public <T> T run(Operation<T> f) {
TaskState retryState = state.nestedState(stateKey);
TaskState operationState = retryState.nestedState(OPERATION);
T result;
try {
result = f.perform(operationState);
} catch (TaskExecutionException e) {
throw e;
} catch (Exception e) {
String formattedErrorMessage = String.format(errorMessage, errorMessageParameters);
if (!retry(e)) {
logger.warn("{}: giving up", formattedErrorMessage, e);
throw new TaskExecutionException(e, TaskExecutionException.buildExceptionErrorConfig(e));
}
int retryIteration = retryState.params().get(RETRY, int.class, 0);
retryState.params().set(RETRY, retryIteration + 1);
int interval =
(int)
Math.min(
retryInterval.min().getSeconds() * Math.pow(2, retryIteration),
retryInterval.max().getSeconds());
logger.warn("{}: retrying in {} seconds", formattedErrorMessage, interval, e);
throw state.pollingTaskExecutionException(interval);
}
// Clear retry state
retryState.params().remove(RETRY);
return result;
}
public class PollingRetryExecutor {
private static Logger logger = LoggerFactory.getLogger(PollingRetryExecutor.class);
private static final DurationInterval DEFAULT_RETRY_INTERVAL =
DurationInterval.of(Duration.ofSeconds(1), Duration.ofSeconds(30));
private static final String DEFAULT_ERROR_MESSAGE = "Operation failed";
private static final Object[] DEFAULT_ERROR_MESSAGE_PARAMETERS = {};
private static final List<Predicate<Exception>> DEAFULT_RETRY_PREDICATES = ImmutableList.of();
private static final String RESULT = "result";
private static final String DONE = "done";
private static final String RETRY = "retry";
private static final String OPERATION = "operation";
private final TaskState state;
private final String stateKey;
private final DurationInterval retryInterval;
private final List<Predicate<Exception>> retryPredicates;
private final String errorMessage;
private final Object[] errorMessageParameters;
private PollingRetryExecutor(
TaskState state,
String stateKey,
DurationInterval retryInterval,
List<Predicate<Exception>> retryPredicates,
String errorMessage,
Object... errorMessageParameters) {
this.state = Objects.requireNonNull(state, "state");
this.stateKey = Objects.requireNonNull(stateKey, "stateKey");
this.retryInterval = Objects.requireNonNull(retryInterval, "retryInterval");
this.retryPredicates = Objects.requireNonNull(retryPredicates, "retryPredicates");
this.errorMessage = Objects.requireNonNull(errorMessage, "errorMessage");
this.errorMessageParameters =
Objects.requireNonNull(errorMessageParameters, "errorMessageParameters");
}
public static PollingRetryExecutor pollingRetryExecutor(TaskState state, String stateKey) {
return new PollingRetryExecutor(
state,
stateKey,
DEFAULT_RETRY_INTERVAL,
DEAFULT_RETRY_PREDICATES,
DEFAULT_ERROR_MESSAGE,
DEFAULT_ERROR_MESSAGE_PARAMETERS);
}
public PollingRetryExecutor withErrorMessage(
String errorMessage, Object... errorMessageParameters) {
return new PollingRetryExecutor(
state, stateKey, retryInterval, retryPredicates, errorMessage, errorMessageParameters);
}
public PollingRetryExecutor retryUnless(Predicate<Exception> predicate) {
return retryIf(e -> !predicate.test(e));
}
public <T extends Exception> PollingRetryExecutor retryUnless(
Class<T> exceptionClass, Predicate<T> retryPredicate) {
return retryUnless(
e -> (exceptionClass.isInstance(e) && retryPredicate.test(exceptionClass.cast(e))));
}
public <T extends Exception> PollingRetryExecutor retryIf(
Class<T> exceptionClass, Predicate<T> retryPredicate) {
return retryIf(
e -> (exceptionClass.isInstance(e) && retryPredicate.test(exceptionClass.cast(e))));
}
public PollingRetryExecutor retryIf(Predicate<Exception> retryPredicate) {
List<Predicate<Exception>> newRetryPredicates =
ImmutableList.<Predicate<Exception>>builder()
.addAll(retryPredicates)
.add(retryPredicate)
.build();
return new PollingRetryExecutor(
state, stateKey, retryInterval, newRetryPredicates, errorMessage, errorMessageParameters);
}
public PollingRetryExecutor withRetryInterval(DurationInterval retryInterval) {
return new PollingRetryExecutor(
state, stateKey, retryInterval, retryPredicates, errorMessage, errorMessageParameters);
}
public void runOnce(Action f) {
runOnce(
Void.class,
taskState -> {
f.perform(taskState);
return null;
});
}
public <T> T runOnce(TypeReference<T> type, Operation<T> f) {
return runOnce(TypeFactory.defaultInstance().constructType(type), f);
}
public <T> T runOnce(Class<T> type, Operation<T> f) {
return runOnce(TypeFactory.defaultInstance().constructType(type), f);
}
private <T> T runOnce(JavaType type, Operation<T> f) {
TaskState retryState = state.nestedState(stateKey);
boolean done = retryState.params().get(DONE, boolean.class, false);
T result = get(type, retryState.params());
if (done) {
return result;
}
result = run(f);
retryState.params().set(RESULT, result);
retryState.params().set(DONE, true);
return result;
}
public void runAction(Action f) {
run(
operationState -> {
f.perform(operationState);
return null;
});
}
public <T> T run(Operation<T> f) {
TaskState retryState = state.nestedState(stateKey);
TaskState operationState = retryState.nestedState(OPERATION);
T result;
try {
result = f.perform(operationState);
} catch (TaskExecutionException e) {
throw e;
} catch (Exception e) {
String formattedErrorMessage = String.format(errorMessage, errorMessageParameters);
if (!retry(e)) {
logger.warn("{}: giving up", formattedErrorMessage, e);
throw new TaskExecutionException(e, TaskExecutionException.buildExceptionErrorConfig(e));
}
int retryIteration = retryState.params().get(RETRY, int.class, 0);
retryState.params().set(RETRY, retryIteration + 1);
int interval =
(int)
Math.min(
retryInterval.min().getSeconds() * Math.pow(2, retryIteration),
retryInterval.max().getSeconds());
logger.warn("{}: retrying in {} seconds", formattedErrorMessage, interval, e);
throw state.pollingTaskExecutionException(interval);
}
// Clear retry state
retryState.params().remove(RETRY);
return result;
}
private boolean retry(Exception e) {
if (retryPredicates.isEmpty()) {
return true;
}
for (Predicate<Exception> retryPredicate : retryPredicates) {
if (retryPredicate.test(e)) {
return true;
}
}
return false;
}
@SuppressWarnings("unchecked")
private static <T> T get(JavaType type, Config config) {
return (T) config.get(RESULT, type, null);
}
}