/*
 * 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.
 */
package org.apache.catalina.connector;

import java.io.IOException;
import java.nio.ByteBuffer;

import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.WriteListener;

import org.apache.tomcat.util.res.StringManager;

Coyote implementation of the servlet output stream.
Author:
Costin Manolache, Remy Maucherat/**
 * Coyote implementation of the servlet output stream.
 *
 * @author Costin Manolache
 * @author Remy Maucherat
 */
public class CoyoteOutputStream extends ServletOutputStream {

    protected static final StringManager sm = StringManager.getManager(CoyoteOutputStream.class);


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

    protected OutputBuffer ob;


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


    protected CoyoteOutputStream(OutputBuffer ob) {
        this.ob = ob;
    }


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


    
Prevent cloning the facade.
/**
     * Prevent cloning the facade.
     */
    @Override
    protected Object clone() throws CloneNotSupportedException {
        throw new CloneNotSupportedException();
    }


    // -------------------------------------------------------- Package Methods


    
Clear facade.
/**
     * Clear facade.
     */
    void clear() {
        ob = null;
    }


    // --------------------------------------------------- OutputStream Methods


    @Override
    public void write(int i) throws IOException {
        boolean nonBlocking = checkNonBlockingWrite();
        ob.writeByte(i);
        if (nonBlocking) {
            checkRegisterForWrite();
        }
    }


    @Override
    public void write(byte[] b) throws IOException {
        write(b, 0, b.length);
    }


    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        boolean nonBlocking = checkNonBlockingWrite();
        ob.write(b, off, len);
        if (nonBlocking) {
            checkRegisterForWrite();
        }
    }


    public void write(ByteBuffer from) throws IOException {
        boolean nonBlocking = checkNonBlockingWrite();
        ob.write(from);
        if (nonBlocking) {
            checkRegisterForWrite();
        }
    }


    
Will send the buffer to the client.
/**
     * Will send the buffer to the client.
     */
    @Override
    public void flush() throws IOException {
        boolean nonBlocking = checkNonBlockingWrite();
        ob.flush();
        if (nonBlocking) {
            checkRegisterForWrite();
        }
    }


    
Checks for concurrent writes which are not permitted. This object has no
state information so the call chain is
CoyoteOutputStream->OutputBuffer->CoyoteResponse.
Returns:
true if this OutputStream is currently in
        non-blocking mode./**
     * Checks for concurrent writes which are not permitted. This object has no
     * state information so the call chain is
     * CoyoteOutputStream->OutputBuffer->CoyoteResponse.
     *
     * @return <code>true</code> if this OutputStream is currently in
     *         non-blocking mode.
     */
    private boolean checkNonBlockingWrite() {
        boolean nonBlocking = !ob.isBlocking();
        if (nonBlocking && !ob.isReady()) {
            throw new IllegalStateException(sm.getString("coyoteOutputStream.nbNotready"));
        }
        return nonBlocking;
    }


    
Checks to see if there is data left in the Coyote output buffers (NOT the
servlet output buffer) and if so registers the associated socket for
write so the buffers will be emptied. The container will take care of
this. As far as the app is concerned, there is a non-blocking write in
progress. It doesn't have visibility of whether the data is buffered in
the socket buffer or the Coyote buffers.
/**
     * Checks to see if there is data left in the Coyote output buffers (NOT the
     * servlet output buffer) and if so registers the associated socket for
     * write so the buffers will be emptied. The container will take care of
     * this. As far as the app is concerned, there is a non-blocking write in
     * progress. It doesn't have visibility of whether the data is buffered in
     * the socket buffer or the Coyote buffers.
     */
    private void checkRegisterForWrite() {
        ob.checkRegisterForWrite();
    }


    @Override
    public void close() throws IOException {
        ob.close();
    }

    @Override
    public boolean isReady() {
        return ob.isReady();
    }


    @Override
    public void setWriteListener(WriteListener listener) {
        ob.setWriteListener(listener);
    }
}