Package org.apache.jena.dboe.base.file

Interface BinaryDataFile

All Superinterfaces:

org.apache.jena.atlas.lib.Closeable, org.apache.jena.atlas.lib.Sync

All Known Implementing Classes:

BinaryDataFileMem, BinaryDataFileRandomAccess, BinaryDataFileSync, BinaryDataFileWrapper, BinaryDataFileWriteBuffered

public interface BinaryDataFile
extends org.apache.jena.atlas.lib.Closeable, org.apache.jena.atlas.lib.Sync

An append-only, read-anywhere, binary file. A BinaryDataFile does not record the length and assumes the entries are self-defining.

See Also:

RandomAccessFile

Method Summary

Modifier and Type	Method	Description
void	close()
default boolean	isEmpty()	Return whether this is an empty file or not
boolean	isOpen()	Is it open?
long	length()	Return the length of the file (including any buffered writes)
void	open()	Open the file
default int	read(long posn, byte[] b)	Read into a byte array, returning the number of bytes read.
int	read(long posn, byte[] b, int start, int length)	Read into a byte array, returning the number of bytes read.
void	sync()
void	truncate(long length)	Truncate the file
default long	write(byte[] b)	Write bytes - bytes are always written to the end of the file.
long	write(byte[] b, int start, int length)	Write bytes - bytes are always written to the end of the file.

Method Detail

open

void open()

Open the file

isOpen

boolean isOpen()

Is it open?

read

default int read(long posn,
                 byte[] b)

Read into a byte array, returning the number of bytes read. Reads are at an absolute position and a read is atomic/thread-safe.

Parameters:

posn - Location of the read operation.

b - byte array

Returns:

The number of bytes read

read

int read(long posn,
         byte[] b,
         int start,
         int length)

Read into a byte array, returning the number of bytes read. Reads are at an absolute position and a read is atomic/thread-safe.

Parameters:

posn - Location of the read operation.

b -

start - of bytesarray to read into

length - Maximum number of bytes to read.

Returns:

The number of bytes read

write

default long write(byte[] b)

Write bytes - bytes are always written to the end of the file. Return the location where the write started.

write

long write(byte[] b,
           int start,
           int length)

Write bytes - bytes are always written to the end of the file. Return the location where the write started.

length

long length()

Return the length of the file (including any buffered writes)

truncate

void truncate(long length)

Truncate the file

isEmpty

default boolean isEmpty()

Return whether this is an empty file or not

sync

void sync()

Specified by:

sync in interface org.apache.jena.atlas.lib.Sync

close

void close()

Specified by:

close in interface org.apache.jena.atlas.lib.Closeable