/* Constructed.java -- Constructed type.
   Copyright (C) 2006  Free Software Foundation, Inc.

This file is a part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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your option) any later version.

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WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
USA

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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independent module, the terms and conditions of the license of that
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package gnu.javax.net.ssl.provider;

/**
 * The base interface to SSL constructed types.
 * 
 * <p><b>Contract for ByteBuffer-based constructed types:</b>
 * 
 * <p>Most implementations of this interface supported by this library
 * take a "view" of an underlying ByteBuffer. The general contract of
 * such classes is that they <em>will not</em> modify the position or
 * limit of the buffer when doing read operations. That is, the position
 * of the underlying buffer <em>should</em> remain at 0 throughout the
 * lifetime of the object, and the limit should be either set to the
 * capacity of the buffer, or to the size of the object (in most cases,
 * the length of the protocol object is determined by the contents of
 * the object, so the limit isn't useful in such cases. Of course, if the
 * limit is set to something other than the object's length, it must be
 * larger than the object length).
 * 
 * <p>Setter methods (usually in a class that implements the {@link Builder}
 * interface) may modify the limit, but the general contract remains that
 * the position remain at zero, and that the limit be at least as large as
 * the object length.
 * 
 * <p>Thus, very often the code will use <em>absolute</em> getters and setters
 * for primitive types, or it will use the {@link java.nio.ByteBuffer#duplicate()}
 * method, and sometimes the {@link java.nio.ByteBuffer#slice()} method, and
 * will change the position or limit of the duplicate buffer.
 */
public interface Constructed
{
  /**
   * Returns the total length, in bytes, of this structure.
   *
   * @return The length of this structure.
   */
  int length();

  /**
   * Returns a printable representation of this structure, with the
   * given prefix prepended to each line.
   *
   * @param prefix The prefix to prepend to each line of the
   * output. This value may be <code>null</code>.
   * @return A printable representation of this structure.
   */
  String toString(String prefix);
}