org.mapdb

Class StoreCached

java.lang.Object

org.mapdb.Store

org.mapdb.StoreDirect

org.mapdb.StoreCached

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Engine

Direct Known Subclasses:

StoreWAL

public class StoreCached
extends StoreDirect

Extends StoreDirect with Write Cache

Nested Class Summary

Nested classes/interfaces inherited from class org.mapdb.StoreDirect

StoreDirect.Snapshot

Nested classes/interfaces inherited from class org.mapdb.Store

Store.Cache, Store.LongLongMap, Store.LongObjectMap<V>, Store.LongObjectObjectMap<V1,V2>, Store.LongQueue, Store.MemoryBarrierLessLock, Store.ReadWriteSingleLock

Nested classes/interfaces inherited from interface org.mapdb.Engine

Engine.CloseOnJVMShutdown, Engine.ReadOnly, Engine.ReadOnlyWrapper

Field Summary

Fields inherited from class org.mapdb.Store

LOCKING_STRATEGY_NOLOCK, LOCKING_STRATEGY_READWRITELOCK, LOCKING_STRATEGY_WRITELOCK, NOLOCK

Fields inherited from interface org.mapdb.Engine

CLOSED_ENGINE, RECID_CLASS_CATALOG, RECID_FIRST, RECID_LAST_RESERVED, RECID_NAME_CATALOG, RECID_RECORD_CHECK

Constructor Summary

Constructors

Constructor and Description
StoreCached(java.lang.String fileName)
StoreCached(java.lang.String fileName, Volume.VolumeFactory volumeFactory, Store.Cache cache, int lockScale, int lockingStrategy, boolean checksum, boolean compress, byte[] password, boolean readonly, boolean snapshotEnable, boolean fileLockDisable, DataIO.HeartbeatFileLock fileLockHeartbeat, java.util.concurrent.ScheduledExecutorService executor, long startSize, long sizeIncrement, boolean recidReuseDisable, long executorScheduledRate, int writeQueueSize)

Method Summary

Modifier and Type	Method and Description
<A> boolean	compareAndSwap(long recid, A expectedOldValue, A newValue, Serializer<A> serializer) Updates existing record in atomic (Compare And Swap) manner.
<A> long	put(A value, Serializer<A> serializer) Insert new record.
<A> void	update(long recid, A value, Serializer<A> serializer) Update existing record with new value.

Methods inherited from class org.mapdb.StoreDirect

backup, backupRestore, canRollback, clearCache, close, commit, compact, fileLoad, getCurrSize, getFreeSize, init, preallocate, rollback, snapshot

Methods inherited from class org.mapdb.Store

canSnapshot, delete, forDB, forEngine, get, getWrappedEngine, isClosed, isReadOnly, metricsCollect

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StoreCached

public StoreCached(java.lang.String fileName,
                   Volume.VolumeFactory volumeFactory,
                   Store.Cache cache,
                   int lockScale,
                   int lockingStrategy,
                   boolean checksum,
                   boolean compress,
                   byte[] password,
                   boolean readonly,
                   boolean snapshotEnable,
                   boolean fileLockDisable,
                   DataIO.HeartbeatFileLock fileLockHeartbeat,
                   java.util.concurrent.ScheduledExecutorService executor,
                   long startSize,
                   long sizeIncrement,
                   boolean recidReuseDisable,
                   long executorScheduledRate,
                   int writeQueueSize)

StoreCached

public StoreCached(java.lang.String fileName)

Method Detail

put

public <A> long put(A value,
                    Serializer<A> serializer)

Description copied from interface: Engine

Insert new record.

Specified by:

put in interface Engine

Overrides:

put in class StoreDirect

Parameters:

value - records to be added

serializer - used to convert record into/from binary form

Returns:

recid (record identifier) under which record is stored.

update

public <A> void update(long recid,
                       A value,
                       Serializer<A> serializer)

Description copied from interface: Engine

Update existing record with new value.

Recid must be a number returned by 'put' method. Behaviour for invalid recid (random number or already deleted record) is not defined, typically it throws 'EndOfFileException', but it may also corrupt store.

Specified by:

update in interface Engine

Overrides:

update in class Store

Parameters:

recid - (record identifier) under which record was persisted.

value - new record value to be stored

serializer - used to serialize record into binary form

compareAndSwap

public <A> boolean compareAndSwap(long recid,
                                  A expectedOldValue,
                                  A newValue,
                                  Serializer<A> serializer)

Description copied from interface: Engine

Updates existing record in atomic (Compare And Swap) manner. Value is modified only if old value matches expected value. There are three ways to match values, MapDB may use any of them:

1. Equality check oldValue==expectedOldValue when old value is found in instance cache
2. Deserializing oldValue using serializer and checking oldValue.equals(expectedOldValue)
3. Serializing expectedOldValue using serializer and comparing binary array with already serialized oldValue

Recid must be a number returned by 'put' method. Behaviour for invalid recid (random number or already deleted record) is not defined, typically it throws 'EndOfFileException', but it may also corrupt store.

Specified by:

compareAndSwap in interface Engine

Overrides:

compareAndSwap in class Store

Parameters:

recid - (record identifier) under which record was persisted.

expectedOldValue - old value to be compared with existing record

newValue - to be written if values are matching

serializer - used to serialize record into binary form

Returns:

true if values matched and newValue was written