/**
 * Initialize standard input and output filters.
 */
protected void initializeFilters(int maxTrailerSize, Set<String> allowedTrailerHeaders,
        int maxExtensionSize, int maxSwallowSize) {
    // Create and add the identity filters.
    getInputBuffer().addFilter(new IdentityInputFilter(maxSwallowSize));
    getOutputBuffer().addFilter(new IdentityOutputFilter());

    // Create and add the chunked filters.
    getInputBuffer().addFilter( new ChunkedInputFilter(maxTrailerSize,allowedTrailerHeaders,
            maxExtensionSize, maxSwallowSize));
    getOutputBuffer().addFilter(new ChunkedOutputFilter());

    // Create and add the void filters
    getInputBuffer().addFilter(new VoidInputFilter());
    getOutputBuffer().addFilter(new VoidOutputFilter());

    // Create and add buffered input filter
    getInputBuffer().addFilter(new BufferedInputFilter());

    // Create and add the chunked filters.
    //getInputBuffer().addFilter(new GzipInputFilter());
    getOutputBuffer().addFilter(new GzipOutputFilter());

    pluggableFilterIndex = getInputBuffer().getFilters().length;
}
 

/**
 * Flush the response.
 * 
 * @throws IOException an underlying I/O error occurred
 */
public void flush()
    throws IOException {

    if (!committed) {

        // Send the connector a request for commit. The connector should
        // then validate the headers, send them (using sendHeader) and 
        // set the filters accordingly.
        response.action(ActionCode.COMMIT, null);

    }
    
    // go through the filters and if there is gzip filter
    // invoke it to flush
    for (int i = 0; i <= lastActiveFilter; i++) {
        if (activeFilters[i] instanceof GzipOutputFilter) {
            if (log.isDebugEnabled()) {
                log.debug("Flushing the gzip filter at position " + i +
                        " of the filter chain...");
            }
            ((GzipOutputFilter) activeFilters[i]).flush();
            break;
        }
    }
}
 

/**
 * Flush the response.
 * 
 * @throws IOException an underlying I/O error occurred
 */
public void flush()
    throws IOException {

    if (!committed) {

        // Send the connector a request for commit. The connector should
        // then validate the headers, send them (using sendHeader) and 
        // set the filters accordingly.
        response.action(ActionCode.COMMIT, null);

    }
    
    // go through the filters and if there is gzip filter
    // invoke it to flush
    for (int i = 0; i <= lastActiveFilter; i++) {
        if (activeFilters[i] instanceof GzipOutputFilter) {
            if (log.isDebugEnabled()) {
                log.debug("Flushing the gzip filter at position " + i +
                        " of the filter chain...");
            }
            ((GzipOutputFilter) activeFilters[i]).flush();
            break;
        }
    }
}
 

static void prepareHeaders(Request coyoteRequest, Response coyoteResponse,
        Http2Protocol protocol, Stream stream) {
    MimeHeaders headers = coyoteResponse.getMimeHeaders();
    int statusCode = coyoteResponse.getStatus();

    // Add the pseudo header for status
    headers.addValue(":status").setString(Integer.toString(statusCode));

    // Check to see if a response body is present
    if (!(statusCode < 200 || statusCode == 204 || statusCode == 205 || statusCode == 304)) {
        String contentType = coyoteResponse.getContentType();
        if (contentType != null) {
            headers.setValue("content-type").setString(contentType);
        }
        String contentLanguage = coyoteResponse.getContentLanguage();
        if (contentLanguage != null) {
            headers.setValue("content-language").setString(contentLanguage);
        }
        // Add a content-length header if a content length has been set unless
        // the application has already added one
        long contentLength = coyoteResponse.getContentLengthLong();
        if (contentLength != -1 && headers.getValue("content-length") == null) {
            headers.addValue("content-length").setLong(contentLength);
        }
    } else {
        if (statusCode == 205) {
            // RFC 7231 requires the server to explicitly signal an empty
            // response in this case
            coyoteResponse.setContentLength(0);
        } else {
            coyoteResponse.setContentLength(-1);
        }
    }

    // Add date header unless it is an informational response or the
    // application has already set one
    if (statusCode >= 200 && headers.getValue("date") == null) {
        headers.addValue("date").setString(FastHttpDateFormat.getCurrentDate());
    }

    if (protocol != null && protocol.useCompression(coyoteRequest, coyoteResponse)) {
        // Enable compression. Headers will have been set. Need to configure
        // output filter at this point.
        stream.addOutputFilter(new GzipOutputFilter());
    }
}
 

/**
 * Http11 NIO处理器.
 * 拿到连接.传递连接.处理连接.处理的关键地方.
 * 1.inputBuffer and  outputBuffer绑定在了NioSocketWrapper.
 * 2. Http11Processor持有NioSocketWrapper对象.
 * 3. NioSocketWrapper去读写数据填充到对应的两个Buffer内.
 * @param protocol
 * @param endpoint
 */
@SuppressWarnings("deprecation")
public Http11Processor(AbstractHttp11Protocol<?> protocol, AbstractEndpoint<?> endpoint) {
    super(endpoint);
    this.protocol = protocol;

    httpParser = new HttpParser(protocol.getRelaxedPathChars(),
            protocol.getRelaxedQueryChars());
    /**
     * Http11 InputBuffer  绑定到 {@link org.apache.coyote.Request}
     */
    inputBuffer = new Http11InputBuffer(request, protocol.getMaxHttpHeaderSize(),
            protocol.getRejectIllegalHeaderName(), httpParser);
    request.setInputBuffer(inputBuffer);
    /**
     * Http11 OutputBuffer  绑定到{@link org.apache.coyote.Response}
     */
    outputBuffer = new Http11OutputBuffer(response, protocol.getMaxHttpHeaderSize(),
            protocol.getSendReasonPhrase());
    response.setOutputBuffer(outputBuffer);

    // Create and add the identity filters.
    inputBuffer.addFilter(new IdentityInputFilter(protocol.getMaxSwallowSize()));
    outputBuffer.addFilter(new IdentityOutputFilter());

    // Create and add the chunked filters.
    inputBuffer.addFilter(new ChunkedInputFilter(protocol.getMaxTrailerSize(),
            protocol.getAllowedTrailerHeadersInternal(), protocol.getMaxExtensionSize(),
            protocol.getMaxSwallowSize()));
    outputBuffer.addFilter(new ChunkedOutputFilter());

    // Create and add the void filters.
    inputBuffer.addFilter(new VoidInputFilter());
    outputBuffer.addFilter(new VoidOutputFilter());

    // Create and add buffered input filter
    inputBuffer.addFilter(new BufferedInputFilter());

    // Create and add the gzip filters.
    //inputBuffer.addFilter(new GzipInputFilter());
    outputBuffer.addFilter(new GzipOutputFilter());

    pluggableFilterIndex = inputBuffer.getFilters().length;
}
 

/**
 * Test the interaction betwen gzip and flushing. The idea is to: 1. create
 * a internal output buffer, response, and attach an active gzipoutputfilter
 * to the output buffer 2. set the output stream of the internal buffer to
 * be a ByteArrayOutputStream so we can inspect the output bytes 3. write a
 * chunk out using the gzipoutputfilter and invoke a flush on the
 * InternalOutputBuffer 4. read from the ByteArrayOutputStream to find out
 * what's being written out (flushed) 5. find out what's expected by wrting
 * to GZIPOutputStream and close it (to force flushing) 6. Compare the size
 * of the two arrays, they should be close (instead of one being much
 * shorter than the other one)
 *
 * @throws Exception
 */
@Test
public void testFlushingWithGzip() throws Exception {
    // set up response, InternalOutputBuffer, and ByteArrayOutputStream
    Response res = new Response();
    InternalOutputBuffer iob = new InternalOutputBuffer(res, 8 * 1024);
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    iob.outputStream = bos;
    res.setOutputBuffer(iob);

    // set up GzipOutputFilter to attach to the InternalOutputBuffer
    GzipOutputFilter gf = new GzipOutputFilter();
    iob.addFilter(gf);
    iob.addActiveFilter(gf);

    // write a chunk out
    ByteChunk chunk = new ByteChunk(1024);
    byte[] d = "Hello there tomcat developers, there is a bug in JDK".getBytes();
    chunk.append(d, 0, d.length);
    iob.doWrite(chunk, res);

    // flush the InternalOutputBuffer
    iob.flush();

    // read from the ByteArrayOutputStream to find out what's being written
    // out (flushed)
    byte[] dataFound = bos.toByteArray();

    // find out what's expected by wrting to GZIPOutputStream and close it
    // (to force flushing)
    ByteArrayOutputStream gbos = new ByteArrayOutputStream(1024);
    GZIPOutputStream gos = new GZIPOutputStream(gbos);
    gos.write(d);
    gos.close();

    // read the expected data
    byte[] dataExpected = gbos.toByteArray();

    // most of the data should have been flushed out
    assertTrue(dataFound.length >= (dataExpected.length - 20));
}
 

/**
 * Test the interaction betwen gzip and flushing. The idea is to: 1. create
 * a internal output buffer, response, and attach an active gzipoutputfilter
 * to the output buffer 2. set the output stream of the internal buffer to
 * be a ByteArrayOutputStream so we can inspect the output bytes 3. write a
 * chunk out using the gzipoutputfilter and invoke a flush on the
 * InternalOutputBuffer 4. read from the ByteArrayOutputStream to find out
 * what's being written out (flushed) 5. find out what's expected by wrting
 * to GZIPOutputStream and close it (to force flushing) 6. Compare the size
 * of the two arrays, they should be close (instead of one being much
 * shorter than the other one)
 *
 * @throws Exception
 */
@Test
public void testFlushingWithGzip() throws Exception {
    // set up response, InternalOutputBuffer, and ByteArrayOutputStream
    Response res = new Response();
    InternalOutputBuffer iob = new InternalOutputBuffer(res, 8 * 1024);
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    iob.outputStream = bos;
    res.setOutputBuffer(iob);

    // set up GzipOutputFilter to attach to the InternalOutputBuffer
    GzipOutputFilter gf = new GzipOutputFilter();
    iob.addFilter(gf);
    iob.addActiveFilter(gf);

    // write a chunk out
    ByteChunk chunk = new ByteChunk(1024);
    byte[] d = "Hello there tomcat developers, there is a bug in JDK".getBytes();
    chunk.append(d, 0, d.length);
    iob.doWrite(chunk, res);

    // flush the InternalOutputBuffer
    iob.flush();

    // read from the ByteArrayOutputStream to find out what's being written
    // out (flushed)
    byte[] dataFound = bos.toByteArray();

    // find out what's expected by wrting to GZIPOutputStream and close it
    // (to force flushing)
    ByteArrayOutputStream gbos = new ByteArrayOutputStream(1024);
    GZIPOutputStream gos = new GZIPOutputStream(gbos);
    gos.write(d);
    gos.close();

    // read the expected data
    byte[] dataExpected = gbos.toByteArray();

    // most of the data should have been flushed out
    assertTrue(dataFound.length >= (dataExpected.length - 20));
}