DIRECTMEMORY-121, DIRECTMEMORY-122 Added void scheduleDisposalEvery( long period, TimeUnit unit ) to CacheService.java to give users a nice interface to schedule the disposal interval and started documenting the API interfaces
git-svn-id: https://svn.apache.org/repos/asf/directmemory/trunk@1425903 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheService.java b/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheService.java
index 5031483..b61253a 100644
--- a/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheService.java
+++ b/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheService.java
@@ -19,67 +19,188 @@
* under the License.
*/
+import java.io.Closeable;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+
import org.apache.directmemory.memory.MemoryManagerService;
import org.apache.directmemory.memory.Pointer;
import org.apache.directmemory.serialization.Serializer;
-
-import java.io.Closeable;
-import java.util.concurrent.ConcurrentMap;
+import org.slf4j.Logger;
public interface CacheService<K, V>
extends Closeable
{
- void scheduleDisposalEvery( long l );
+ /**
+ * Schedules the disposal event with the given period in milliseconds.
+ *
+ * @param period The time period in milliseconds
+ */
+ void scheduleDisposalEvery( long period );
/**
- * @param key
- * @param payload
- * @param expiresIn in ms
- * @return
+ * Schedules the disposal event with the given period with the given {@link TimeUnit}.
+ *
+ * @param period The time period
+ * @param unit The period's timeunit
*/
- Pointer<V> putByteArray( K key, byte[] payload, int expiresIn );
+ void scheduleDisposalEvery( long period, TimeUnit unit );
+ /**
+ * Stored a preserialized payload with the given key. The expiration is set to the given expiresIn value in
+ * milliseconds. If not enough space found to store the payload the returned pointer is null.
+ *
+ * @param key The key to save the payload with
+ * @param payload The preserialized payload as bytearray
+ * @param expiresIn The expiration delay
+ * @return The created pointer to directly retrieve the payload or null if not enough space was found
+ */
+ Pointer<V> putByteArray( K key, byte[] payload, long expiresIn );
+
+ /**
+ * Stored a preserialized payload with the given key with no expiration value. If not enough space found to store
+ * the payload the returned pointer is null.
+ *
+ * @param key The key to save the payload with
+ * @param payload The preserialized payload as bytearray
+ * @return The created pointer to directly retrieve the payload or null if not enough space was found
+ */
Pointer<V> putByteArray( K key, byte[] payload );
- Pointer<V> put( K key, V value );
-
/**
- * @param key
- * @param value
- * @param expiresIn in ms
- * @return
+ * Serializes and stored the given value using the key and sets the expiresIn value for the expiration of the key.
+ * If not enough space found to store the payload the returned pointer is null.
+ *
+ * @param key The key to save the value with
+ * @param value The value to serialize and store
+ * @param expiresIn The expiration delay
+ * @return The created pointer to directly retrieve the payload or null if not enough space was found
*/
Pointer<V> put( K key, V value, int expiresIn );
+ /**
+ * Serializes and stored the given value using the key with no expiration value. If not enough space found to store
+ * the payload the returned pointer is null.
+ *
+ * @param key The key to save the value with
+ * @param value The value to serialize and store
+ * @return The created pointer to directly retrieve the payload or null if not enough space was found
+ */
+ Pointer<V> put( K key, V value );
+
+ /**
+ * Retrieves the stored payload for key as a bytearray. If no pointer is found for the given key null is returned.
+ *
+ * @param key The key to retrieve
+ * @return The payload as bytearray or null if key was not found
+ */
byte[] retrieveByteArray( K key );
+ /**
+ * Retrieves the stored, deserialized value for key. If no pointer is found for the given key null is returned.
+ *
+ * @param key The key to retrieve
+ * @return The deserialized value or null if key was not found
+ */
V retrieve( K key );
+ /**
+ * Retrieves the accociated {@link Pointer} to the given key or null if no pointer was found.
+ *
+ * @param key The key to retrieve
+ * @return The pointer of the key or null if key was not found
+ */
Pointer<V> getPointer( K key );
+ /**
+ * Removes the key and frees the underlying memory area.
+ *
+ * @param key The key to remove
+ */
void free( K key );
+ /**
+ * Removes the pointer and frees the underlying memory area.
+ *
+ * @param key The pointer to remove
+ */
void free( Pointer<V> pointer );
+ /**
+ * Tells the {@link CacheService} to collect and remove all expired keys. In most cases this is automatically
+ * handled by scheduling a disposal interval using {@link CacheService#scheduleDisposalEvery} and there are very
+ * rare cases where this needs to be called manually.
+ */
void collectExpired();
+ /**
+ * Tells the {@link CacheService} to collect and remove all least frequently used keys. This operation could
+ * possibly clear the whole cache if there were no recent actions. In most cases this is automatically handled by
+ * scheduling a disposal interval using {@link CacheService#scheduleDisposalEvery} and there are very rare cases
+ * where this needs to be called manually.
+ */
void collectLFU();
+ /**
+ * Tells the {@link CacheService} to collect and remove all expired AND least frequently used keys. In most cases
+ * this is automatically handled by scheduling a disposal interval using {@link CacheService#scheduleDisposalEvery}
+ * and there are very rare cases where this needs to be called manually.
+ */
void collectAll();
+ /**
+ * Clears the whole cache by removing all stored keys. It is up to the underlying {@link MemoryManagerService}
+ * implementation to free allocated memory or not.
+ */
void clear();
+ /**
+ * Retrieves the count of the current entries.
+ *
+ * @return Number of entries
+ */
long entries();
+ /**
+ * Dumps information about the actual internal {@link MemoryManagerService} to the configured {@link Logger} with
+ * info loglevel.
+ */
void dump();
- ConcurrentMap<K, Pointer<V>> getMap();
+ /**
+ * Retrieves a map of all available keys and their according {@link Pointer}s. It is up to the {@link CacheService}
+ * implementation if the retrieved map is threadsafe or not. The standard implementation uses a
+ * {@link ConcurrentHashMap}.
+ *
+ * @return A mapping of keys to their according pointers
+ */
+ Map<K, Pointer<V>> getMap();
+ /**
+ * Retrieves the internally used {@link Serializer} implementation.
+ *
+ * @return The used serializer
+ */
Serializer getSerializer();
+ /**
+ * Retrieves the internally used {@link MemoryManagerService} implementation.
+ *
+ * @return The used memory manager
+ */
MemoryManagerService<V> getMemoryManager();
+ /**
+ * Explicitly allocated a bunch of bytes in the cache using a given key and type and returns the created
+ * {@link Pointer}.
+ *
+ * @param key The key to store as
+ * @param type The datatype of the underlying data
+ * @param size The size to allocate for this pointer
+ * @return
+ */
<T extends V> Pointer<V> allocate( K key, Class<T> type, int size );
}
diff --git a/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheServiceImpl.java b/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheServiceImpl.java
index 21e7c74..76b0920 100644
--- a/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheServiceImpl.java
+++ b/directmemory-cache/src/main/java/org/apache/directmemory/cache/CacheServiceImpl.java
@@ -31,6 +31,7 @@
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.TimeUnit;
import static com.google.common.base.Preconditions.checkArgument;
import static java.lang.String.format;
@@ -65,7 +66,13 @@
}
@Override
- public void scheduleDisposalEvery( long l )
+ public void scheduleDisposalEvery( long period, TimeUnit unit )
+ {
+ scheduleDisposalEvery( unit.toMillis( period ) );
+ }
+
+ @Override
+ public void scheduleDisposalEvery( long period )
{
timer.schedule( new TimerTask()
{
@@ -78,9 +85,9 @@
logger.info( "scheduled disposal complete" );
}
- }, l, l );
+ }, period, period );
- logger.info( "disposal scheduled every {} milliseconds", l );
+ logger.info( "disposal scheduled every {} milliseconds", period );
}
@Override
@@ -90,7 +97,7 @@
}
@Override
- public Pointer<V> putByteArray( K key, byte[] payload, int expiresIn )
+ public Pointer<V> putByteArray( K key, byte[] payload, long expiresIn )
{
return store( key, payload, expiresIn );
}
@@ -132,7 +139,7 @@
}
}
- private Pointer<V> store( K key, byte[] payload, int expiresIn )
+ private Pointer<V> store( K key, byte[] payload, long expiresIn )
{
Pointer<V> pointer = map.get( key );
if ( pointer != null )
