JBPM-6681 - Support for lazy loaded variables (#1095)

jbpm-case-mgmt/jbpm-case-mgmt-impl/src/main/java/org/jbpm/casemgmt/impl/CaseServiceImpl.java

@@ -87,6 +87,7 @@
 import org.kie.internal.runtime.manager.context.ProcessInstanceIdContext;
 import org.kie.internal.task.api.TaskModelFactory;
 import org.kie.internal.task.api.TaskModelProvider;
+import org.kie.internal.utils.LazyLoaded;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -658,6 +659,12 @@ protected CaseFileInstance internalGetCaseFileInstance(String caseId, String dep
             Map<String, Object> filteredData = authorizationManager.filterByDataAuthorization(caseId, caseFile, caseFile.getData());
             ((CaseFileInstanceImpl)caseFile).setData(filteredData);
 
+            for (Object variable : caseFile.getData().values()) {
+                if (variable instanceof LazyLoaded<?>) {
+                    ((LazyLoaded<?>) variable).load();
+                }
+            }
+
             return caseFile;
         } 
         logger.warn("Multiple case files found in working memory (most likely not using PER_CASE strategy), trying to filter out...");
@@ -671,7 +678,16 @@ protected CaseFileInstance internalGetCaseFileInstance(String caseId, String dep
             // apply authorization
             Map<String, Object> filteredData = authorizationManager.filterByDataAuthorization(caseId, caseFile, caseFile.getData());
             ((CaseFileInstanceImpl)caseFile).setData(filteredData);
+
+
+            for (Object variable : caseFile.getData().values()) {
+                if (variable instanceof LazyLoaded<?>) {
+                    ((LazyLoaded<?>) variable).load();
+                }
+            }
         }
+
+
         return caseFile;
     }
 

jbpm-document/pom.xml

@@ -37,6 +37,10 @@
       <groupId>org.kie</groupId>
       <artifactId>kie-api</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.kie</groupId>
+      <artifactId>kie-internal</artifactId>
+    </dependency>
     <dependency>
       <groupId>org.drools</groupId>
       <artifactId>drools-core</artifactId>

jbpm-document/src/main/java/org/jbpm/document/Document.java

@@ -23,6 +23,7 @@ public interface Document extends Serializable {
 
     public static final String DOCUMENT_DATE_PATTERN = "yyyy-MM-dd HH:mm:ss";
     public static final String PROPERTIES_SEPARATOR = "####";
+    public static final String UPDATED_ATTRIBUTE = "_UPDATED_";
 
     void setIdentifier(String identifier);
 

jbpm-document/src/main/java/org/jbpm/document/marshalling/DocumentMarshallingStrategy.java

@@ -34,11 +34,15 @@ public class DocumentMarshallingStrategy extends AbstractDocumentMarshallingStra
     private DocumentStorageService documentStorageService;
 
     public DocumentMarshallingStrategy() {
-        documentStorageService = DocumentStorageServiceProvider.get().getStorageService();
+        this.documentStorageService = DocumentStorageServiceProvider.get().getStorageService();
     }
 
     public DocumentMarshallingStrategy(String path) {
-        documentStorageService = DocumentStorageServiceProvider.get().getStorageService();
+        this.documentStorageService = DocumentStorageServiceProvider.get().getStorageService();
+    }
+
+    public DocumentMarshallingStrategy(DocumentStorageService documentStorageService) {
+        this.documentStorageService = documentStorageService;
     }
 
     @Override
@@ -48,40 +52,22 @@ public Document buildDocument( String name, long size, Date lastModified, Map<St
 
     @Override
     public void write(ObjectOutputStream os, Object object) throws IOException {
-        Document document = (Document) object;
-
-        if (document != null && document.getContent() != null) {
-            documentStorageService.saveDocument(document, document.getContent());
-        }
-        os.writeUTF(document.getIdentifier());
-        os.writeUTF(document.getClass().getCanonicalName());
-        os.writeUTF(document.getLink());
+        throw new UnsupportedOperationException("write is not supported anymore, use marshal instead");
     }
 
     public Object read(ObjectInputStream os) throws IOException, ClassNotFoundException {
-        String objectId = os.readUTF();
-        String canonicalName = os.readUTF();
-        String link = os.readUTF();
-        try {
-            Document doc = documentStorageService.getDocument(objectId);
-            Document document = (Document) Class.forName(canonicalName).newInstance();
-            document.setIdentifier(objectId);
-            document.setLink(link);
-            document.setName(doc.getName());
-            document.setSize(doc.getSize());
-            document.setLastModified(doc.getLastModified());
-            document.setAttributes(doc.getAttributes());
-            document.setContent(doc.getContent());
-            return document;
-        } catch(Exception e) {
-            throw new RuntimeException("Cannot read document", e);
-        }
+        throw new UnsupportedOperationException("read is not supported anymore, use unmarshal instead");
     }
 
     @Override
     public byte[] marshal(Context context, ObjectOutputStream objectOutputStream, Object o) throws IOException {
         Document document = (Document) o;
-        documentStorageService.saveDocument(document, document.getContent());
+        String updatedAttribute = document.getAttribute(Document.UPDATED_ATTRIBUTE);
+        if (Boolean.parseBoolean(updatedAttribute)) {
+            // store via service only when it was actually updated
+            documentStorageService.saveDocument(document, document.getContent());
+            document.addAttribute(Document.UPDATED_ATTRIBUTE, "false");
+        }
         ByteArrayOutputStream buff = new ByteArrayOutputStream();
         ObjectOutputStream oos = new ObjectOutputStream(buff);
         oos.writeUTF(document.getIdentifier());
@@ -91,28 +77,24 @@ public byte[] marshal(Context context, ObjectOutputStream objectOutputStream, Ob
         return buff.toByteArray();
     }
 
+    @SuppressWarnings({"resource", "unused"})
     @Override
     public Object unmarshal(Context context, ObjectInputStream objectInputStream, byte[] object, ClassLoader classLoader) throws IOException, ClassNotFoundException {
         DroolsObjectInputStream is = new DroolsObjectInputStream(new ByteArrayInputStream(object), classLoader);
         // first we read out the object id and class name we stored during marshaling
         String objectId = is.readUTF();
         String canonicalName = is.readUTF();
         String link = is.readUTF();
-        Document document = null;
-        try {
-            document = (Document) Class.forName(canonicalName).newInstance();
-            Document storedDoc = documentStorageService.getDocument(objectId);
-            document.setIdentifier(storedDoc.getIdentifier());
-            document.setName( storedDoc.getName() );
-            document.setLink( link );
-            document.setLastModified( storedDoc.getLastModified() );
-            document.setSize( storedDoc.getSize() );
-            document.setAttributes( storedDoc.getAttributes() );
-            document.setContent(storedDoc.getContent());
+        Document storedDoc = null;
+        try {            
+            storedDoc = documentStorageService.getDocument(objectId);            
+            storedDoc.setLink( link );
+            // when loaded, mark it as not updated to avoid not needed marshalling
+            storedDoc.addAttribute(Document.UPDATED_ATTRIBUTE, "false");
         } catch (Exception e) {
             throw new RuntimeException("Cannot read document from storage service", e);
         }
-        return document;
+        return storedDoc;
     }
 
     @Override

jbpm-document/src/main/java/org/jbpm/document/service/DocumentStorageService.java

@@ -51,6 +51,13 @@ public interface DocumentStorageService {
      * @return              The java.io.File identified with the id
      */
     Document getDocument(String id);
+
+    /**
+     * Loads document content 
+     * @param id unique id of the document
+     * @return loaded document's content
+     */
+    byte[] loadContent(String id);
 
     /**
      * Deletes the File identified by the given id

jbpm-document/src/main/java/org/jbpm/document/service/impl/DocumentImpl.java

@@ -26,24 +26,33 @@
 import javax.xml.bind.annotation.XmlRootElement;
 
 import org.jbpm.document.Document;
+import org.jbpm.document.service.DocumentStorageService;
+import org.kie.internal.utils.LazyLoaded;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 @XmlAccessorType(XmlAccessType.FIELD)
 @XmlRootElement(name = "document-object")
-public class DocumentImpl implements Document {
+public class DocumentImpl implements Document, LazyLoaded<DocumentStorageService> {
 
     private static final long serialVersionUID = -7422666286189013484L;
 
+    private static final Logger logger = LoggerFactory.getLogger(DocumentImpl.class);
+
     private String identifier = "";
     private String name;
     private String link = "";
     private long size;
     private Date lastModified;
     private byte[] content;
     private Map<String, String> attributes;
+
+    private transient DocumentStorageService service;
 
     public DocumentImpl() {
         // Setting default values for identifier && download link
         this.identifier = UUID.randomUUID().toString();
+        this.attributes = new HashMap<String, String>();
     }
 
     public DocumentImpl(String identifier,
@@ -155,10 +164,13 @@ public Map<String, String> getAttributes() {
     @Override
     public void setContent(byte[] content) {
         this.content = content;
+        addAttribute(UPDATED_ATTRIBUTE, "true");
     }
 
     @Override
     public byte[] getContent() {
+        load();
+
         return content;
     }
 
@@ -167,4 +179,22 @@ public String toString() {
         SimpleDateFormat sdf = new SimpleDateFormat(DOCUMENT_DATE_PATTERN);
         return name + PROPERTIES_SEPARATOR + size + PROPERTIES_SEPARATOR + ((lastModified != null) ? sdf.format(lastModified) : "") + PROPERTIES_SEPARATOR + identifier;
     }
+
+    /*
+     * lazy load support
+     */
+
+    @Override
+    public void setLoadService(DocumentStorageService service) {
+        this.service = service;
+    }
+
+    @Override
+    public void load() {
+        if (content == null && service != null && identifier != null) {
+            content = service.loadContent(identifier);
+        } else {
+            logger.debug("Cannot load content due to missing service {} or identifier {}", service, identifier);
+        }
+    }
 }

jbpm-document/src/main/java/org/jbpm/document/service/impl/DocumentStorageServiceImpl.java

@@ -104,13 +104,13 @@ public Document getDocument(String id) {
         if (file.exists() && !file.isFile() && !ArrayUtils.isEmpty(file.listFiles())) {
             try {
                 File destination = file.listFiles()[0];
-                Document doc = new DocumentImpl(id,
+                DocumentImpl doc = new DocumentImpl(id,
                                                 destination.getName(),
                                                 destination.length(),
                                                 new Date(destination.lastModified()));
-                doc.setContent(FileUtils.readFileToByteArray(destination));
+                doc.setLoadService(this);
                 return doc;
-            } catch (IOException e) {
+            } catch (Exception e) {
                 log.error("Error loading document '{}': {}",
                           id,
                           e);
@@ -217,4 +217,20 @@ public List<Document> listDocuments(Integer page, Integer pageSize) {
         }
         return listOfDocs;
     }
+
+    @Override
+    public byte[] loadContent(String id) {
+        File file = getFileByPath(id);
+
+        if (file.exists() && !file.isFile() && !ArrayUtils.isEmpty(file.listFiles())) {
+            try {
+                File destination = file.listFiles()[0];
+                return FileUtils.readFileToByteArray(destination);
+            } catch (IOException e) {
+                log.error("Unable to laod content due to {}", e.getMessage(), e);
+            }
+        } 
+
+        return null;
+    }
 }

jbpm-document/src/test/java/org/jbpm/document/marshalling/DocumentsMarshallingStrategyTest.java

@@ -22,9 +22,11 @@
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import org.jbpm.document.Document;
 import org.jbpm.document.Documents;
+import org.jbpm.document.service.impl.CustomDocumentStorageServiceImpl;
 import org.jbpm.document.service.impl.DocumentImpl;
 import org.junit.Test;
 
@@ -78,6 +80,34 @@ public void testNoDocumentsMarshallUnmarshall() throws IOException, ClassNotFoun
 		assertEquals(docs.getDocuments().size(), unmarshalledDocuments.getDocuments().size());
 	}
 
+	@Test
+    public void testSingleDocMarshallUnmarshallTracking() throws IOException, ClassNotFoundException {
+        final AtomicInteger counter = new AtomicInteger(0);
+	    DocumentMarshallingStrategy docMarshallingStrategy = new DocumentMarshallingStrategy(new CustomDocumentStorageServiceImpl(){
+
+            @Override
+            public Document saveDocument(Document document, byte[] content) {
+                counter.incrementAndGet();
+                return super.saveDocument(document, content);
+            }
+
+        });
+        Document document = getDocument("docOne");
+        byte[] marshalledDocument = docMarshallingStrategy.marshal(null, null, document);
+        assertEquals(1, counter.get());
+        Document unmarshalledDocument = (Document) docMarshallingStrategy.unmarshal(null, null, marshalledDocument, this.getClass().getClassLoader());
+
+        assertEquals(document.getName(), unmarshalledDocument.getName());
+        assertEquals(document.getLink(), unmarshalledDocument.getLink());
+
+        // marhsall it again, it should not call the save on document service since document didn't change
+        marshalledDocument = docMarshallingStrategy.marshal(null, null, unmarshalledDocument);
+        assertEquals(1, counter.get());
+
+        unmarshalledDocument.setContent("updated content".getBytes());
+        marshalledDocument = docMarshallingStrategy.marshal(null, null, unmarshalledDocument);
+        assertEquals(2, counter.get());
+    }
 
 	private Document getDocument(String documentName) {
 		Document documentOne = new DocumentImpl();

jbpm-services/jbpm-kie-services/src/main/java/org/jbpm/kie/services/impl/ProcessServiceImpl.java

@@ -60,6 +60,7 @@
 import org.kie.internal.runtime.manager.context.CaseContext;
 import org.kie.internal.runtime.manager.context.CorrelationKeyContext;
 import org.kie.internal.runtime.manager.context.ProcessInstanceIdContext;
+import org.kie.internal.utils.LazyLoaded;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -412,7 +413,11 @@ public Object execute(org.kie.api.runtime.Context context) {
                     if (pi == null) {
                         throw new ProcessInstanceNotFoundException("Process instance with id " + processInstanceId + " was not found");
                     }
-                    return pi.getVariable(variableName);
+                    Object variable = pi.getVariable(variableName);
+                    if (variable instanceof LazyLoaded<?>) {
+                        ((LazyLoaded<?>) variable).load();
+                    }
+                    return variable;
                 }
             });
         } catch(SessionNotFoundException e) {
@@ -445,7 +450,15 @@ public Map<String, Object> getProcessInstanceVariables(String deploymentId, Long
             KieSession ksession = engine.getKieSession();
             WorkflowProcessInstanceImpl pi = (WorkflowProcessInstanceImpl) ksession.getProcessInstance(processInstanceId, true);
 
-        	return pi.getVariables();
+        	Map<String, Object> variables = pi.getVariables();
+
+        	for (Object variable : variables.values()) {
+        	    if (variable instanceof LazyLoaded<?>) {
+                    ((LazyLoaded<?>) variable).load();
+                }
+        	}
+
+        	return variables;
         } catch(SessionNotFoundException e) {
             throw new ProcessInstanceNotFoundException("Process instance with id " + processInstanceId + " was not found", e);
         } finally {