InvocationRequestPayload.java

/*
** Module   : InvocationRequestPayload.java
** Abstract : A payload with data for an invoke request into the legacy converted code, 
**            originating from a customer-specific application.
**
** Copyright (c) 2016-2020, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------Description----------------------------------
** 001 CA  20160418 Created initial version
** 002 IAS 20200908 Rework (de)serialization.
** 003 IAS 20200922 Get rid of possible NPE on serialization.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
**   2. No Misrepresentation of Affiliation.
** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
** 
**     You may not represent yourself for publicity purposes as associated with
**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
** 
**   3. No Misrepresentation of Source or Origin.
** 
**     You may not represent the covered work as solely your work.  All modified
**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.util;

import static com.goldencode.util.NativeTypeSerializer.*; 
import java.io.*;
import java.util.*;

/**
 * This payload is responsible for defining the details of a call into 4GL code, originating from
 * a customer-specific application (used in cases when the client runs in an embedded mode, inside
 * another application).
 * <p>
 * The invocation targets can be any external program, procedure or function which can be found
 * in the user's propath; it is possible to also emulate a <code>IN handle</code> clause when
 * targeting a procedure or function, by specifying the handle of an external program which was
 * previously executed in persistent mode. 
 */
public class InvocationRequestPayload
implements Externalizable
{
   /** The invocation types. */
   public static enum InvokeType
   {
      /** */
      EXTERNAL_PROGRAM((byte) 0),
      /** */
      PROCEDURE((byte) 1),
      /** */
      FUNCTION((byte) 2);
      
      /** A numeric representation of the enum's entry. */
      private final byte type;
      
      /**
       * Construct a new type and associate its unique numeric code.
       * 
       * @param   type
       *          The numeric representation of this type.
       */
      private InvokeType(byte type)
      {
         this.type = type;
      }
      
      /**
       * Get the type of this target.
       * 
       * @return   See above.
       */
      public byte getType()
      {
         return type;
      }
      
      /**
       * Resolve a invocation type, from its numeric representation.
       * 
       * @param    code
       *           The numeric representation of this type.
       *           
       * @return   The found enum entry.
       * 
       * @throws   IllegalArgumentException
       *           If <code>code</code> is something other than 0, 1 or 2 value. 
       */
      public static InvokeType fromByte(byte code)
      {
         switch (code)
         {
            case 0:
               return EXTERNAL_PROGRAM;
            case 1:
               return PROCEDURE;
            case 2:
               return FUNCTION;
         }
         
         throw new IllegalArgumentException(code + " is not a valid InvokeType entry!");
      }
   }
   
   /** Flag indicating if this call should set the NO-ERROR mode on. */
   public boolean noError;
   
   /** 
    * The call target name; depending on the {@link #type}, this is a name of an external program,
    * procedure or function.
    */
   public String name;
   
   /** 
    * The handle ID.  Is used only when executing an internal procedure or function, in an external
    * program ran persistent.
    */
   public long handle;
   
   /** The call type.  See {@link InvokeType} for the supported types.*/
   public InvokeType type;
   
   /**
    * A map with the arguments to be passed to the caller.  The keys represent the legacy parameter
    * names (case-insensitive) as defined in the <code>name_map.xml</code> file, and the values
    * hold the string-representation of the argument's value.  At invocation, the values will be
    * converted to a value with the type specific to that argument. 
    */
   public Map<String, String> arguments;

   /**
    * When invoking an {@link InvokeType#EXTERNAL_PROGRAM}, this flag will specify if the program
    * will be ran persistent or not.
    */
   public boolean persistent;
   
   /** Default constructor */
   public InvocationRequestPayload()
   {
      super();
   }

   /**
    * Replacement for the default object reading method. The request data is read from the input 
    * source.
    * 
    * @param    in
    *           The input source from which fields will be restored.
    *
    * @throws   IOException
    *           In case of I/O errors.
    * @throws   ClassNotFoundException
    *           If payload can't be instantiated.
    */
   @Override
   public void readExternal(ObjectInput in)
   throws IOException, 
          ClassNotFoundException
   {
      noError    = in.readBoolean();
      name       = readString(in);
      handle     = in.readLong();
      type       = readEnum(in, InvokeType.values());
      persistent = in.readBoolean();
      arguments  = readMap(in, HashMap::new, ObjectInput::readUTF, ObjectInput::readUTF);
   }
   
   /**
    * Replacement for the default object writing method. The request data is written to the output 
    * destination.
    * 
    * @param    out
    *           The output destination to which the fields will be saved.
    *
    * @throws   IOException
    *           In case of I/O errors.
    */
   @Override
   public void writeExternal(ObjectOutput out)
   throws IOException
   {
      out.writeBoolean(noError);
      writeString(out, name);
      out.writeLong(handle);
      writeEnum(out, type);
      out.writeBoolean(persistent);
      writeMap(out, arguments, ObjectOutput::writeUTF, ObjectOutput::writeUTF);
   }
}