From b2bf3445afe9519017f07e41da3c6bc2bccedc6f Mon Sep 17 00:00:00 2001
From: Marko Luukkainen <marko.luukkainen@semantum.fi>
Date: Thu, 24 Feb 2022 11:39:27 +0200
Subject: [PATCH] Process changes in smaller chunks

gitlab #39

Change-Id: I82fab040ceb9c93246ca7db7ffa9f62dfb654ddb
---
 .../update/model/UpdateOperations.java        | 17 ++++
 .../interop/update/model/UpdateTree.java      | 79 ++++++++++++++++---
 2 files changed, 84 insertions(+), 12 deletions(-)

diff --git a/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateOperations.java b/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateOperations.java
index 0c1882c..825ccf1 100644
--- a/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateOperations.java
+++ b/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateOperations.java
@@ -8,8 +8,10 @@ import java.util.Stack;
 
 import org.simantics.db.ReadGraph;
 import org.simantics.db.Resource;
+import org.simantics.db.Session;
 import org.simantics.db.Statement;
 import org.simantics.db.WriteGraph;
+import org.simantics.db.common.request.ReadRequest;
 import org.simantics.db.exception.DatabaseException;
 import org.simantics.interop.test.GraphChanges;
 
@@ -128,6 +130,21 @@ public abstract  class UpdateOperations {
 
 	public abstract void populate(ReadGraph g) throws DatabaseException;
 	
+	/**
+	 * Secondary populate method. Override this for chunked DB operations.  
+	 * @param session
+	 * @throws DatabaseException
+	 */
+	public void populate(Session session) throws DatabaseException {
+		session.syncRequest(new ReadRequest() {
+			
+			@Override
+			public void run(ReadGraph graph) throws DatabaseException {
+				populate(graph);
+			}
+		});
+	}
+	
 	protected boolean compares(Resource r1, Resource r2) {
 		if (r1.equals(r2))
 			return true;
diff --git a/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateTree.java b/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateTree.java
index a971da4..a558f84 100644
--- a/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateTree.java
+++ b/org.simantics.interop.update/src/org/simantics/interop/update/model/UpdateTree.java
@@ -5,7 +5,10 @@ import java.util.Map;
 
 import org.simantics.db.ReadGraph;
 import org.simantics.db.Resource;
+import org.simantics.db.Session;
+import org.simantics.db.common.request.ResourceRead;
 import org.simantics.db.exception.DatabaseException;
+import org.simantics.db.request.Read;
 import org.simantics.interop.test.GraphChanges;
 
 
@@ -28,6 +31,29 @@ public class UpdateTree {
 		populate(g);
 	}
 	
+	public UpdateTree(Session session, GraphChanges changes, UpdateOperations updateOps) throws DatabaseException {
+		this.changes = changes;
+		this.nodes = new HashMap<Resource, UpdateNode>();
+		this.rootNode = session.syncRequest(new NodeRequest(UpdateStatus.EXIST, changes.getResource1()));
+		nodes.put(changes.getResource1(), rootNode);
+		nodes.put(changes.getResource2(), rootNode);
+		this.updateOps = updateOps;
+		this.updateOps.populate(session);
+		populate(session);
+	}
+	
+	private class NodeRequest extends ResourceRead<UpdateNode> {
+		UpdateStatus status;
+		public NodeRequest(UpdateStatus status, Resource r) {
+			super(r);
+			this.status = status;
+		}
+		@Override
+		public UpdateNode perform(ReadGraph graph) throws DatabaseException {
+			return createNode(graph, status, resource);
+		}
+	}
+	
 	public UpdateOperations getUpdateOps() {
 		return updateOps;
 	}
@@ -127,23 +153,52 @@ public class UpdateTree {
 		return false;
 	}
 	
-	private void populate(ReadGraph g) throws DatabaseException{
+	protected void populate(ReadGraph g) throws DatabaseException{
 
 		for (UpdateOp op : updateOps.getOperations()) {
-			if (!handleCustom(g, op)) {
-				if (op.isAdd()) {
-					addNode(g, null,op.getResource());
-				} else if (op.isDelete()){
-					addNode(g, op.getResource(), null);
-				} else if (op.isChange()) {
-					Resource o = op.getResource();
-				    Resource l = getChanges().getComparable().containsLeft(o) ? o :getChanges().getComparable().getLeft(o);
-				    Resource r = getChanges().getComparable().containsRight(o) ? o :getChanges().getComparable().getRight(o);
-				    addNode(g, l, r);
-				}
+			populate(g, op);
+		}
+		
+	}
+	
+	protected void populate(ReadGraph g, UpdateOp op) throws DatabaseException{
+		if (!handleCustom(g, op)) {
+			if (op.isAdd()) {
+				addNode(g, null,op.getResource());
+			} else if (op.isDelete()){
+				addNode(g, op.getResource(), null);
+			} else if (op.isChange()) {
+				Resource o = op.getResource();
+			    Resource l = getChanges().getComparable().containsLeft(o) ? o :getChanges().getComparable().getLeft(o);
+			    Resource r = getChanges().getComparable().containsRight(o) ? o :getChanges().getComparable().getRight(o);
+			    addNode(g, l, r);
 			}
 		}
+	}
+	
+	protected void populate(Session session) throws DatabaseException{
+		int i = 0;
+		while (i < updateOps.getOperations().size()) {
+			i = session.syncRequest(new PopulateRead(i));
+		}
+	}
+	
+	protected class PopulateRead implements Read<Integer> {
+		int s;
+		public PopulateRead(int s) {
+			this.s = s;
+		}
 		
+		public Integer perform(ReadGraph graph) throws DatabaseException {
+			int l = s + 100;
+			if (l > updateOps.getOperations().size())
+				l = updateOps.getOperations().size();
+			for (int i = s; i < l; i++) {
+				UpdateOp op = updateOps.getOperations().get(i);
+				populate(graph, op);
+			}
+			return l;
+		}
 	}
 
 }
-- 
2.45.1