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Posted to dev@brooklyn.apache.org by sjcorbett <gi...@git.apache.org> on 2016/10/13 10:33:12 UTC
[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
GitHub user sjcorbett opened a pull request:
https://github.com/apache/brooklyn-server/pull/382
InvokeEffectorOnSetChange
Tracks a collection and invokes effectors when elements are added and removed.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/sjcorbett/brooklyn-server invoke-set-change
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/brooklyn-server/pull/382.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #382
----
commit 8bbf68a07f86b06900fcd84cf9b6f71669f97bc5
Author: Sam Corbett <sa...@cloudsoftcorp.com>
Date: 2016-10-13T10:24:15Z
getEffectorByName returns absent rather than throwing NPE when arg null.
commit 2797e0c23d53ae4e0e3900f8b92e117d1da92783
Author: Sam Corbett <sa...@cloudsoftcorp.com>
Date: 2016-10-13T10:24:35Z
Add Sensors.newSensor(TypeToken, name)
commit f3017f6a3e129ebf026da89d98113657aa649c61
Author: Sam Corbett <sa...@cloudsoftcorp.com>
Date: 2016-10-13T10:32:43Z
InvokeEffectorOnSetChange
Tracks a collection and invokes effectors when elements are added and
removed.
----
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by sjcorbett <gi...@git.apache.org>.
Github user sjcorbett commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83260337
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
--- End diff --
We have to take the difference with the lock so that we can determine whether the collection is changed and thus should set the `previous` sensor. I'll move the `onAdded` and `onRemoved` calls out of the critical section.
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---
[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by neykov <gi...@git.apache.org>.
Github user neykov commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83199736
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
+
+ // Only perform an update if the collections have changed.
+ if (!added.isEmpty() || !removed.isEmpty()) {
+ for (Object o : added) {
+ onAdded(o);
+ }
+ for (Object o : removed) {
+ onRemoved(o);
+ }
+ entity.sensors().set(getPreviousSensor(), previous);
+ requestPersist();
+ // In advance of the next event.
+ previous = Collections.unmodifiableSet(newValue);
--- End diff --
Do we really need a separate sensor for `previous`? It's actually always equal to the current value of `TRIGGER_SENSOR` (apart for the very short period after update and before this executes).
Can initialize it from `TRIGGER_SENSOR` on rebind. That's actually what you already do. So the previous sensor is just for users to look at?
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---
[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by sjcorbett <gi...@git.apache.org>.
Github user sjcorbett commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83262396
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
--- End diff --
If we move `onAdded` and `onRemoved` do we risk having this kind of race?
```
previous value of sensor is []
Thread A calls onEvent with [1]
Thread B calls onEvent with []
A obtains updateLock and calculates added and removed.
A releases updateLock.
A pauses.
B obtains updateLock and calculates added and removed
B releases updateLock
B invokes onRemoved(1)
A wakes up and invokes onAdded(1)
```
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---
[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by neykov <gi...@git.apache.org>.
Github user neykov commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83198850
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
--- End diff --
You can hold the lock just for the following actions.
* copying the `previous` reference in a local var
* updating `previous` to `newValue`
* moving `entity.sensors().set(getPreviousSensor(), previous);` up here
* using the local variable to work out the differences
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[GitHub] brooklyn-server issue #382: InvokeEffectorOnCollectionSensorChange
Posted by sjcorbett <gi...@git.apache.org>.
Github user sjcorbett commented on the issue:
https://github.com/apache/brooklyn-server/pull/382
I will merge this.
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnCollectionSensorChange
Posted by sjcorbett <gi...@git.apache.org>.
Github user sjcorbett commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83282121
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
--- End diff --
Though to be honest since effectors are asynchronous this will just be a problem further down the line, won't it?
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by neykov <gi...@git.apache.org>.
Github user neykov commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83199029
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
+
+ // Only perform an update if the collections have changed.
+ if (!added.isEmpty() || !removed.isEmpty()) {
+ for (Object o : added) {
+ onAdded(o);
+ }
+ for (Object o : removed) {
+ onRemoved(o);
+ }
+ entity.sensors().set(getPreviousSensor(), previous);
+ requestPersist();
+ // In advance of the next event.
+ previous = Collections.unmodifiableSet(newValue);
--- End diff --
The sensor value for `previous` is one iteration behind the value hold in the field. Wouldn't this be a problem after rebind?
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by neykov <gi...@git.apache.org>.
Github user neykov commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83200686
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
+ synchronized (updateLock) {
+ // Not using .immutableCopy() in case either set contains `null`.
+ Sets.difference(newValue, previous).copyInto(added);
+ Sets.difference(previous, newValue).copyInto(removed);
+
+ // Only perform an update if the collections have changed.
+ if (!added.isEmpty() || !removed.isEmpty()) {
+ for (Object o : added) {
+ onAdded(o);
+ }
+ for (Object o : removed) {
+ onRemoved(o);
+ }
+ entity.sensors().set(getPreviousSensor(), previous);
+ requestPersist();
--- End diff --
Shouldn't be needed, all important info is stored in sensors (which will trigger update on change).
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnCollectionSensorChange
Posted by asfgit <gi...@git.apache.org>.
Github user asfgit closed the pull request at:
https://github.com/apache/brooklyn-server/pull/382
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[GitHub] brooklyn-server issue #382: InvokeEffectorOnSetChange
Posted by sjcorbett <gi...@git.apache.org>.
Github user sjcorbett commented on the issue:
https://github.com/apache/brooklyn-server/pull/382
@neykov thank you for your comments. I've addressed everything I didn't comment on. I've also renamed the policy to `InvokeEffectorOnCollectionSensorChange` to be consistent with the existing `InvokeEffectorOnSensorChange`, but no strong feelings there really.
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by neykov <gi...@git.apache.org>.
Github user neykov commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83197672
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
--- End diff --
new value could be null
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[GitHub] brooklyn-server pull request #382: InvokeEffectorOnSetChange
Posted by neykov <gi...@git.apache.org>.
Github user neykov commented on a diff in the pull request:
https://github.com/apache/brooklyn-server/pull/382#discussion_r83198053
--- Diff: core/src/main/java/org/apache/brooklyn/policy/InvokeEffectorOnSetChange.java ---
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.brooklyn.policy;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.brooklyn.api.effector.Effector;
+import org.apache.brooklyn.api.entity.EntityLocal;
+import org.apache.brooklyn.api.sensor.AttributeSensor;
+import org.apache.brooklyn.api.sensor.Sensor;
+import org.apache.brooklyn.api.sensor.SensorEvent;
+import org.apache.brooklyn.api.sensor.SensorEventListener;
+import org.apache.brooklyn.config.ConfigKey;
+import org.apache.brooklyn.core.config.ConfigKeys;
+import org.apache.brooklyn.core.policy.AbstractPolicy;
+import org.apache.brooklyn.core.sensor.BasicAttributeSensor;
+import org.apache.brooklyn.util.collections.MutableMap;
+import org.apache.brooklyn.util.core.flags.TypeCoercions;
+import org.apache.brooklyn.util.guava.Maybe;
+import org.apache.brooklyn.util.text.Strings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.collect.Sets;
+import com.google.common.reflect.TypeToken;
+
+/**
+ * Subscribes to events on a collection {@link AttributeSensor} and invokes the named
+ * effectors for each element that was added and removed.
+ * <p>
+ * The policy only detects <em>replacements</em> of the collection; it does not act on
+ * modifications. If the sensor has value <code>A</code> and an element is added –
+ * value <code>A'</code> – the on-added effector is not invoked. If the sensor is
+ * later set to <code>B</code> the delta is made between <code>A</code> and <code>B</code>,
+ * not <code>A'</code> and <code>B</code>.
+ * <p>
+ * To simplify the detection of additions and removals the collection is converted to a
+ * {@link Set}. This means that only a single event will fire for duplicate elements in
+ * the collection.
+ * <p>
+ * The effectors are provided the elements that changed in their parameter map. If the
+ * sensor is a collection of maps the elements are provided with their keys coerced to
+ * strings and their values unchanged. Otherwise the elements are provided in a
+ * single-entry map keyed by the value for {@link #PARAMETER_NAME}.
+ */
+public class InvokeEffectorOnSetChange extends AbstractPolicy implements SensorEventListener<Collection<?>> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(InvokeEffectorOnSetChange.class);
+
+ public static final ConfigKey<AttributeSensor<? extends Collection<?>>> TRIGGER_SENSOR = ConfigKeys.newConfigKey(
+ new TypeToken<AttributeSensor<? extends Collection<?>>>() {},
+ "sensor",
+ "Sensor to be monitored.");
+
+ public static final ConfigKey<String> PREVIOUS_SENSOR_NAME = ConfigKeys.newStringConfigKey(
+ "previousSensorName",
+ "The name under which the previous value for the trigger sensor should be published. " +
+ "If unset \".previous\" will be appended to the name of the trigger sensor.");
+
+ public static final ConfigKey<String> ON_ADDED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onAdded",
+ "Name of the effector to invoke when entries are added to the collection.");
+
+ public static final ConfigKey<String> ON_REMOVED_EFFECTOR_NAME = ConfigKeys.newStringConfigKey(
+ "onRemoved",
+ "Name of the effector to invoke when entries are removed from the collection.");
+
+ public static final ConfigKey<String> PARAMETER_NAME = ConfigKeys.newStringConfigKey(
+ "parameterName",
+ "The name of the parameter to supply to the effectors",
+ "value");
+
+ /** The previous version of the set against which events will be compared. */
+ private Set<Object> previous = Collections.emptySet();
+
+ /** Guards accesses of previous. */
+ private final Object[] updateLock = new Object[0];
+
+ @Override
+ public void setEntity(EntityLocal entity) {
+ super.setEntity(entity);
+ Sensor<? extends Collection<?>> sensor =
+ checkNotNull(getConfig(TRIGGER_SENSOR), "Value required for " + TRIGGER_SENSOR.getName());
+
+ checkArgument(Strings.isNonBlank(getConfig(PARAMETER_NAME)), "Value required for " + PARAMETER_NAME.getName());
+
+ // Fail straight away if neither effector is found.
+ if (getEffector(getOnAddedEffector()).isAbsentOrNull() &&
+ getEffector(getOnRemovedEffector()).isAbsentOrNull()) {
+ throw new IllegalArgumentException("Value required for one or both of " + ON_ADDED_EFFECTOR_NAME.getName() +
+ " and " + ON_REMOVED_EFFECTOR_NAME.getName());
+ }
+
+ // Initialise `present` before subscribing.
+ Collection<?> current = entity.sensors().get(getTriggerSensor());
+ synchronized (updateLock) {
+ previous = (current != null) ? new HashSet<>(current) : Collections.emptySet();
+ }
+ subscriptions().subscribe(entity, sensor, this);
+ }
+
+ @Override
+ public void onEvent(SensorEvent<Collection<?>> event) {
+ final Set<Object> added = new HashSet<>(), removed = new HashSet<>();
+ Set<Object> newValue = new HashSet<>(event.getValue());
--- End diff --
Could use linked set to keep iteration order.
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