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Refactor CASLockFactory to eliminate "PMD.GodClass" and Uncouple sub …
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@@ -16,3 +16,4 @@ dependency-reduced-pom.xml | |
| *.iml | ||
| .coverage | ||
| *htmlcov | ||
| statistics/ | ||
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core/src/main/java/com/ericsson/bss/cassandra/ecchronos/core/CASLock.java
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| /* | ||
| * Copyright 2024 Telefonaktiebolaget LM Ericsson | ||
| * | ||
| * Licensed 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 com.ericsson.bss.cassandra.ecchronos.core; | ||
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| import java.util.ArrayList; | ||
| import java.util.List; | ||
| import java.util.Map; | ||
| import java.util.UUID; | ||
| import java.util.concurrent.ScheduledExecutorService; | ||
| import java.util.concurrent.ScheduledFuture; | ||
| import java.util.concurrent.TimeUnit; | ||
| import java.util.concurrent.atomic.AtomicInteger; | ||
| import java.util.concurrent.atomic.AtomicReference; | ||
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| import org.slf4j.Logger; | ||
| import org.slf4j.LoggerFactory; | ||
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| import com.datastax.oss.driver.api.core.cql.ResultSet; | ||
| import com.datastax.oss.driver.api.core.cql.Row; | ||
| import com.ericsson.bss.cassandra.ecchronos.core.exceptions.LockException; | ||
| import com.ericsson.bss.cassandra.ecchronos.core.scheduling.LockFactory.DistributedLock; | ||
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| /** | ||
| * Represents a container for builder configurations and state for the CASLock. | ||
| * This class is used to decouple builder fields from CASLockFactory to avoid excessive field count. | ||
| */ | ||
| class CASLock implements DistributedLock, Runnable | ||
| { | ||
| private static final Logger LOG = LoggerFactory.getLogger(CASLock.class); | ||
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| private final String myDataCenter; | ||
| private final String myResource; | ||
| private final int myPriority; | ||
| private final Map<String, String> myMetadata; | ||
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| private final AtomicReference<ScheduledFuture<?>> myUpdateFuture = new AtomicReference<>(); | ||
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| private final AtomicInteger myFailedUpdateAttempts = new AtomicInteger(); | ||
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| private final int myLocallyHighestPriority; | ||
| private final int globalHighPriority; | ||
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| private final UUID myUuid; | ||
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| private final CASLockStatement myCasLockStatement; | ||
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| CASLock(final String dataCenter, | ||
| final String resource, | ||
| final int priority, | ||
| final Map<String, String> metadata, | ||
| final UUID uuid, | ||
| final CASLockStatement casLockStatement) | ||
| { | ||
| myDataCenter = dataCenter; | ||
| myResource = resource; | ||
| myPriority = priority; | ||
| myMetadata = metadata; | ||
| myUuid = uuid; | ||
| myCasLockStatement = casLockStatement; | ||
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| List<NodePriority> nodePriorities = computePriorities(); | ||
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| myLocallyHighestPriority = nodePriorities.stream() | ||
| .filter(n -> n.getUuid().equals(myUuid)) | ||
| .map(NodePriority::getPriority) | ||
| .findFirst() | ||
| .orElse(myPriority); | ||
| globalHighPriority = nodePriorities.stream() | ||
| .filter(n -> !n.getUuid().equals(myUuid)) | ||
| .map(NodePriority::getPriority) | ||
| .max(Integer::compare) | ||
| .orElse(myPriority); | ||
| } | ||
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| public boolean lock() | ||
| { | ||
| if (compete()) | ||
| { | ||
| LOG.trace("Trying to acquire lock for resource {}", myResource); | ||
| if (tryLock()) | ||
| { | ||
| ScheduledExecutorService executor = myCasLockStatement.getCasLockProperties().getExecutor(); | ||
| LOG.trace("Lock for resource {} acquired", myResource); | ||
| ScheduledFuture<?> future = executor.scheduleAtFixedRate(this, | ||
| myCasLockStatement.getCasLockFactoryCacheContext().getLockUpdateTimeInSeconds(), | ||
| myCasLockStatement.getCasLockFactoryCacheContext().getLockUpdateTimeInSeconds(), TimeUnit.SECONDS); | ||
| myUpdateFuture.set(future); | ||
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| return true; | ||
| } | ||
| } | ||
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| return false; | ||
| } | ||
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| @Override | ||
| public void run() | ||
| { | ||
| try | ||
| { | ||
| updateLock(); | ||
| myFailedUpdateAttempts.set(0); | ||
| } | ||
| catch (LockException e) | ||
| { | ||
| int failedAttempts = myFailedUpdateAttempts.incrementAndGet(); | ||
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| if (failedAttempts >= myCasLockStatement.getCasLockFactoryCacheContext().getFailedLockRetryAttempts()) | ||
| { | ||
| LOG.error("Unable to re-lock resource '{}' after {} failed attempts", myResource, failedAttempts); | ||
| } | ||
| else | ||
| { | ||
| LOG.warn("Unable to re-lock resource '{}', {} failed attempts", myResource, failedAttempts, e); | ||
| } | ||
| } | ||
| } | ||
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| @Override | ||
| public void close() | ||
| { | ||
| ScheduledFuture<?> future = myUpdateFuture.get(); | ||
| if (future != null) | ||
| { | ||
| future.cancel(true); | ||
| myCasLockStatement.execute( | ||
| myDataCenter, | ||
| myCasLockStatement.getRemoveLockStatement().bind(myResource, myUuid)); | ||
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| if (myLocallyHighestPriority <= myPriority) | ||
| { | ||
| myCasLockStatement.execute( | ||
| myDataCenter, | ||
| myCasLockStatement.getRemoveLockPriorityStatement().bind(myResource, myUuid)); | ||
| } | ||
| else | ||
| { | ||
| LOG.debug("Locally highest priority ({}) is higher than current ({}), will not remove", | ||
| myLocallyHighestPriority, myPriority); | ||
| } | ||
| } | ||
| } | ||
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| private void updateLock() throws LockException | ||
| { | ||
| ResultSet resultSet = myCasLockStatement.execute(myDataCenter, | ||
| myCasLockStatement.getUpdateLockStatement().bind(myUuid, myMetadata, myResource, myUuid)); | ||
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| if (!resultSet.wasApplied()) | ||
| { | ||
| throw new LockException("CAS query failed"); | ||
| } | ||
| } | ||
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| private boolean compete() | ||
| { | ||
| if (myLocallyHighestPriority <= myPriority) | ||
| { | ||
| insertPriority(); | ||
| } | ||
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| LOG.trace("Highest priority for resource {}: {}", myResource, globalHighPriority); | ||
| return myPriority >= globalHighPriority; | ||
| } | ||
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| private void insertPriority() | ||
| { | ||
| myCasLockStatement.execute( | ||
| myDataCenter, | ||
| myCasLockStatement.getCompeteStatement().bind(myResource, myUuid, myPriority)); | ||
| } | ||
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| private boolean tryLock() | ||
| { | ||
| return myCasLockStatement.execute( | ||
| myDataCenter, | ||
| myCasLockStatement.getLockStatement().bind(myResource, myUuid, myMetadata)).wasApplied(); | ||
| } | ||
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| private List<NodePriority> computePriorities() | ||
| { | ||
| List<NodePriority> nodePriorities = new ArrayList<>(); | ||
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| ResultSet resultSet = myCasLockStatement.execute( | ||
| myDataCenter, | ||
| myCasLockStatement.getGetPriorityStatement().bind(myResource)); | ||
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| for (Row row : resultSet) | ||
| { | ||
| int priority = row.getInt(CASLockStatement.COLUMN_PRIORITY); | ||
| UUID hostId = row.getUuid(CASLockStatement.COLUMN_NODE); | ||
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| nodePriorities.add(new NodePriority(hostId, priority)); | ||
| } | ||
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| return nodePriorities; | ||
| } | ||
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| int getFailedAttempts() | ||
| { | ||
| return myFailedUpdateAttempts.get(); | ||
| } | ||
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| } |
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