From 6da46379296ecec681d6b72d053f82f637ed1c3c Mon Sep 17 00:00:00 2001
From: Jussi Koskela <jussi.koskela@semantum.fi>
Date: Wed, 31 Oct 2018 16:03:38 +0200
Subject: [PATCH] Update structure and value cache when refreshing variable

Previous implementation only updated value cache contents after the
previous cached results expired, which could cause unacceptable delays
in new NodeManager query results. Also, if there were no listeners for
the NodeManager query results, results wouldn't get updated anymore.

gitlab #173

Change-Id: I162fbddea7a5b312c7dceb1448d6ef1cc1f07b73
---
 .../db/layer0/variable/NodeCache.java          | 18 ++++++++++++++++++
 .../db/layer0/variable/NodeSupport.java        | 14 ++++++++++++++
 .../db/StandardVariableNodeManager.java        | 12 ++++++++++--
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeCache.java b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeCache.java
index 309efe31e..5ed9678e9 100644
--- a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeCache.java
+++ b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeCache.java
@@ -116,6 +116,24 @@ public class NodeCache<Node,Value> {
 		scheduleExpiration(node, System.nanoTime() + defaultExpirationTimeInNs);
 	}
 
+	public synchronized void remove(Node node) {
+		if (disposed)
+			return;
+		Long expTime = exp.get(node);
+		if (expTime != null) {
+			expirationTimes.remove(expTime);
+		}
+		map.remove(node);
+	}
+
+	public synchronized void clear() {
+		if (disposed)
+			return;
+		expirationTimes.clear();
+		exp.clear();
+		map.clear();
+	}
+
 	public synchronized void dispose() {
 		disposed = true;
 		expirationTimes.clear();
diff --git a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeSupport.java b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeSupport.java
index 79bc4eb5e..3ac88ae67 100644
--- a/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeSupport.java
+++ b/bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/variable/NodeSupport.java
@@ -5,6 +5,8 @@ import java.util.concurrent.TimeUnit;
 import org.simantics.databoard.binding.mutable.Variant;
 import org.simantics.db.layer0.variable.Variables.NodeStructure;
 import org.simantics.simulator.variable.NodeManager;
+import org.simantics.simulator.variable.exceptions.NoValueException;
+import org.simantics.simulator.variable.exceptions.NodeManagerException;
 
 /**
  * @author Antti Villberg
@@ -55,6 +57,18 @@ public class NodeSupport<Node> {
 				&& manager.equals(other.manager);
 	}
 
+	public void refreshCache(Node node) throws NodeManagerException {
+		VariableNode<Node> variableNode = new VariableNode<>(this, node);
+		NodeStructure ns = NodeStructureRequest.get(variableNode);
+		structureCache.put(node, ns);
+		try {
+			Variant value = manager.getValue(node);
+			valueCache.put(node, value);
+		} catch (NoValueException e) {
+			valueCache.remove(node);
+		};
+	}
+
 	public void dispose() {
 		valueCache.dispose();
 		structureCache.dispose();
diff --git a/bundles/org.simantics.simulator.toolkit.db/src/org/simantics/simulator/toolkit/db/StandardVariableNodeManager.java b/bundles/org.simantics.simulator.toolkit.db/src/org/simantics/simulator/toolkit/db/StandardVariableNodeManager.java
index a08d733d1..aefa672d4 100644
--- a/bundles/org.simantics.simulator.toolkit.db/src/org/simantics/simulator/toolkit/db/StandardVariableNodeManager.java
+++ b/bundles/org.simantics.simulator.toolkit.db/src/org/simantics/simulator/toolkit/db/StandardVariableNodeManager.java
@@ -16,6 +16,9 @@ import org.simantics.db.layer0.variable.NodeSupport;
 import org.simantics.simulator.toolkit.StandardNodeManager;
 import org.simantics.simulator.toolkit.StandardNodeManagerSupport;
 import org.simantics.simulator.toolkit.StandardRealm;
+import org.simantics.simulator.variable.exceptions.NodeManagerException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Adds support for Layer0 Variable interface in StandardNodeManager
@@ -24,6 +27,7 @@ import org.simantics.simulator.toolkit.StandardRealm;
  */
 public class StandardVariableNodeManager<Node, Engine extends StandardNodeManagerSupport<Node>> extends StandardNodeManager<Node,Engine> {
 
+    private static final Logger LOGGER = LoggerFactory.getLogger(StandardVariableNodeManager.class); 
     protected NodeSupport<Node> support;
 
     public StandardVariableNodeManager(StandardRealm<Node, Engine> realm, Node root) {
@@ -33,9 +37,13 @@ public class StandardVariableNodeManager<Node, Engine extends StandardNodeManage
 
     @Override
     public void refreshVariable(Node node) {
+        try {
+            support.refreshCache(node);
+        } catch (NodeManagerException e) {
+            LOGGER.error("Failed to refresh variable", e);
+            throw new RuntimeException(e);
+        }
         super.refreshVariable(node);
-        support.valueCache.clearExpired();
-        support.structureCache.clearExpired();
     }
 
 }
\ No newline at end of file
-- 
2.47.1