com.aoindustries.util.persistent

Class LargeMappedPersistentBuffer

java.lang.Object

com.aoindustries.util.persistent.AbstractPersistentBuffer

com.aoindustries.util.persistent.LargeMappedPersistentBuffer

All Implemented Interfaces:

PersistentBuffer

public class LargeMappedPersistentBuffer
extends AbstractPersistentBuffer

Uses a set of MappedByteBuffer for persistence. Each buffer covers a maximum of 2^30 bytes. This handles mapping of up to 2^30 * 2^31-2 bytes.

Author:

AO Industries, Inc.

See Also:

MappedPersistentBuffer

Field Summary

Fields inherited from class com.aoindustries.util.persistent.AbstractPersistentBuffer

protectionLevel

Constructor Summary

Constructors

Constructor and Description
LargeMappedPersistentBuffer() Creates a read-write buffer backed by a temporary file.
LargeMappedPersistentBuffer(File file) Creates a read-write buffer with BARRIER protection level.
LargeMappedPersistentBuffer(File file, ProtectionLevel protectionLevel) Creates a buffer.
LargeMappedPersistentBuffer(RandomAccessFile raf, ProtectionLevel protectionLevel) Creates a buffer using the provided RandomAccessFile.
LargeMappedPersistentBuffer(String name) Creates a read-write buffer with BARRIER protection level.
LargeMappedPersistentBuffer(String name, ProtectionLevel protectionLevel) Creates a buffer.

Method Summary

Modifier and Type	Method and Description
void	barrier(boolean force) There is not currently a way to provide a barrier without using force.
long	capacity() Gets the capacity of this buffer.
void	close() Closes this buffer.
void	ensureZeros(long position, long len) Ensures that all values from the position for the provided length are zeros.
protected void	finalize()
byte	get(long position) Gets a single byte from the buffer.
void	get(long position, byte[] buff, int off, int len) Implemented as calls to getSome(long,byte[],int,int)
boolean	getBoolean(long position) Implemented as call to readByte(long)
int	getInt(long position) Implemented as call to get(long,byte[],int,int)
long	getLong(long position) Implemented as call to get(long,byte[],int,int)
int	getSome(long position, byte[] buff, int off, int len) Reads to the provided byte[], may read fewer than len bytes, but will always read at least one byte.
boolean	isClosed() Checks if this buffer is closed.
void	put(long position, byte value) Puts a single byte in the buffer.
void	put(long position, byte[] buff, int off, int len) Writes the bytes to the provided position.
void	putInt(long position, int value) Implemented as call to write(long,byte[],int,int)
void	putLong(long position, long value) Implemented as call to write(long,byte[],int,int)
void	setCapacity(long newLength) Sets the capacity of this buffer.

Methods inherited from class com.aoindustries.util.persistent.AbstractPersistentBuffer

getInputStream, getOutputStream, getProtectionLevel

Methods inherited from class java.lang.Object

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

Constructor Detail

LargeMappedPersistentBuffer

public LargeMappedPersistentBuffer()
                            throws IOException

Creates a read-write buffer backed by a temporary file. The protection level is set to NONE. The temporary file will be deleted when this buffer is closed or on JVM shutdown.

Throws:

IOException

LargeMappedPersistentBuffer

public LargeMappedPersistentBuffer(String name)
                            throws IOException

Creates a read-write buffer with BARRIER protection level.

Throws:

IOException

LargeMappedPersistentBuffer

public LargeMappedPersistentBuffer(String name,
                                   ProtectionLevel protectionLevel)
                            throws IOException

Creates a buffer.

Throws:

IOException

LargeMappedPersistentBuffer

public LargeMappedPersistentBuffer(File file)
                            throws IOException

Creates a read-write buffer with BARRIER protection level.

Throws:

IOException

LargeMappedPersistentBuffer

public LargeMappedPersistentBuffer(File file,
                                   ProtectionLevel protectionLevel)
                            throws IOException

Creates a buffer.

Throws:

IOException

LargeMappedPersistentBuffer

public LargeMappedPersistentBuffer(RandomAccessFile raf,
                                   ProtectionLevel protectionLevel)
                            throws IOException

Creates a buffer using the provided RandomAccessFile.

Throws:

IOException

Method Detail

isClosed

public boolean isClosed()

Description copied from interface: PersistentBuffer

Checks if this buffer is closed.

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable

close

public void close()
           throws IOException

Description copied from interface: PersistentBuffer

Closes this buffer. It is OK to close an already closed buffer.

Throws:

IOException

capacity

public long capacity()
              throws IOException

Description copied from interface: PersistentBuffer

Gets the capacity of this buffer.

Throws:

IOException

setCapacity

public void setCapacity(long newLength)
                 throws IOException

Description copied from interface: PersistentBuffer

Sets the capacity of this buffer. If the buffer is increased in size, the new space will be zero-filled. Setting the capacity may impose an automatic barrier(true), depending on implementation. This should be considered an expensive operation.

Throws:

IOException

get

public void get(long position,
                byte[] buff,
                int off,
                int len)
         throws IOException

Description copied from class: AbstractPersistentBuffer

Implemented as calls to getSome(long,byte[],int,int)

Specified by:

get in interface PersistentBuffer

Overrides:

get in class AbstractPersistentBuffer

Throws:

IOException

See Also:

#read(long, byte[], int, int)

getSome

public int getSome(long position,
                   byte[] buff,
                   int off,
                   int len)
            throws IOException

Description copied from interface: PersistentBuffer

Reads to the provided byte[], may read fewer than len bytes, but will always read at least one byte. Blocks if no data is available.

Throws:

IOException

get

public byte get(long position)
         throws IOException

Gets a single byte from the buffer.

Specified by:

get in interface PersistentBuffer

Overrides:

get in class AbstractPersistentBuffer

Throws:

IOException

See Also:

AbstractPersistentBuffer.get(long, byte[], int, int)

ensureZeros

public void ensureZeros(long position,
                        long len)
                 throws IOException

Description copied from interface: PersistentBuffer

Ensures that all values from the position for the provided length are zeros. This may or may not modify the buffer in the process. The values will all be zero upon return. Some implementations may choose to overwrite zeros and return modified, others may choose to detect zeros and avoid modifications. Thus it is possible for existing zeros to still result in a modification.

Throws:

IOException

put

public void put(long position,
                byte value)
         throws IOException

Puts a single byte in the buffer.

Specified by:

put in interface PersistentBuffer

Overrides:

put in class AbstractPersistentBuffer

Throws:

IOException

See Also:

PersistentBuffer.put(long, byte[], int, int)

put

public void put(long position,
                byte[] buff,
                int off,
                int len)
         throws IOException

Description copied from interface: PersistentBuffer

Writes the bytes to the provided position. The buffer will not be expanded automatically.

Throws:

IOException

barrier

public void barrier(boolean force)
             throws IOException

There is not currently a way to provide a barrier without using force. This just uses force for both.

Throws:

IOException

See Also:

PersistentBuffer.getProtectionLevel()

getBoolean

public boolean getBoolean(long position)
                   throws IOException

Description copied from class: AbstractPersistentBuffer

Implemented as call to readByte(long)

Specified by:

getBoolean in interface PersistentBuffer

Overrides:

getBoolean in class AbstractPersistentBuffer

Throws:

IOException

See Also:

#readByte(long)

getInt

public int getInt(long position)
           throws IOException

Description copied from class: AbstractPersistentBuffer

Implemented as call to get(long,byte[],int,int)

Specified by:

getInt in interface PersistentBuffer

Overrides:

getInt in class AbstractPersistentBuffer

Throws:

IOException

See Also:

AbstractPersistentBuffer.get(long, byte[], int, int)

getLong

public long getLong(long position)
             throws IOException

Description copied from class: AbstractPersistentBuffer

Implemented as call to get(long,byte[],int,int)

Specified by:

getLong in interface PersistentBuffer

Overrides:

getLong in class AbstractPersistentBuffer

Throws:

IOException

See Also:

AbstractPersistentBuffer.get(long, byte[], int, int)

putInt

public void putInt(long position,
                   int value)
            throws IOException

Description copied from class: AbstractPersistentBuffer

Implemented as call to write(long,byte[],int,int)

Specified by:

putInt in interface PersistentBuffer

Overrides:

putInt in class AbstractPersistentBuffer

Throws:

IOException

See Also:

#write(long, byte[], int, int)

putLong

public void putLong(long position,
                    long value)
             throws IOException

Description copied from class: AbstractPersistentBuffer

Implemented as call to write(long,byte[],int,int)

Specified by:

putLong in interface PersistentBuffer

Overrides:

putLong in class AbstractPersistentBuffer

Throws:

IOException

See Also:

#write(long, byte[], int, int)