResetApplyAllDeletes() 
+        public bool GetAndResetApplyAllDeletes()
         {
             return flushDeletes.GetAndSet(false);
         }
@@ -688,7 +688,7 @@ internal void MarkForFullFlush()
                 if (Debugging.AssertsEnabled)
                 {
                     Debugging.Assert(!fullFlush, "called DWFC#markForFullFlush() while full flush is still running");
-                    Debugging.Assert(fullFlushBuffer.Count == 0,"full flush buffer should be empty: {0}", fullFlushBuffer);
+                    Debugging.Assert(fullFlushBuffer.Count == 0, "full flush buffer should be empty: {0}", fullFlushBuffer);
                 }
                 fullFlush = true;
                 flushingQueue = documentsWriter.deleteQueue;
@@ -765,7 +765,7 @@ private bool AssertActiveDeleteQueue(DocumentsWriterDeleteQueue queue)
                 next.@Lock();
                 try
                 {
-                    if (Debugging.AssertsEnabled) Debugging.Assert(!next.IsInitialized || next.dwpt.deleteQueue == queue,"isInitialized: {0} numDocs: {1}", next.IsInitialized, (next.IsInitialized ? next.dwpt.NumDocsInRAM : 0));
+                    if (Debugging.AssertsEnabled) Debugging.Assert(!next.IsInitialized || next.dwpt.deleteQueue == queue, "isInitialized: {0} numDocs: {1}", next.IsInitialized, (next.IsInitialized ? next.dwpt.NumDocsInRAM : 0));
                 }
                 finally
                 {

src/Lucene.Net/Index/DocumentsWriterFlushQueue.cs

@@ -1,6 +1,7 @@
 using J2N.Threading.Atomic;
 using Lucene.Net.Diagnostics;
 using Lucene.Net.Support.Threading;
+using Lucene.Net.Support;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Threading;
@@ -142,7 +143,7 @@ internal virtual bool HasTickets
         {
             get
             {
-                if (Debugging.AssertsEnabled) Debugging.Assert(ticketCount >= 0,"ticketCount should be >= 0 but was: {0}", ticketCount);
+                if (Debugging.AssertsEnabled) Debugging.Assert(ticketCount >= 0, "ticketCount should be >= 0 but was: {0}", ticketCount);
                 return ticketCount != 0;
             }
         }
@@ -158,8 +159,7 @@ private int InnerPurge(IndexWriter writer)
                 UninterruptableMonitor.Enter(this);
                 try
                 {
-                    head = queue.Count <= 0 ? null : queue.Peek();
-                    canPublish = head != null && head.CanPublish; // do this synced
+                    canPublish = queue.TryPeek(out head) && head.CanPublish; // do this synced
                 }
                 finally
                 {