2 * ============LICENSE_START=======================================================
4 * ================================================================================
5 * Copyright (C) 2020 AT&T Intellectual Property. All rights reserved.
6 * ================================================================================
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * ============LICENSE_END=========================================================
21 package org.onap.policy.controlloop.actorserviceprovider.impl;
23 import java.util.ArrayDeque;
24 import java.util.ArrayList;
25 import java.util.Arrays;
26 import java.util.HashMap;
27 import java.util.LinkedHashMap;
28 import java.util.LinkedList;
29 import java.util.List;
31 import java.util.Queue;
32 import java.util.UUID;
33 import java.util.concurrent.CancellationException;
34 import java.util.concurrent.CompletableFuture;
35 import java.util.concurrent.CompletionException;
36 import java.util.concurrent.Executor;
37 import java.util.concurrent.TimeUnit;
38 import java.util.concurrent.TimeoutException;
39 import java.util.function.BiConsumer;
40 import java.util.function.Function;
41 import java.util.function.Supplier;
42 import java.util.function.UnaryOperator;
43 import lombok.AccessLevel;
46 import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
47 import org.onap.policy.common.endpoints.utils.NetLoggerUtil;
48 import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
49 import org.onap.policy.common.utils.coder.Coder;
50 import org.onap.policy.common.utils.coder.CoderException;
51 import org.onap.policy.common.utils.coder.StandardCoder;
52 import org.onap.policy.controlloop.ControlLoopOperation;
53 import org.onap.policy.controlloop.actorserviceprovider.CallbackManager;
54 import org.onap.policy.controlloop.actorserviceprovider.Operation;
55 import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
56 import org.onap.policy.controlloop.actorserviceprovider.parameters.ControlLoopOperationParams;
57 import org.onap.policy.controlloop.actorserviceprovider.parameters.OperatorConfig;
58 import org.onap.policy.controlloop.actorserviceprovider.pipeline.PipelineControllerFuture;
59 import org.onap.policy.controlloop.policy.PolicyResult;
60 import org.slf4j.Logger;
61 import org.slf4j.LoggerFactory;
64 * Partial implementation of an operator. In general, it's preferable that subclasses
65 * would override {@link #startOperationAsync(int, OperationOutcome)
66 * startOperationAsync()}. However, if that proves to be too difficult, then they can
67 * simply override {@link #doOperation(int, OperationOutcome) doOperation()}. In addition,
68 * if the operation requires any preprocessor steps, the subclass may choose to override
69 * {@link #startPreprocessorAsync()}.
71 * The futures returned by the methods within this class can be canceled, and will
72 * propagate the cancellation to any subtasks. Thus it is also expected that any futures
73 * returned by overridden methods will do the same. Of course, if a class overrides
74 * {@link #doOperation(int, OperationOutcome) doOperation()}, then there's little that can
75 * be done to cancel that particular operation.
77 * In general tasks in a pipeline are executed by the same thread. However, the following
78 * should always be executed via the executor specified in "params":
80 * <li>start callback</li>
81 * <li>completion callback</li>
82 * <li>controller completion (i.e., delayedComplete())</li>
85 public abstract class OperationPartial implements Operation {
86 private static final Logger logger = LoggerFactory.getLogger(OperationPartial.class);
87 private static final Coder coder = new StandardCoder();
89 public static final String GUARD_ACTOR_NAME = "GUARD";
90 public static final String GUARD_OPERATION_NAME = "Decision";
91 public static final long DEFAULT_RETRY_WAIT_MS = 1000L;
93 private final OperatorConfig config;
96 * Operation parameters.
98 protected final ControlLoopOperationParams params;
101 private final String fullName;
104 @Setter(AccessLevel.PROTECTED)
105 private String subRequestId;
108 private final List<String> propertyNames;
111 * Values for the properties identified by {@link #getPropertyNames()}.
113 private final Map<String, Object> properties = new HashMap<>();
117 * Constructs the object.
119 * @param params operation parameters
120 * @param config configuration for this operation
121 * @param propertyNames names of properties required by this operation
123 public OperationPartial(ControlLoopOperationParams params, OperatorConfig config, List<String> propertyNames) {
124 this.params = params;
125 this.config = config;
126 this.fullName = params.getActor() + "." + params.getOperation();
127 this.propertyNames = propertyNames;
130 public Executor getBlockingExecutor() {
131 return config.getBlockingExecutor();
134 public String getActorName() {
135 return params.getActor();
138 public String getName() {
139 return params.getOperation();
145 * @param name property name
146 * @param value new value
148 public void setProperty(String name, Object value) {
149 properties.put(name, value);
153 * Gets a property's value.
155 * @param name name of the property of interest
156 * @return the property's value, or {@code null} if it has no value
158 @SuppressWarnings("unchecked")
159 public <T> T getProperty(String name) {
160 return (T) properties.get(name);
164 public CompletableFuture<OperationOutcome> start() {
165 // allocate a controller for the entire operation
166 final PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
168 CompletableFuture<OperationOutcome> preproc = startPreprocessorAsync();
169 if (preproc == null) {
170 // no preprocessor required - just start the operation
171 return startOperationAttempt(controller, 1);
175 * Do preprocessor first and then, if successful, start the operation. Note:
176 * operations create their own outcome, ignoring the outcome from any previous
179 * Wrap the preprocessor to ensure "stop" is propagated to it.
182 controller.wrap(preproc)
183 .exceptionally(fromException("preprocessor of operation"))
184 .thenCompose(handlePreprocessorFailure(controller))
185 .thenCompose(unusedOutcome -> startOperationAttempt(controller, 1))
186 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
193 * Handles a failure in the preprocessor pipeline. If a failure occurred, then it
194 * invokes the call-backs, marks the controller complete, and returns an incomplete
195 * future, effectively halting the pipeline. Otherwise, it returns the outcome that it
198 * Assumes that no callbacks have been invoked yet.
200 * @param controller pipeline controller
201 * @return a function that checks the outcome status and continues, if successful, or
202 * indicates a failure otherwise
204 private Function<OperationOutcome, CompletableFuture<OperationOutcome>> handlePreprocessorFailure(
205 PipelineControllerFuture<OperationOutcome> controller) {
209 if (isSuccess(outcome)) {
210 logger.info("{}: preprocessor succeeded for {}", getFullName(), params.getRequestId());
211 return CompletableFuture.completedFuture(outcome);
214 logger.warn("preprocessor failed, discontinuing operation {} for {}", getFullName(), params.getRequestId());
216 final Executor executor = params.getExecutor();
217 final CallbackManager callbacks = new CallbackManager();
219 // propagate "stop" to the callbacks
220 controller.add(callbacks);
222 final OperationOutcome outcome2 = params.makeOutcome();
224 // TODO need a FAILURE_MISSING_DATA (e.g., A&AI)
226 outcome2.setFinalOutcome(true);
227 outcome2.setResult(PolicyResult.FAILURE_GUARD);
228 outcome2.setMessage(outcome != null ? outcome.getMessage() : null);
231 CompletableFuture.completedFuture(outcome2)
232 .whenCompleteAsync(callbackStarted(callbacks), executor)
233 .whenCompleteAsync(callbackCompleted(callbacks), executor)
234 .whenCompleteAsync(controller.delayedComplete(), executor);
237 return new CompletableFuture<>();
242 * Invokes the operation's preprocessor step(s) as a "future". This method simply
243 * returns {@code null}.
245 * This method assumes the following:
247 * <li>the operator is alive</li>
248 * <li>exceptions generated within the pipeline will be handled by the invoker</li>
251 * @return a function that will start the preprocessor and returns its outcome, or
252 * {@code null} if this operation needs no preprocessor
254 protected CompletableFuture<OperationOutcome> startPreprocessorAsync() {
259 * Invokes the operation's guard step(s) as a "future".
261 * This method assumes the following:
263 * <li>the operator is alive</li>
264 * <li>exceptions generated within the pipeline will be handled by the invoker</li>
267 * @return a function that will start the guard checks and returns its outcome, or
268 * {@code null} if this operation has no guard
270 protected CompletableFuture<OperationOutcome> startGuardAsync() {
271 // get the guard payload
272 Map<String, Object> payload = makeGuardPayload();
275 * Note: can't use constants from actor.guard, because that would create a
276 * circular dependency.
278 return params.toBuilder().actor(GUARD_ACTOR_NAME).operation(GUARD_OPERATION_NAME).retry(null).timeoutSec(null)
279 .payload(payload).build().start();
283 * Creates a payload to execute a guard operation.
285 * @return a new guard payload
287 protected Map<String, Object> makeGuardPayload() {
288 Map<String, Object> guard = new LinkedHashMap<>();
289 guard.put("actor", params.getActor());
290 guard.put("operation", params.getOperation());
291 guard.put("target", params.getTargetEntity());
292 guard.put("requestId", params.getRequestId());
294 String clname = params.getContext().getEvent().getClosedLoopControlName();
295 if (clname != null) {
296 guard.put("clname", clname);
303 * Starts the operation attempt, with no preprocessor. When all retries complete, it
304 * will complete the controller.
306 * @param controller controller for all operation attempts
307 * @param attempt attempt number, typically starting with 1
308 * @return a future that will return the final result of all attempts
310 private CompletableFuture<OperationOutcome> startOperationAttempt(
311 PipelineControllerFuture<OperationOutcome> controller, int attempt) {
313 generateSubRequestId(attempt);
315 // propagate "stop" to the operation attempt
316 controller.wrap(startAttemptWithoutRetries(attempt)).thenCompose(retryOnFailure(controller, attempt))
317 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
323 * Generates and sets {@link #subRequestId} to a new subrequest ID.
324 * @param attempt attempt number, typically starting with 1
326 public void generateSubRequestId(int attempt) {
327 // Note: this should be "protected", but that makes junits much messier
329 setSubRequestId(UUID.randomUUID().toString());
333 * Starts the operation attempt, without doing any retries.
335 * @param params operation parameters
336 * @param attempt attempt number, typically starting with 1
337 * @return a future that will return the result of a single operation attempt
339 private CompletableFuture<OperationOutcome> startAttemptWithoutRetries(int attempt) {
341 logger.info("{}: start operation attempt {} for {}", getFullName(), attempt, params.getRequestId());
343 final Executor executor = params.getExecutor();
344 final OperationOutcome outcome = params.makeOutcome();
345 final CallbackManager callbacks = new CallbackManager();
347 // this operation attempt gets its own controller
348 final PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
350 // propagate "stop" to the callbacks
351 controller.add(callbacks);
354 CompletableFuture<OperationOutcome> future = CompletableFuture.completedFuture(outcome)
355 .whenCompleteAsync(callbackStarted(callbacks), executor)
356 .thenCompose(controller.wrap(outcome2 -> startOperationAsync(attempt, outcome2)));
359 // handle timeouts, if specified
360 long timeoutMillis = getTimeoutMs(params.getTimeoutSec());
361 if (timeoutMillis > 0) {
362 logger.info("{}: set timeout to {}ms for {}", getFullName(), timeoutMillis, params.getRequestId());
363 future = future.orTimeout(timeoutMillis, TimeUnit.MILLISECONDS);
367 * Note: we re-invoke callbackStarted() just to be sure the callback is invoked
368 * before callbackCompleted() is invoked.
370 * Note: no need to remove "callbacks" from the pipeline, as we're going to stop
371 * the pipeline as the last step anyway.
375 future.exceptionally(fromException("operation"))
376 .thenApply(setRetryFlag(attempt))
377 .whenCompleteAsync(callbackStarted(callbacks), executor)
378 .whenCompleteAsync(callbackCompleted(callbacks), executor)
379 .whenCompleteAsync(controller.delayedComplete(), executor);
386 * Determines if the outcome was successful.
388 * @param outcome outcome to examine
389 * @return {@code true} if the outcome was successful
391 protected boolean isSuccess(OperationOutcome outcome) {
392 return (outcome != null && outcome.getResult() == PolicyResult.SUCCESS);
396 * Determines if the outcome was a failure for this operator.
398 * @param outcome outcome to examine, or {@code null}
399 * @return {@code true} if the outcome is not {@code null} and was a failure
400 * <i>and</i> was associated with this operator, {@code false} otherwise
402 protected boolean isActorFailed(OperationOutcome outcome) {
403 return (isSameOperation(outcome) && outcome.getResult() == PolicyResult.FAILURE);
407 * Determines if the given outcome is for this operation.
409 * @param outcome outcome to examine
410 * @return {@code true} if the outcome is for this operation, {@code false} otherwise
412 protected boolean isSameOperation(OperationOutcome outcome) {
413 return OperationOutcome.isFor(outcome, getActorName(), getName());
417 * Invokes the operation as a "future". This method simply invokes
418 * {@link #doOperation()} using the {@link #blockingExecutor "blocking executor"},
419 * returning the result via a "future".
421 * Note: if the operation uses blocking I/O, then it should <i>not</i> be run using
422 * the executor in the "params", as that may bring the background thread pool to a
423 * grinding halt. The {@link #blockingExecutor "blocking executor"} should be used
426 * This method assumes the following:
428 * <li>the operator is alive</li>
429 * <li>verifyRunning() has been invoked</li>
430 * <li>callbackStarted() has been invoked</li>
431 * <li>the invoker will perform appropriate timeout checks</li>
432 * <li>exceptions generated within the pipeline will be handled by the invoker</li>
435 * @param attempt attempt number, typically starting with 1
436 * @return a function that will start the operation and return its result when
439 protected CompletableFuture<OperationOutcome> startOperationAsync(int attempt, OperationOutcome outcome) {
441 return CompletableFuture.supplyAsync(() -> doOperation(attempt, outcome), getBlockingExecutor());
445 * Low-level method that performs the operation. This can make the same assumptions
446 * that are made by {@link #doOperationAsFuture()}. This particular method simply
447 * throws an {@link UnsupportedOperationException}.
449 * @param attempt attempt number, typically starting with 1
450 * @param operation the operation being performed
451 * @return the outcome of the operation
453 protected OperationOutcome doOperation(int attempt, OperationOutcome operation) {
455 throw new UnsupportedOperationException("start operation " + getFullName());
459 * Sets the outcome status to FAILURE_RETRIES, if the current operation outcome is
460 * FAILURE, assuming the policy specifies retries and the retry count has been
463 * @param attempt latest attempt number, starting with 1
464 * @return a function to get the next future to execute
466 private Function<OperationOutcome, OperationOutcome> setRetryFlag(int attempt) {
468 return origOutcome -> {
469 // ensure we have a non-null outcome
470 OperationOutcome outcome;
471 if (origOutcome != null) {
472 outcome = origOutcome;
474 logger.warn("{}: null outcome; treating as a failure for {}", getFullName(), params.getRequestId());
475 outcome = this.setOutcome(params.makeOutcome(), PolicyResult.FAILURE);
478 // ensure correct actor/operation
479 outcome.setActor(getActorName());
480 outcome.setOperation(getName());
482 // determine if we should retry, based on the result
483 if (outcome.getResult() != PolicyResult.FAILURE) {
484 // do not retry success or other failure types (e.g., exception)
485 outcome.setFinalOutcome(true);
489 int retry = getRetry(params.getRetry());
491 // no retries were specified
492 outcome.setFinalOutcome(true);
494 } else if (attempt <= retry) {
495 // have more retries - not the final outcome
496 outcome.setFinalOutcome(false);
500 * retries were specified and we've already tried them all - change to
503 logger.info("operation {} retries exhausted for {}", getFullName(), params.getRequestId());
504 outcome.setResult(PolicyResult.FAILURE_RETRIES);
505 outcome.setFinalOutcome(true);
513 * Restarts the operation if it was a FAILURE. Assumes that {@link #setRetryFlag(int)}
514 * was previously invoked, and thus that the "operation" is not {@code null}.
516 * @param controller controller for all of the retries
517 * @param attempt latest attempt number, starting with 1
518 * @return a function to get the next future to execute
520 private Function<OperationOutcome, CompletableFuture<OperationOutcome>> retryOnFailure(
521 PipelineControllerFuture<OperationOutcome> controller, int attempt) {
523 return operation -> {
524 if (!isActorFailed(operation)) {
525 // wrong type or wrong operation - just leave it as is
526 logger.info("not retrying operation {} for {}", getFullName(), params.getRequestId());
527 controller.complete(operation);
528 return new CompletableFuture<>();
531 if (getRetry(params.getRetry()) <= 0) {
532 // no retries - already marked as FAILURE, so just return it
533 logger.info("operation {} no retries for {}", getFullName(), params.getRequestId());
534 controller.complete(operation);
535 return new CompletableFuture<>();
539 * Retry the operation.
541 long waitMs = getRetryWaitMs();
542 logger.info("retry operation {} in {}ms for {}", getFullName(), waitMs, params.getRequestId());
544 return sleep(waitMs, TimeUnit.MILLISECONDS)
545 .thenCompose(unused -> startOperationAttempt(controller, attempt + 1));
550 * Convenience method that starts a sleep(), running via a future.
552 * @param sleepTime time to sleep
553 * @param unit time unit
554 * @return a future that will complete when the sleep completes
556 protected CompletableFuture<Void> sleep(long sleepTime, TimeUnit unit) {
557 if (sleepTime <= 0) {
558 return CompletableFuture.completedFuture(null);
561 return new CompletableFuture<Void>().completeOnTimeout(null, sleepTime, unit);
565 * Converts an exception into an operation outcome, returning a copy of the outcome to
566 * prevent background jobs from changing it.
568 * @param type type of item throwing the exception
569 * @return a function that will convert an exception into an operation outcome
571 private Function<Throwable, OperationOutcome> fromException(String type) {
574 OperationOutcome outcome = params.makeOutcome();
576 if (thrown instanceof CancellationException || thrown.getCause() instanceof CancellationException) {
577 // do not include exception in the message, as it just clutters the log
578 logger.warn("{} canceled {}.{} for {}", type, outcome.getActor(), outcome.getOperation(),
579 params.getRequestId());
581 logger.warn("exception thrown by {} {}.{} for {}", type, outcome.getActor(), outcome.getOperation(),
582 params.getRequestId(), thrown);
585 return setOutcome(outcome, thrown);
590 * Similar to {@link CompletableFuture#anyOf(CompletableFuture...)}, but it cancels
591 * any outstanding futures when one completes.
593 * @param futureMakers function to make a future. If the function returns
594 * {@code null}, then no future is created for that function. On the other
595 * hand, if the function throws an exception, then the previously created
596 * functions are canceled and the exception is re-thrown
597 * @return a future to cancel or await an outcome, or {@code null} if no futures were
598 * created. If this future is canceled, then all of the futures will be
601 public CompletableFuture<OperationOutcome> anyOf(
602 @SuppressWarnings("unchecked") Supplier<CompletableFuture<OperationOutcome>>... futureMakers) {
604 return anyOf(Arrays.asList(futureMakers));
608 * Similar to {@link CompletableFuture#anyOf(CompletableFuture...)}, but it cancels
609 * any outstanding futures when one completes.
611 * @param futureMakers function to make a future. If the function returns
612 * {@code null}, then no future is created for that function. On the other
613 * hand, if the function throws an exception, then the previously created
614 * functions are canceled and the exception is re-thrown
615 * @return a future to cancel or await an outcome, or {@code null} if no futures were
616 * created. If this future is canceled, then all of the futures will be
617 * canceled. Similarly, when this future completes, any incomplete futures
620 public CompletableFuture<OperationOutcome> anyOf(List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers) {
622 PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
624 CompletableFuture<OperationOutcome>[] futures =
625 attachFutures(controller, futureMakers, UnaryOperator.identity());
627 if (futures.length == 0) {
628 // no futures were started
632 if (futures.length == 1) {
636 CompletableFuture.anyOf(futures).thenApply(outcome -> (OperationOutcome) outcome)
637 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
643 * Similar to {@link CompletableFuture#allOf(CompletableFuture...)}.
645 * @param futureMakers function to make a future. If the function returns
646 * {@code null}, then no future is created for that function. On the other
647 * hand, if the function throws an exception, then the previously created
648 * functions are canceled and the exception is re-thrown
649 * @return a future to cancel or await an outcome, or {@code null} if no futures were
650 * created. If this future is canceled, then all of the futures will be
653 public CompletableFuture<OperationOutcome> allOf(
654 @SuppressWarnings("unchecked") Supplier<CompletableFuture<OperationOutcome>>... futureMakers) {
656 return allOf(Arrays.asList(futureMakers));
660 * Similar to {@link CompletableFuture#allOf(CompletableFuture...)}.
662 * @param futureMakers function to make a future. If the function returns
663 * {@code null}, then no future is created for that function. On the other
664 * hand, if the function throws an exception, then the previously created
665 * functions are canceled and the exception is re-thrown
666 * @return a future to cancel or await an outcome, or {@code null} if no futures were
667 * created. If this future is canceled, then all of the futures will be
668 * canceled. Similarly, when this future completes, any incomplete futures
671 public CompletableFuture<OperationOutcome> allOf(List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers) {
672 PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
674 Queue<OperationOutcome> outcomes = new LinkedList<>();
676 CompletableFuture<OperationOutcome>[] futures =
677 attachFutures(controller, futureMakers, future -> future.thenApply(outcome -> {
678 synchronized (outcomes) {
679 outcomes.add(outcome);
684 if (futures.length == 0) {
685 // no futures were started
689 if (futures.length == 1) {
694 CompletableFuture.allOf(futures)
695 .thenApply(unused -> combineOutcomes(outcomes))
696 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
703 * Invokes the functions to create the futures and attaches them to the controller.
705 * @param controller master controller for all of the futures
706 * @param futureMakers futures to be attached to the controller
707 * @param adorn function that "adorns" the future, possible adding onto its pipeline.
708 * Returns the adorned future
709 * @return an array of futures, possibly zero-length. If the array is of size one,
710 * then that one item should be returned instead of the controller
712 private CompletableFuture<OperationOutcome>[] attachFutures(PipelineControllerFuture<OperationOutcome> controller,
713 List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers,
714 UnaryOperator<CompletableFuture<OperationOutcome>> adorn) {
716 if (futureMakers.isEmpty()) {
717 @SuppressWarnings("unchecked")
718 CompletableFuture<OperationOutcome>[] result = new CompletableFuture[0];
722 // the last, unadorned future that is created
723 CompletableFuture<OperationOutcome> lastFuture = null;
725 List<CompletableFuture<OperationOutcome>> futures = new ArrayList<>(futureMakers.size());
728 for (var maker : futureMakers) {
730 CompletableFuture<OperationOutcome> future = maker.get();
731 if (future == null) {
735 // propagate "stop" to the future
736 controller.add(future);
738 futures.add(adorn.apply(future));
742 } catch (RuntimeException e) {
743 logger.warn("{}: exception creating 'future' for {}", getFullName(), params.getRequestId());
744 controller.cancel(false);
749 @SuppressWarnings("unchecked")
750 CompletableFuture<OperationOutcome>[] result = new CompletableFuture[futures.size()];
752 if (result.length == 1) {
753 // special case - return the unadorned future
754 result[0] = lastFuture;
758 return futures.toArray(result);
762 * Combines the outcomes from a set of tasks.
764 * @param outcomes outcomes to be examined
765 * @return the combined outcome
767 private OperationOutcome combineOutcomes(Queue<OperationOutcome> outcomes) {
769 // identify the outcome with the highest priority
770 OperationOutcome outcome = outcomes.remove();
771 int priority = detmPriority(outcome);
773 for (OperationOutcome outcome2 : outcomes) {
774 int priority2 = detmPriority(outcome2);
776 if (priority2 > priority) {
778 priority = priority2;
782 logger.info("{}: combined outcome of tasks is {} for {}", getFullName(),
783 (outcome == null ? null : outcome.getResult()), params.getRequestId());
789 * Determines the priority of an outcome based on its result.
791 * @param outcome outcome to examine, or {@code null}
792 * @return the outcome's priority
794 protected int detmPriority(OperationOutcome outcome) {
795 if (outcome == null || outcome.getResult() == null) {
799 switch (outcome.getResult()) {
806 case FAILURE_RETRIES:
812 case FAILURE_TIMEOUT:
815 case FAILURE_EXCEPTION:
822 * Performs a sequence of tasks, stopping if a task fails. A given task's future is
823 * not created until the previous task completes. The pipeline returns the outcome of
824 * the last task executed.
826 * @param futureMakers functions to make the futures
827 * @return a future to cancel the sequence or await the outcome
829 public CompletableFuture<OperationOutcome> sequence(
830 @SuppressWarnings("unchecked") Supplier<CompletableFuture<OperationOutcome>>... futureMakers) {
832 return sequence(Arrays.asList(futureMakers));
836 * Performs a sequence of tasks, stopping if a task fails. A given task's future is
837 * not created until the previous task completes. The pipeline returns the outcome of
838 * the last task executed.
840 * @param futureMakers functions to make the futures
841 * @return a future to cancel the sequence or await the outcome, or {@code null} if
842 * there were no tasks to perform
844 public CompletableFuture<OperationOutcome> sequence(
845 List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers) {
847 Queue<Supplier<CompletableFuture<OperationOutcome>>> queue = new ArrayDeque<>(futureMakers);
849 CompletableFuture<OperationOutcome> nextTask = getNextTask(queue);
850 if (nextTask == null) {
855 if (queue.isEmpty()) {
856 // only one task - just return it rather than wrapping it in a controller
861 * multiple tasks - need a controller to stop whichever task is currently
864 final PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
865 final Executor executor = params.getExecutor();
868 controller.wrap(nextTask)
869 .thenCompose(nextTaskOnSuccess(controller, queue))
870 .whenCompleteAsync(controller.delayedComplete(), executor);
877 * Executes the next task in the queue, if the previous outcome was successful.
879 * @param controller pipeline controller
880 * @param taskQueue queue of tasks to be performed
881 * @return a future to execute the remaining tasks, or the current outcome, if it's a
882 * failure, or if there are no more tasks
884 private Function<OperationOutcome, CompletableFuture<OperationOutcome>> nextTaskOnSuccess(
885 PipelineControllerFuture<OperationOutcome> controller,
886 Queue<Supplier<CompletableFuture<OperationOutcome>>> taskQueue) {
889 if (!isSuccess(outcome)) {
890 // return the failure
891 return CompletableFuture.completedFuture(outcome);
894 CompletableFuture<OperationOutcome> nextTask = getNextTask(taskQueue);
895 if (nextTask == null) {
896 // no tasks - just return the success
897 return CompletableFuture.completedFuture(outcome);
903 .thenCompose(nextTaskOnSuccess(controller, taskQueue));
909 * Gets the next task from the queue, skipping those that are {@code null}.
911 * @param taskQueue task queue
912 * @return the next task, or {@code null} if the queue is now empty
914 private CompletableFuture<OperationOutcome> getNextTask(
915 Queue<Supplier<CompletableFuture<OperationOutcome>>> taskQueue) {
917 Supplier<CompletableFuture<OperationOutcome>> maker;
919 while ((maker = taskQueue.poll()) != null) {
920 CompletableFuture<OperationOutcome> future = maker.get();
921 if (future != null) {
930 * Sets the start time of the operation and invokes the callback to indicate that the
931 * operation has started. Does nothing if the pipeline has been stopped.
933 * This assumes that the "outcome" is not {@code null}.
935 * @param callbacks used to determine if the start callback can be invoked
936 * @return a function that sets the start time and invokes the callback
938 protected BiConsumer<OperationOutcome, Throwable> callbackStarted(CallbackManager callbacks) {
940 return (outcome, thrown) -> {
942 if (callbacks.canStart()) {
943 outcome.setSubRequestId(getSubRequestId());
944 outcome.setStart(callbacks.getStartTime());
945 outcome.setEnd(null);
947 // pass a copy to the callback
948 OperationOutcome outcome2 = new OperationOutcome(outcome);
949 outcome2.setFinalOutcome(false);
950 params.callbackStarted(outcome2);
956 * Sets the end time of the operation and invokes the callback to indicate that the
957 * operation has completed. Does nothing if the pipeline has been stopped.
959 * This assumes that the "outcome" is not {@code null}.
961 * Note: the start time must be a reference rather than a plain value, because it's
962 * value must be gotten on-demand, when the returned function is executed at a later
965 * @param callbacks used to determine if the end callback can be invoked
966 * @return a function that sets the end time and invokes the callback
968 protected BiConsumer<OperationOutcome, Throwable> callbackCompleted(CallbackManager callbacks) {
970 return (outcome, thrown) -> {
971 if (callbacks.canEnd()) {
972 outcome.setSubRequestId(getSubRequestId());
973 outcome.setStart(callbacks.getStartTime());
974 outcome.setEnd(callbacks.getEndTime());
976 // pass a copy to the callback
977 params.callbackCompleted(new OperationOutcome(outcome));
983 * Sets an operation's outcome and message, based on a throwable.
985 * @param operation operation to be updated
986 * @return the updated operation
988 public OperationOutcome setOutcome(OperationOutcome operation, Throwable thrown) {
989 PolicyResult result = (isTimeout(thrown) ? PolicyResult.FAILURE_TIMEOUT : PolicyResult.FAILURE_EXCEPTION);
990 return setOutcome(operation, result);
994 * Sets an operation's outcome and default message based on the result.
996 * @param operation operation to be updated
997 * @param result result of the operation
998 * @return the updated operation
1000 public OperationOutcome setOutcome(OperationOutcome operation, PolicyResult result) {
1001 logger.trace("{}: set outcome {} for {}", getFullName(), result, params.getRequestId());
1002 operation.setResult(result);
1003 operation.setMessage(result == PolicyResult.SUCCESS ? ControlLoopOperation.SUCCESS_MSG
1004 : ControlLoopOperation.FAILED_MSG);
1010 * Determines if a throwable is due to a timeout.
1012 * @param thrown throwable of interest
1013 * @return {@code true} if the throwable is due to a timeout, {@code false} otherwise
1015 protected boolean isTimeout(Throwable thrown) {
1016 if (thrown instanceof CompletionException) {
1017 thrown = thrown.getCause();
1020 return (thrown instanceof TimeoutException);
1024 * Logs a message. If the message is not of type, String, then it attempts to
1025 * pretty-print it into JSON before logging.
1027 * @param direction IN or OUT
1028 * @param infra communication infrastructure on which it was published
1029 * @param source source name (e.g., the URL or Topic name)
1030 * @param message message to be logged
1031 * @return the JSON text that was logged
1033 public <T> String logMessage(EventType direction, CommInfrastructure infra, String source, T message) {
1036 json = prettyPrint(message);
1038 } catch (IllegalArgumentException e) {
1039 String type = (direction == EventType.IN ? "response" : "request");
1040 logger.warn("cannot pretty-print {}", type, e);
1041 json = message.toString();
1044 logger.info("[{}|{}|{}|]{}{}", direction, infra, source, NetLoggerUtil.SYSTEM_LS, json);
1050 * Converts a message to a "pretty-printed" String using the operation's normal
1051 * serialization provider (i.e., it's <i>coder</i>).
1053 * @param message response to be logged
1054 * @return the JSON text that was logged
1055 * @throws IllegalArgumentException if the message cannot be converted
1057 public <T> String prettyPrint(T message) {
1058 if (message == null) {
1060 } else if (message instanceof String) {
1061 return message.toString();
1064 return getCoder().encode(message, true);
1065 } catch (CoderException e) {
1066 throw new IllegalArgumentException("cannot encode message", e);
1071 // these may be overridden by subclasses or junit tests
1074 * Gets the retry count.
1076 * @param retry retry, extracted from the parameters, or {@code null}
1077 * @return the number of retries, or {@code 0} if no retries were specified
1079 protected int getRetry(Integer retry) {
1080 return (retry == null ? 0 : retry);
1084 * Gets the retry wait, in milliseconds.
1086 * @return the retry wait, in milliseconds
1088 protected long getRetryWaitMs() {
1089 return DEFAULT_RETRY_WAIT_MS;
1093 * Gets the operation timeout.
1095 * @param timeoutSec timeout, in seconds, extracted from the parameters, or
1097 * @return the operation timeout, in milliseconds, or {@code 0} if no timeout was
1100 protected long getTimeoutMs(Integer timeoutSec) {
1101 return (timeoutSec == null ? 0 : TimeUnit.MILLISECONDS.convert(timeoutSec, TimeUnit.SECONDS));
1104 // these may be overridden by junit tests
1106 protected Coder getCoder() {