port pr1883

dspace-api/src/main/java/org/dspace/content/BitstreamServiceImpl.java

@@ -92,6 +92,31 @@ public class BitstreamServiceImpl extends DSpaceObjectServiceImpl<Bitstream> imp
         return bitstreamDAO.findAll(context, Bitstream.class);
     }
 
+    @Override
+    public Bitstream clone(Context context, Bitstream bitstream)
+            throws SQLException {
+        // Create a new bitstream with a new ID.
+        Bitstream clonedBitstream = bitstreamDAO.create(context, new Bitstream());
+        // Set the internal identifier, file size, checksum, and
+        // checksum algorithm as same as the given bitstream.
+        clonedBitstream.setInternalId(bitstream.getInternalId());
+        clonedBitstream.setSizeBytes(bitstream.getSize());
+        clonedBitstream.setChecksum(bitstream.getChecksum());
+        clonedBitstream.setChecksumAlgorithm(bitstream.getChecksumAlgorithm());
+        try {
+            //Update our bitstream but turn off the authorization system since permissions
+            //haven't been set at this point in time.
+            context.turnOffAuthorisationSystem();
+            update(context, clonedBitstream);
+        } catch (AuthorizeException e) {
+            log.error(e);
+            //Can never happen since we turn off authorization before we update
+        } finally {
+            context.restoreAuthSystemState();
+        }
+        return clonedBitstream;
+    }
+
     @Override
     public Iterator<Bitstream> findAll(Context context, int limit, int offset) throws SQLException {
         return bitstreamDAO.findAll(context, limit, offset);

dspace-api/src/main/java/org/dspace/content/service/BitstreamService.java

@@ -35,6 +35,22 @@ public interface BitstreamService extends DSpaceObjectService<Bitstream>, DSpace
 
     public Iterator<Bitstream> findAll(Context context, int limit, int offset) throws SQLException;
 
+    /**
+     * Clone the given bitstream by firstly creating a new bitstream, with a new ID.
+     * Then set the internal identifier, file size, checksum, and
+     * checksum algorithm as same as the given bitstream.
+     * This allows multiple bitstreams to share the same internal identifier of assets .
+     * An example of such a use case scenario is versioning.
+     * 
+     * @param context
+     *            DSpace context object
+     * @param bitstream
+     *            Bitstream to be cloned
+     * @return the clone
+     * @throws SQLException if database error
+     */
+    public Bitstream clone(Context context, Bitstream bitstream) throws SQLException;
+
     /**
      * Create a new bitstream, with a new ID. The checksum and file size are
      * calculated. No authorization checks are made in this method.

dspace-api/src/main/java/org/dspace/storage/bitstore/BitstreamStorageServiceImpl.java

@@ -348,14 +348,18 @@ public class BitstreamStorageServiceImpl implements BitstreamStorageService, Ini
      */
     @Override
     public Bitstream clone(Context context, Bitstream bitstream) throws SQLException, IOException, AuthorizeException {
-        Bitstream clonedBitstream = bitstreamService.create(context, bitstreamService.retrieve(context, bitstream));
+        Bitstream clonedBitstream = bitstreamService.clone(context, bitstream);
+        clonedBitstream.setStoreNumber(bitstream.getStoreNumber());
+
         List<MetadataValue> metadataValues = bitstreamService
             .getMetadata(bitstream, Item.ANY, Item.ANY, Item.ANY, Item.ANY);
+
         for (MetadataValue metadataValue : metadataValues) {
-            bitstreamService
-                .addMetadata(context, clonedBitstream, metadataValue.getMetadataField(), metadataValue.getLanguage(),
-                             metadataValue.getValue(), metadataValue.getAuthority(), metadataValue.getConfidence());
+            bitstreamService.addMetadata(context, clonedBitstream, metadataValue.getMetadataField(),
+                metadataValue.getLanguage(), metadataValue.getValue(), metadataValue.getAuthority(),
+                metadataValue.getConfidence());
         }
+        bitstreamService.update(context, clonedBitstream);
         return clonedBitstream;
 
     }

dspace-api/src/main/java/org/dspace/storage/bitstore/service/BitstreamStorageService.java

@@ -140,6 +140,19 @@ public interface BitstreamStorageService {
      */
     public void cleanup(boolean deleteDbRecords, boolean verbose) throws SQLException, IOException, AuthorizeException;
 
+    /**
+     * Clone the given bitstream to a new bitstream with a new ID.
+     * Metadata of the given bitstream are also copied to the new bitstream.
+     * 
+     * @param context
+     *            DSpace context object
+     * @param bitstream
+     *            the bitstream to be cloned
+     * @return id of the clone bitstream.
+     * @throws SQLException if database error
+     * @throws IOException if IO error
+     * @throws AuthorizeException if authorization error
+     */
     public Bitstream clone(Context context, Bitstream bitstream) throws SQLException, IOException, AuthorizeException;
 
     /**

dspace-api/src/main/java/org/dspace/versioning/AbstractVersionProvider.java

@@ -81,7 +81,10 @@ public abstract class AbstractVersionProvider {
             authorizeService.addPolicies(c, bundlePolicies, bundleNew);
 
             for (Bitstream nativeBitstream : nativeBundle.getBitstreams()) {
-                Bitstream bitstreamNew = createBitstream(c, nativeBitstream);
+                // Metadata and additional information like internal identifier,
+                // file size, checksum, and checksum algorithm are set by the bitstreamStorageService.clone(...)
+                // and respectively bitstreamService.clone(...) method.
+                Bitstream bitstreamNew =  bitstreamStorageService.clone(c, nativeBitstream);
 
                 bundleService.addBitstream(c, bundleNew, bitstreamNew);
 
@@ -106,19 +109,6 @@ public abstract class AbstractVersionProvider {
     }
 
 
-    protected Bitstream createBitstream(Context context, Bitstream nativeBitstream)
-        throws AuthorizeException, SQLException, IOException {
-        Bitstream newBitstream = bitstreamStorageService.clone(context, nativeBitstream);
-        List<MetadataValue> bitstreamMeta = bitstreamService
-            .getMetadata(nativeBitstream, Item.ANY, Item.ANY, Item.ANY, Item.ANY);
-        for (MetadataValue value : bitstreamMeta) {
-            bitstreamService
-                .addMetadata(context, newBitstream, value.getMetadataField(), value.getLanguage(), value.getValue(),
-                             value.getAuthority(), value.getConfidence());
-        }
-        return newBitstream;
-    }
-
     public void setIgnoredMetadataFields(Set<String> ignoredMetadataFields) {
         this.ignoredMetadataFields = ignoredMetadataFields;
     }