org.mapdb

Class StoreAppend

java.lang.Object

org.mapdb.Store

org.mapdb.StoreAppend

All Implemented Interfaces:

Closeable, AutoCloseable, Engine

public class StoreAppend
extends Store

append only store

Nested Class Summary

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

Store.Cache, Store.LongList, 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

Modifier and Type	Field and Description
protected ScheduledExecutorService	compactionExecutor
protected static int	HEADER 4 byte file header
protected static long	headerSize
protected Volume	headVol
protected AtomicLong	highestRecid
protected Volume	indexTable In memory table which maps recids into their offsets.
protected boolean	isSnapshot
protected Store.LongLongMap[]	modified
protected long	sizeIncrement
protected int	sliceShift
protected Set<StoreAppend>	snapshots
protected long	startSize
protected static StoreAppend[]	STORE_APPENDS_ZERO_ARRAY
protected static int	STORE_VERSION 2 byte store version
protected boolean	tx
protected WriteAheadLog	wal

Fields inherited from class org.mapdb.Store

caches, checksum, closed, commitLock, compress, deserializeExtra, encrypt, encryptionXTEA, FEAT_COMP_LZF, FEAT_CRC, FEAT_ENC_XTEA, fileLockDisable, fileLockHeartbeat, fileName, HEAD_CHECKSUM, HEAD_FEATURES, LOCKING_STRATEGY_NOLOCK, LOCKING_STRATEGY_READWRITELOCK, LOCKING_STRATEGY_WRITELOCK, lockMask, locks, lockScale, LOG, LZF, metricsDataRead, metricsDataWrite, metricsRecordRead, metricsRecordWrite, NOLOCK, readonly, recycledDataOut, snapshotEnable, structuralLock, volumeFactory

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

Modifier	Constructor and Description
protected	StoreAppend(StoreAppend host, Store.LongLongMap[] uncommitedData) protected constructor used to take snapshots
	StoreAppend(String fileName)
protected	StoreAppend(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, boolean txDisabled, ScheduledExecutorService compactionExecutor, long startSize, long sizeIncrement)

Method Summary

Methods

Modifier and Type	Method and Description
void	backup(OutputStream out, boolean incremental)
void	backupRestore(InputStream[] in)
boolean	canRollback()
boolean	canSnapshot()
void	close() Close store/cache.
void	commit() Makes all changes made since the previous commit/rollback permanent.
void	compact()
protected <A> void	delete2(long recid, Serializer<A> serializer)
boolean	fileLoad() If underlying storage is memory-mapped-file, this method will try to load and precache all file data into disk cache.
protected <A> A	get2(long recid, Serializer<A> serializer)
long	getCurrSize()
long	getFreeSize()
protected void	indexTablePut(long recid, long walId)
void	init()
protected void	initCreate()
protected void	initOpen()
long	preallocate() Preallocates recid for not yet created record.
<A> long	put(A value, Serializer<A> serializer) Insert new record.
void	rollback() Undoes all changes made in the current transaction.
Engine	snapshot() Returns read-only snapshot of data in Engine.
protected void	update2(long recid, DataIO.DataOutputByteArray out)

Methods inherited from class org.mapdb.Store

assertReadLocked, assertWriteLocked, checkFeaturesBitmap, clearCache, compareAndSwap, delete, deserialize, forDB, forEngine, get, getWrappedEngine, isClosed, isReadOnly, lockPos, longParityGet, longParitySet, makeFeaturesBitmap, metricsCollect, newDataOut2, serialize, update

Methods inherited from class java.lang.Object

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

Field Detail

STORE_VERSION

protected static final int STORE_VERSION

2 byte store version

See Also:

Constant Field Values

HEADER

protected static final int HEADER

4 byte file header

See Also:

Constant Field Values

headerSize

protected static final long headerSize

See Also:

Constant Field Values

STORE_APPENDS_ZERO_ARRAY

protected static final StoreAppend[] STORE_APPENDS_ZERO_ARRAY

wal

protected WriteAheadLog wal

headVol

protected Volume headVol

indexTable

protected Volume indexTable

In memory table which maps recids into their offsets. Positive values are offsets. Zero value indicates on-used records Negative values are:

     -1 - records was deleted, return null
     -2 - record has zero size
     -3 - null record, return null
 

highestRecid

protected final AtomicLong highestRecid

tx

protected final boolean tx

modified

protected final Store.LongLongMap[] modified

compactionExecutor

protected final ScheduledExecutorService compactionExecutor

snapshots

protected final Set<StoreAppend> snapshots

isSnapshot

protected final boolean isSnapshot

startSize

protected final long startSize

sizeIncrement

protected final long sizeIncrement

sliceShift

protected final int sliceShift

Constructor Detail

StoreAppend

protected StoreAppend(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,
           boolean txDisabled,
           ScheduledExecutorService compactionExecutor,
           long startSize,
           long sizeIncrement)

StoreAppend

public StoreAppend(String fileName)

StoreAppend

protected StoreAppend(StoreAppend host,
           Store.LongLongMap[] uncommitedData)

protected constructor used to take snapshots

Method Detail

init

public void init()

Overrides:

init in class Store

initCreate

protected void initCreate()

initOpen

protected void initOpen()

get2

protected <A> A get2(long recid,
         Serializer<A> serializer)

Specified by:

get2 in class Store

update2

protected void update2(long recid,
           DataIO.DataOutputByteArray out)

Specified by:

update2 in class Store

delete2

protected <A> void delete2(long recid,
               Serializer<A> serializer)

Specified by:

delete2 in class Store

getCurrSize

public long getCurrSize()

Specified by:

getCurrSize in class Store

getFreeSize

public long getFreeSize()

Specified by:

getFreeSize in class Store

fileLoad

public boolean fileLoad()

Description copied from class: Store

If underlying storage is memory-mapped-file, this method will try to load and precache all file data into disk cache. Most likely it will call MappedByteBuffer.load(), but could also read content of entire file etc This method will not pin data into memory, they might be removed at any time.

Specified by:

fileLoad in class Store

Returns:

true if this method did something, false if underlying storage does not support loading, or is already in-memory

preallocate

public long preallocate()

Description copied from interface: Engine

Preallocates recid for not yet created record. It does not insert any data into it.

Returns:

new recid

indexTablePut

protected void indexTablePut(long recid,
                 long walId)

put

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

Description copied from interface: Engine

Insert new record.

Parameters:

value - records to be added

serializer - used to convert record into/from binary form

Returns:

recid (record identifier) under which record is stored.

close

public void close()

Description copied from interface: Engine

Close store/cache. This method must be called before JVM exits to flush all caches and prevent store corruption. Also it releases resources used by MapDB (disk, memory..).

Engine can no longer be used after this method was called. If Engine is used after closing, it may throw any exception including NullPointerException

There is an configuration option DBMaker.Maker.closeOnJvmShutdown() which uses shutdown hook to automatically close Engine when JVM shutdowns.

commit

public void commit()

Description copied from interface: Engine

Makes all changes made since the previous commit/rollback permanent. In transactional mode (on by default) it means creating journal file and replaying it to storage. In other modes it may flush disk caches or do nothing at all (check your config options)

rollback

public void rollback()
              throws UnsupportedOperationException

Description copied from interface: Engine

Undoes all changes made in the current transaction. If transactions are disabled it throws UnsupportedOperationException.

Throws:

UnsupportedOperationException - if transactions are disabled

canRollback

public boolean canRollback()

Returns:

true if engine supports rollback

canSnapshot

public boolean canSnapshot()

Specified by:

canSnapshot in interface Engine

Overrides:

canSnapshot in class Store

Returns:

true if engine can create read-only snapshots

snapshot

public Engine snapshot()
                throws UnsupportedOperationException

Description copied from interface: Engine

Returns read-only snapshot of data in Engine.

Throws:

UnsupportedOperationException - if snapshots are not supported/enabled

compact

public void compact()

backup

public void backup(OutputStream out,
          boolean incremental)

Specified by:

backup in class Store

backupRestore

public void backupRestore(InputStream[] in)

Specified by:

backupRestore in class Store