TermAttribute.cs

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/* 
 * 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.
 */

using System;
using Lucene.Net.Support;
using ArrayUtil = Lucene.Net.Util.ArrayUtil;
using Attribute = Lucene.Net.Util.Attribute;

namespace Lucene.Net.Analysis.Tokenattributes
{
    
    [Serializable]
    public class TermAttribute:Attribute, ITermAttribute, System.ICloneable
    {
        private static int MIN_BUFFER_SIZE = 10;
        
        private char[] termBuffer;
        private int termLength;

        public virtual string Term
        {
            get
            {
                InitTermBuffer();
                return new System.String(termBuffer, 0, termLength);
            }
        }

        public virtual void  SetTermBuffer(char[] buffer, int offset, int length)
        {
            GrowTermBuffer(length);
            Array.Copy(buffer, offset, termBuffer, 0, length);
            termLength = length;
        }
        
        public virtual void  SetTermBuffer(System.String buffer)
        {
            int length = buffer.Length;
            GrowTermBuffer(length);
            TextSupport.GetCharsFromString(buffer, 0, length, termBuffer, 0);
            termLength = length;
        }
        
        public virtual void  SetTermBuffer(System.String buffer, int offset, int length)
        {
            System.Diagnostics.Debug.Assert(offset <= buffer.Length);
            System.Diagnostics.Debug.Assert(offset + length <= buffer.Length);
            GrowTermBuffer(length);
            TextSupport.GetCharsFromString(buffer, offset, offset + length, termBuffer, 0);
            termLength = length;
        }
        
        public virtual char[] TermBuffer()
        {
            InitTermBuffer();
            return termBuffer;
        }
        
        public virtual char[] ResizeTermBuffer(int newSize)
        {
            if (termBuffer == null)
            {
                // The buffer is always at least MIN_BUFFER_SIZE
                termBuffer = new char[ArrayUtil.GetNextSize(newSize < MIN_BUFFER_SIZE?MIN_BUFFER_SIZE:newSize)];
            }
            else
            {
                if (termBuffer.Length < newSize)
                {
                    // Not big enough; create a new array with slight
                    // over allocation and preserve content
                    char[] newCharBuffer = new char[ArrayUtil.GetNextSize(newSize)];
                    Array.Copy(termBuffer, 0, newCharBuffer, 0, termBuffer.Length);
                    termBuffer = newCharBuffer;
                }
            }
            return termBuffer;
        }
        
        
        private void  GrowTermBuffer(int newSize)
        {
            if (termBuffer == null)
            {
                // The buffer is always at least MIN_BUFFER_SIZE
                termBuffer = new char[ArrayUtil.GetNextSize(newSize < MIN_BUFFER_SIZE?MIN_BUFFER_SIZE:newSize)];
            }
            else
            {
                if (termBuffer.Length < newSize)
                {
                    // Not big enough; create a new array with slight
                    // over allocation:
                    termBuffer = new char[ArrayUtil.GetNextSize(newSize)];
                }
            }
        }
        
        private void  InitTermBuffer()
        {
            if (termBuffer == null)
            {
                termBuffer = new char[ArrayUtil.GetNextSize(MIN_BUFFER_SIZE)];
                termLength = 0;
            }
        }
        
        public virtual int TermLength()
        {
            return termLength;
        }
        
        public virtual void  SetTermLength(int length)
        {
            InitTermBuffer();
            if (length > termBuffer.Length)
                throw new System.ArgumentException("length " + length + " exceeds the size of the termBuffer (" + termBuffer.Length + ")");
            termLength = length;
        }
        
        public override int GetHashCode()
        {
            InitTermBuffer();
            int code = termLength;
            code = code * 31 + ArrayUtil.HashCode(termBuffer, 0, termLength);
            return code;
        }
        
        public override void  Clear()
        {
            termLength = 0;
        }
        
        public override System.Object Clone()
        {
            TermAttribute t = (TermAttribute) base.Clone();
            // Do a deep clone
            if (termBuffer != null)
            {
                t.termBuffer = new char[termBuffer.Length];
                termBuffer.CopyTo(t.termBuffer, 0);
            }
            return t;
        }
        
        public  override bool Equals(System.Object other)
        {
            if (other == this)
            {
                return true;
            }
            
            if (other is ITermAttribute)
            {
                InitTermBuffer();
                TermAttribute o = ((TermAttribute) other);
                o.InitTermBuffer();
                
                if (termLength != o.termLength)
                    return false;
                for (int i = 0; i < termLength; i++)
                {
                    if (termBuffer[i] != o.termBuffer[i])
                    {
                        return false;
                    }
                }
                return true;
            }
            
            return false;
        }
        
        public override System.String ToString()
        {
            InitTermBuffer();
            return "term=" + new System.String(termBuffer, 0, termLength);
        }
        
        public override void  CopyTo(Attribute target)
        {
            InitTermBuffer();
            ITermAttribute t = (ITermAttribute) target;
            t.SetTermBuffer(termBuffer, 0, termLength);
        }
    }
}