/* The contents of this file are subject to the license and copyright terms
* detailed in the license directory at the root of the source tree (also
* available online at http://fedora-commons.org/license/).
*/
package fedora.server.storage;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import org.jrdf.graph.ObjectNode;
import org.jrdf.graph.Triple;
import org.trippi.RDFFormat;
import org.trippi.TripleIterator;
import org.trippi.TrippiException;
import fedora.common.Constants;
import fedora.common.PID;
import fedora.common.rdf.SimpleLiteral;
import fedora.common.rdf.SimpleTriple;
import fedora.common.rdf.SimpleURIReference;
import fedora.server.Context;
import fedora.server.Server;
import fedora.server.errors.GeneralException;
import fedora.server.errors.ObjectIntegrityException;
import fedora.server.errors.ServerException;
import fedora.server.storage.translation.DOTranslator;
import fedora.server.storage.types.Datastream;
import fedora.server.storage.types.DatastreamXMLMetadata;
import fedora.server.storage.types.DigitalObject;
import fedora.server.utilities.FilteredTripleIterator;
import fedora.server.validation.ValidationUtility;
/**
* A DigitalObject-backed DOWriter.
* <p>
* This interface supports transaction behavior with the commit(String) and
* rollBack() methods. When a DOWriter is instantiated, there is an implicit
* transaction. Write methods may be called, but they won't affect the the
* underlying data store until commit(String) is invoked. This also has the
* effect of creating another implicit transaction. If temporary changes are no
* longer wanted, rollBack() may be called to return the object to it's original
* form. rollBack() is only valid for the current transaction.
* </p>
* <p>
* The read methods of DOWriter reflect on the composition of the object in the
* context of the current transaction.
* </p>
*
* @author Chris Wilper
*/
public class SimpleDOWriter
extends SimpleDOReader
implements Constants, DOWriter {
private static ObjectIntegrityException ERROR_PENDING_REMOVAL =
new ObjectIntegrityException("That can't be done because you said "
+ "I should remove the object and i assume that's what you "
+ "want unless you call rollback()");
private static ObjectIntegrityException ERROR_INVALIDATED =
new ObjectIntegrityException("The handle is no longer valid "
+ "... this object has already been committed or explicitly"
+ " invalidated.");
private final DigitalObject m_obj;
private final Context m_context;
private final DefaultDOManager m_mgr;
private boolean m_pendingRemoval = false;
private boolean m_invalidated = false;
private boolean m_committed = false;
public SimpleDOWriter(Context context,
DefaultDOManager mgr,
DOTranslator translator,
String exportFormat,
String encoding,
DigitalObject obj) {
super(context, mgr, translator, exportFormat, encoding, obj);
m_context = context;
m_obj = obj;
m_mgr = mgr;
}
public void setState(String state) throws ObjectIntegrityException {
assertNotInvalidated();
assertNotPendingRemoval();
m_obj.setState(state);
}
public void setOwnerId(String ownerId) throws ObjectIntegrityException {
assertNotInvalidated();
assertNotPendingRemoval();
m_obj.setOwnerId(ownerId);
}
public void setDatastreamState(String datastreamID, String dsState)
throws ServerException {
assertNotInvalidated();
assertNotPendingRemoval();
// Set all versions of this datastreamID to the specified state
for (Datastream ds : m_obj.datastreams(datastreamID)) {
ds.DSState = dsState;
}
}
public void setDatastreamVersionable(String datastreamID,
boolean versionable)
throws ServerException {
assertNotInvalidated();
assertNotPendingRemoval();
// Set all versions of this datastreamID to the specified versionable
// status
for (Datastream ds : m_obj.datastreams(datastreamID)) {
ds.DSVersionable = versionable;
}
}
public void setLabel(String label) throws ObjectIntegrityException {
assertNotInvalidated();
assertNotPendingRemoval();
if (label != null && label.equals("")) {
label = null;
}
m_obj.setLabel(label);
}
/**
* Removes the entire digital object.
*
* @throws ServerException
* If any type of error occurred fulfilling the request.
*/
public void remove() throws ObjectIntegrityException {
assertNotInvalidated();
assertNotPendingRemoval();
m_pendingRemoval = true;
}
/**
* Adds a datastream to the object.
*
* @param datastream
* The datastream.
* @throws ServerException
* If any type of error occurred fulfilling the request.
*/
public void addDatastream(Datastream datastream, boolean addNewVersion)
throws ServerException {
assertNotInvalidated();
assertNotPendingRemoval();
// use this call to handle versionable
m_obj.addDatastreamVersion(datastream, addNewVersion);
}
/**
* Removes a datastream from the object.
*
* @param id
* The id of the datastream.
* @param start
* The start date (inclusive) of versions to remove. If
* <code>null</code>, this is taken to be the smallest possible
* value.
* @param end
* The end date (inclusive) of versions to remove. If
* <code>null</code>, this is taken to be the greatest possible
* value.
* @throws ServerException
* If any type of error occurred fulfilling the request.
*/
public Date[] removeDatastream(String id, Date start, Date end)
throws ServerException {
assertNotInvalidated();
assertNotPendingRemoval();
ArrayList<Datastream> removeList = new ArrayList<Datastream>();
for (Datastream ds : m_obj.datastreams(id)) {
boolean doRemove = false;
if (start != null) {
if (end != null) {
if (ds.DSCreateDT.compareTo(start) >= 0
&& ds.DSCreateDT.compareTo(end) <= 0) {
doRemove = true;
}
} else {
if (ds.DSCreateDT.compareTo(start) >= 0) {
doRemove = true;
}
}
} else {
if (end != null) {
if (ds.DSCreateDT.compareTo(end) <= 0) {
doRemove = true;
}
} else {
doRemove = true;
}
}
if (doRemove) {
// Note: We don't remove old audit records by design.
// add this datastream to the datastream to-be-removed list.
removeList.add(ds);
}
}
/* Now that we've identified all ds versions to remove, remove 'em */
for (Datastream toRemove : removeList) {
m_obj.removeDatastreamVersion(toRemove);
}
// finally, return the dates of each deleted item
Date[] deletedDates = new Date[removeList.size()];
for (int i = 0; i < removeList.size(); i++) {
deletedDates[i] = (removeList.get(i)).DSCreateDT;
}
return deletedDates;
}
// from the relationship subject, determine which datastream to modify etc
private String resolveSubjectToDatastream(String subject) throws ServerException{
String dsId = null;
String pidURI = PID.toURI(m_obj.getPid());
if (subject.equals(pidURI)) {
dsId = "RELS-EXT";
} else {
if (subject.startsWith(pidURI + "/")) {
dsId = "RELS-INT";
} else {
throw new GeneralException("Cannot determine which relationship datastream to update for subject " + subject + ". Relationship subjects must be the URI of the object or the URI of a datastream within the object.");
}
}
return dsId;
}
public boolean addRelationship(String subject,
String relationship,
String object,
boolean isLiteral,
String datatype) throws ServerException {
return addRelationship(resolveSubjectToDatastream(subject),
subject,
relationship,
object,
isLiteral,
datatype);
}
public boolean addRelationship(String dsId,
String subject,
String relationship,
String object,
boolean isLiteral,
String datatype) throws ServerException {
Triple toAdd =
createTriple(subject, relationship, object, isLiteral, datatype);
Datastream relsDatastream = GetDatastream(dsId, null);
if (relsDatastream == null) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
Map<String, String> map = new HashMap<String, String>();
// namespaces for RELS-EXT
if (dsId.equals("RELS-EXT")) {
map.put(RELS_EXT.prefix, RELS_EXT.uri);
map.put(MODEL.prefix, MODEL.uri);
}
map.put(RDF.prefix, RDF.uri);
try {
TripleIterator triples =
new FilteredTripleIterator(map, toAdd, true);
triples.toStream(out, RDFFormat.RDF_XML, false);
} catch (TrippiException e) {
throw new GeneralException(e.getMessage(), e);
}
DatastreamXMLMetadata newds = new DatastreamXMLMetadata();
newds.DatastreamID = dsId;
newds.DatastreamAltIDs = new String[0];
// formats for internal datastreams
if (dsId.equals("RELS-EXT")) {
newds.DSFormatURI = RELS_EXT1_0.uri;
} else {
if (dsId.equals("RELS-INT"))
newds.DSFormatURI = RELS_INT1_0.uri;
}
newds.DSMIME = "application/rdf+xml";
newds.DSControlGrp = "X";
newds.DSInfoType = null;
newds.DSState = "A";
newds.DSVersionable = false;
newds.DSVersionID = dsId + ".0";
newds.DSLabel = "Relationships";
newds.DSCreateDT = Server.getCurrentDate(m_context);
newds.DSLocation = null;
newds.DSLocationType = null;
newds.DSChecksumType = Datastream.getDefaultChecksumType();
newds.xmlContent = out.toByteArray();
newds.DSSize = newds.xmlContent.length;
ValidationUtility.validateReservedDatastream(PID.getInstance(m_obj.getPid()),
newds.DatastreamID,
newds.getContentStream());
addDatastream(newds, false);
} else { // (relsDatastream != null)
FilteredTripleIterator newIter = null;
try {
ByteArrayOutputStream out = new ByteArrayOutputStream();
TripleIterator iter =
TripleIterator.fromStream(relsDatastream.getContentStream(),
RDFFormat.RDF_XML);
newIter = new FilteredTripleIterator(iter, toAdd, true);
newIter.toStream(out, RDFFormat.RDF_XML, false);
if (newIter.wasChangeMade()) {
DatastreamXMLMetadata newds = new DatastreamXMLMetadata();
newds.DSMDClass =
((DatastreamXMLMetadata) relsDatastream).DSMDClass;
newds.DatastreamID = relsDatastream.DatastreamID;
newds.DatastreamAltIDs = relsDatastream.DatastreamAltIDs;
newds.DSFormatURI = relsDatastream.DSFormatURI;
newds.DSMIME = relsDatastream.DSMIME;
newds.DSControlGrp = "X";
newds.DSInfoType = relsDatastream.DSInfoType;
newds.DSState = relsDatastream.DSState;
newds.DSVersionable = relsDatastream.DSVersionable;
newds.DSVersionID = newDatastreamID(dsId);
newds.DSLabel = relsDatastream.DSLabel;
newds.DSCreateDT = Server.getCurrentDate(m_context);
newds.DSLocation = null;
newds.DSLocationType = null;
newds.DSChecksumType = relsDatastream.DSChecksumType;
newds.xmlContent = out.toByteArray();
newds.DSSize = newds.xmlContent.length;
ValidationUtility.validateReservedDatastream(PID.getInstance(m_obj.getPid()),
newds.DatastreamID,
newds.getContentStream());
addDatastream(newds, newds.DSVersionable);
} else {
// relationship already exists
return false;
}
} catch (TrippiException e) {
throw new GeneralException(e.getMessage(), e);
} finally {
try {
if (newIter != null) {
newIter.close();
}
} catch (TrippiException e) {
throw new GeneralException(e.getMessage(), e);
}
}
}
return true;
}
public boolean purgeRelationship(String subject,
String relationship,
String object,
boolean isLiteral,
String datatype) throws ServerException {
return purgeRelationship(resolveSubjectToDatastream(subject),
subject,
relationship,
object,
isLiteral,
datatype);
}
public boolean purgeRelationship(String dsId,
String subject,
String relationship,
String object,
boolean isLiteral,
String datatype) throws ServerException {
Triple toPurge =
createTriple(subject, relationship, object, isLiteral, datatype);
Datastream relsDatastream = GetDatastream(dsId, null);
if (relsDatastream == null) {
// relationship does not exist
return false;
} else { // (relsExt != null)
InputStream relsDatastreamIS = relsDatastream.getContentStream();
TripleIterator iter = null;
FilteredTripleIterator newIter = null;
try {
iter = TripleIterator.fromStream(relsDatastreamIS, RDFFormat.RDF_XML);
newIter = new FilteredTripleIterator(iter, toPurge, false);
ByteArrayOutputStream out = new ByteArrayOutputStream();
newIter.toStream(out, RDFFormat.RDF_XML, false);
if (newIter.wasChangeMade()) {
DatastreamXMLMetadata newds = new DatastreamXMLMetadata();
newds.DSMDClass =
((DatastreamXMLMetadata) relsDatastream).DSMDClass;
newds.DatastreamID = dsId;
newds.DatastreamAltIDs = relsDatastream.DatastreamAltIDs;
newds.DSFormatURI = relsDatastream.DSFormatURI;
newds.DSMIME = relsDatastream.DSMIME;
newds.DSControlGrp = "X";
newds.DSInfoType = relsDatastream.DSInfoType;
newds.DSState = relsDatastream.DSState;
newds.DSVersionable = relsDatastream.DSVersionable;
newds.DSVersionID = newDatastreamID(dsId);
newds.DSLabel = relsDatastream.DSLabel;
newds.DSCreateDT = Server.getCurrentDate(m_context);
newds.DSLocation = null;
newds.DSLocationType = null;
newds.DSChecksumType = relsDatastream.DSChecksumType;
newds.xmlContent = out.toByteArray();
newds.DSSize = newds.xmlContent.length;
ValidationUtility.validateReservedDatastream(PID.getInstance(m_obj.getPid()),
newds.DatastreamID,
newds.getContentStream());
addDatastream(newds, newds.DSVersionable);
} else {
// relationship does not exist
return false;
}
} catch (TrippiException e) {
throw new GeneralException(e.getMessage(), e);
} finally {
try {
if (newIter != null) {
newIter.close(); // also closes the contained iter
}
} catch (TrippiException e) {
throw new GeneralException(e.getMessage(), e);
}
}
}
return true;
}
private static Triple createTriple(String subject,
String predicate,
String object,
boolean isLiteral,
String datatype)
throws ServerException {
ObjectNode o = null;
try {
if (isLiteral) {
if (datatype == null || datatype.length() == 0) {
o = new SimpleLiteral(object);
} else {
o = new SimpleLiteral(object, new URI(datatype));
}
} else {
o = new SimpleURIReference(new URI(object));
}
return new SimpleTriple(new SimpleURIReference(new URI(subject)),
new SimpleURIReference(new URI(predicate)),
o);
} catch (URISyntaxException e) {
throw new GeneralException(e.getMessage(), e);
}
}
/**
* Saves the changes thus far to the permanent copy of the digital object.
*
* @param logMessage
* An explanation of the change(s).
* @throws ServerException
* If any type of error occurred fulfilling the request.
*/
public void commit(String logMessage) throws ServerException {
assertNotInvalidated();
m_mgr.doCommit(Server.USE_DEFINITIVE_STORE,
m_context,
m_obj,
logMessage,
m_pendingRemoval);
m_committed = true;
invalidate();
}
public void invalidate() {
m_invalidated = true;
}
/**
* Generate a unique id for a datastream.
*/
public String newDatastreamID() {
return m_obj.newDatastreamID();
}
/**
* Generate a unique id for a datastream version.
*/
public String newDatastreamID(String dsID) {
return m_obj.newDatastreamID(dsID);
}
/**
* Generate a unique id for an audit record.
*/
public String newAuditRecordID() {
return m_obj.newAuditRecordID();
}
private void assertNotPendingRemoval() throws ObjectIntegrityException {
if (m_pendingRemoval) {
throw ERROR_PENDING_REMOVAL;
}
}
private void assertNotInvalidated() throws ObjectIntegrityException {
if (m_invalidated) {
throw ERROR_INVALIDATED;
}
}
public boolean isCommitted() {
return m_committed;
}
public boolean isNew() {
return m_obj.isNew();
}
}