com.oracle.bedrock.deferred.Repetitively Maven / Gradle / Ivy
/*
* File: Repetitively.java
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* the Common Development and Distribution License 1.0 (the "License").
*
* You may not use this file except in compliance with the License.
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* You can obtain a copy of the License by consulting the LICENSE.txt file
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*
* MODIFICATIONS:
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package com.oracle.bedrock.deferred;
import com.oracle.bedrock.Option;
import com.oracle.bedrock.OptionsByType;
import com.oracle.bedrock.deferred.options.InitialDelay;
import com.oracle.bedrock.deferred.options.MaximumRetryDelay;
import com.oracle.bedrock.deferred.options.RetryFrequency;
import com.oracle.bedrock.options.Timeout;
import com.oracle.bedrock.runtime.concurrent.RemoteCallable;
import com.oracle.bedrock.runtime.java.JavaApplication;
import com.oracle.bedrock.util.Duration;
import org.hamcrest.Matcher;
import org.hamcrest.StringDescription;
import java.util.Iterator;
import java.util.concurrent.TimeUnit;
import static com.oracle.bedrock.deferred.DeferredHelper.eventually;
import static com.oracle.bedrock.deferred.DeferredHelper.valueOf;
/**
* Commonly used "assertThat" methods for the purposes of repetitively asserting
* the state of {@link Deferred} values.
*
* To customize assertion behavior and timeouts, this class allows extensive use
* of {@link Option}s. For example, the following {@link Option}s may be used
* to customize timeout constraints when asserting {@link Deferred} values;
* {@link Timeout}, {@link MaximumRetryDelay}, Initial {@link InitialDelay} and
* {@link RetryFrequency}.
*
* Copyright (c) 2016. All Rights Reserved. Oracle Corporation.
* Oracle is a registered trademark of Oracle Corporation and/or its affiliates.
*
* @see Eventually
* @see Concurrently
*
* @author Brian Oliver
*/
public class Repetitively
{
/**
* Asserts that a value will repetitively satisfy the specified {@link Matcher}
* using the specified {@link Option}s.
*
* Should the value be the result of a call to {@link DeferredHelper#invoking(Deferred)}
* the result is unwrapped into a {@link Deferred} that is then used for the assert.
*
* @param the type of the value
*
* @param value the value
* @param matcher the {@link Matcher} for the value
* @param options the {@link Option}s for the assertion
*
* @throws AssertionError if the assertion fails
*/
public static void assertThat(T value,
Matcher matcher,
Option... options) throws AssertionError
{
assertThat(null, eventually(value), matcher, options);
}
/**
* Asserts that a value will repetitively satisfy the specified {@link Matcher}.
*
* Should the value be the result of a call to {@link DeferredHelper#invoking(Deferred)}
* the result is unwrapped into a {@link Deferred} that is then used for the assert.
*
* @param the type of the value
*
* @param message the message for the AssertionError (null ok)
* @param value the value
* @param matcher the {@link Matcher} for the value
*
* @throws AssertionError if the assertion fails
*/
public static void assertThat(String message,
T value,
Matcher matcher) throws AssertionError
{
assertThat(message, eventually(value), matcher);
}
/**
* Asserts that a value will repetitively satisfy the specified {@link Matcher}
* using the provided {@link Option}s.
*
* Should the value be the result of a call to {@link DeferredHelper#invoking(Deferred)}
* the result is unwrapped into a {@link Deferred} that is then used for the assert.
*
* @param the type of the value
*
* @param message the message for the AssertionError (null ok)
* @param value the value
* @param matcher the {@link Matcher} for the value
* @param options the {@link Option}s
*
* @throws AssertionError if the assertion fails
*/
public static void assertThat(String message,
T value,
Matcher matcher,
Option... options) throws AssertionError
{
assertThat(message, eventually(value), matcher, options);
}
/**
* Asserts that a {@link Deferred} value, when available, repetitively satisfies
* the specified {@link Matcher} over the {@link Timeout}
* and other constraints defined by the provided {@link Option}s.
*
* @param the type of the value
*
* @param message the message for the AssertionError (null ok)
* @param deferred the {@link Deferred} value
* @param matcher the {@link Matcher} for the value
* @param options the {@link Option}s
*
* @throws AssertionError if the assertion fails
*/
public static void assertThat(String message,
Deferred deferred,
Matcher matcher,
Option... options) throws AssertionError
{
// determine the time-out and retry constraints
OptionsByType optionsByType = OptionsByType.of(options);
long initialDelayDurationMS = optionsByType.getOrDefault(InitialDelay.class,
InitialDelay.none()).to(TimeUnit.MILLISECONDS);
long maximumRetryDurationMS = optionsByType.getOrDefault(Timeout.class,
Timeout.after(DeferredHelper.getDefaultEnsuredMaximumRetryDuration()))
.to(TimeUnit.MILLISECONDS);
long maximumPollingDurationMS = optionsByType.getOrDefault(MaximumRetryDelay.class,
MaximumRetryDelay.of(DeferredHelper.getDefaultEnsuredMaximumPollingDuration()))
.to(TimeUnit.MILLISECONDS);
Iterator retryDurations = optionsByType.getOrDefault(RetryFrequency.class,
RetryFrequency.of(DeferredHelper.getDefaultEnsuredRetryDurationsIterable()))
.get().iterator();
// the number of times successfully matched
int matchCount = 0;
// the number of matches attempted
int attemptCount = 0;
// determine the maximum time we can wait
long remainingRetryDurationMS = maximumRetryDurationMS;
do
{
// wait the initial duration
if (initialDelayDurationMS > 0)
{
try
{
Thread.sleep(initialDelayDurationMS);
}
catch (InterruptedException e)
{
throw new AssertionError("Interrupted while resolving " + deferred, e);
}
// reduce the remaining time
remainingRetryDurationMS -= initialDelayDurationMS;
// NOTE: even if there's no time remaining we'll at least
// attempt to acquire the object reference just once!
}
// the time the most recent acquisition took
long acquisitionDurationMS = 0;
try
{
long started = System.currentTimeMillis();
// set the remaining timeout
optionsByType.add(Timeout.after(Math.min(remainingRetryDurationMS, 0), TimeUnit.MILLISECONDS));
T object = DeferredHelper.ensure(deferred, optionsByType.asArray());
long stopped = System.currentTimeMillis();
// the time spent trying to access the resource
// is considered as part of the remaining time
acquisitionDurationMS = stopped - started;
remainingRetryDurationMS -= acquisitionDurationMS < 0 ? 0 : acquisitionDurationMS;
// count this attempt
attemptCount++;
if (matcher.matches(object))
{
// continue matching!
matchCount++;
}
else
{
// generate a description for the match failure
StringDescription description = new StringDescription();
matcher.describeMismatch(object, description);
// throw an assertion with the error
throw new AssertionError(description.toString() + " (attempted " + attemptCount
+ " time(s), succeeded " + matchCount + " time(s))");
}
}
catch (PermanentlyUnavailableException e)
{
// give up immediately!
throw new AssertionError("Failed to resolve value for " + deferred, e);
}
catch (UnsupportedOperationException e)
{
// give up immediately when an operation is not supported
throw new AssertionError("Failed to resolve value for " + deferred, e);
}
catch (TemporarilyUnavailableException e)
{
// SKIP: we will retry if the instance is temporarily unavailable
}
catch (RuntimeException e)
{
// SKIP: we assume all other runtime exceptions
// simply means that we should retry
}
// determine if we need to retry
if (maximumRetryDurationMS < 0 || remainingRetryDurationMS > 0)
{
// we can only retry while we have retry durations
if (retryDurations.hasNext())
{
try
{
Duration duration = retryDurations.next();
long durationMS = duration.to(TimeUnit.MILLISECONDS);
// ensure we don't wait longer than the maximum polling duration
if (durationMS > maximumPollingDurationMS)
{
durationMS = maximumPollingDurationMS;
}
// ensure we don't wait longer that the remaining duration
if (remainingRetryDurationMS - durationMS < 0)
{
durationMS = remainingRetryDurationMS;
}
// only wait if we have a duration
if (durationMS > 0)
{
TimeUnit.MILLISECONDS.sleep(durationMS);
}
// reduce the remaining time
remainingRetryDurationMS -= durationMS;
}
catch (InterruptedException e)
{
// if we're interrupted, we give up immediately
throw new AssertionError("Interrupted while resolving " + deferred, e);
}
}
else
{
// if we run out of retry durations, we give up immediately
throw new AssertionError("Exhausted retry time-out durations");
}
}
}
while (maximumRetryDurationMS < 0 || remainingRetryDurationMS > 0);
if (matchCount == 0)
{
throw new AssertionError("Failed to resolve a value for " + deferred);
}
}
/**
* Asserts that the specified {@link RemoteCallable} submitted to the
* {@link JavaApplication} repetitively matches the specified matcher
* using the specified {@link Option}s.
*
* @param the type of the value
*
* @param application the {@link JavaApplication} to which the {@link RemoteCallable} will be submitted
* @param callable the {@link RemoteCallable}
* @param matcher the {@link Matcher} representing the desire condition to match
*
* @throws AssertionError if the assertion fails
*/
public static void assertThat(JavaApplication application,
RemoteCallable callable,
Matcher matcher) throws AssertionError
{
assertThat(valueOf(new DeferredRemoteExecution(application, callable)), matcher);
}
/**
* Asserts that the specified {@link RemoteCallable} submitted to
* the {@link JavaApplication} repetitively matches the specified matcher
* using the provided {@link Option}s.
*
* @param the type of the value
*
* @param application the {@link JavaApplication} to which the {@link RemoteCallable} will be submitted
* @param callable the {@link RemoteCallable}
* @param matcher the {@link Matcher} representing the desire condition to match
* @param options the {@link Option}s
*
* @throws AssertionError if the assertion fails
*/
public static void assertThat(JavaApplication application,
RemoteCallable callable,
Matcher matcher,
Option... options) throws AssertionError
{
assertThat(valueOf(new DeferredRemoteExecution(application, callable)), matcher, options);
}
}