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GATE - general achitecture for text engineering - is open source software capable of solving almost any text processing problem. This artifact enables you to embed the core GATE Embedded with its essential dependencies. You will able to use the GATE Embedded API and load and store GATE XML documents. This artifact is the perfect dependency for CREOLE plugins or for applications that need to customize the GATE dependencies due to confict with their own dependencies or for lower footprint.

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/*
 *  Copyright (c) 1995-2012, The University of Sheffield. See the file
 *  COPYRIGHT.txt in the software or at http://gate.ac.uk/gate/COPYRIGHT.txt
 *
 *  This file is part of GATE (see http://gate.ac.uk/), and is free
 *  software, licenced under the GNU Library General Public License,
 *  Version 2, June 1991 (in the distribution as file licence.html,
 *  and also available at http://gate.ac.uk/gate/licence.html).
 *
 *  Valentin Tablan 25/10/2001
 *
 *  $Id: ResourcePersistence.java 20046 2017-02-01 10:10:20Z markagreenwood $
 *
 */
package gate.util.persistence;

import gate.Factory;
import gate.FeatureMap;
import gate.Gate;
import gate.Resource;
import gate.creole.Parameter;
import gate.creole.ParameterException;
import gate.creole.ParameterList;
import gate.creole.ResourceData;
import gate.creole.ResourceInstantiationException;
import gate.persist.PersistenceException;
import gate.util.NameBearer;

import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Holds the data needed to serialise and recreate a {@link Resource}.
 * This data is considered to be: the resource class name, the resource name,
 * the resource features and the resource initialistion parameters.
 */
class ResourcePersistence extends AbstractPersistence{

  protected static final Logger log = LoggerFactory.getLogger(ResourcePersistence.class);
  
  @Override
  public void extractDataFromSource(Object source) throws PersistenceException{
    if(! (source instanceof Resource)){
      throw new UnsupportedOperationException(
                getClass().getName() + " can only be used for " +
                Resource.class.getName() +
                " objects!\n" + source.getClass().getName() +
                " is not a " + Resource.class.getName());
    }
    Resource res = (Resource)source;
    resourceType = res.getClass().getName();
    resourceName = ((NameBearer)res).getName();

    ResourceData rData = Gate.getCreoleRegister().get(resourceType);
    if(rData == null) throw new PersistenceException(
                                "Could not find CREOLE data for " +
                                resourceType);
    ParameterList params = rData.getParameterList();
    try{
      //get the values for the init time parameters
      initParams = Factory.newFeatureMap();
      //this is a list of lists
      Iterator> parDisjIter = params.getInitimeParameters().iterator();
      while(parDisjIter.hasNext()){
        Iterator parIter = parDisjIter.next().iterator();
        while(parIter.hasNext()){
          Parameter parameter = parIter.next();
          String parName = parameter.getName();
          Object parValue = res.getParameterValue(parName);
          if (storeParameterValue(parValue, parameter.getDefaultValue())) {
        	  ((FeatureMap)initParams).put(parName, parValue);
          }
        }
      }
      initParams = PersistenceManager.getPersistentRepresentation(initParams);

      //get the features
      if(res.getFeatures() != null){
        features = Factory.newFeatureMap();
        ((FeatureMap)features).putAll(res.getFeatures());
        features = PersistenceManager.getPersistentRepresentation(features);
      }
    }catch(ResourceInstantiationException | ParameterException rie){
      throw new PersistenceException(rie);
    }
  }
  
	/**
	 * Returns true if we should store the parameter value as it is different
	 * from the default value.
	 * 
	 * @param value
	 *            the value we might store
	 * @param defaultValue
	 *            the default value
	 * @return true if we should store the parameter value as it is different
	 *         from the default value, false otherwise
	 */
	protected static boolean storeParameterValue(Object value, Object defaultValue) {
		// if both are null then we don't need to store the value
		if (value == null && defaultValue == null)
			return false;

		// if only one of them is null then we do need to store
		if (value == null || defaultValue == null)
			return true;

		// if neither are null and they are identical objects then we don't need
		// to store
		if (value == defaultValue)
			return false;

		// only store if the two objects are truly differnet
		return !value.equals(defaultValue);
	}

  @Override
  public Object createObject()throws PersistenceException,
                                     ResourceInstantiationException {
    if(initParams != null)
      initParams = PersistenceManager.getTransientRepresentation(
              initParams,containingControllerName,initParamOverrides);
    if(features != null)
      features = PersistenceManager.getTransientRepresentation(
              features,containingControllerName,initParamOverrides);
    if(initParamOverrides != null) {
      // check if there is a map for this resource Id in the overrides
      String containingControllerNameToUse = 
              containingControllerName == null ? "" : containingControllerName;
      String resourceId = containingControllerNameToUse+"\t"+resourceName;
      if(initParamOverrides.containsKey(resourceId)) {
        Map parmOverrides = initParamOverrides.get(resourceId);
        if(initParams instanceof FeatureMap) {
          FeatureMap fm = (FeatureMap)initParams;
          // override the values
          // do this in a loop instead of using putAll so we can log the changes
          for(String name : parmOverrides.keySet()) {
            Object obj = parmOverrides.get(name);
            log.info(
                    "Overriding init parameter "+name+
                    " for "+containingControllerNameToUse+
                    "//"+resourceName+" with "+obj);
            fm.put(name, obj);
          }
        }
      }
    } 
    Resource res = Factory.createResource(resourceType, (FeatureMap)initParams,
                                          (FeatureMap)features,resourceName);
    return res;
  }

  protected String resourceType;
  protected String resourceName;
  protected Object initParams;
  protected Object features;
  static final long serialVersionUID = -3196664486112887875L;
}