feat: apache#954 - TryDequeue and TryPeek Queue extension methods (ap…

…ache#957)

* feat: apache#954 - Add TryDequeue and TryPeek Queue extension methods

* feat: apache#954 - Use TryDequeue and TryPeek Queue extension methods

* Add license

* Use Queue.TryDequeue where possible

* Use Queue.TryPeek where possible

* Use explicit type over var

* Fix tests

* Run tests depending on feature flag

* Reinstate previous performance optimizations

* Fix QueueExtensions exception docs

* Remove unnecessary ParamName assertion in QueueExtensionsTests

* Add nullable support to QueueExtensions

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
  {