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diff --git a/bundles/org.simantics.db/src/org/simantics/db/service/internal/RawDataSupport.java b/bundles/org.simantics.db/src/org/simantics/db/service/internal/RawDataSupport.java
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index 000000000..af33a6a67
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+++ b/bundles/org.simantics.db/src/org/simantics/db/service/internal/RawDataSupport.java
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+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.db.service.internal;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.simantics.db.AsyncReadGraph;
+import org.simantics.db.Resource;
+import org.simantics.db.VirtualGraph;
+import org.simantics.db.WriteOnlyGraph;
+import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.service.TransferableGraphSupport;
+
+/**
+ * This interface is a proposition of a replacement for
+ * {@link TransferableGraphSupport}. The main arguments for this interface are:
+ * <ol>
+ * <li>Streaming support for large data (using I/O streams)</li>
+ * <li>Remaining performant with small data (using OutputStream in
+ * {@link #getValue(AsyncReadGraph, Resource, OutputStream)})</li>
+ * <li>Still very similar to {@link TransferableGraphSupport} and therefore
+ * should be easy to implement</li>
+ * </ol>
+ * 
+ * @author Tuukka Lehtonen
+ */
+public interface RawDataSupport {
+
+    /**
+     * Retrieve raw value/file data attached to the specified resource into the
+     * specified output stream.
+     * 
+     * @param graph valid database read handle to prove the request is performed
+     *        from within a read or write transaction.
+     * @param resource resource to get value/file from
+     * @param output stream to write the raw data into
+     * @return -1 if resource contained no value/file, number of bytes written
+     *         to the stream otherwise.
+     * @throws IOException problems writing the output stream
+     * @throws DatabaseException error occurred while writing the database
+     */
+    long getValue(AsyncReadGraph graph, Resource resource, OutputStream stream) throws IOException, DatabaseException;
+
+    /**
+     * Set raw value/file data attached to the specified resource from the
+     * specified input stream.
+     * 
+     * <p>
+     * Write transactions are single-threaded and exclusive which implies that a
+     * client cannot invoke
+     * {@link #getValue(AsyncReadGraph, Resource, OutputStream)} and
+     * {@link #setValue(WriteOnlyGraph, Resource, VirtualGraph, InputStream)}
+     * simultaneously in another read transaction.
+     * 
+     * @param graph valid database read handle to prove the request is performed
+     *        from within a write transaction.
+     * @param resource resource to set value/file for
+     * @param provider provider for writing to virtual graphs, may be
+     *        <code>null</code>
+     * @param input stream to read the raw data from
+     * @return number of raw data bytes written to the database.
+     * @throws IOException problems reading the input stream
+     * @throws DatabaseException error occurred while writing the database
+     */
+    long setValue(WriteOnlyGraph graph, Resource resource, VirtualGraph provider, InputStream input)
+    throws IOException, DatabaseException;
+
+}