From ad0aa149a7de3e3ce3034a59ad7761d03d697501 Mon Sep 17 00:00:00 2001
From: Tuukka Lehtonen <tuukka.lehtonen@semantum.fi>
Date: Mon, 8 Nov 2021 13:04:24 +0200
Subject: [PATCH] Add Collector.isEnabled and implement support in
 CollectorImpl

Also add default constructor for SubscriptionItem that uses cached
BINDING instead of retrieving it from Bindings for every instance.

CollectorImpl methods invoked by datasource adapters are now
short-circuited based on the enabledness of the collector.

gitlab #771
---
 .../src/org/simantics/history/Collector.java  | 11 +++++++
 .../simantics/history/impl/CollectorImpl.java | 31 +++++++++++++++++--
 .../util/subscription/SubscriptionItem.java   |  8 +++++
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/bundles/org.simantics.history/src/org/simantics/history/Collector.java b/bundles/org.simantics.history/src/org/simantics/history/Collector.java
index 234c832f5..9dbce9bc1 100644
--- a/bundles/org.simantics.history/src/org/simantics/history/Collector.java
+++ b/bundles/org.simantics.history/src/org/simantics/history/Collector.java
@@ -215,4 +215,15 @@ public interface Collector {
 	 */
 	void setState(Bean newState);
 
+	/**
+	 * Allows history collector writers to optimize their invocations of the collector.
+	 * 
+	 * @return <code>true</code> if the this collector is enabled for collection or
+	 *         <code>false</code> otherwise.
+	 * @since 1.50.0, 1.35.3, 1.48.0.1
+	 */
+	default boolean isEnabled() {
+		return true;
+	}
+
 }
diff --git a/bundles/org.simantics.history/src/org/simantics/history/impl/CollectorImpl.java b/bundles/org.simantics.history/src/org/simantics/history/impl/CollectorImpl.java
index e956b3711..c202f733c 100644
--- a/bundles/org.simantics.history/src/org/simantics/history/impl/CollectorImpl.java
+++ b/bundles/org.simantics.history/src/org/simantics/history/impl/CollectorImpl.java
@@ -87,6 +87,15 @@ public class CollectorImpl implements Collector {
 	
 	/** True when all items are open */
 	boolean itemsOpen = true;
+
+	/** True when history collection will write data to disk */
+	boolean enabled = true;
+
+	/**
+	 * Transient info only set in {@link #beginStep(NumberBinding, Object)} based on
+	 * {@link #enabled}
+	 */
+	private transient boolean stepEnabled = true;
 	
 	public FlushPolicy flushPolicy = FlushPolicy.FlushOnEveryStep;
 	
@@ -122,7 +131,16 @@ public class CollectorImpl implements Collector {
 		this.history = history;
 		this.state = (CollectorState) previousState.clone();
 	}
-	
+
+	public void setEnabled(boolean enabled) {
+		this.enabled = enabled;
+	}
+
+	@Override
+	public boolean isEnabled() {
+		return enabled;
+	}
+
 	@Override
 	public synchronized void addItem(Bean item) throws HistoryException {
 		try {
@@ -494,13 +512,20 @@ public class CollectorImpl implements Collector {
 	
 	@Override
 	public void beginStep(NumberBinding binding, Object time) throws HistoryException {
-		openAllItems();
+		stepEnabled = enabled;
 		updateDt(binding, time);
 		state.time.setValue(binding, time);
+		if (enabled) {
+			openAllItems();
+		}
 	}
 
 	@Override
 	public void setValue(String id, Binding binding, Object value) throws HistoryException {
+		// Short-circuit calls when collection not enabled
+		if (!stepEnabled)
+			return;
+
 		VariableState vs = state.values.get( id );
 		if (vs == null) {
 			vs = new VariableState();
@@ -554,6 +579,8 @@ public class CollectorImpl implements Collector {
 
 	@Override
 	public void endStep() throws HistoryException {
+		if (!stepEnabled)
+			return;
 		// Write values to streams
 		for (ActiveStream i : items)
 		{
diff --git a/bundles/org.simantics.history/src/org/simantics/history/util/subscription/SubscriptionItem.java b/bundles/org.simantics.history/src/org/simantics/history/util/subscription/SubscriptionItem.java
index 2bb078c21..fb0613ab6 100644
--- a/bundles/org.simantics.history/src/org/simantics/history/util/subscription/SubscriptionItem.java
+++ b/bundles/org.simantics.history/src/org/simantics/history/util/subscription/SubscriptionItem.java
@@ -14,7 +14,9 @@ package org.simantics.history.util.subscription;
 import java.util.Collection;
 import java.util.Iterator;
 
+import org.simantics.databoard.Bindings;
 import org.simantics.databoard.annotations.Identifier;
+import org.simantics.databoard.binding.Binding;
 import org.simantics.databoard.type.Datatype;
 import org.simantics.databoard.util.Bean;
 
@@ -31,6 +33,12 @@ import org.simantics.databoard.util.Bean;
  */
 public class SubscriptionItem extends Bean {
 
+	private static final Binding BINDING = Bindings.getBindingUnchecked(SubscriptionItem.class);
+
+	public SubscriptionItem() {
+		super(BINDING);
+	}
+
 	/**
 	 * Create HistoryItem descriptions for collecting one variable with multiple
 	 * sampling formats.
-- 
2.47.1