Added ageing capabilities to SessionCache and NullCache

Added ageing methods to the Cache Adaptor interface so it's now universal

TODO.txt

@@ -1,10 +1,8 @@
 TODO:
 	* Combine the DateTimeUtils and DateLiterals where appropriate
 	* Document TestDateTimeUtils and how to set now and today
-	* Test ageing using dates on the OrgCache
-	* Implement ageing into the SessionCache
-	* Add the aged get definitions into ICacheAdaptor
 	* Add 'maximum age' into CachedSoqlExecutor
+	* Consider a superclass for OrgCache and SessionCache?
 
 
 

framework/default/ortoo-core/default/classes/fflib-extension/caching/ICacheAdaptor.cls

@@ -12,6 +12,8 @@ public interface ICacheAdaptor
 	Boolean hasAccessToCache();
 	Boolean isACache();
 	Object get( String key );
+	Object get( String key, DateTime minimumDateTime );
+	Object get( String key, Long maximumAgeInSeconds );
 	void put( String key, Object value, Integer lifespan );
 	Boolean contains( String key );
 	void remove( String key );

framework/default/ortoo-core/default/classes/fflib-extension/caching/NullCache.cls

@@ -22,6 +22,16 @@ public inherited sharing class NullCache implements ICacheAdaptor
 		return null;
 	}
 
+	public Object get( String key, DateTime minimumDateTime )
+	{
+		return null;
+	}
+
+	public Object get( String key, Long maximumAgeInSeconds )
+	{
+		return null;
+	}
+
 	public Set<String> getKeys()
 	{
 		return new Set<String>();

framework/default/ortoo-core/default/classes/fflib-extension/caching/SessionCache.cls

@@ -3,7 +3,6 @@
  *
  * All users are assumed to have access to the cache.
  */
-// TODO: add age capabilities
 public inherited sharing class SessionCache implements ICacheAdaptor
 {
 	private static final String PARTITION_NAME = 'core';
@@ -35,9 +34,58 @@ public inherited sharing class SessionCache implements ICacheAdaptor
 	 * @return	Object	The cached object, if it exists
 	 */
 	public Object get( String key )
+	{
+		Long maximumAgeInSeconds = null;
+		return get( key, maximumAgeInSeconds );
+	}
+
+	/**
+	 * Retrieve the cache entry with the given key, but only if it was created after the stated date time
+	 *
+	 * If the entry does not exist in the cache (I.E. is a "cache miss"), will return null
+	 *
+	 * @param	String	The key for the object to retrieve
+	 * @return	Object	The cached object, if it exists
+	 */
+	public Object get( String key, DateTime minimumDateTime )
+	{
+		Long maximumAgeInSeconds;
+		if ( minimumDateTime != null )
+		{
+			maximumAgeInSeconds = DateTimeUtils.getEpochTime() - DateTimeUtils.getEpochTime( minimumDateTime );
+		}
+		return get( key, maximumAgeInSeconds );
+	}
+
+	/**
+	 * Retrieve the cache entry with the given key, but only if it is younger than the stated number of seconds
+	 *
+	 * If the entry does not exist in the cache (I.E. is a "cache miss"), will return null
+	 *
+	 * @param	String	The key for the object to retrieve
+	 * @return	Object	The cached object, if it exists
+	 */
+	public Object get( String key, Long maximumAgeInSeconds )
 	{
 		Contract.requires( String.isNotBlank( key ), 'get called with a blank key' );
-		return Cache.Session.get( key );
+
+		Object rawCacheValue = Cache.Session.get( createFullyQualifiedKey( key ) );
+
+		if ( rawCacheValue instanceOf CacheEntry )
+		{
+			CacheEntry cacheValue = (CacheEntry)rawCacheValue;
+			if ( maximumAgeInSeconds == null || cacheValue.isYoungerThanOrEqualTo( maximumAgeInSeconds ) )
+			{
+				return cacheValue.getValue();
+			}
+		}
+
+		if ( maximumAgeInSeconds == null ) // if we don't care about the age, then return it
+		{
+			return rawCacheValue;
+		}
+
+		return null; // if there is no age, or it is too old, regard it as a cache miss
 	}
 
 	/**
@@ -66,7 +114,9 @@ public inherited sharing class SessionCache implements ICacheAdaptor
 		Contract.requires( lifespan >= 0, 'put called with a negative lifespan' );
 		// Note that the maximum is handled by Salesforce, just in case it increases
 
-		Cache.Session.put( key, value, lifespan, Cache.Visibility.NAMESPACE, true ); // immutable outside of namespace
+		CacheEntry cacheEntry = new CacheEntry( value );
+
+		Cache.Session.put( key, cacheEntry, lifespan, Cache.Visibility.NAMESPACE, true ); // immutable outside of namespace
 	}
 
 	/**
@@ -112,6 +162,7 @@ public inherited sharing class SessionCache implements ICacheAdaptor
 		return Cache.SessionPartition.createFullyQualifiedPartition( PackageUtils.NAMESPACE_PREFIX, PARTITION_NAME );
 	}
 
+	@testVisible
 	private String createFullyQualifiedKey( String key )
 	{
 		return Cache.SessionPartition.createFullyQualifiedKey( PackageUtils.NAMESPACE_PREFIX, PARTITION_NAME, key );

framework/default/ortoo-core/default/classes/fflib-extension/caching/tests/NullCacheTest.cls

@@ -1,6 +1,9 @@
 @isTest
 private without sharing class NullCacheTest
 {
+	private final static Long NULL_AGE = null;
+	private final static DateTime NULL_MIN_DATE_TIME = null;
+
 	@isTest
 	private static void hasAccessToCache_whenCalled_returnsTrue() // NOPMD: Test method name format
 	{
@@ -25,6 +28,22 @@ private without sharing class NullCacheTest
 		System.assertEquals( null, got, 'get, when called, will return null' );
 	}
 
+	@isTest
+	private static void get_maxAge_whenCalled_returnsNull() // NOPMD: Test method name format
+	{
+		NullCache cache = new NullCache();
+		Object got = cache.get( null, NULL_AGE );
+		System.assertEquals( null, got, 'get, when called with a max age, will return null' );
+	}
+
+	@isTest
+	private static void get_minDate_whenCalled_returnsNull() // NOPMD: Test method name format
+	{
+		NullCache cache = new NullCache();
+		Object got = cache.get( null, NULL_MIN_DATE_TIME );
+		System.assertEquals( null, got, 'get, when called with a min datetime, will return null' );
+	}
+
 	@isTest
 	private static void put_whenCalled_doesNothing() // NOPMD: Test method name format
 	{

framework/default/ortoo-core/default/classes/fflib-extension/caching/tests/OrgCacheTest.cls

@@ -4,7 +4,7 @@ private without sharing class OrgCacheTest
 	private final static Integer DEFAULT_LIFESPAN = 1000;
 	private final static DateTime BASE_TIME = DateTime.newInstanceGmt( 1974, 08, 24, 22, 45, 00 );
 	private final static Long NULL_AGE = null;
-	private final static DateTime NULL_MAX_DATE_TIME = null;
+	private final static DateTime NULL_MIN_DATE_TIME = null;
 
 	@isTest
 	private static void hasAccessToCache_whenCalledByUserWithCacheAccess_returnsTrue() // NOPMD: Test method name format
@@ -314,7 +314,7 @@ private without sharing class OrgCacheTest
 		Cache.Org.put( cacheInstance.createFullyQualifiedKey( 'key' ), cachedObject );
 
 		Test.startTest();
-			Object got = cacheInstance.get( 'key', NULL_MAX_DATE_TIME );
+			Object got = cacheInstance.get( 'key', NULL_MIN_DATE_TIME );
 		Test.stopTest();
 
 		System.assertEquals( cachedObject, got, 'get, passing minimumDateTime, when no time is specified and the cached value has no age, will return the value' );