jakarta.mail.internet.SharedInputStream Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2023 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.mail.internet;
import java.io.InputStream;
/**
* An InputStream that is backed by data that can be shared by multiple
* readers may implement this interface. This allows users of such an
* InputStream to determine the current position in the InputStream, and
* to create new InputStreams representing a subset of the data in the
* original InputStream. The new InputStream will access the same
* underlying data as the original, without copying the data.
*
* Note that implementations of this interface must ensure that the
* close method does not close any underlying stream
* that might be shared by multiple instances of SharedInputStream
* until all shared instances have been closed.
*
* @author Bill Shannon
* @since JavaMail 1.2
*/
public interface SharedInputStream {
/**
* Return the current position in the InputStream, as an
* offset from the beginning of the InputStream.
*
* @return the current position
*/
long getPosition();
/**
* Return a new InputStream representing a subset of the data
* from this InputStream, starting at start (inclusive)
* up to end (exclusive). start must be
* non-negative. If end is -1, the new stream ends
* at the same place as this stream. The returned InputStream
* will also implement the SharedInputStream interface.
*
* @param start the starting position
* @param end the ending position + 1
* @return the new stream
*/
InputStream newStream(long start, long end);
}