abstractbuffer.java

jetty SERVER連接資料庫用的軟體

// ========================================================================
// Copyright 2004-2005 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed 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.
// ========================================================================

package org.mortbay.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * @author gregw
 *  
 */
public abstract class AbstractBuffer implements Buffer
{
    protected final static String 
    __IMMUTABLE = "IMMUTABLE", 
    __READONLY = "READONLY",
    __READWRITE = "READWRITE", 
    __VOLATILE = "VOLATILE";
    
    protected int _access;
    protected boolean _volatile;

    protected int _get;
    protected int _put;
    protected int _hash;
    protected int _hashGet;
    protected int _hashPut;
    protected int _mark;
    protected String _string;
    protected View _view;

    /**
     * Constructor for BufferView
     * 
     * @param access 0==IMMUTABLE, 1==READONLY, 2==READWRITE
     */
    public AbstractBuffer(int access, boolean isVolatile)
    {
        if (access == IMMUTABLE && isVolatile)
                throw new IllegalArgumentException("IMMUTABLE && VOLATILE");
        setMarkIndex(-1);
        _access = access;
        _volatile = isVolatile;
    }

    /*
     * @see org.mortbay.io.Buffer#toArray()
     */
    public byte[] asArray()
    {
        byte[] bytes = new byte[length()];
        byte[] array = array();
        if (array != null)
            Portable.arraycopy(array, getIndex(), bytes, 0, bytes.length);
        else
            peek(getIndex(), bytes, 0, length());
        return bytes;
    }

    public ByteArrayBuffer duplicate(int access)
    {
        Buffer b=this.buffer();
        if (b instanceof Buffer.CaseInsensitve)
            return new ByteArrayBuffer.CaseInsensitive(asArray(), 0, length(),access);
        else
            return new ByteArrayBuffer(asArray(), 0, length(), access);
    }
    
    /*
     * @see org.mortbay.io.Buffer#asNonVolatile()
     */
    public Buffer asNonVolatileBuffer()
    {
        if (!isVolatile()) return this;
        return duplicate(_access);
    }

    public Buffer asImmutableBuffer()
    {
        if (isImmutable()) return this;
        return duplicate(IMMUTABLE);
    }

    /*
     * @see org.mortbay.util.Buffer#asReadOnlyBuffer()
     */
    public Buffer asReadOnlyBuffer()
    {
        if (isReadOnly()) return this;
        return new View(this, markIndex(), getIndex(), putIndex(), READONLY);
    }

    public Buffer asMutableBuffer()
    {
        if (!isImmutable()) return this;
        
        Buffer b=this.buffer();
        if (b.isReadOnly())
        {
            return duplicate(READWRITE);
        }
        return new View(b, markIndex(), getIndex(), putIndex(), _access);
    }

    public Buffer buffer()
    {
        return this;
    }

    public void clear()
    {
        setMarkIndex(-1);
        setGetIndex(0);
        setPutIndex(0);
    }

    public void compact()
    {
        if (isReadOnly()) throw new IllegalStateException(__READONLY);
        int s = markIndex() >= 0 ? markIndex() : getIndex();
        if (s > 0)
        {
            byte array[] = array();
            int length = putIndex() - s;
            if (length > 0)
            {
                if (array != null)
                    Portable.arraycopy(array(), s, array(), 0, length);
                else
                    poke(0, peek(s, length));
            }
            if (markIndex() > 0) setMarkIndex(markIndex() - s);
            setGetIndex(getIndex() - s);
            setPutIndex(putIndex() - s);
        }
    }

    public boolean equals(Object obj)
    {
        if (obj==this)
            return true;
        
        // reject non buffers;
        if (obj == null || !(obj instanceof Buffer)) return false;
        Buffer b = (Buffer) obj;

        if (this instanceof Buffer.CaseInsensitve ||  b instanceof Buffer.CaseInsensitve)
            return equalsIgnoreCase(b);
        
        // reject different lengths
        if (b.length() != length()) return false;

        // reject AbstractBuffer with different hash value
        if (_hash != 0 && obj instanceof AbstractBuffer)
        {
            AbstractBuffer ab = (AbstractBuffer) obj;
            if (ab._hash != 0 && _hash != ab._hash) return false;
        }

        // Nothing for it but to do the hard grind.
        int get=getIndex();
        int bi=b.putIndex();
        for (int i = putIndex(); i-->get;)
        {
            byte b1 = peek(i);
            byte b2 = b.peek(--bi);
            if (b1 != b2) return false;
        }
        return true;
    }

    public boolean equalsIgnoreCase(Buffer b)
    {
        if (b==this)
            return true;
        
        // reject different lengths
        if (b.length() != length()) return false;

        // reject AbstractBuffer with different hash value
        if (_hash != 0 && b instanceof AbstractBuffer)
        {
            AbstractBuffer ab = (AbstractBuffer) b;
            if (ab._hash != 0 && _hash != ab._hash) return false;
        }

        // Nothing for it but to do the hard grind.
        int get=getIndex();
        int bi=b.putIndex();
        
        byte[] array = array();
        byte[] barray= b.array();
        if (array!=null && barray!=null)
        {
            for (int i = putIndex(); i-->get;)
            {
                byte b1 = array[i];
                byte b2 = barray[--bi];
                if (b1 != b2)
                {
                    if ('a' <= b1 && b1 <= 'z') b1 = (byte) (b1 - 'a' + 'A');
                    if ('a' <= b2 && b2 <= 'z') b2 = (byte) (b2 - 'a' + 'A');
                    if (b1 != b2) return false;
                }
            }
        }
        else
        {
            for (int i = putIndex(); i-->get;)
            {
                byte b1 = peek(i);
                byte b2 = b.peek(--bi);
                if (b1 != b2)
                {
                    if ('a' <= b1 && b1 <= 'z') b1 = (byte) (b1 - 'a' + 'A');
                    if ('a' <= b2 && b2 <= 'z') b2 = (byte) (b2 - 'a' + 'A');
                    if (b1 != b2) return false;
                }
            }
        }
        return true;
    }

    public byte get()
    {
        return peek(_get++);
    }

    public int get(byte[] b, int offset, int length)
    {
        int gi = getIndex();
        int l=length();
        if (l==0)
            return -1;
        
        if (length>l)
            length=l;
        
        length = peek(gi, b, offset, length);
        if (length>0)
            setGetIndex(gi + length);
        return length;
    }

    public Buffer get(int length)
    {
        int gi = getIndex();
        Buffer view = peek(gi, length);
        setGetIndex(gi + length);
        return view;
    }

    public final int getIndex()
    {
        return _get;
    }

    public boolean hasContent()
    {
        return _put > _get;
    }
    
    public int hashCode()
    {
        if (_hash == 0 || _hashGet!=_get || _hashPut!=_put) 
        {
            int get=getIndex();
            byte[] array = array();
            if (array==null)
            {
                for (int i = putIndex(); i-- >get;)
                {
                    byte b = peek(i);
                    if ('a' <= b && b <= 'z') 
                        b = (byte) (b - 'a' + 'A');
                    _hash = 31 * _hash + b;
                }
            }
            else
            {
                for (int i = putIndex(); i-- >get;)
                {
                    byte b = array[i];
                    if ('a' <= b && b <= 'z') 
                        b = (byte) (b - 'a' + 'A');
                    _hash = 31 * _hash + b;
                }
            }
            if (_hash == 0) 
                _hash = -1;
            _hashGet=_get;
            _hashPut=_put;
            
        }
        return _hash;
    }

    public boolean isImmutable()
    {
        return _access <= IMMUTABLE;
    }

    public boolean isReadOnly()
    {
        return _access <= READONLY;
    }

    public boolean isVolatile()
    {
        return _volatile;
    }

    public int length()
    {
        return _put - _get;
    }

    public void mark()
    {
        setMarkIndex(_get - 1);
    }

    public void mark(int offset)
    {
        setMarkIndex(_get + offset);
    }

    public int markIndex()
    {
        return _mark;
    }