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.LinkedList;
27 import java.util.List;
28 import java.util.Queue;
29 import java.util.concurrent.CompletableFuture;
30 import java.util.concurrent.CompletionException;
31 import java.util.concurrent.Executor;
32 import java.util.concurrent.TimeUnit;
33 import java.util.concurrent.TimeoutException;
34 import java.util.function.BiConsumer;
35 import java.util.function.Function;
36 import java.util.function.Supplier;
37 import java.util.function.UnaryOperator;
38 import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
39 import org.onap.policy.common.endpoints.utils.NetLoggerUtil;
40 import org.onap.policy.common.endpoints.utils.NetLoggerUtil.EventType;
41 import org.onap.policy.common.utils.coder.Coder;
42 import org.onap.policy.common.utils.coder.CoderException;
43 import org.onap.policy.common.utils.coder.StandardCoder;
44 import org.onap.policy.controlloop.ControlLoopOperation;
45 import org.onap.policy.controlloop.actorserviceprovider.CallbackManager;
46 import org.onap.policy.controlloop.actorserviceprovider.Operation;
47 import org.onap.policy.controlloop.actorserviceprovider.OperationOutcome;
48 import org.onap.policy.controlloop.actorserviceprovider.parameters.ControlLoopOperationParams;
49 import org.onap.policy.controlloop.actorserviceprovider.pipeline.PipelineControllerFuture;
50 import org.onap.policy.controlloop.policy.PolicyResult;
51 import org.slf4j.Logger;
52 import org.slf4j.LoggerFactory;
55 * Partial implementation of an operator. In general, it's preferable that subclasses
56 * would override {@link #startOperationAsync(int, OperationOutcome)
57 * startOperationAsync()}. However, if that proves to be too difficult, then they can
58 * simply override {@link #doOperation(int, OperationOutcome) doOperation()}. In addition,
59 * if the operation requires any preprocessor steps, the subclass may choose to override
60 * {@link #startPreprocessorAsync()}.
62 * The futures returned by the methods within this class can be canceled, and will
63 * propagate the cancellation to any subtasks. Thus it is also expected that any futures
64 * returned by overridden methods will do the same. Of course, if a class overrides
65 * {@link #doOperation(int, OperationOutcome) doOperation()}, then there's little that can
66 * be done to cancel that particular operation.
68 public abstract class OperationPartial implements Operation {
69 private static final Logger logger = LoggerFactory.getLogger(OperationPartial.class);
70 private static final Coder coder = new StandardCoder();
72 public static final long DEFAULT_RETRY_WAIT_MS = 1000L;
74 // values extracted from the operator
76 private final OperatorPartial operator;
79 * Operation parameters.
81 protected final ControlLoopOperationParams params;
85 * Constructs the object.
87 * @param params operation parameters
88 * @param operator operator that created this operation
90 public OperationPartial(ControlLoopOperationParams params, OperatorPartial operator) {
92 this.operator = operator;
95 public Executor getBlockingExecutor() {
96 return operator.getBlockingExecutor();
99 public String getFullName() {
100 return operator.getFullName();
103 public String getActorName() {
104 return operator.getActorName();
107 public String getName() {
108 return operator.getName();
112 public final CompletableFuture<OperationOutcome> start() {
113 if (!operator.isAlive()) {
114 throw new IllegalStateException("operation is not running: " + getFullName());
117 // allocate a controller for the entire operation
118 final PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
120 CompletableFuture<OperationOutcome> preproc = startPreprocessorAsync();
121 if (preproc == null) {
122 // no preprocessor required - just start the operation
123 return startOperationAttempt(controller, 1);
127 * Do preprocessor first and then, if successful, start the operation. Note:
128 * operations create their own outcome, ignoring the outcome from any previous
131 * Wrap the preprocessor to ensure "stop" is propagated to it.
134 controller.wrap(preproc)
135 .exceptionally(fromException("preprocessor of operation"))
136 .thenCompose(handlePreprocessorFailure(controller))
137 .thenCompose(unusedOutcome -> startOperationAttempt(controller, 1))
138 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
145 * Handles a failure in the preprocessor pipeline. If a failure occurred, then it
146 * invokes the call-backs, marks the controller complete, and returns an incomplete
147 * future, effectively halting the pipeline. Otherwise, it returns the outcome that it
150 * Assumes that no callbacks have been invoked yet.
152 * @param controller pipeline controller
153 * @return a function that checks the outcome status and continues, if successful, or
154 * indicates a failure otherwise
156 private Function<OperationOutcome, CompletableFuture<OperationOutcome>> handlePreprocessorFailure(
157 PipelineControllerFuture<OperationOutcome> controller) {
161 if (outcome != null && isSuccess(outcome)) {
162 logger.info("{}: preprocessor succeeded for {}", getFullName(), params.getRequestId());
163 return CompletableFuture.completedFuture(outcome);
166 logger.warn("preprocessor failed, discontinuing operation {} for {}", getFullName(), params.getRequestId());
168 final Executor executor = params.getExecutor();
169 final CallbackManager callbacks = new CallbackManager();
171 // propagate "stop" to the callbacks
172 controller.add(callbacks);
174 final OperationOutcome outcome2 = params.makeOutcome();
176 // TODO need a FAILURE_MISSING_DATA (e.g., A&AI)
178 outcome2.setResult(PolicyResult.FAILURE_GUARD);
179 outcome2.setMessage(outcome != null ? outcome.getMessage() : null);
182 CompletableFuture.completedFuture(outcome2)
183 .whenCompleteAsync(callbackStarted(callbacks), executor)
184 .whenCompleteAsync(callbackCompleted(callbacks), executor)
185 .whenCompleteAsync(controller.delayedComplete(), executor);
188 return new CompletableFuture<>();
193 * Invokes the operation's preprocessor step(s) as a "future". This method simply
194 * invokes {@link #startGuardAsync()}.
196 * This method assumes the following:
198 * <li>the operator is alive</li>
199 * <li>exceptions generated within the pipeline will be handled by the invoker</li>
202 * @return a function that will start the preprocessor and returns its outcome, or
203 * {@code null} if this operation needs no preprocessor
205 protected CompletableFuture<OperationOutcome> startPreprocessorAsync() {
206 return startGuardAsync();
210 * Invokes the operation's guard step(s) as a "future". This method simply returns
213 * This method assumes the following:
215 * <li>the operator is alive</li>
216 * <li>exceptions generated within the pipeline will be handled by the invoker</li>
219 * @return a function that will start the guard checks and returns its outcome, or
220 * {@code null} if this operation has no guard
222 protected CompletableFuture<OperationOutcome> startGuardAsync() {
227 * Starts the operation attempt, with no preprocessor. When all retries complete, it
228 * will complete the controller.
230 * @param controller controller for all operation attempts
231 * @param attempt attempt number, typically starting with 1
232 * @return a future that will return the final result of all attempts
234 private CompletableFuture<OperationOutcome> startOperationAttempt(
235 PipelineControllerFuture<OperationOutcome> controller, int attempt) {
237 // propagate "stop" to the operation attempt
238 controller.wrap(startAttemptWithoutRetries(attempt)).thenCompose(retryOnFailure(controller, attempt))
239 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
245 * Starts the operation attempt, without doing any retries.
247 * @param params operation parameters
248 * @param attempt attempt number, typically starting with 1
249 * @return a future that will return the result of a single operation attempt
251 private CompletableFuture<OperationOutcome> startAttemptWithoutRetries(int attempt) {
253 logger.info("{}: start operation attempt {} for {}", getFullName(), attempt, params.getRequestId());
255 final Executor executor = params.getExecutor();
256 final OperationOutcome outcome = params.makeOutcome();
257 final CallbackManager callbacks = new CallbackManager();
259 // this operation attempt gets its own controller
260 final PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
262 // propagate "stop" to the callbacks
263 controller.add(callbacks);
266 CompletableFuture<OperationOutcome> future = CompletableFuture.completedFuture(outcome)
267 .whenCompleteAsync(callbackStarted(callbacks), executor)
268 .thenCompose(controller.wrap(outcome2 -> startOperationAsync(attempt, outcome2)));
271 // handle timeouts, if specified
272 long timeoutMillis = getTimeoutMs(params.getTimeoutSec());
273 if (timeoutMillis > 0) {
274 logger.info("{}: set timeout to {}ms for {}", getFullName(), timeoutMillis, params.getRequestId());
275 future = future.orTimeout(timeoutMillis, TimeUnit.MILLISECONDS);
279 * Note: we re-invoke callbackStarted() just to be sure the callback is invoked
280 * before callbackCompleted() is invoked.
282 * Note: no need to remove "callbacks" from the pipeline, as we're going to stop
283 * the pipeline as the last step anyway.
287 future.exceptionally(fromException("operation"))
288 .thenApply(setRetryFlag(attempt))
289 .whenCompleteAsync(callbackStarted(callbacks), executor)
290 .whenCompleteAsync(callbackCompleted(callbacks), executor)
291 .whenCompleteAsync(controller.delayedComplete(), executor);
298 * Determines if the outcome was successful.
300 * @param outcome outcome to examine
301 * @return {@code true} if the outcome was successful
303 protected boolean isSuccess(OperationOutcome outcome) {
304 return (outcome.getResult() == PolicyResult.SUCCESS);
308 * Determines if the outcome was a failure for this operator.
310 * @param outcome outcome to examine, or {@code null}
311 * @return {@code true} if the outcome is not {@code null} and was a failure
312 * <i>and</i> was associated with this operator, {@code false} otherwise
314 protected boolean isActorFailed(OperationOutcome outcome) {
315 return (isSameOperation(outcome) && outcome.getResult() == PolicyResult.FAILURE);
319 * Determines if the given outcome is for this operation.
321 * @param outcome outcome to examine
322 * @return {@code true} if the outcome is for this operation, {@code false} otherwise
324 protected boolean isSameOperation(OperationOutcome outcome) {
325 return OperationOutcome.isFor(outcome, getActorName(), getName());
329 * Invokes the operation as a "future". This method simply invokes
330 * {@link #doOperation()} using the {@link #blockingExecutor "blocking executor"},
331 * returning the result via a "future".
333 * Note: if the operation uses blocking I/O, then it should <i>not</i> be run using
334 * the executor in the "params", as that may bring the background thread pool to a
335 * grinding halt. The {@link #blockingExecutor "blocking executor"} should be used
338 * This method assumes the following:
340 * <li>the operator is alive</li>
341 * <li>verifyRunning() has been invoked</li>
342 * <li>callbackStarted() has been invoked</li>
343 * <li>the invoker will perform appropriate timeout checks</li>
344 * <li>exceptions generated within the pipeline will be handled by the invoker</li>
347 * @param attempt attempt number, typically starting with 1
348 * @return a function that will start the operation and return its result when
351 protected CompletableFuture<OperationOutcome> startOperationAsync(int attempt, OperationOutcome outcome) {
353 return CompletableFuture.supplyAsync(() -> doOperation(attempt, outcome), getBlockingExecutor());
357 * Low-level method that performs the operation. This can make the same assumptions
358 * that are made by {@link #doOperationAsFuture()}. This particular method simply
359 * throws an {@link UnsupportedOperationException}.
361 * @param attempt attempt number, typically starting with 1
362 * @param operation the operation being performed
363 * @return the outcome of the operation
365 protected OperationOutcome doOperation(int attempt, OperationOutcome operation) {
367 throw new UnsupportedOperationException("start operation " + getFullName());
371 * Sets the outcome status to FAILURE_RETRIES, if the current operation outcome is
372 * FAILURE, assuming the policy specifies retries and the retry count has been
375 * @param attempt latest attempt number, starting with 1
376 * @return a function to get the next future to execute
378 private Function<OperationOutcome, OperationOutcome> setRetryFlag(int attempt) {
380 return operation -> {
381 if (operation != null && !isActorFailed(operation)) {
383 * wrong type or wrong operation - just leave it as is. No need to log
384 * anything here, as retryOnFailure() will log a message
389 // get a non-null operation
390 OperationOutcome oper2;
391 if (operation != null) {
394 oper2 = params.makeOutcome();
395 oper2.setResult(PolicyResult.FAILURE);
398 int retry = getRetry(params.getRetry());
399 if (retry > 0 && attempt > retry) {
401 * retries were specified and we've already tried them all - change to
404 logger.info("operation {} retries exhausted for {}", getFullName(), params.getRequestId());
405 oper2.setResult(PolicyResult.FAILURE_RETRIES);
413 * Restarts the operation if it was a FAILURE. Assumes that {@link #setRetryFlag(int)}
414 * was previously invoked, and thus that the "operation" is not {@code null}.
416 * @param controller controller for all of the retries
417 * @param attempt latest attempt number, starting with 1
418 * @return a function to get the next future to execute
420 private Function<OperationOutcome, CompletableFuture<OperationOutcome>> retryOnFailure(
421 PipelineControllerFuture<OperationOutcome> controller, int attempt) {
423 return operation -> {
424 if (!isActorFailed(operation)) {
425 // wrong type or wrong operation - just leave it as is
426 logger.info("not retrying operation {} for {}", getFullName(), params.getRequestId());
427 controller.complete(operation);
428 return new CompletableFuture<>();
431 if (getRetry(params.getRetry()) <= 0) {
432 // no retries - already marked as FAILURE, so just return it
433 logger.info("operation {} no retries for {}", getFullName(), params.getRequestId());
434 controller.complete(operation);
435 return new CompletableFuture<>();
439 * Retry the operation.
441 long waitMs = getRetryWaitMs();
442 logger.info("retry operation {} in {}ms for {}", getFullName(), waitMs, params.getRequestId());
444 return sleep(waitMs, TimeUnit.MILLISECONDS)
445 .thenCompose(unused -> startOperationAttempt(controller, attempt + 1));
450 * Convenience method that starts a sleep(), running via a future.
452 * @param sleepTime time to sleep
453 * @param unit time unit
454 * @return a future that will complete when the sleep completes
456 protected CompletableFuture<Void> sleep(long sleepTime, TimeUnit unit) {
457 if (sleepTime <= 0) {
458 return CompletableFuture.completedFuture(null);
461 return new CompletableFuture<Void>().completeOnTimeout(null, sleepTime, unit);
465 * Converts an exception into an operation outcome, returning a copy of the outcome to
466 * prevent background jobs from changing it.
468 * @param type type of item throwing the exception
469 * @return a function that will convert an exception into an operation outcome
471 private Function<Throwable, OperationOutcome> fromException(String type) {
474 OperationOutcome outcome = params.makeOutcome();
476 logger.warn("exception throw by {} {}.{} for {}", type, outcome.getActor(), outcome.getOperation(),
477 params.getRequestId(), thrown);
479 return setOutcome(outcome, thrown);
484 * Similar to {@link CompletableFuture#anyOf(CompletableFuture...)}, but it cancels
485 * any outstanding futures when one completes.
487 * @param futureMakers function to make a future. If the function returns
488 * {@code null}, then no future is created for that function. On the other
489 * hand, if the function throws an exception, then the previously created
490 * functions are canceled and the exception is re-thrown
491 * @return a future to cancel or await an outcome, or {@code null} if no futures were
492 * created. If this future is canceled, then all of the futures will be
495 protected CompletableFuture<OperationOutcome> anyOf(
496 @SuppressWarnings("unchecked") Supplier<CompletableFuture<OperationOutcome>>... futureMakers) {
498 return anyOf(Arrays.asList(futureMakers));
502 * Similar to {@link CompletableFuture#anyOf(CompletableFuture...)}, but it cancels
503 * any outstanding futures when one completes.
505 * @param futureMakers function to make a future. If the function returns
506 * {@code null}, then no future is created for that function. On the other
507 * hand, if the function throws an exception, then the previously created
508 * functions are canceled and the exception is re-thrown
509 * @return a future to cancel or await an outcome, or {@code null} if no futures were
510 * created. If this future is canceled, then all of the futures will be
511 * canceled. Similarly, when this future completes, any incomplete futures
514 protected CompletableFuture<OperationOutcome> anyOf(
515 List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers) {
517 PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
519 CompletableFuture<OperationOutcome>[] futures =
520 attachFutures(controller, futureMakers, UnaryOperator.identity());
522 if (futures.length == 0) {
523 // no futures were started
527 if (futures.length == 1) {
531 CompletableFuture.anyOf(futures).thenApply(outcome -> (OperationOutcome) outcome)
532 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
538 * Similar to {@link CompletableFuture#allOf(CompletableFuture...)}.
540 * @param futureMakers function to make a future. If the function returns
541 * {@code null}, then no future is created for that function. On the other
542 * hand, if the function throws an exception, then the previously created
543 * functions are canceled and the exception is re-thrown
544 * @return a future to cancel or await an outcome, or {@code null} if no futures were
545 * created. If this future is canceled, then all of the futures will be
548 protected CompletableFuture<OperationOutcome> allOf(
549 @SuppressWarnings("unchecked") Supplier<CompletableFuture<OperationOutcome>>... futureMakers) {
551 return allOf(Arrays.asList(futureMakers));
555 * Similar to {@link CompletableFuture#allOf(CompletableFuture...)}.
557 * @param futureMakers function to make a future. If the function returns
558 * {@code null}, then no future is created for that function. On the other
559 * hand, if the function throws an exception, then the previously created
560 * functions are canceled and the exception is re-thrown
561 * @return a future to cancel or await an outcome, or {@code null} if no futures were
562 * created. If this future is canceled, then all of the futures will be
563 * canceled. Similarly, when this future completes, any incomplete futures
566 protected CompletableFuture<OperationOutcome> allOf(
567 List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers) {
568 PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
570 Queue<OperationOutcome> outcomes = new LinkedList<>();
572 CompletableFuture<OperationOutcome>[] futures =
573 attachFutures(controller, futureMakers, future -> future.thenApply(outcome -> {
574 synchronized (outcomes) {
575 outcomes.add(outcome);
580 if (futures.length == 0) {
581 // no futures were started
585 if (futures.length == 1) {
590 CompletableFuture.allOf(futures)
591 .thenApply(unused -> combineOutcomes(outcomes))
592 .whenCompleteAsync(controller.delayedComplete(), params.getExecutor());
599 * Invokes the functions to create the futures and attaches them to the controller.
601 * @param controller master controller for all of the futures
602 * @param futureMakers futures to be attached to the controller
603 * @param adorn function that "adorns" the future, possible adding onto its pipeline.
604 * Returns the adorned future
605 * @return an array of futures, possibly zero-length. If the array is of size one,
606 * then that one item should be returned instead of the controller
608 private CompletableFuture<OperationOutcome>[] attachFutures(PipelineControllerFuture<OperationOutcome> controller,
609 List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers,
610 UnaryOperator<CompletableFuture<OperationOutcome>> adorn) {
612 if (futureMakers.isEmpty()) {
613 @SuppressWarnings("unchecked")
614 CompletableFuture<OperationOutcome>[] result = new CompletableFuture[0];
618 // the last, unadorned future that is created
619 CompletableFuture<OperationOutcome> lastFuture = null;
621 List<CompletableFuture<OperationOutcome>> futures = new ArrayList<>(futureMakers.size());
624 for (var maker : futureMakers) {
626 CompletableFuture<OperationOutcome> future = maker.get();
627 if (future == null) {
631 // propagate "stop" to the future
632 controller.add(future);
634 futures.add(adorn.apply(future));
638 } catch (RuntimeException e) {
639 logger.warn("{}: exception creating 'future' for {}", getFullName(), params.getRequestId());
640 controller.cancel(false);
645 @SuppressWarnings("unchecked")
646 CompletableFuture<OperationOutcome>[] result = new CompletableFuture[futures.size()];
648 if (result.length == 1) {
649 // special case - return the unadorned future
650 result[0] = lastFuture;
654 return futures.toArray(result);
658 * Combines the outcomes from a set of tasks.
660 * @param outcomes outcomes to be examined
661 * @return the combined outcome
663 private OperationOutcome combineOutcomes(Queue<OperationOutcome> outcomes) {
665 // identify the outcome with the highest priority
666 OperationOutcome outcome = outcomes.remove();
667 int priority = detmPriority(outcome);
669 for (OperationOutcome outcome2 : outcomes) {
670 int priority2 = detmPriority(outcome2);
672 if (priority2 > priority) {
674 priority = priority2;
678 logger.info("{}: combined outcome of tasks is {} for {}", getFullName(),
679 (outcome == null ? null : outcome.getResult()), params.getRequestId());
685 * Determines the priority of an outcome based on its result.
687 * @param outcome outcome to examine, or {@code null}
688 * @return the outcome's priority
690 protected int detmPriority(OperationOutcome outcome) {
691 if (outcome == null || outcome.getResult() == null) {
695 switch (outcome.getResult()) {
702 case FAILURE_RETRIES:
708 case FAILURE_TIMEOUT:
711 case FAILURE_EXCEPTION:
718 * Performs a sequence of tasks, stopping if a task fails. A given task's future is
719 * not created until the previous task completes. The pipeline returns the outcome of
720 * the last task executed.
722 * @param futureMakers functions to make the futures
723 * @return a future to cancel the sequence or await the outcome
725 protected CompletableFuture<OperationOutcome> sequence(
726 @SuppressWarnings("unchecked") Supplier<CompletableFuture<OperationOutcome>>... futureMakers) {
728 return sequence(Arrays.asList(futureMakers));
732 * Performs a sequence of tasks, stopping if a task fails. A given task's future is
733 * not created until the previous task completes. The pipeline returns the outcome of
734 * the last task executed.
736 * @param futureMakers functions to make the futures
737 * @return a future to cancel the sequence or await the outcome, or {@code null} if
738 * there were no tasks to perform
740 protected CompletableFuture<OperationOutcome> sequence(
741 List<Supplier<CompletableFuture<OperationOutcome>>> futureMakers) {
743 Queue<Supplier<CompletableFuture<OperationOutcome>>> queue = new ArrayDeque<>(futureMakers);
745 CompletableFuture<OperationOutcome> nextTask = getNextTask(queue);
746 if (nextTask == null) {
751 if (queue.isEmpty()) {
752 // only one task - just return it rather than wrapping it in a controller
757 * multiple tasks - need a controller to stop whichever task is currently
760 final PipelineControllerFuture<OperationOutcome> controller = new PipelineControllerFuture<>();
761 final Executor executor = params.getExecutor();
764 controller.wrap(nextTask)
765 .thenComposeAsync(nextTaskOnSuccess(controller, queue), executor)
766 .whenCompleteAsync(controller.delayedComplete(), executor);
773 * Executes the next task in the queue, if the previous outcome was successful.
775 * @param controller pipeline controller
776 * @param taskQueue queue of tasks to be performed
777 * @return a future to execute the remaining tasks, or the current outcome, if it's a
778 * failure, or if there are no more tasks
780 private Function<OperationOutcome, CompletableFuture<OperationOutcome>> nextTaskOnSuccess(
781 PipelineControllerFuture<OperationOutcome> controller,
782 Queue<Supplier<CompletableFuture<OperationOutcome>>> taskQueue) {
785 if (!isSuccess(outcome)) {
786 // return the failure
787 return CompletableFuture.completedFuture(outcome);
790 CompletableFuture<OperationOutcome> nextTask = getNextTask(taskQueue);
791 if (nextTask == null) {
792 // no tasks - just return the success
793 return CompletableFuture.completedFuture(outcome);
799 .thenComposeAsync(nextTaskOnSuccess(controller, taskQueue), params.getExecutor());
805 * Gets the next task from the queue, skipping those that are {@code null}.
807 * @param taskQueue task queue
808 * @return the next task, or {@code null} if the queue is now empty
810 private CompletableFuture<OperationOutcome> getNextTask(
811 Queue<Supplier<CompletableFuture<OperationOutcome>>> taskQueue) {
813 Supplier<CompletableFuture<OperationOutcome>> maker;
815 while ((maker = taskQueue.poll()) != null) {
816 CompletableFuture<OperationOutcome> future = maker.get();
817 if (future != null) {
826 * Sets the start time of the operation and invokes the callback to indicate that the
827 * operation has started. Does nothing if the pipeline has been stopped.
829 * This assumes that the "outcome" is not {@code null}.
831 * @param callbacks used to determine if the start callback can be invoked
832 * @return a function that sets the start time and invokes the callback
834 private BiConsumer<OperationOutcome, Throwable> callbackStarted(CallbackManager callbacks) {
836 return (outcome, thrown) -> {
838 if (callbacks.canStart()) {
839 // haven't invoked "start" callback yet
840 outcome.setStart(callbacks.getStartTime());
841 outcome.setEnd(null);
842 params.callbackStarted(outcome);
848 * Sets the end time of the operation and invokes the callback to indicate that the
849 * operation has completed. Does nothing if the pipeline has been stopped.
851 * This assumes that the "outcome" is not {@code null}.
853 * Note: the start time must be a reference rather than a plain value, because it's
854 * value must be gotten on-demand, when the returned function is executed at a later
857 * @param callbacks used to determine if the end callback can be invoked
858 * @return a function that sets the end time and invokes the callback
860 private BiConsumer<OperationOutcome, Throwable> callbackCompleted(CallbackManager callbacks) {
862 return (outcome, thrown) -> {
864 if (callbacks.canEnd()) {
865 outcome.setStart(callbacks.getStartTime());
866 outcome.setEnd(callbacks.getEndTime());
867 params.callbackCompleted(outcome);
873 * Sets an operation's outcome and message, based on a throwable.
875 * @param operation operation to be updated
876 * @return the updated operation
878 protected OperationOutcome setOutcome(OperationOutcome operation, Throwable thrown) {
879 PolicyResult result = (isTimeout(thrown) ? PolicyResult.FAILURE_TIMEOUT : PolicyResult.FAILURE_EXCEPTION);
880 return setOutcome(operation, result);
884 * Sets an operation's outcome and default message based on the result.
886 * @param operation operation to be updated
887 * @param result result of the operation
888 * @return the updated operation
890 public OperationOutcome setOutcome(OperationOutcome operation, PolicyResult result) {
891 logger.trace("{}: set outcome {} for {}", getFullName(), result, params.getRequestId());
892 operation.setResult(result);
893 operation.setMessage(result == PolicyResult.SUCCESS ? ControlLoopOperation.SUCCESS_MSG
894 : ControlLoopOperation.FAILED_MSG);
900 * Determines if a throwable is due to a timeout.
902 * @param thrown throwable of interest
903 * @return {@code true} if the throwable is due to a timeout, {@code false} otherwise
905 protected boolean isTimeout(Throwable thrown) {
906 if (thrown instanceof CompletionException) {
907 thrown = thrown.getCause();
910 return (thrown instanceof TimeoutException);
914 * Logs a response. If the response is not of type, String, then it attempts to
915 * pretty-print it into JSON before logging.
917 * @param direction IN or OUT
918 * @param infra communication infrastructure on which it was published
919 * @param source source name (e.g., the URL or Topic name)
920 * @param response response to be logged
921 * @return the JSON text that was logged
923 public <T> String logMessage(EventType direction, CommInfrastructure infra, String source, T response) {
926 if (response == null) {
928 } else if (response instanceof String) {
929 json = response.toString();
931 json = makeCoder().encode(response, true);
934 } catch (CoderException e) {
935 String type = (direction == EventType.IN ? "response" : "request");
936 logger.warn("cannot pretty-print {}", type, e);
937 json = response.toString();
940 logger.info("[{}|{}|{}|]{}{}", direction, infra, source, NetLoggerUtil.SYSTEM_LS, json);
945 // these may be overridden by subclasses or junit tests
948 * Gets the retry count.
950 * @param retry retry, extracted from the parameters, or {@code null}
951 * @return the number of retries, or {@code 0} if no retries were specified
953 protected int getRetry(Integer retry) {
954 return (retry == null ? 0 : retry);
958 * Gets the retry wait, in milliseconds.
960 * @return the retry wait, in milliseconds
962 protected long getRetryWaitMs() {
963 return DEFAULT_RETRY_WAIT_MS;
967 * Gets the operation timeout.
969 * @param timeoutSec timeout, in seconds, extracted from the parameters, or
971 * @return the operation timeout, in milliseconds, or {@code 0} if no timeout was
974 protected long getTimeoutMs(Integer timeoutSec) {
975 return (timeoutSec == null ? 0 : TimeUnit.MILLISECONDS.convert(timeoutSec, TimeUnit.SECONDS));
978 // these may be overridden by junit tests
980 protected Coder makeCoder() {