/*
 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/entity/InputStreamEntity.java $
 * $Revision: 617591 $
 * $Date: 2008-02-01 10:21:17 -0800 (Fri, 01 Feb 2008) $
 *
 * ====================================================================
 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.entity;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
 
/**
 * A streamed entity obtaining content from an {@link InputStream InputStream}.
 *
 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
 *
 * @version $Revision: 617591 $
 * 
 * @since 4.0
 */
public class InputStreamEntity extends AbstractHttpEntity {

    private final static int BUFFER_SIZE = 2048;

    private final InputStream content;
    private final long length;
    private boolean consumed = false;

    public InputStreamEntity(final InputStream instream, long length) {
        super();        
        if (instream == null) {
            throw new IllegalArgumentException("Source input stream may not be null");
        }
        this.content = instream;
        this.length = length;
    }

    public boolean isRepeatable() {
        return false;
    }

    public long getContentLength() {
        return this.length;
    }

    public InputStream getContent() throws IOException {
        return this.content;
    }
        
    public void writeTo(final OutputStream outstream) throws IOException {
        if (outstream == null) {
            throw new IllegalArgumentException("Output stream may not be null");
        }
        InputStream instream = this.content;
        byte[] buffer = new byte[BUFFER_SIZE];
        int l;
        if (this.length < 0) {
            // consume until EOF
            while ((l = instream.read(buffer)) != -1) {
                outstream.write(buffer, 0, l);
            }
        } else {
            // consume no more than length
            long remaining = this.length;
            while (remaining > 0) {
                l = instream.read(buffer, 0, (int)Math.min(BUFFER_SIZE, remaining));
                if (l == -1) {
                    break;
                }
                outstream.write(buffer, 0, l);
                remaining -= l;
            }
        }
        this.consumed = true;
    }

    // non-javadoc, see interface HttpEntity
    public boolean isStreaming() {
        return !this.consumed;
    }

    // non-javadoc, see interface HttpEntity
    public void consumeContent() throws IOException {
        this.consumed = true;
        // If the input stream is from a connection, closing it will read to
        // the end of the content. Otherwise, we don't care what it does.
        this.content.close();
    }
    
} // class InputStreamEntity