package com.atlassian.vcache.internal.core.service;
   
   import com.atlassian.vcache.internal.core.ExternalCacheKeyGenerator;
   
   import java.time.Duration;
   import java.util.Optional;
   import java.util.function.Supplier;
   
   /**
   * Represents the request context for an {@link com.atlassian.vcache.ExternalCache} that maintains a
   * cache version.
   *
   * @param <V> the value type
   * @since 1.0.0
   */
  public class VersionedExternalCacheRequestContext<V> extends AbstractExternalCacheRequestContext<V> {
      protected final String externalCacheVersionKey;
      private Optional<Long> cacheVersion = Optional.empty();
  
      public VersionedExternalCacheRequestContext(ExternalCacheKeyGenerator keyGenerator,
                                                  String name,
                                                  Supplier<String> partitionSupplier,
                                                  Duration lockTimeout) {
          super(keyGenerator, name, partitionSupplier, lockTimeout);
          this.externalCacheVersionKey =
                  keyGenerator.cacheVersionKey(partitionSupplier.get(), name);
      }
  
      @Override
      protected long cacheVersion() {
          return cacheVersion.get();
      }
  
      public void updateCacheVersion(long value) {
          cacheVersion = Optional.of(value);
          clearKeyMaps();
      }
  
      public String externalCacheVersionKey() {
          return externalCacheVersionKey;
      }
  }