X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.db.impl%2Fsrc%2Forg%2Fsimantics%2Fdb%2Fimpl%2Fquery%2FExternalReadEntry.java;fp=bundles%2Forg.simantics.db.impl%2Fsrc%2Forg%2Fsimantics%2Fdb%2Fimpl%2Fquery%2FExternalReadEntry.java;h=a411fa7730be1c5ed874719c00093d2c331971c9;hp=0000000000000000000000000000000000000000;hb=969bd23cab98a79ca9101af33334000879fb60c5;hpb=866dba5cd5a3929bbeae85991796acb212338a08

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/ExternalReadEntry.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/ExternalReadEntry.java
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+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/ExternalReadEntry.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.impl.query;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+
+import org.simantics.db.impl.graph.ReadGraphImpl;
+import org.simantics.db.procedure.Procedure;
+import org.simantics.db.request.ExternalRead;
+import org.simantics.db.request.RequestFlags;
+
+final public class ExternalReadEntry<T> extends CacheEntryBase {
+
+    final LinkedList<T> items = new LinkedList<T>();
+    
+//    public ArrayList<Procedure<T>> procs;
+
+    protected ExternalRead<T> request;
+
+    @Override
+    int makeHash() {
+    	return request.hashCode();
+    }
+    
+    @Override
+    public Object getOriginalRequest() {
+        return request;
+    }
+    
+    @Override
+    public void clearResult(QuerySupport support) {
+    }
+    
+    @Override
+    public void discard() {
+        request.unregistered();
+        request = null;
+        super.discard();
+    }
+    
+    public ExternalReadEntry(ExternalRead<T> request) {
+        assert request != null;
+        this.request = request;
+    }
+    
+    final public void queue(T item) {
+    	synchronized(items) {
+    		items.addLast(item);
+    		// TODO: implement flags/logic in ExternalRead to state that all but the latest request result can be evaporated
+    		// In some cases where data is produced really fast this might be necessary but currently this queueing will do.
+    	}
+    }
+    
+    final public void addOrSet(QueryProcessor processor, Object item) {
+
+        try {
+        
+            assert(isPending());
+
+            ArrayList<Procedure<T>> p = null;
+
+            synchronized(this) {
+
+                setResult(item);
+                setReady();
+//                p = procs;
+//                procs = null;
+
+            }
+
+//            if(p != null)
+//                for(Procedure proc : p) {
+//                    proc.execute((T)item);
+//                }
+
+        } catch (Throwable t) {
+            t.printStackTrace();
+        }
+        
+    }
+    
+    @Override
+    final public Query getQuery() {
+    	
+        return new Query() {
+
+			@Override
+			public void recompute(ReadGraphImpl graph, Object provider, CacheEntry entry) {
+
+			    final QueryProcessor qp = (QueryProcessor)provider;
+			    synchronized(items) {
+
+			    	if(entry.isExcepted()) {
+			    		
+			    		// Exception persists
+			    		
+			    	} else {
+			    	
+				    	// Update
+				    	if(!items.isEmpty()) {
+				    		setResult(items.removeFirst());
+				    	}
+				    	// Reschedule
+					    if(!items.isEmpty()) {
+					        qp.updatePrimitive(request);
+					    }
+					    
+					    setReady();
+					    
+			    	}
+			    	
+			    }
+				
+			}
+
+			@Override
+			public void removeEntry(QueryProcessor processor) {
+				processor.externalReadMap.remove(request);
+			}
+
+			@Override
+			public int type() {
+				return RequestFlags.IMMEDIATE_UPDATE;
+			}
+			
+			@Override
+			public String toString() {
+				if(request == null) return "DISCARDED ExternalRead";
+				else return request.toString();
+			}
+        	
+        };
+        
+    }
+
+	public void performFromCache(Object procedure) {
+		
+        Procedure<T> proc = (Procedure<T>)procedure;
+
+	    if(isExcepted()) {
+            
+            proc.exception((Throwable)getResult());
+            
+        } else {
+            
+            proc.execute((T)getResult());
+
+        }
+		
+	}
+
+	@Override
+	public String toString() {
+		if(request == null) return "DISCARDED ExternalRead " + System.identityHashCode(this);
+		else return request.toString() + " " + + System.identityHashCode(this);
+	}
+
+    @Override
+    public void performFromCache(ReadGraphImpl graph, Object provider, Object procedure) {
+        performFromCache(procedure);
+    }
+    
+    @Override
+    public void setReady() {
+    	super.setReady();
+    }
+    
+    @Override
+    void prepareRecompute(QuerySupport querySupport) {
+    	// Do nothing - the state is already set and cannot be recomputed on demand
+    }
+
+}