java/src/main/com/google/appengine/api/datastore/EntityCacheConfig.java

   1 package com.google.appengine.api.datastore;
   2
   3 import static com.google.common.base.Preconditions.checkNotNull;
   4
   5 /**
   6  * Specifies the entity cache configuration for the datastore service.
   7  * <p>
   8  * The default entity cache configuration values for an {@code EntityCacheConfig} instance are
   9  * a memcache backed entity cache, {@link EntityCachingCriteria#ALL_KEYS} for the caching criteria,
  10  * and {@link EntityCachePolicy#CACHE} for the caching policy.
  11  * <p>
  12  * See {@link DatastoreServiceConfig#entityCacheConfig} for details on how to specify an
  13  * {@code EntityCacheConfig} to enable caching of datastore entities when using the
  14  * datastore service.
  15  */
  16 final class EntityCacheConfig {
  17
  18   private EntityCachingCriteria entityCachingCriteria = EntityCachingCriteria.ALL_KEYS;
  19   private EntityCachePolicy entityCachePolicy = EntityCachePolicy.CACHE;
  20
  21   /**
  22    * Sets the {@link EntityCachingCriteria}.
  23    *
  24    * @param entityCachingCriteria the {@link EntityCachingCriteria} to use to determine if an entity
  25    *     should be cached.
  26    * @return {@code this} (for chaining)
  27    */
  28   public EntityCacheConfig entityCachingCriteria(EntityCachingCriteria entityCachingCriteria) {
  29     this.entityCachingCriteria =
  30         checkNotNull(entityCachingCriteria, "The entityCachingCriteria argument can not be null");
  31     return this;
  32   }
  33
  34   /**
  35    * @return the {@link EntityCachingCriteria} specified in this entity cache configuration.
  36    */
  37   public EntityCachingCriteria getEntityCachingCriteria() {
  38     return entityCachingCriteria;
  39   }
  40
  41   /**
  42    * Sets the {@link EntityCachePolicy}.
  43    *
  44    * @param entityCachePolicy the {@link EntityCachePolicy} to use for entity caching.
  45    * @return {@code this} (for chaining)
  46    */
  47   public EntityCacheConfig entityCachePolicy(EntityCachePolicy entityCachePolicy) {
  48     this.entityCachePolicy =
  49         checkNotNull(entityCachePolicy, "The entityCachePolicy argument can not be null");
  50     return this;
  51   }
  52
  53   /**
  54    * @return the {@link EntityCachePolicy} specified in this entity cache configuration.
  55    */
  56   public EntityCachePolicy getEntityCachePolicy() {
  57     return entityCachePolicy;
  58   }
  59
  60   private EntityCacheConfig() {
  61   }
  62
  63   /**
  64    * Contains static creation methods for {@link EntityCacheConfig} instances.
  65    */
  66   public static final class Builder {
  67
  68     /**
  69      * Create an {@link EntityCacheConfig} instance with the specified
  70      * {@code entityCachingCriteria} and with the default configuration values for all other fields.
  71      *
  72      * @param entityCachingCriteria the {@link EntityCachingCriteria} to use to determine if an
  73      *     entity should be cached.
  74      * @return the newly created EntityCacheConfig instance.
  75      */
  76     public static EntityCacheConfig withEntityCachingCriteria(
  77         EntityCachingCriteria entityCachingCriteria) {
  78       return withDefaults().entityCachingCriteria(entityCachingCriteria);
  79     }
  80
  81     /**
  82      * Create an {@link EntityCacheConfig} instance with the specified {@code entityCachePolicy} and
  83      * with the default configuration values for all other fields.
  84      *
  85      * @param entityCachePolicy the {@link EntityCachePolicy} to use for entity caching.
  86      * @return the newly created EntityCacheConfig instance.
  87      */
  88     public static EntityCacheConfig withEntityCachePolicy(EntityCachePolicy entityCachePolicy) {
  89       return withDefaults().entityCachePolicy(entityCachePolicy);
  90     }
  91
  92     /**
  93      * Create an {@link EntityCacheConfig} instance with the default configuration values.
  94      *
  95      * @return the newly created EntityCacheConfig instance.
  96      */
  97     public static EntityCacheConfig withDefaults() {
  98       return new EntityCacheConfig();
  99     }
 100
 101     private Builder() {}
 102   }
 103 }