/*
 * 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 java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;

import jakarta.servlet.ReadListener;
import jakarta.servlet.ServletInputStream;

import org.apache.catalina.security.SecurityUtil;
import org.apache.tomcat.util.res.StringManager;

This class handles reading bytes.
Author:
Remy Maucherat/**
 * This class handles reading bytes.
 *
 * @author Remy Maucherat
 */
public class CoyoteInputStream extends ServletInputStream {

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


    protected InputBuffer ib;


    protected CoyoteInputStream(InputBuffer ib) {
        this.ib = ib;
    }


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


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


    @Override
    public int read() throws IOException {
        checkNonBlockingRead();

        if (SecurityUtil.isPackageProtectionEnabled()) {

            try {
                Integer result = AccessController.doPrivileged(new PrivilegedRead(ib));
                return result.intValue();
            } catch (PrivilegedActionException pae) {
                Exception e = pae.getException();
                if (e instanceof IOException) {
                    throw (IOException) e;
                } else {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        } else {
            return ib.readByte();
        }
    }

    @Override
    public int available() throws IOException {

        if (SecurityUtil.isPackageProtectionEnabled()) {
            try {
                Integer result = AccessController.doPrivileged(new PrivilegedAvailable(ib));
                return result.intValue();
            } catch (PrivilegedActionException pae) {
                Exception e = pae.getException();
                if (e instanceof IOException) {
                    throw (IOException) e;
                } else {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        } else {
            return ib.available();
        }
    }

    @Override
    public int read(final byte[] b) throws IOException {
        return read(b, 0, b.length);
    }


    @Override
    public int read(final byte[] b, final int off, final int len) throws IOException {
        checkNonBlockingRead();

        if (SecurityUtil.isPackageProtectionEnabled()) {
            try {
                Integer result = AccessController.doPrivileged(
                        new PrivilegedReadArray(ib, b, off, len));
                return result.intValue();
            } catch (PrivilegedActionException pae) {
                Exception e = pae.getException();
                if (e instanceof IOException) {
                    throw (IOException) e;
                } else {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        } else {
            return ib.read(b, off, len);
        }
    }


    
Transfers bytes from the buffer to the specified ByteBuffer. After the
operation the position of the ByteBuffer will be returned to the one
before the operation, the limit will be the position incremented by
the number of the transferred bytes.
Params:
b – the ByteBuffer into which bytes are to be written.
Throws:
IOException – if an input or output exception has occurred
Returns:
an integer specifying the actual number of bytes read, or -1 if
        the end of the stream is reached/**
     * Transfers bytes from the buffer to the specified ByteBuffer. After the
     * operation the position of the ByteBuffer will be returned to the one
     * before the operation, the limit will be the position incremented by
     * the number of the transferred bytes.
     *
     * @param b the ByteBuffer into which bytes are to be written.
     * @return an integer specifying the actual number of bytes read, or -1 if
     *         the end of the stream is reached
     * @throws IOException if an input or output exception has occurred
     */
    public int read(final ByteBuffer b) throws IOException {
        checkNonBlockingRead();

        if (SecurityUtil.isPackageProtectionEnabled()) {
            try {
                Integer result = AccessController.doPrivileged(new PrivilegedReadBuffer(ib, b));
                return result.intValue();
            } catch (PrivilegedActionException pae) {
                Exception e = pae.getException();
                if (e instanceof IOException) {
                    throw (IOException) e;
                } else {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        } else {
            return ib.read(b);
        }
    }


    
Close the stream
Since we re-cycle, we can't allow the call to super.close()
which would permanently disable us.
/**
     * Close the stream
     * Since we re-cycle, we can't allow the call to super.close()
     * which would permanently disable us.
     */
    @Override
    public void close() throws IOException {

        if (SecurityUtil.isPackageProtectionEnabled()) {
            try {
                AccessController.doPrivileged(new PrivilegedClose(ib));
            } catch (PrivilegedActionException pae) {
                Exception e = pae.getException();
                if (e instanceof IOException) {
                    throw (IOException) e;
                } else {
                    throw new RuntimeException(e.getMessage(), e);
                }
            }
        } else {
            ib.close();
        }
    }

    @Override
    public boolean isFinished() {
        return ib.isFinished();
    }


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


    @Override
    public void setReadListener(ReadListener listener) {
        ib.setReadListener(listener);
    }


    private void checkNonBlockingRead() {
        if (!ib.isBlocking() && !ib.isReady()) {
            throw new IllegalStateException(sm.getString("coyoteInputStream.nbNotready"));
        }
    }


    private static class PrivilegedAvailable implements PrivilegedExceptionAction<Integer> {

        private final InputBuffer inputBuffer;

        public PrivilegedAvailable(InputBuffer inputBuffer) {
            this.inputBuffer = inputBuffer;
        }

        @Override
        public Integer run() throws IOException {
            return Integer.valueOf(inputBuffer.available());
        }
    }


    private static class PrivilegedClose implements PrivilegedExceptionAction<Void> {

        private final InputBuffer inputBuffer;

        public PrivilegedClose(InputBuffer inputBuffer) {
            this.inputBuffer = inputBuffer;
        }

        @Override
        public Void run() throws IOException {
            inputBuffer.close();
            return null;
        }
    }


    private static class PrivilegedRead implements PrivilegedExceptionAction<Integer> {

        private final InputBuffer inputBuffer;

        public PrivilegedRead(InputBuffer inputBuffer) {
            this.inputBuffer = inputBuffer;
        }

        @Override
        public Integer run() throws IOException {
            Integer integer = Integer.valueOf(inputBuffer.readByte());
            return integer;
        }
    }


    private static class PrivilegedReadArray implements PrivilegedExceptionAction<Integer> {

        private final InputBuffer inputBuffer;
        private final byte[] buf;
        private final int off;
        private final int len;

        public PrivilegedReadArray(InputBuffer inputBuffer, byte[] buf, int off, int len) {
            this.inputBuffer = inputBuffer;
            this.buf = buf;
            this.off = off;
            this.len = len;
        }

        @Override
        public Integer run() throws IOException {
            Integer integer = Integer.valueOf(inputBuffer.read(buf, off, len));
            return integer;
        }
    }


    private static class PrivilegedReadBuffer implements PrivilegedExceptionAction<Integer> {

        private final InputBuffer inputBuffer;
        private final ByteBuffer bb;

        public PrivilegedReadBuffer(InputBuffer inputBuffer, ByteBuffer bb) {
            this.inputBuffer = inputBuffer;
            this.bb = bb;
        }

        @Override
        public Integer run() throws IOException {
            Integer integer = Integer.valueOf(inputBuffer.read(bb));
            return integer;
        }
    }
}