support prescanning entities for dynamic group
to see if there are changes
diff --git a/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroup.java b/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroup.java
index a4fdace..3e61ec8 100644
--- a/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroup.java
+++ b/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroup.java
@@ -70,6 +70,8 @@
/** Rescans <em>all</em> entities to determine whether they match the filter. */
@Effector(description = "Rescans all entities to determine whether they match the configured filter.")
void rescanEntities();
+ /** return true/false whether there are any changes detected */
+ boolean prescanEntities();
/** Sets {@link #ENTITY_FILTER}, overriding (and rescanning all) if already set. */
void setEntityFilter(Predicate<? super Entity> filter);
diff --git a/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroupImpl.java b/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroupImpl.java
index abeaaee..b755b1f 100644
--- a/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroupImpl.java
+++ b/core/src/main/java/org/apache/brooklyn/entity/group/DynamicGroupImpl.java
@@ -205,15 +205,23 @@
@Override
public void rescanEntities() {
+ rescanEntitiesInternal(true);
+ }
+
+ public boolean prescanEntities() {
+ return rescanEntitiesInternal(false);
+ }
+
+ protected boolean rescanEntitiesInternal(boolean makeChanges) {
synchronized (memberChangeMutex) {
if (!isRunning() || !getManagementSupport().isDeployed()) {
if (log.isDebugEnabled()) log.debug("{} not scanning for children: stopped", this);
- return;
+ return false;
}
if (getAncestorToScan() == null) {
BrooklynLogging.log(log, BrooklynLogging.levelDependingIfReadOnly(this, LoggingLevel.WARN, LoggingLevel.TRACE, LoggingLevel.TRACE),
"{} not (yet) scanning for children: no application defined", this);
- return;
+ return false;
}
boolean changed = false;
Collection<Entity> currentMembers = getMembers();
@@ -225,17 +233,20 @@
toRemove.remove(it);
if (!currentMembers.contains(it)) {
if (log.isDebugEnabled()) log.debug("{} rescan detected new item {}", this, it);
+ if (!makeChanges) return true;
addMember(it);
changed = true;
}
}
for (Entity it : toRemove) {
if (log.isDebugEnabled()) log.debug("{} rescan detected vanished item {}", this, it);
+ if (!makeChanges) return true;
removeMember(it);
changed = true;
}
if (changed && log.isDebugEnabled())
log.debug("{} rescan complete, members now {}", this, getMembers());
+ return changed;
}
}
diff --git a/core/src/test/java/org/apache/brooklyn/core/workflow/WorkflowConfigSensorEffectorTest.java b/core/src/test/java/org/apache/brooklyn/core/workflow/WorkflowConfigSensorEffectorTest.java
index ea02bc1..d1b81f6 100644
--- a/core/src/test/java/org/apache/brooklyn/core/workflow/WorkflowConfigSensorEffectorTest.java
+++ b/core/src/test/java/org/apache/brooklyn/core/workflow/WorkflowConfigSensorEffectorTest.java
@@ -194,6 +194,9 @@
Entity chilld = Iterables.getOnlyElement(app.getChildren());
Asserts.assertEquals(lastInvocation.getUnchecked(), chilld);
+ runWorkflow(MutableList.of("let entity x = "+chilld.getId(), "return ${x}"));
+ Asserts.assertEquals(lastInvocation.getUnchecked(), chilld);
+
runWorkflow(MutableList.of("let entity x = chilldx",
"let y = ${x} ?? missing",
"return ${y}"));
