| using System; |
| using System.Threading; |
| |
| namespace Lucene.Net.Facet.Taxonomy.WriterCache |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// <see cref="ITaxonomyWriterCache"/> using <see cref="CompactLabelToOrdinal"/>. Although |
| /// called cache, it maintains in memory all the mappings from category to |
| /// ordinal, relying on that <see cref="CompactLabelToOrdinal"/> is an efficient |
| /// mapping for this purpose. |
| /// |
| /// @lucene.experimental |
| /// </summary> |
| public class Cl2oTaxonomyWriterCache : ITaxonomyWriterCache |
| { |
| private const int LOCK_TIMEOUT = 1000; |
| private readonly ReaderWriterLockSlim @lock = new ReaderWriterLockSlim(); |
| private readonly int initialCapcity, numHashArrays; |
| private readonly float loadFactor; |
| |
| private volatile CompactLabelToOrdinal cache; |
| private bool isDisposed = false; |
| |
| /// <summary> |
| /// Sole constructor. |
| /// </summary> |
| public Cl2oTaxonomyWriterCache(int initialCapcity, float loadFactor, int numHashArrays) |
| { |
| this.cache = new CompactLabelToOrdinal(initialCapcity, loadFactor, numHashArrays); |
| this.initialCapcity = initialCapcity; |
| this.numHashArrays = numHashArrays; |
| this.loadFactor = loadFactor; |
| } |
| |
| public virtual void Clear() |
| { |
| if (@lock.TryEnterWriteLock(LOCK_TIMEOUT)) |
| { |
| try |
| { |
| cache = new CompactLabelToOrdinal(initialCapcity, loadFactor, numHashArrays); |
| } |
| finally |
| { |
| @lock.ExitWriteLock(); |
| } |
| } |
| else { |
| //Throwing ArguementException to maintain behavoir with ReaderWriterLock.AquireWriteLock. |
| throw new ArgumentException(); |
| } |
| } |
| |
| public void Dispose() |
| { |
| Dispose(true); |
| GC.SuppressFinalize(this); |
| } |
| |
| protected virtual void Dispose(bool disposing) // LUCENENET specific - use proper dispose pattern |
| { |
| if (disposing) |
| { |
| if (isDisposed) return; |
| if (@lock.TryEnterWriteLock(LOCK_TIMEOUT)) |
| { |
| if (isDisposed) return; |
| try |
| { |
| cache = null; |
| } |
| finally |
| { |
| isDisposed = true; |
| @lock.ExitWriteLock(); |
| @lock.Dispose(); |
| } |
| } |
| else |
| //Throwing ArguementException to maintain behavoir with ReaderWriterLock.AquireWriteLock. |
| throw new ArgumentException(); |
| } |
| } |
| |
| public virtual bool IsFull => |
| // This cache is never full |
| false; |
| |
| public virtual int Get(FacetLabel categoryPath) |
| { |
| if (@lock.TryEnterReadLock(LOCK_TIMEOUT)) |
| { |
| try |
| { |
| return cache.GetOrdinal(categoryPath); |
| } |
| finally |
| { |
| @lock.ExitReadLock(); |
| } |
| } |
| else |
| { |
| //Throwing ArguementException to maintain behavoir with ReaderWriterLock.AquireWriteLock. |
| throw new ArgumentException(); |
| } |
| } |
| |
| public virtual bool Put(FacetLabel categoryPath, int ordinal) |
| { |
| if (@lock.TryEnterWriteLock(LOCK_TIMEOUT)) |
| { |
| try |
| { |
| cache.AddLabel(categoryPath, ordinal); |
| // Tell the caller we didn't clear part of the cache, so it doesn't |
| // have to flush its on-disk index now |
| return false; |
| } |
| finally |
| { |
| @lock.ExitWriteLock(); |
| } |
| } |
| else |
| { |
| //Throwing ArguementException to maintain behavoir with ReaderWriterLock.AquireWriteLock. |
| throw new ArgumentException(); |
| } |
| } |
| |
| /// <summary> |
| /// Returns the number of bytes in memory used by this object. |
| /// </summary> |
| public virtual int GetMemoryUsage() |
| { |
| return cache == null ? 0 : cache.GetMemoryUsage(); |
| } |
| } |
| } |