/* InputStream.java --
   Copyright (C) 2005 Free Software Foundation, Inc.

This file is 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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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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package org.omg.CORBA_2_3.portable;

import gnu.CORBA.CDR.Vio;

import org.omg.CORBA.portable.BoxedValueHelper;

import java.io.Serializable;

/**
 * This class defines a new CDR input stream methods, added since
 * CORBA 2.3.
 *
 * This class is abstract; no direct instances can be instantiated.
 * Also, up till v 1.4 inclusive there are no methods that would
 * return it, and only one unimplemented interface,
 * {@link org.omg.CORBA.portable.ValueFactory }, needs it as a parameter.
 *
 * However since 1.3 all methods, declared as returning an
 * org.omg.CORBA.portable.InputStream actually return the instance of this
 * derived class and the new methods are accessible after the casting
 * operation.
 *
 * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
 */
public abstract class InputStream
  extends org.omg.CORBA.portable.InputStream
{
  /**
   * Read the abstract interface. An abstract interface can be either
   * CORBA value type or CORBA object and is returned as an abstract
   * java.lang.Object.
   *
   * As specified in OMG specification, this reads a single
   * boolean and then delegates either to {@link #read_Object()} (for false)
   * or to {@link #read_Value()} (for true).
   *
   * @return an abstract interface, unmarshaled from the stream.
   */
  public Object read_abstract_interface()
  {
    boolean isValue = read_boolean();

    if (isValue)
      return read_value();
    else
      return read_Object();
  }

  /**
   * Read the abstract interface, corresponding to the passed type.
   * An abstract interface can be either CORBA value type or CORBA
   * object and is returned as an abstract java.lang.Object.
   *
   * As specified in OMG specification, this reads a single
   * boolean and then delegates either to {@link #read_Object(Class)} (for false)
   * or to {@link #read_Value(Class)} (for true).
   *
   * @param clz a base class for the abstract interface.
   *
   * @return an abstract interface, unmarshaled from the stream
   */
  public Object read_abstract_interface(Class clz)
  {
    boolean isValue = read_boolean();

    if (isValue)
      return read_value(clz);
    else
      return read_Object(clz);
  }

  /**
   * Read a value type structure, extracting the repository id
   * from the input stream itself. The repository id is optional
   * in the value type record, but it  must be present for this
   * method to succeed. The {@link OutputStream} of this
   * implementation always stores the repository id.
   *
   * The casts the streams ORB into a CORBA 2.3 ORB and then
   * searched for a suitable value factory, where it delegates
   * the functionality.
   *
   * If you know the exact class or can create an unitialised instance
   * of the value type, it is recommended (faster) to use
   * {@link #read_value(Class)} or {@link #read_value(Serializable)}
   * instead.
   *
   * @param repository_id a repository id of the value type.
   *
   * @return an value type structure, unmarshaled from the stream
   */
  public Serializable read_value()
  {
    return Vio.read(this);
  }

  /**
   * Read a value type structure, corresponing to the passed type.
   * As the type is known, the repository Id in the input stream is
   * optional an not required. The codebase, if present, is also ignored.
   *
   * The passed class must implement either {@link CustomMarshal}
   * for the user-defined reading operations or {@link StreamableValue}
   * for the standard (generated by IDL compiler) reading operations.
   * Also, it must have the parameterless constructor to create a new
   * instance.
   *
   * @param clz a base class for a value type.
   *
   * @return an value type structure, unmarshaled from the stream
   */
  public Serializable read_value(Class clz)
  {
    return Vio.read(this, clz);
  }

  /**
   * Read a value type structure content, when the unitialised
   * instance is passed as a parameter. It is a fastest method to read
   * a value type.
   *
   * As the type is known, the repository Id in the input stream is
   * optional an not required. The codebase, if present, is also ignored.
   *
   * The passed instance must implement either {@link CustomMarshal}
   * for the user-defined reading operations or {@link StreamableValue}
   * for the standard (generated by IDL compiler) reading operations.
   *
   * @param unitialised_value the unitialised value.
   *
   * @return same value, filled in by the stream content.
   */
  public Serializable read_value(Serializable unitialised_value)
  {
    return Vio.read(this, unitialised_value);
  }

  /**
   * Read a value type structure, having the given repository id.
   * The casts the streams ORB into a CORBA 2.3 ORB and then
   * searched for a suitable value factory, where it delegates
   * the functionality.
   *
   * If you know the exact class or can create an unitialised instance
   * of the value type, it is recommended (faster) to use
   * {@link #read_value(Class)} or {@link #read_value(Serializable)}
   * instead.
   *
   * @param repository_id a repository id of the value type.
   *
   * @return an value type structure, unmarshaled from the stream
   */
  public Serializable read_value(String repository_id)
  {
    return ((org.omg.CORBA_2_3.ORB) orb()).lookup_value_factory(repository_id)
            .read_value(this);
  }

  /**
   * Use the provided boxed value helper to read the value.
   *
   * @param helper a helper for reading the value from the stream.
   *
   * @return an value type structure, unmarshaled from the stream.
   */
  public Serializable read_value(BoxedValueHelper helper)
  {
    return helper.read_value(this);
  }
}