Package org.apache.derby.impl.sql.execute

Source Code of org.apache.derby.impl.sql.execute.CreateAliasConstantAction

/*

   Derby - Class org.apache.derby.impl.sql.execute.CreateAliasConstantAction

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to you under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

*/

package org.apache.derby.impl.sql.execute;

import org.apache.derby.catalog.AliasInfo;
import org.apache.derby.catalog.UUID;
import org.apache.derby.catalog.types.RoutineAliasInfo;
import org.apache.derby.catalog.types.SynonymAliasInfo;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.reference.SQLState;
import org.apache.derby.iapi.services.sanity.SanityManager;
import org.apache.derby.iapi.sql.Activation;
import org.apache.derby.iapi.sql.conn.LanguageConnectionContext;
import org.apache.derby.iapi.sql.dictionary.AliasDescriptor;
import org.apache.derby.iapi.sql.dictionary.DataDescriptorGenerator;
import org.apache.derby.iapi.sql.dictionary.DataDictionary;
import org.apache.derby.iapi.sql.dictionary.SchemaDescriptor;
import org.apache.derby.iapi.sql.dictionary.TableDescriptor;
import org.apache.derby.iapi.sql.execute.ConstantAction;
import org.apache.derby.iapi.store.access.TransactionController;

/**
*  This class performs actions that are ALWAYS performed for a
*  CREATE FUNCTION, PROCEDURE or SYNONYM Statement at execution time.
*  These SQL objects are stored in the SYS.SYSALIASES table and
*  represented as AliasDescriptors.
*
*/
class CreateAliasConstantAction extends DDLConstantAction
{

  private final String          aliasName;
  private final String          schemaName;
  private final String          javaClassName;
  private final char          aliasType;
  private final char          nameSpace;
  private final AliasInfo        aliasInfo;

  // CONSTRUCTORS

  /**
   *  Make the ConstantAction for a CREATE alias statement.
   *
   *  @param aliasName    Name of alias.
   *  @param schemaName    Name of alias's schema.
   *  @param javaClassName  Name of java class.
   *  @param aliasInfo    AliasInfo
   *  @param aliasType    The type of the alias
   */
  CreateAliasConstantAction(
                String  aliasName,
                String  schemaName,
                String  javaClassName,
                AliasInfo  aliasInfo,
                char  aliasType)
  {
    this.aliasName = aliasName;
    this.schemaName = schemaName;
    this.javaClassName = javaClassName;
    this.aliasInfo = aliasInfo;
    this.aliasType = aliasType;
    switch (aliasType)
    {
      case AliasInfo.ALIAS_TYPE_PROCEDURE_AS_CHAR:
        nameSpace = AliasInfo.ALIAS_NAME_SPACE_PROCEDURE_AS_CHAR;
        break;

      case AliasInfo.ALIAS_TYPE_FUNCTION_AS_CHAR:
        nameSpace = AliasInfo.ALIAS_NAME_SPACE_FUNCTION_AS_CHAR;
        break;

      case AliasInfo.ALIAS_TYPE_SYNONYM_AS_CHAR:
        nameSpace = AliasInfo.ALIAS_NAME_SPACE_SYNONYM_AS_CHAR;
        break;

      case AliasInfo.ALIAS_TYPE_UDT_AS_CHAR:
        nameSpace = AliasInfo.ALIAS_NAME_SPACE_UDT_AS_CHAR;
        break;

      default:
        if (SanityManager.DEBUG)
        {
          SanityManager.THROWASSERT(
            "Unexpected value for aliasType (" + aliasType + ")");
        }
        nameSpace = '\0';
        break;
    }
  }

  // OBJECT SHADOWS

  public  String  toString()
  {
    // Do not put this under SanityManager.DEBUG - it is needed for
    // error reporting.
    String type = null;

    switch (aliasType)
    {
      case AliasInfo.ALIAS_TYPE_PROCEDURE_AS_CHAR:
        type = "CREATE PROCEDURE ";
        break;

      case AliasInfo.ALIAS_TYPE_FUNCTION_AS_CHAR:
        type = "CREATE FUNCTION ";
        break;

      case AliasInfo.ALIAS_TYPE_SYNONYM_AS_CHAR:
        type = "CREATE SYNONYM ";
        break;

      case AliasInfo.ALIAS_TYPE_UDT_AS_CHAR:
        type = "CREATE TYPE ";
        break;

      default:
        if (SanityManager.DEBUG)
        {
          SanityManager.THROWASSERT(
            "Unexpected value for aliasType (" + aliasType + ")");
        }
    }

    return  type + aliasName;
  }

  // INTERFACE METHODS


  /**
   *  This is the guts of the Execution-time logic for
     *  CREATE FUNCTION, PROCEDURE, SYNONYM, and TYPE.
     *  <P>
     *  A function, procedure, or udt is represented as:
     *  <UL>
     <LI> AliasDescriptor
     *  </UL>
     *  Routine dependencies are created as:
     *  <UL>
     <LI> None
     *  </UL>
    
     *  <P>
     *  A synonym is represented as:
     *  <UL>
     <LI> AliasDescriptor
     *  <LI> TableDescriptor
     *  </UL>
     *  Synonym dependencies are created as:
     *  <UL>
     <LI> None
     *  </UL>
    
     *  In both cases a SchemaDescriptor will be created if
     *  needed. No dependency is created on the SchemaDescriptor.
     * 
   * @see ConstantAction#executeConstantAction
     * @see AliasDescriptor
     * @see TableDescriptor
     * @see SchemaDescriptor
   *
   * @exception StandardException    Thrown on failure
   */
  public void  executeConstantAction( Activation activation )
            throws StandardException
  {
    LanguageConnectionContext lcc =
            activation.getLanguageConnectionContext();

    DataDictionary dd = lcc.getDataDictionary();
    TransactionController tc = lcc.getTransactionExecute();

    // For routines no validity checking is made
        // on the Java method, that is checked when the
        // routine is executed.
       
    /*
    ** Inform the data dictionary that we are about to write to it.
    ** There are several calls to data dictionary "get" methods here
    ** that might be done in "read" mode in the data dictionary, but
    ** it seemed safer to do this whole operation in "write" mode.
    **
    ** We tell the data dictionary we're done writing at the end of
    ** the transaction.
    */
    dd.startWriting(lcc);

   
    SchemaDescriptor sd =
            DDLConstantAction.getSchemaDescriptorForCreate(dd, activation, schemaName);

    //
    // Create a new alias descriptor with aliasID filled in.
    //
    UUID aliasID = dd.getUUIDFactory().createUUID();

    AliasDescriptor ads = new AliasDescriptor(dd, aliasID,
                   aliasName,
                   sd.getUUID(),
                   javaClassName,
                   aliasType,
                   nameSpace,
                   false,
                   aliasInfo, null);

    // perform duplicate rule checking
    switch (aliasType) {
    case AliasInfo.ALIAS_TYPE_UDT_AS_CHAR:

            AliasDescriptor duplicateUDT = dd.getAliasDescriptor( sd.getUUID().toString(), aliasName, nameSpace );
            if ( duplicateUDT != null ) { throw StandardException.newException( SQLState.LANG_OBJECT_ALREADY_EXISTS, ads.getDescriptorType(), aliasName ); }
            break;
           
    case AliasInfo.ALIAS_TYPE_PROCEDURE_AS_CHAR:
    case AliasInfo.ALIAS_TYPE_FUNCTION_AS_CHAR:
    {

      java.util.List list = dd.getRoutineList(
        sd.getUUID().toString(), aliasName, aliasType);
      for (int i = list.size() - 1; i >= 0; i--) {

        AliasDescriptor proc = (AliasDescriptor) list.get(i);

        RoutineAliasInfo procedureInfo = (RoutineAliasInfo) proc.getAliasInfo();
        int parameterCount = procedureInfo.getParameterCount();
        if (parameterCount != ((RoutineAliasInfo) aliasInfo).getParameterCount())
          continue;

        // procedure duplicate checking is simple, only
        // one procedure with a given number of parameters.
        throw StandardException.newException(SQLState.LANG_OBJECT_ALREADY_EXISTS,
                        ads.getDescriptorType(),
                        aliasName);
      }
    }
    break;
    case AliasInfo.ALIAS_TYPE_SYNONYM_AS_CHAR:
      // If target table/view exists already, error.
      TableDescriptor targetTD = dd.getTableDescriptor(aliasName, sd, tc);
      if (targetTD != null)
      {
        throw StandardException.newException(
                SQLState.LANG_OBJECT_ALREADY_EXISTS,
                targetTD.getDescriptorType(),
                targetTD.getDescriptorName());
      }

      // Detect synonym cycles, if present.
      String nextSynTable = ((SynonymAliasInfo)aliasInfo).getSynonymTable();
      String nextSynSchema = ((SynonymAliasInfo)aliasInfo).getSynonymSchema();
      SchemaDescriptor nextSD;
      for (;;)
      {
        nextSD = dd.getSchemaDescriptor(nextSynSchema, tc, false);
        if (nextSD == null)
          break;
       
        AliasDescriptor nextAD = dd.getAliasDescriptor(nextSD.getUUID().toString(),
             nextSynTable, nameSpace);
        if (nextAD == null)
          break;

        SynonymAliasInfo info = (SynonymAliasInfo) nextAD.getAliasInfo();
        nextSynTable = info.getSynonymTable();
        nextSynSchema = info.getSynonymSchema();

        if (aliasName.equals(nextSynTable) && schemaName.equals(nextSynSchema))
          throw StandardException.newException(SQLState.LANG_SYNONYM_CIRCULAR,
              aliasName, ((SynonymAliasInfo)aliasInfo).getSynonymTable());
      }

      // If synonym final target is not present, raise a warning
      if (nextSD != null)
        targetTD = dd.getTableDescriptor(nextSynTable, nextSD, tc);
      if (nextSD == null || targetTD == null)
        activation.addWarning(
          StandardException.newWarning(SQLState.LANG_SYNONYM_UNDEFINED,
                aliasName, nextSynSchema+"."+nextSynTable));

      // To prevent any possible deadlocks with SYSTABLES, we insert a row into
      // SYSTABLES also for synonyms. This also ensures tables/views/synonyms share
      // same namespace
      TableDescriptor td;
      DataDescriptorGenerator ddg = dd.getDataDescriptorGenerator();
      td = ddg.newTableDescriptor(aliasName, sd, TableDescriptor.SYNONYM_TYPE,
            TableDescriptor.DEFAULT_LOCK_GRANULARITY);
      dd.addDescriptor(td, sd, DataDictionary.SYSTABLES_CATALOG_NUM, false, tc);
            break;
   
    default:
      break;
    }

    dd.addDescriptor(ads, null, DataDictionary.SYSALIASES_CATALOG_NUM,
             false, tc);

        adjustUDTDependencies( lcc, dd, ads, true );
  }
}
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