Package net.sf.ehcache.store

Class MemoryStore

    • Constructor Detail

      • MemoryStore

        protected MemoryStore​(Ehcache cache,
                      Pool pool,
                      MemoryStore.BackingFactory factory,
                      SearchManager searchManager)
        Constructs things that all MemoryStores have in common.
        Parameters:
        cache - the cache
        pool - the pool tracking the on-heap usage
        searchManager - the search manager

    • Method Detail

      • getInitialCapacityForLoadFactor

        protected static int getInitialCapacityForLoadFactor​(int maximumSizeGoal,
                                                     float loadFactor)
        Calculates the initialCapacity for a desired maximumSize goal and loadFactor.
        Parameters:
        maximumSizeGoal - the desired maximum size goal
        loadFactor - the load factor
        Returns:
        the calculated initialCapacity. Returns 0 if the parameter maximumSizeGoal is less than or equal to 0

      • create

        public static Store create​(Ehcache cache,
                           Pool pool)
        A factory method to create a MemoryStore.
        Parameters:
        cache - the cache
        pool - the pool tracking the on-heap usage
        Returns:
        an instance of a NotifyingMemoryStore, configured with the appropriate eviction policy

      • createBruteForceSource

        protected static net.sf.ehcache.store.BruteForceSource createBruteForceSource​(MemoryStore memoryStore,
                                                                              CacheConfiguration cacheConfiguration)
        Factory method to wrap the MemoryStore into a BruteForceSource, accounting for transactional and copy configuration
        Parameters:
        memoryStore - the underlying store acting as source
        cacheConfiguration - the cache configuration
        Returns:
        a BruteForceSource connected to underlying MemoryStore and matching configuration

      • put

        public boolean put​(Element element)
            throws CacheException
        Puts an item in the store. Note that this automatically results in an eviction if the store is full.
        Specified by:
        put in interface Store
        Parameters:
        element - the element to add
        Returns:
        true if this is a new put for the key or element is null. Returns false if it was an update.
        Throws:
        CacheException

      • putWithWriter

        public boolean putWithWriter​(Element element,
                             CacheWriterManager writerManager)
                      throws CacheException
        Puts an item into the store and the cache writer manager in an atomic operation
        Specified by:
        putWithWriter in interface Store
        Returns:
        true if this is a new put for the key or element is null. Returns false if it was an update.
        Throws:
        CacheException

      • get

        public final Element get​(java.lang.Object key)
        Gets an item from the cache.

        The last access time in Element is updated.

        Specified by:
        get in interface Store
        Parameters:
        key - the key of the Element
        Returns:
        the element, or null if there was no match for the key

      • getQuiet

        public final Element getQuiet​(java.lang.Object key)
        Gets an item from the cache, without updating statistics.
        Specified by:
        getQuiet in interface Store
        Parameters:
        key - the cache key
        Returns:
        the element, or null if there was no match for the key

      • remove

        public Element remove​(java.lang.Object key)
        Removes an Element from the store.
        Specified by:
        remove in interface Store
        Parameters:
        key - the key of the Element, usually a String
        Returns:
        the Element if one was found, else null

      • bufferFull

        public final boolean bufferFull()
        Memory stores are never backed up and always return false
        Specified by:
        bufferFull in interface Store
        Returns:
        true if the store write buffer is backed up.

      • expireElements

        public void expireElements()
        Expire all elements.

        This is a default implementation which does nothing. Expiration on demand is only implemented for disk stores.

        Specified by:
        expireElements in interface Store

      • expireElement

        protected Element expireElement​(java.lang.Object key)
        Evicts the element for the given key, if it exists and is expired
        Parameters:
        key - the key
        Returns:
        the evicted element, if any. Otherwise null

      • dispose

        public void dispose()
        Prepares for shutdown.
        Specified by:
        dispose in interface Store

      • flush

        public void flush()
        Flush to disk only if the cache is diskPersistent.
        Specified by:
        flush in interface Store

      • getKeys

        public final java.util.List<?> getKeys()
        Gets an Array of the keys for all elements in the memory cache.

        Does not check for expired entries

        Specified by:
        getKeys in interface Store
        Returns:
        An List

      • keySet

        protected java.util.Set<?> keySet()
        Returns the keySet for this store
        Returns:
        keySet

      • getSize

        public final int getSize()
        Returns the current store size.
        Specified by:
        getSize in interface Store
        Returns:
        The size value

      • getTerracottaClusteredSize

        public final int getTerracottaClusteredSize()
        Returns nothing since a disk store isn't clustered
        Specified by:
        getTerracottaClusteredSize in interface Store
        Returns:
        returns 0

      • containsKey

        public final boolean containsKey​(java.lang.Object key)
        A check to see if a key is in the Store. No check is made to see if the Element is expired.
        Specified by:
        containsKey in interface Store
        Parameters:
        key - The Element key
        Returns:
        true if found. If this method return false, it means that an Element with the given key is definitely not in the MemoryStore. If it returns true, there is an Element there. An attempt to get it may return null if the Element has expired.

      • notifyDirectEviction

        protected void notifyDirectEviction​(Element element)
        Called when an element is evicted even before it could be installed inside the store
        Parameters:
        element - the evicted element

      • isFull

        public final boolean isFull()
        An algorithm to tell if the MemoryStore is at or beyond its carrying capacity.
        Returns:
        true if the store is full, false otherwise

      • canPutWithoutEvicting

        public final boolean canPutWithoutEvicting​(Element element)
        Check if adding an element won't provoke an eviction.
        Parameters:
        element - the element
        Returns:
        true if the element can be added without provoking an eviction.

      • getInternalContext

        public java.lang.Object getInternalContext()
        This should not be used, and will generally return null
        Specified by:
        getInternalContext in interface Store
        Returns:
        some internal context (probably null)

      • getStatus

        public final Status getStatus()
        Gets the status of the MemoryStore.
        Specified by:
        getStatus in interface Store

      • timeToIdleChanged

        public void timeToIdleChanged​(long oldTti,
                              long newTti)
        Indicates a change in the configurations time to idle
        Specified by:
        timeToIdleChanged in interface CacheConfigurationListener
        Parameters:
        oldTti - previous time to idle value
        newTti - new time to idle value

      • timeToLiveChanged

        public void timeToLiveChanged​(long oldTtl,
                              long newTtl)
        Indicates a change in the configurations time to live
        Specified by:
        timeToLiveChanged in interface CacheConfigurationListener
        Parameters:
        oldTtl - previous time to live value
        newTtl - new time to live value

      • diskCapacityChanged

        public void diskCapacityChanged​(int oldCapacity,
                                int newCapacity)
        Indicates a change in the configurations disk store capacity
        Specified by:
        diskCapacityChanged in interface CacheConfigurationListener
        Parameters:
        oldCapacity - previous capacity
        newCapacity - new capacity

      • loggingChanged

        public void loggingChanged​(boolean oldValue,
                           boolean newValue)
        Indicates a change in the configuration for enable/disable logging
        Specified by:
        loggingChanged in interface CacheConfigurationListener
        Parameters:
        oldValue - old value whether logging was enabled or not
        newValue - new value whether logging was enabled or not

      • memoryCapacityChanged

        public void memoryCapacityChanged​(int oldCapacity,
                                  int newCapacity)
        Indicates a change in the configurations memory store capacity
        Specified by:
        memoryCapacityChanged in interface CacheConfigurationListener
        Parameters:
        oldCapacity - previous capacity
        newCapacity - new capacity

      • maxBytesLocalHeapChanged

        public void maxBytesLocalHeapChanged​(long oldValue,
                                     long newValue)
        Indicates a change in the configuration for maxBytesLocalHeap setting
        Specified by:
        maxBytesLocalHeapChanged in interface CacheConfigurationListener
        Parameters:
        oldValue - old value in bytes
        newValue - new value in bytes

      • maxBytesLocalDiskChanged

        public void maxBytesLocalDiskChanged​(long oldValue,
                                     long newValue)
        Indicates a change in the configuration for maxBytesLocalDisk setting
        Specified by:
        maxBytesLocalDiskChanged in interface CacheConfigurationListener
        Parameters:
        oldValue - old value in bytes
        newValue - new value in bytes

      • maxEntriesInCacheChanged

        public void maxEntriesInCacheChanged​(long oldValue,
                                     long newValue)
        Indicates a change in the configuration for maxEntriesInCache setting
        Specified by:
        maxEntriesInCacheChanged in interface CacheConfigurationListener
        Parameters:
        oldValue - old value
        newValue - new value

      • containsKeyInMemory

        public boolean containsKeyInMemory​(java.lang.Object key)
        A check to see if a key is in the Store and is currently held in memory.
        Specified by:
        containsKeyInMemory in interface Store
        Parameters:
        key - The Element key
        Returns:
        true if found. No check is made to see if the Element is expired.

      • containsKeyOffHeap

        public boolean containsKeyOffHeap​(java.lang.Object key)
        A check to see if a key is in the Store and is currently held off-heap.
        Specified by:
        containsKeyOffHeap in interface Store
        Parameters:
        key - The Element key
        Returns:
        true if found. No check is made to see if the Element is expired.

      • containsKeyOnDisk

        public boolean containsKeyOnDisk​(java.lang.Object key)
        A check to see if a key is in the Store and is currently held on disk.
        Specified by:
        containsKeyOnDisk in interface Store
        Parameters:
        key - The Element key
        Returns:
        true if found. No check is made to see if the Element is expired.

      • getInMemorySize

        public int getInMemorySize()
        Returns the current local in-memory store size
        Specified by:
        getInMemorySize in interface Store
        Returns:
        the count of the Elements in the Store and in-memory on the local machine

      • getInMemorySizeInBytes

        public long getInMemorySizeInBytes()
        Gets the size of the in-memory portion of the store, in bytes.

        This method may be expensive to run, depending on implementation. Implementers may choose to return an approximate size.

        Specified by:
        getInMemorySizeInBytes in interface Store
        Returns:
        the approximate in-memory size of the store in bytes

      • getOffHeapSize

        public int getOffHeapSize()
        Returns the current local off-heap store size
        Specified by:
        getOffHeapSize in interface Store
        Returns:
        the count of the Elements in the Store and off-heap on the local machine

      • getOffHeapSizeInBytes

        public long getOffHeapSizeInBytes()
        Gets the size of the off-heap portion of the store, in bytes.
        Specified by:
        getOffHeapSizeInBytes in interface Store
        Returns:
        the approximate off-heap size of the store in bytes

      • getOnDiskSize

        public int getOnDiskSize()
        Returns the current local on-disk store size
        Specified by:
        getOnDiskSize in interface Store
        Returns:
        the count of the Elements in the Store and on-disk on the local machine

      • getOnDiskSizeInBytes

        public long getOnDiskSizeInBytes()
        Gets the size of the on-disk portion of the store, in bytes.
        Specified by:
        getOnDiskSizeInBytes in interface Store
        Returns:
        the on-disk size of the store in bytes

      • hasAbortedSizeOf

        public boolean hasAbortedSizeOf()
        Checks if the cache may contain elements for which the SizeOf engine gave up and only partially calculated the size.
        Specified by:
        hasAbortedSizeOf in interface Store
        Overrides:
        hasAbortedSizeOf in class AbstractStore
        Returns:
        true if at least one partially sized element may be in the cache

      • setInMemoryEvictionPolicy

        public void setInMemoryEvictionPolicy​(Policy policy)
        Sets the eviction policy strategy. The Store will use a policy at startup. The store may allow changing the eviction policy strategy dynamically. Otherwise implementations will throw an exception if this method is called.
        Specified by:
        setInMemoryEvictionPolicy in interface Store
        Parameters:
        policy - the new policy

      • putIfAbsent

        public Element putIfAbsent​(Element element)
                    throws java.lang.NullPointerException
        Put an element in the store if no element is currently mapped to the elements key.
        Specified by:
        putIfAbsent in interface Store
        Parameters:
        element - element to be added
        Returns:
        the element previously cached for this key, or null if none.
        Throws:
        java.lang.NullPointerException - if the element is null, or has a null key

      • evict

        protected boolean evict​(Element element)
        Evicts the element from the store
        Parameters:
        element - the element to be evicted
        Returns:
        true if succeeded, false otherwise

      • expire

        protected boolean expire​(Element element)
        Evicts the element from the store
        Parameters:
        element - the element to be evicted
        Returns:
        true if succeeded, false otherwise

      • removeElement

        public Element removeElement​(Element element,
                             ElementValueComparator comparator)
                      throws java.lang.NullPointerException
        Remove the Element mapped to the key for the supplied element if the value of the supplied Element is equal to the value of the cached Element. This is a CAS operation. It is consistent even against a distributed cache that is not coherent. If the old value is stale when this operation is attempted the remove does not take place.
        Specified by:
        removeElement in interface Store
        Parameters:
        element - Element to be removed
        comparator - ElementValueComparator to use to compare elements
        Returns:
        the Element removed or null if no Element was removed
        Throws:
        java.lang.NullPointerException - if the element is null, or has a null key

      • replace

        public boolean replace​(Element old,
                       Element element,
                       ElementValueComparator comparator)
                throws java.lang.NullPointerException,
                       java.lang.IllegalArgumentException
        Replace the cached element only if the value of the current Element is equal to the value of the supplied old Element.
        Specified by:
        replace in interface Store
        Parameters:
        old - Element to be test against
        element - Element to be cached
        comparator - ElementValueComparator to use to compare elements
        Returns:
        true is the Element was replaced
        Throws:
        java.lang.NullPointerException - if the either Element is null or has a null key
        java.lang.IllegalArgumentException - if the two Element keys are non-null but not equal

      • replace

        public Element replace​(Element element)
                throws java.lang.NullPointerException
        Replace the cached element only if an Element is currently cached for this key
        Specified by:
        replace in interface Store
        Parameters:
        element - Element to be cached
        Returns:
        the Element previously cached for this key, or null if no Element was cached
        Throws:
        java.lang.NullPointerException - if the Element is null or has a null key

      • getMBean

        public java.lang.Object getMBean()
        Optional implementation specific MBean exposed by the store.
        Specified by:
        getMBean in interface Store
        Returns:
        implementation specific management bean

      • elementSet

        public java.util.Collection<Element> elementSet()
        Get a collection of the elements in this store
        Returns:
        element collection