Interface StorageEngine<K,V>

Type Parameters:
K - key type handled by this engine
V - value type handled by this engine
All Known Subinterfaces:
PersistentStorageEngine<K,V>
All Known Implementing Classes:
FileBackedStorageEngine, LongStorageEngine, OffHeapBufferStorageEngine, PersistentSplitStorageEngine, PortabilityBasedStorageEngine, SerializableStorageEngine, SplitStorageEngine, StringStorageEngine
public interface StorageEngine<K,V>
An object that encodes map/cache keys and values to integers.

StorageEngine instances can choose their own method of value/key encoding. Keys that are small enough to be fully encoded in the Integer return can be stored directly in the table, others could be stored in some additional data structure.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static interface 
    StorageEngine.Owner
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    attachedMapping(long encoding, int hash, int metadata)
     
    void
    bind(StorageEngine.Owner owner)
     
    void
    clear()
    Called to indicate that all keys and values are now free.
    void
    destroy()
     
    boolean
    equalsKey(Object key, long encoding)
    Called to determine the equality of the given object against the given encoded form.
    boolean
    equalsValue(Object value, long encoding)
    Called to determine the equality of the given Java object value against the given encoded form.
    void
    freeMapping(long encoding, int hash, boolean removal)
    Called to indicate that the associated encoded value is no longer needed.
    long
    getAllocatedMemory()
    Returns a measure of the amount of memory allocated for this storage engine.
    long
    getDataSize()
    Returns a measure of the total size of the keys and values stored in this storage engine.
    long
    getOccupiedMemory()
    Returns a measure of the amount of memory consumed by this storage engine.
    long
    getVitalMemory()
    Returns a measure of the amount of vital memory allocated for this storage engine.
    void
    invalidateCache()
    Invalidate any local key/value caches.
    K
    readKey(long encoding, int hashCode)
    Converts the supplied encoded key into its correct object form.
    V
    readValue(long encoding)
    Converts the supplied encoded value into its correct object form.
    boolean
    shrink()
     
    Long
    writeMapping(K key, V value, int hash, int metadata)
    Converts the supplied key and value objects into their encoded form.

  • Method Details

    • writeMapping

      Long writeMapping(K key, V value, int hash, int metadata)
      Converts the supplied key and value objects into their encoded form.
      Parameters:
      key - a key object
      value - a value object
      hash - the key hash
      metadata - the metadata bits
      Returns:
      the encoded mapping

    • attachedMapping

      void attachedMapping(long encoding, int hash, int metadata)

    • freeMapping

      void freeMapping(long encoding, int hash, boolean removal)
      Called to indicate that the associated encoded value is no longer needed.

      This call can be used to free any associated resources tied to the lifecycle of the supplied encoded value.

      Parameters:
      encoding - encoded value
      hash - hash of the freed mapping
      removal - marks removal from a map

    • readValue

      V readValue(long encoding)
      Converts the supplied encoded value into its correct object form.
      Parameters:
      encoding - encoded value
      Returns:
      a decoded value object

    • equalsValue

      boolean equalsValue(Object value, long encoding)
      Called to determine the equality of the given Java object value against the given encoded form.

      Simple implementations will probably perform a decode on the given encoded form in order to do a regular Object.equals(Object) comparison. This method is provided to allow implementations to optimize this comparison if possible.

      Parameters:
      value - a value object
      encoding - encoded value
      Returns:
      true if the value and the encoding are equal

    • readKey

      K readKey(long encoding, int hashCode)
      Converts the supplied encoded key into its correct object form.
      Parameters:
      encoding - encoded key
      hashCode - hash-code of the decoded key
      Returns:
      a decoded key object

    • equalsKey

      boolean equalsKey(Object key, long encoding)
      Called to determine the equality of the given object against the given encoded form.

      Simple implementations will probably perform a decode on the given encoded form in order to do a regular Object.equals(Object) comparison. This method is provided to allow implementations to optimize this comparison if possible.

      Parameters:
      key - a key object
      encoding - encoded value
      Returns:
      true if the key and the encoding are equal

    • clear

      void clear()
      Called to indicate that all keys and values are now free.

    • getAllocatedMemory

      long getAllocatedMemory()
      Returns a measure of the amount of memory allocated for this storage engine.
      Returns:
      memory allocated for this engine in bytes

    • getOccupiedMemory

      long getOccupiedMemory()
      Returns a measure of the amount of memory consumed by this storage engine.
      Returns:
      memory occupied by this engine in bytes

    • getVitalMemory

      long getVitalMemory()
      Returns a measure of the amount of vital memory allocated for this storage engine.
      Returns:
      vital memory allocated for this engine in bytes

    • getDataSize

      long getDataSize()
      Returns a measure of the total size of the keys and values stored in this storage engine.
      Returns:
      size of the stored keys and values in bytes

    • invalidateCache

      void invalidateCache()
      Invalidate any local key/value caches.

      This is called to indicate the termination of a map write "phase". Caching is permitted within a write operation (i.e. to cache around allocation failures during eviction processes).

    • bind

      void bind(StorageEngine.Owner owner)

    • destroy

      void destroy()

    • shrink

      boolean shrink()