Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2000-2011 Regents of the University of California and the

 *              National Center for Ecological Analysis and Synthesis

 *

 *   '$Author:  $'

 *     '$Date:  $'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.dataone;

import java.io.InputStream;

import java.math.BigInteger;

import java.util.Date;

import java.util.List;

import org.apache.log4j.Logger;

import org.dataone.service.cn.CNAuthorization;

import org.dataone.service.cn.CNCore;

import org.dataone.service.cn.CNRead;

import org.dataone.service.cn.CNReplication;

import org.dataone.service.exceptions.IdentifierNotUnique;

import org.dataone.service.exceptions.InsufficientResources;

import org.dataone.service.exceptions.InvalidRequest;

import org.dataone.service.exceptions.InvalidSystemMetadata;

import org.dataone.service.exceptions.InvalidToken;

import org.dataone.service.exceptions.NotAuthorized;

import org.dataone.service.exceptions.NotFound;

import org.dataone.service.exceptions.NotImplemented;

import org.dataone.service.exceptions.ServiceFailure;

import org.dataone.service.exceptions.UnsupportedType;

import org.dataone.service.types.Checksum;

import org.dataone.service.types.Identifier;

import org.dataone.service.types.Node;

import org.dataone.service.types.NodeList;

import org.dataone.service.types.NodeReference;

import org.dataone.service.types.ObjectFormat;

import org.dataone.service.types.ObjectFormatIdentifier;

import org.dataone.service.types.ObjectFormatList;

import org.dataone.service.types.ObjectList;

import org.dataone.service.types.ObjectLocation;

import org.dataone.service.types.ObjectLocationList;

import org.dataone.service.types.Permission;

import org.dataone.service.types.QueryType;

import org.dataone.service.types.Replica;

import org.dataone.service.types.ReplicationPolicy;

import org.dataone.service.types.ReplicationStatus;

import org.dataone.service.types.Session;

import org.dataone.service.types.Subject;

import org.dataone.service.types.SystemMetadata;

import edu.ucsb.nceas.metacat.EventLog;

import edu.ucsb.nceas.metacat.IdentifierManager;

import edu.ucsb.nceas.metacat.McdbDocNotFoundException;

import edu.ucsb.nceas.metacat.replication.ForceReplicationSystemMetadataHandler;

/**

 * Represents Metacat's implementation of the DataONE Coordinating Node 

 * service API. Methods implement the various CN* interfaces, and methods common

 * to both Member Node and Coordinating Node interfaces are found in the

 * D1NodeService super class.

 *

 */

public class CNodeService extends D1NodeService implements CNAuthorization,

    CNCore, CNRead, CNReplication {

	/* the instance of the CNodeService object */

  private static CNodeService instance = null;

  /* the logger instance */

  private Logger logMetacat = null;

  /**

   * singleton accessor

   */

  public static CNodeService getInstance() 

  {

    if (instance == null) {

      instance = new CNodeService();

    }

    return instance;

  }

  /**

   * Constructor, private for singleton access

   */

  private CNodeService() {

  	super();

    logMetacat = Logger.getLogger(CNodeService.class);

  }

	/**

	 * Set the replication policy for an object given the object identifier

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - the object identifier for the given object

	 * @param policy - the replication policy to be applied

	 * 

	 * @return true or false

	 * 

	 * @throws NotImplemented

	 * @throws NotAuthorized

	 * @throws ServiceFailure

	 * @throws InvalidRequest

	 * 

	 */

	@Override

	public boolean setReplicationPolicy(Session session, Identifier pid,

	  ReplicationPolicy policy) 

	  throws NotImplemented, NotFound, NotAuthorized, ServiceFailure, InvalidRequest, InvalidToken {

		// get the subject

		Subject subject = session.getSubject();

		// get the system metadata

		String guid = pid.getValue();

		// are we allowed to do this?

		if (!isAuthorized(session, pid, Permission.CHANGE_PERMISSION)) {

			throw new NotAuthorized("4881", Permission.CHANGE_PERMISSION + " not allowed by " + subject.getValue() + " on " + guid);	

		}

		SystemMetadata systemMetadata = null;

		try {

			systemMetadata = IdentifierManager.getInstance().getSystemMetadata(guid);

		} catch (McdbDocNotFoundException e) {

			throw new NotFound("4884", "No record found for: " + guid);

		}

		// set the new policy

		systemMetadata.setReplicationPolicy(policy);

		// update the metadata

		try {

			IdentifierManager.getInstance().updateSystemMetadata(systemMetadata);

		} catch (McdbDocNotFoundException e) {

			throw new ServiceFailure("4882", e.getMessage());

		}

		return true;

	}

	/**

	 * Set the replication status for an object given the object identifier

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - the object identifier for the given object

	 * @param status - the replication status to be applied

	 * 

	 * @return true or false

	 * 

	 * @throws NotImplemented

	 * @throws NotAuthorized

	 * @throws ServiceFailure

	 * @throws InvalidRequest

	 * @throws InvalidToken

	 * @throws NotFound

	 * 

	 */

	@Override

	public boolean setReplicationStatus(Session session, Identifier pid,

	  ReplicationStatus status) 

	  throws ServiceFailure, NotImplemented, InvalidToken, NotAuthorized, 

	  InvalidRequest, NotFound {

		// get the subject

		Subject subject = session.getSubject();

		// get the system metadata

		String guid = pid.getValue();

		// are we allowed to do this?

		if (!isAuthorized(session, pid, Permission.WRITE)) {

			throw new NotAuthorized("4720", Permission.WRITE + " not allowed by " + subject.getValue() + " on " + guid);	

		}

		SystemMetadata systemMetadata = null;

		try {

			systemMetadata = IdentifierManager.getInstance().getSystemMetadata(guid);

		} catch (McdbDocNotFoundException e) {

			throw new NotFound("4740", "No record found for: " + guid);

		}

		// set the status for each replica

		// TODO: should this method select a certain replica?

		List<Replica> replicas = systemMetadata.getReplicaList();

		for (Replica replica: replicas) {

			replica.setReplicationStatus(status);

		}

		// [re]set the list -- redundant?

		systemMetadata.setReplicaList(replicas);

		// update the metadata

		try {

			IdentifierManager.getInstance().updateSystemMetadata(systemMetadata);

		} catch (McdbDocNotFoundException e) {

			throw new ServiceFailure("4700", e.getMessage());

		}

		return true;

	}

	/**

	 * Test that the specified relationship between pidOfSubject and pidOfObject exists

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param node - the node information for the given node be modified

	 * 

	 * @return true if the relationship exists

	 * 

	 * @throws InvalidToken

	 * @throws ServiceFailure

	 * @throws NotAuthorized

	 * @throws NotFound

	 * @throws InvalidRequest

	 * @throws NotImplemented

	 */

	@Override

	public boolean assertRelation(Session session, Identifier pidOfSubject, 

		String relationship, Identifier pidOfObject) 

	  throws InvalidToken, ServiceFailure, NotAuthorized, NotFound, 

	  InvalidRequest, NotImplemented {

		// get the system metadata

		String guid1 = pidOfSubject.getValue();

		// are we allowed to do this?

		if (!isAuthorized(session, pidOfSubject, Permission.READ)) {

			throw new NotAuthorized("4881", Permission.READ + " not allowed on " + guid1);	

		}

		SystemMetadata systemMetadata = null;

		try {

			systemMetadata = IdentifierManager.getInstance().getSystemMetadata(guid1);

		} catch (McdbDocNotFoundException e) {

			throw new NotFound("4884", "No record found for: " + guid1);

		}

		// check relationships

		// TODO: make this more strongly typed?

		if (relationship.equalsIgnoreCase("describes")) {

			return systemMetadata.getDescribeList().contains(pidOfObject);

		}

		if (relationship.equalsIgnoreCase("describedBy")) {

			return systemMetadata.getDescribedByList().contains(pidOfObject);

		}

		if (relationship.equalsIgnoreCase("derivedFrom")) {

			return systemMetadata.getDerivedFromList().contains(pidOfObject);

		}

		if (relationship.equalsIgnoreCase("obsoletes")) {

			return systemMetadata.getObsoleteList().contains(pidOfObject);

		}

		if (relationship.equalsIgnoreCase("obsoletedBy")) {

			return systemMetadata.getObsoletedByList().contains(pidOfObject);

		}

		return false;

	}

	/**

	 * Return the checksum of the object given the identifier 

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - the object identifier for the given object

	 * 

	 * @return checksum - the checksum of the object

	 * 

	 * @throws InvalidToken

	 * @throws ServiceFailure

	 * @throws NotAuthorized

	 * @throws NotFound

	 * @throws InvalidRequest

	 * @throws NotImplemented

	 */

	@Override

	public Checksum getChecksum(Session session, Identifier pid)

	  throws InvalidToken, ServiceFailure, NotAuthorized, NotFound, 

	  InvalidRequest, NotImplemented {

		if (!isAuthorized(session, pid, Permission.READ)) {

			throw new NotAuthorized("1400", Permission.READ + " not allowed on " + pid.getValue());	

		}

		SystemMetadata systemMetadata = null;

		try {

			systemMetadata = IdentifierManager.getInstance().getSystemMetadata(pid.getValue());

		} catch (McdbDocNotFoundException e) {

			throw new NotFound("1420", "No record found for: " + pid.getValue());

		}

		Checksum checksum = systemMetadata.getChecksum();

		return checksum;

	}

	/**

	 * Resolve the location of a given object

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - the object identifier for the given object

	 * 

	 * @return objectLocationList - the list of nodes known to contain the object

	 * 

	 * @throws InvalidRequest

	 * @throws InvalidToken

	 * @throws ServiceFailure

	 * @throws NotAuthorized

	 * @throws NotFound

	 * @throws NotImplemented

	 */

	@Override

	public ObjectLocationList resolve(Session session, Identifier pid)

	  throws InvalidRequest, InvalidToken, ServiceFailure, NotAuthorized,

	  NotFound, NotImplemented {

		ObjectLocationList objLocList = new ObjectLocationList();

		objLocList.setIdentifier(pid);

		// get the system metadata

		String guid = pid.getValue();

		// are we allowed to do this?

		if (!isAuthorized(session, pid, Permission.READ)) {

			throw new NotAuthorized("4720", Permission.READ + " not allowed on " + guid);	

		}

		SystemMetadata systemMetadata = null;

		try {

			systemMetadata = IdentifierManager.getInstance().getSystemMetadata(guid);

		} catch (McdbDocNotFoundException e) {

			throw new NotFound("4740", "No record found for: " + guid);

		}

		NodeList nodes = listNodes();

		// get the locations

		List<Replica> replicas = systemMetadata.getReplicaList();

		for (Replica replica: replicas) {

			NodeReference nodeReference = replica.getReplicaMemberNode();

			ObjectLocation objectLocation = new ObjectLocation();

			objectLocation.setNodeIdentifier(nodeReference);

			// get the node

			Node node = null;

			for (Node n: nodes.getNodeList()) {

				if (n.getIdentifier().equals(nodeReference)) {

					node = n;

					break;

				}

			}

			// set base URL

			objectLocation.setBaseURL(node.getBaseURL());

			// set URL

			objectLocation.setUrl(node.getBaseURL() + "/object/" + pid.getValue());

			// TODO set meaningful preference

			objectLocation.setPreference(BigInteger.ONE);

			objLocList.addObjectLocation(objectLocation);

		}

		return objLocList;

	}

	/**

	 * Search the metadata catalog for identifiers that match the criteria

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param queryType - An identifier for the type of query expression 

	 *                    provided in the query

	 * @param query -  The criteria for matching the characteristics of the 

	 *                 metadata objects of interest

	 * 

	 * @return objectList - the list of objects matching the criteria

	 * 

	 * @throws InvalidToken

	 * @throws ServiceFailure

	 * @throws NotAuthorized

	 * @throws InvalidRequest

	 * @throws NotImplemented

	 */

	@Override

	public ObjectList search(Session session, QueryType queryType, String query)

	  throws InvalidToken, ServiceFailure, NotAuthorized, InvalidRequest,

	  NotImplemented {

		throw new NotImplemented("4281", "search not implemented");

	}

	/**

	 * Used internally within a Coordinating Node to add a new object 

	 * to the object store

	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - The object identifier to be created

	 * @param object - the object bytes

	 * @param sysmeta - the system metadata that describes the object  

	 * 

	 * @return pid - the object identifier created

	 * 

	 * @throws InvalidToken

	 * @throws ServiceFailure

	 * @throws NotAuthorized

	 * @throws IdentifierNotUnique

	 * @throws UnsupportedType

	 * @throws InsufficientResources

	 * @throws InvalidSystemMetadata

	 * @throws NotImplemented

	 * @throws InvalidRequest

	 */

	@Override

	public Identifier create(Session session, Identifier pid, InputStream object,

	  SystemMetadata sysmeta) 

	  throws InvalidToken, ServiceFailure, NotAuthorized, IdentifierNotUnique, 

	  UnsupportedType, InsufficientResources, InvalidSystemMetadata, 

	  NotImplemented, InvalidRequest {

		throw new NotImplemented("4890", "create not implemented");

	}

	/**

	 * Returns the object format registered in the DataONE Object Format 

	 * Vocabulary for the given format identifier

	 * 

	 * @param fmtid - the identifier of the format requested

	 * 

	 * @return objectFormat - the object format requested

	 * 

	 * @throws InvalidRequest

	 * @throws ServiceFailure

	 * @throws NotFound

	 * @throws InsufficientResources

	 * @throws NotImplemented

	 */

	@Override

	public ObjectFormat getFormat(ObjectFormatIdentifier fmtid)

	  throws InvalidRequest, ServiceFailure, NotFound, InsufficientResources,

	  NotImplemented {

	  	return ObjectFormatService.getInstance().getFormat(fmtid);

	}

	/**

   * Returns a list of all object formats registered in the DataONE Object 

   * Format Vocabulary

 	 * 

	 * @return objectFormatList - The list of object formats registered in 

	 *                            the DataONE Object Format Vocabulary

	 * 

	 * @throws InvalidRequest

	 * @throws ServiceFailure

	 * @throws NotImplemented

	 * @throws NotFound

	 * @throws InsufficientResources

	 */

	@Override

	public ObjectFormatList listFormats() 

	  throws InvalidRequest, ServiceFailure, NotFound, InsufficientResources, 

	  NotImplemented {

		return ObjectFormatService.getInstance().listFormats();

	}

	/**

   * Returns a list of nodes that have been registered with the DataONE infrastructure

 	 * 

	 * @return nodeList - List of nodes from the registry

	 * 

	 * @throws ServiceFailure

	 * @throws NotImplemented

	 */

	@Override

	public NodeList listNodes() 

	  throws NotImplemented, ServiceFailure {

		throw new NotImplemented("4800", "listNodes not implemented");

	}

	/**

   * Provides a mechanism for adding system metadata independently of its 

   * associated object, such as when adding system metadata for data objects.

 	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - The identifier of the object to register the system metadata against

	 * @param sysmeta - The system metadata to be registered

	 * 

	 * @return true if the registration succeeds

	 * 

	 * @throws NotImplemented

	 * @throws NotAuthorized

	 * @throws ServiceFailure

	 * @throws InvalidRequest

	 * @throws InvalidSystemMetadata

	 */

	@Override

	public boolean registerSystemMetadata(Session session, Identifier guid,

	  SystemMetadata sysmeta) 

	  throws NotImplemented, NotAuthorized, ServiceFailure, InvalidRequest, 

	  InvalidSystemMetadata {

		// TODO: control who can call this?

	      if (session == null) {

	          //TODO: many of the thrown exceptions do not use the correct error codes

	          //check these against the docs and correct them

	          throw new NotAuthorized("4861", "No Session - could not authorize for registration." +

	                  "  If you are not logged in, please do so and retry the request.");

	      }

	      // verify that guid == SystemMetadata.getIdentifier()

	      logMetacat.debug("Comparing guid|sysmeta_guid: " + guid.getValue() + "|" + sysmeta.getIdentifier().getValue());

	      if (!guid.getValue().equals(sysmeta.getIdentifier().getValue())) {

	          throw new InvalidRequest("4863", 

	              "GUID in method call (" + guid.getValue() + ") does not match GUID in system metadata (" +

	              sysmeta.getIdentifier().getValue() + ").");

	      }

	      logMetacat.debug("Checking if identifier exists...");

	      // Check that the identifier does not already exist

	      IdentifierManager im = IdentifierManager.getInstance();

	      if (im.identifierExists(guid.getValue())) {

	          throw new InvalidRequest("4863", 

	              "GUID is already in use by an existing object.");

	      }

	      // insert the system metadata into the object store

	      logMetacat.debug("Starting to insert SystemMetadata...");

	      sysmeta.setDateSysMetadataModified(new Date());

	      try {

			    IdentifierManager.getInstance().createSystemMetadata(sysmeta);

			    IdentifierManager.getInstance().updateSystemMetadata(sysmeta);

			    // force replication of this record

			    ForceReplicationSystemMetadataHandler forceReplication = 

			    	new ForceReplicationSystemMetadataHandler(guid.getValue(), null);

		    } catch (Exception e) {

	          throw new ServiceFailure("4862", "Error inserting system metadata: " + e.getClass() + ": " + e.getMessage());

		    }

	      logMetacat.debug("Returning from registerSystemMetadata");

	      EventLog.getInstance().log(null, session.getSubject().getValue(), guid.getValue(), "registerSystemMetadata");

	      return true;

	}

	/**

   * Given an optional scope and format, reserves and returns an identifier 

   * within that scope and format that is unique and will not be 

   * used by any other sessions. 

 	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - The identifier of the object to register the system metadata against

	 * @param scope - An optional string to be used to qualify the scope of 

	 *                the identifier namespace, which is applied differently 

	 *                depending on the format requested. If scope is not 

	 *                supplied, a default scope will be used.

	 * @param format - The optional name of the identifier format to be used, 

	 * 								 drawn from a DataONE-specific vocabulary of identifier 

	 *                 format names, including several common syntaxes such 

	 *                 as DOI, LSID, UUID, and LSRN, among others. If the 

	 *                 format is not supplied by the caller, the CN service 

	 *                 will use a default identifier format, which may change 

	 *                 over time.

	 * 

	 * @return true if the registration succeeds

	 * 

	 * @throws InvalidToken

	 * @throws ServiceFailure

	 * @throws NotAuthorized

	 * @throws IdentifierNotUnique

	 * @throws NotImplemented

	 */

	@Override

	public Identifier reserveIdentifier(Session session, Identifier pid,

	  String scope, String format) 

	  throws InvalidToken, ServiceFailure, NotAuthorized, IdentifierNotUnique, 

	  NotImplemented, InvalidRequest {

		throw new NotImplemented("4191", "reserveIdentifier not implemented");

	}

	/**

   * Changes ownership (RightsHolder) of the specified object to the 

   * subject specified by userId

 	 * 

	 * @param session - the Session object containing the credentials for the Subject

	 * @param pid - Identifier of the object to be modified

	 * @param userId - The subject that will be taking ownership of the specified object.

	 *

	 * @return pid - the identifier of the modified object

	 * 

	 * @throws ServiceFailure

	 * @throws InvalidToken

	 * @throws NotFound

	 * @throws NotAuthorized

	 * @throws NotImplemented

	 * @throws InvalidRequest

	 */	

	@Override

	public Identifier setOwner(Session session, Identifier pid, Subject userId)

	  throws InvalidToken, ServiceFailure, NotFound, NotAuthorized,

	  NotImplemented, InvalidRequest {

		// get the subject

		Subject subject = session.getSubject();

		// get the system metadata

		String guid = pid.getValue();

		// are we allowed to do this?

		if (!isAuthorized(session, pid, Permission.CHANGE_PERMISSION)) {

			throw new NotAuthorized("4440", "not allowed by " + subject.getValue() + " on " + guid);	

		}

		SystemMetadata systemMetadata = null;

		try {

			systemMetadata = IdentifierManager.getInstance().getSystemMetadata(guid);

		} catch (McdbDocNotFoundException e) {

			throw new NotFound("4460", "No record found for: " + guid);

		}

		// set the new rights holder

		systemMetadata.setRightsHolder(userId);

		// update the metadata

		try {

			IdentifierManager.getInstance().updateSystemMetadata(systemMetadata);

		} catch (McdbDocNotFoundException e) {

			throw new ServiceFailure("4490", e.getMessage());

		}

		return pid;

	}

}