net.openhft.chronicle.queue.impl.table

Class SingleTableStore<T extends Metadata>

java.lang.Object

net.openhft.chronicle.queue.impl.table.SingleTableStore<T>

All Implemented Interfaces:

Closeable, AutoCloseable, net.openhft.chronicle.core.ReferenceCounted, CommonStore, TableStore<T>, net.openhft.chronicle.wire.Demarshallable, net.openhft.chronicle.wire.WriteMarshallable, net.openhft.chronicle.wire.WriteValue

public class SingleTableStore<T extends Metadata>
extends Object
implements TableStore<T>

Field Summary

Fields

Modifier and Type	Field and Description
static String	SUFFIX

Fields inherited from interface net.openhft.chronicle.wire.Demarshallable

DEMARSHALLABLES

Fields inherited from interface net.openhft.chronicle.wire.WriteMarshallable

EMPTY

Constructor Summary

Constructors

Constructor and Description
SingleTableStore(net.openhft.chronicle.wire.WireType wireType, net.openhft.chronicle.bytes.MappedBytes mappedBytes, StoreRecovery recovery, T metadata)

Method Summary

Modifier and Type	Method and Description
net.openhft.chronicle.core.values.LongValue	acquireValueFor(CharSequence key) Acquire LongValue mapped to underlying file, providing atomic operations on the value that is shared across threads and/or JVMs.
net.openhft.chronicle.bytes.MappedBytes	bytes()
void	close()
static <T,R> R	doWithExclusiveLock(File file, Function<T,? extends R> code, Supplier<T> target)
<R> R	doWithExclusiveLock(Function<TableStore<T>,? extends R> code) Acquires file-system level lock on the underlying file, to prevent concurrent access from multiple processes.
String	dump()
File	file()
boolean	isClosed()
T	metadata()
long	refCount()
void	release()
void	reserve()
String	toString()
void	writeMarshallable(net.openhft.chronicle.wire.WireOut wire)

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.openhft.chronicle.core.ReferenceCounted

release, releaseAll, tryReserve

Methods inherited from interface net.openhft.chronicle.wire.Demarshallable

newInstance

Methods inherited from interface net.openhft.chronicle.wire.WriteMarshallable

writeValue

Methods inherited from interface net.openhft.chronicle.core.io.Closeable

closeQuietly, closeQuietly, notifyClosing

Field Detail

SUFFIX

public static final String SUFFIX

See Also:

Constant Field Values

Constructor Detail

SingleTableStore

public SingleTableStore(@NotNull
                        net.openhft.chronicle.wire.WireType wireType,
                        @NotNull
                        net.openhft.chronicle.bytes.MappedBytes mappedBytes,
                        @NotNull
                        StoreRecovery recovery,
                        @NotNull
                        T metadata)

Parameters:

wireType - the wire type that is being used

mappedBytes - used to mapped the data store file

recovery - used to recover from concurrent modifications

Method Detail

isClosed

public boolean isClosed()

file

@NotNull
public File file()

Specified by:

file in interface CommonStore

Returns:

the file associated with this store.

dump

@NotNull
public String dump()

Specified by:

dump in interface CommonStore

reserve

public void reserve()
             throws IllegalStateException

Specified by:

reserve in interface net.openhft.chronicle.core.ReferenceCounted

Throws:

IllegalStateException

release

public void release()
             throws IllegalStateException

Specified by:

release in interface net.openhft.chronicle.core.ReferenceCounted

Throws:

IllegalStateException

refCount

public long refCount()

Specified by:

refCount in interface net.openhft.chronicle.core.ReferenceCounted

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

bytes

@NotNull
public net.openhft.chronicle.bytes.MappedBytes bytes()

Specified by:

bytes in interface CommonStore

Returns:

creates a new instance of mapped bytes, because, for example the tailer and appender can be at different locations.

toString

@NotNull
public String toString()

Overrides:

toString in class Object

writeMarshallable

public void writeMarshallable(@NotNull
                              net.openhft.chronicle.wire.WireOut wire)

Specified by:

writeMarshallable in interface net.openhft.chronicle.wire.WriteMarshallable

acquireValueFor

public net.openhft.chronicle.core.values.LongValue acquireValueFor(CharSequence key)

Acquire LongValue mapped to underlying file, providing atomic operations on the value that is shared across threads and/or JVMs. Note: The implementation of this method is not required to guarantee that if the value does not exist in the file, it will create one and only one value in the file in case of concurrent access. On the contrary, it's possible that different threads or processes acquire LongValues pointing to different fields in the underlying file. To prevent this, it is advised to use TableStore.doWithExclusiveLock(Function) to wrap calls to this method, which will ensure exclusive access to file while initially acquiring values.

Specified by:

acquireValueFor in interface TableStore<T extends Metadata>

Parameters:

key - the key of the value

Returns:

LongValue object pointing to particular location in mapped underlying file

doWithExclusiveLock

public <R> R doWithExclusiveLock(Function<TableStore<T>,? extends R> code)

Acquires file-system level lock on the underlying file, to prevent concurrent access from multiple processes. It is recommended to use this when acquiring your values for the first time, otherwise it is possible to get unpredictable results in case of multiple processes/threads trying to acquire values for the same key. In addition, it allows to batch multiple TableStore.acquireValueFor(CharSequence) calls, to atomically acquire multiple values.

Specified by:

doWithExclusiveLock in interface TableStore<T extends Metadata>

Type Parameters:

R - result type

Parameters:

code - code block to execute using locked table store

Returns:

result of code block execution

metadata

public T metadata()

Specified by:

metadata in interface TableStore<T extends Metadata>

doWithExclusiveLock

public static <T,R> R doWithExclusiveLock(File file,
                                          Function<T,? extends R> code,
                                          Supplier<T> target)