internaloutputbuffer.java

Tomcat 4.1与WebServer集成组件的源代码包.

/*
 * ====================================================================
 * 
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
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 *    distribution.
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 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
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 *    if and wherever such third-party acknowlegements normally appear.
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 * [Additional notices, if required by prior licensing conditions]
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package org.apache.coyote.http11;

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

import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.http.HttpMessages;
import org.apache.tomcat.util.http.MimeHeaders;
import org.apache.tomcat.util.res.StringManager;

import org.apache.coyote.ActionCode;
import org.apache.coyote.OutputBuffer;
import org.apache.coyote.Response;

/**
 * Output buffer.
 * 
 * @author <a href="mailto:[e-mail]">Remy Maucherat</a>
 */
public class InternalOutputBuffer implements OutputBuffer {


    // -------------------------------------------------------------- Constants


    // ----------------------------------------------------------- Constructors


    /**
     * Default constructor.
     */
    public InternalOutputBuffer(Response response) {
        this(response, Constants.DEFAULT_HTTP_HEADER_BUFFER_SIZE);
    }


    /**
     * Alternate constructor.
     */
    public InternalOutputBuffer(Response response, int headerBufferSize) {

        this.response = response;
        headers = response.getMimeHeaders();

        headerBuffer = new byte[headerBufferSize];
        buf = headerBuffer;

        outputStreamOutputBuffer = new OutputStreamOutputBuffer();

        filterLibrary = new OutputFilter[0];
        activeFilters = new OutputFilter[0];
        lastActiveFilter = -1;

        committed = false;
        finished = false;

    }


    // -------------------------------------------------------------- Variables


    /**
     * The string manager for this package.
     */
    protected static StringManager sm =
        StringManager.getManager(Constants.Package);


    // ----------------------------------------------------- Instance Variables


    /**
     * Associated Coyote response.
     */
    protected Response response;


    /**
     * Headers of the associated request.
     */
    protected MimeHeaders headers;


    /**
     * Committed flag.
     */
    protected boolean committed;


    /**
     * Finished flag.
     */
    protected boolean finished;


    /**
     * Pointer to the current read buffer.
     */
    protected byte[] buf;


    /**
     * Position in the buffer.
     */
    protected int pos;


    /**
     * HTTP header buffer.
     */
    protected byte[] headerBuffer;


    /**
     * Underlying output stream.
     */
    protected OutputStream outputStream;


    /**
     * Underlying output buffer.
     */
    protected OutputBuffer outputStreamOutputBuffer;


    /**
     * Filter library.
     * Note: Filter[0] is always the "chunked" filter.
     */
    protected OutputFilter[] filterLibrary;


    /**
     * Active filter (which is actually the top of the pipeline).
     */
    protected OutputFilter[] activeFilters;


    /**
     * Index of the last active filter.
     */
    protected int lastActiveFilter;


    // ------------------------------------------------------------- Properties


    /**
     * Set the underlying socket output stream.
     */
    public void setOutputStream(OutputStream outputStream) {

        // FIXME: Check for null ?

        this.outputStream = outputStream;

    }


    /**
     * Get the underlying socket output stream.
     */
    public OutputStream getOutputStream() {

        return outputStream;

    }


    /**
     * Add an output filter to the filter library.
     */
    public void addFilter(OutputFilter filter) {

        OutputFilter[] newFilterLibrary = 
            new OutputFilter[filterLibrary.length + 1];
        for (int i = 0; i < filterLibrary.length; i++) {
            newFilterLibrary[i] = filterLibrary[i];
        }
        newFilterLibrary[filterLibrary.length] = filter;
        filterLibrary = newFilterLibrary;

        activeFilters = new OutputFilter[filterLibrary.length];

    }


    /**
     * Get filters.
     */
    public OutputFilter[] getFilters() {

        return filterLibrary;

    }


    /**
     * Clear filters.
     */
    public void clearFilters() {

        filterLibrary = new OutputFilter[0];
        lastActiveFilter = -1;

    }


    /**
     * Add an output filter to the filter library.
     */
    public void addActiveFilter(OutputFilter filter) {

        if (lastActiveFilter == -1) {
            filter.setBuffer(outputStreamOutputBuffer);
        } else {
            for (int i = 0; i <= lastActiveFilter; i++) {
                if (activeFilters[i] == filter)
                    return;
            }
            filter.setBuffer(activeFilters[lastActiveFilter]);
        }

        activeFilters[++lastActiveFilter] = filter;

        filter.setResponse(response);

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Reset current response.
     * 
     * @throws IllegalStateException if the response has already been committed
     */
    public void reset() {

        if (committed)
            throw new IllegalStateException(/*FIXME:Put an error message*/);

        // Recycle Request object
        response.recycle();

    }


    /**
     * Recycle the output buffer. This should be called when closing the 
     * connection.
     */
    public void recycle() {

        // Recycle Request object
        response.recycle();

        outputStream = null;
        buf = headerBuffer;
        pos = 0;
        lastActiveFilter = -1;
        committed = false;
        finished = false;

    }


    /**
     * End processing of current HTTP request.
     * Note: All bytes of the current request should have been already 
     * consumed. This method only resets all the pointers so that we are ready
     * to parse the next HTTP request.
     */
    public void nextRequest() {

        // Recycle Request object
        response.recycle();