LobCopyInput.java

/*
** Module   : LobCopyInput.java
** Abstract : Input value to a converted COPY-LOB statement.
**
** Copyright (c) 2019-2022, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description---------------------------------------
** 001 ECF 20190510 Created initial version.
** 002 ECF 20190628 Implemented COPY-LOB runtime.
** 003 CA  20191203 Fixed overlay and unknown COPY-LOB related bugs.
** 004 MED 20200331 Fix length and validation for offset/length.
** 005 OM  20210328 Improved copy lob engine and validations.
**     EVL 20220405 Abstract method validateOffset is now moved to base interface.
**     EVL 20220408 Added error emission for attempt to copy non-zero size binary data to clob.
**     EVL 20220720 Re-enabled copy binary source to clob in validate() method.  The error previously emitted
**                  is related to the ability to convert binary source to text and for some internal code
**                  pages can produce the error.  But this checking should be done in other class (I18nOps).
*/

/*
** 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.
** 
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**     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.
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** 
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*/

package com.goldencode.p2j.util;

/**
 * Abstract base class for an object that can be the input value to a converted COPY-LOB statement.
 */
public abstract class LobCopyInput
implements LobCopyParameter
{
   /** Offset (in bytes or characters) at which to start reading content for the copy */
   NumberType offset = null;
   
   /** Number of bytes or characters to read; zero means all */
   private NumberType length = null;
   
   /**
    * Set the starting offset at which to read content; corresponds with the STARTING AT option.
    *
    * @param   offset
    *          Starting offset.
    *
    * @return  This object instance, to allow method chaining.
    */
   public LobCopyInput offset(NumberType offset)
   {
      this.offset = offset;
      
      return this;
   }
   
   /**
    * Set the starting offset at which to read content; corresponds with the STARTING AT option.
    *
    * @param   offset
    *          Starting offset.
    *
    * @return  This object instance, to allow method chaining.
    */
   public LobCopyInput offset(int offset)
   {
      this.offset = new integer(offset);
      
      return this;
   }
   
   /**
    * Set the length of the content to read; corresponds with the FOR option.
    *
    * @param   length
    *          Length of content to read.
    *
    * @return  This object instance, to allow method chaining.
    */
   public LobCopyInput length(NumberType length)
   {
      this.length = length;
      
      return this;
   }
   
   /**
    * Set the length of the content to read; corresponds with the FOR option.
    *
    * @param   length
    *          Length of content to read.
    *
    * @return  This object instance, to allow method chaining.
    */
   public LobCopyInput length(int length)
   {
      this.length = new integer(length);
      
      return this;
   }
   
   /**
    * Validate this parameter. The following parameters are checked: offset, 
    *
    * @param   targetType
    *          The type of the target object. The error messages are different in some cases.
    *
    * @return  {@code true} if validation did not encounter any issue and {@code false} otherwise, when in
    *          NO-ERROR mode and the {@code ErrorConditionException} is not thrown.
    *
    * @throws  ErrorConditionException
    *          if the parameter fails validation and silent error mode is not active.
    */
   @Override
   public boolean validate(int targetType)
   {
      long vOffset = 0;
      long size = getSize();
      int objectType = getObjectType();
      boolean isFile = (objectType == TYPE_FILE);
      
      if (offset != null)
      {
         vOffset = offset.longValue();
         
         // the [offset] is allowed to be the at most the next-after last character, in which case the "read"
         // value from the source is the empty string. 
         if (vOffset > size + 1)
         {
            if (isFile)
            {
               if (targetType == TYPE_FILE)
               {
                  ErrorManager.recordOrThrowError(11331,
                                                  Long.toString(vOffset),
                                                  Long.toString(getSize()),
                                                  ((SourceLobFile) this).getFileName());
                  // File offset  is greater than size of file  for file ''. (11331)
                  return false;
               }
               else if (targetType == TYPE_LONGCHAR || targetType == TYPE_MEMPTR)
               {
                  ErrorManager.recordOrThrowError(11329,
                                                  Long.toString(vOffset),
                                                  Long.toString(getSize()),
                                                  ((SourceLobFile) this).getFileName());
                  // File offset  is greater than size of file  for file ''. (11329)
                  return false;
               }
               else
               {
                  ErrorManager.recordOrThrowError(11279,
                                                  Long.toString(vOffset),
                                                  Long.toString(size),
                                                  ((SourceLobFile) this).getFileName());
                  // File offset <number> is greater than size of file <number> for file '<file-name>' (11279)
                  return false;
               }
            }
            else if (targetType == TYPE_FILE)
            {
               // in case the target is a FILE the and the offset is greater than the sources' size,
               // the length (aka FOR option) is ignored
               return true;
            }
            else
            {
               ErrorManager.recordOrThrowError(11334);
               // Offset supplied for source large object is greater than object size. (11334)
               return false;
            }
         }
      }
      
      long vLen = 0;
      if (length != null)
      {
         if (length.isUnknown() || length.intValue() < 0)
         {
            ErrorManager.recordOrThrowError(11344);
            // Unknown or invalid length specified in COPY-LOB statement. (11344)
            return false;
         }
         vLen = length.longValue();
         
         long toProcess = size - vOffset + 1;
         if (vLen > toProcess)
         {
            if (isFile)
            {
               if (targetType == TYPE_LONGCHAR || targetType == TYPE_MEMPTR)
               {
                  ErrorManager.recordOrThrowError(11330,
                                                  Long.toString(vOffset),
                                                  Long.toString(vLen),
                                                  Long.toString(size),
                                                  ((SourceLobFile) this).getFileName());
                  // File offset  plus copy length  is greater than size of file  for ''. (11330)
                  return false;
               }
               else if (targetType != TYPE_FILE)
               {
                  ErrorManager.recordOrThrowError(14500, Long.toString(vOffset), Long.toString(vLen));
                  // Source file does not contain sufficient data starting at  to copy  bytes (14500)
                  return false;
               }
               else
               {
                  // in this case, just process the available data
                  length.assign(toProcess);
               }
            }
            else if (objectType == TYPE_LONGCHAR || objectType == TYPE_MEMPTR)
            {
               if (targetType == TYPE_FILE)
               {
                  ErrorManager.recordOrThrowError(11295);
                  // Attempt to access past end of MEMPTR during COPY-LOB (11295)
               }
               else
               {
                  ErrorManager.recordOrThrowError(11305,
                                                  Long.toString(vOffset),
                                                  Long.toString(size),
                                                  Long.toString(size));
                  // Cannot copy large object starting at <offset> for <len> bytes when object size is <size>. (11305)
               }
               return false;
            }
            else
            {
               if (targetType == LobCopyParameter.TYPE_FILE)
               {
                  System.out.println("?"); // what happens in case of FILE?
               }
               else
               {
                  ErrorManager.recordOrThrowError(11305,
                                                  Long.toString(vOffset),
                                                  Long.toString(size),
                                                  Long.toString(size));
                  // Cannot copy large object starting at <offset> for <len> bytes when object size is <size>. (11305)
                  return false;
               }
            }
         }
      }
      
      int len = getLength();
      int off = getOffset(); // zero-based
      
      // NOTE: if the target is a file, the a larger value for [length] works, but the resulting file will
      //       reflect the size of the source
      if (off + len > size && targetType != TYPE_FILE)
      {
         ErrorManager.recordOrThrowError(11305,
                                         Integer.toString(off),
                                         Integer.toString(len),
                                         Long.toString(size));
         // Cannot copy large object starting at <offset> for <len> bytes when object size is <size>. (11305)
         return false;
      }
      
      if (objectType == TYPE_BLOB && size == 0 && targetType == TYPE_CLOB)
      {
         // not an error, but since there is no data to copy, just abort the mission
         return false;
      }
      
      // everything seems fine now
      return true;
   }
   
   /**
    * Get the starting offset (in bytes or characters) for the source content.
    *
    * @return  Zero-based offset at which to start reading.
    */
   protected int getOffset()
   {
      if (offset == null)
      {
         return 0;
      }
      
      return offset.isUnknown() ? 0 : offset.intValue() - 1;
   }
   
   /**
    * Get the length of data to read (in bytes or characters) from the source content.
    *
    * @return  Length of data to read. Negative value indicates length was specified, but was
    *          unknown value. If length is {@code null} (i.e., the original statement had no
    *          FOR option, the size of the source data is returned).
    */
   protected int getLength()
   {
      if (length == null)
      {
         return getSize() - getOffset();
      }
      
      return length.isUnknown() ? 0 : length.intValue();
   }
   
   /**
    * Get the size of the object to be copied.
    *
    * @return  Size of object, in bytes or characters, as appropriate to the object type.
    */
   protected abstract int getSize();
   
   /**
    * Read the content of the backing LOB from the starting offset up to the length and return
    * it as a string using the given encoding.
    *
    * @param   charsetName
    *          Name of the character set to be used to encode the read string. If {@code null},
    *          the default charset will be used.
    *
    * @return  The data as described above.
    */
   protected abstract String readString(String charsetName);
   
   /**
    * Read the content of the backing LOB from the starting offset up to the length and return
    * it as a byte buffer.
    * <p>
    * Note that the returned buffer must not be modified, as it could either be a copy of the LOB's data or
    * its real backing data.
    *
    * @return  The data as described above.
    */
   protected abstract byte[] readBytes();
}