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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * 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.sshd.common.util.io;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.channels.Channel;
import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Reads from another {@link InputStream} up to specified max. length
 *
 * @author Apache MINA SSHD Project
 */
public class LimitInputStream extends FilterInputStream implements Channel {
    private final AtomicBoolean open = new AtomicBoolean(true);
    private long remaining;

    public LimitInputStream(InputStream in, long length) {
        super(in);
        remaining = length;
    }

    @Override
    public boolean isOpen() {
        return open.get();
    }

    @Override
    public int read() throws IOException {
        if (!isOpen()) {
            throw new IOException("read() - stream is closed (remaining=" + remaining + ")");
        }

        if (remaining > 0) {
            remaining--;
            return super.read();
        } else {
            return -1;
        }
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (!isOpen()) {
            throw new IOException("read(len=" + len + ") stream is closed (remaining=" + remaining + ")");
        }

        int nb = len;
        if (nb > remaining) {
            nb = (int) remaining;
        }
        if (nb > 0) {
            int read = super.read(b, off, nb);
            remaining -= read;
            return read;
        } else {
            return -1;
        }
    }

    @Override
    public long skip(long n) throws IOException {
        if (!isOpen()) {
            throw new IOException("skip(" + n + ") stream is closed (remaining=" + remaining + ")");
        }

        long skipped = super.skip(n);
        remaining -= skipped;
        return skipped;
    }

    @Override
    public int available() throws IOException {
        if (!isOpen()) {
            throw new IOException("available() stream is closed (remaining=" + remaining + ")");
        }

        int av = super.available();
        if (av > remaining) {
            return (int) remaining;
        } else {
            return av;
        }
    }

    @Override
    public void close() throws IOException {
        // do not close the original input stream since it serves for ACK(s)
        if (open.getAndSet(false)) {
            // noinspection UnnecessaryReturnStatement
            return; // debug breakpoint
        }
    }
}