org.xerial.db.storage
Class MemoryFile

java.lang.Object
  org.xerial.db.storage.MemoryFile

All Implemented Interfaces:

DBFile

public class MemoryFile
extends Object
implements DBFile

MemoryFile is a class to handle main memory as if it were a file

Author:

leo

Constructor Summary

MemoryFile()

Method Summary

void	close() Closes the file.
void	loadFromFile(String fileName)
void	read(byte[] buffer, int offset, int byteSize) Reads data from the file, and writes the read data to the specified buffer
void	seek(long fileBytePos) Sets the file pointer offset, measured from the beginning of the file, at which the next read/write request occurs.
void	write(byte[] buffer, int offset, int byteSize) Writes the given data into the file

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryFile

public MemoryFile()

Method Detail

loadFromFile

public void loadFromFile(String fileName)
                  throws IOException,
                         DBException

Throws:

IOException

DBException

read

public void read(byte[] buffer,
                 int offset,
                 int byteSize)
          throws DBException

Description copied from interface: DBFile

Reads data from the file, and writes the read data to the specified buffer

Specified by:

read in interface DBFile

Parameters:

buffer - the buffer into which the data is read

offset - the start offset in the buffer at which the data is written

byteSize - the bytes to read

Throws:

DBException

seek

public void seek(long fileBytePos)
          throws DBException

Description copied from interface: DBFile

Sets the file pointer offset, measured from the beginning of the file, at which the next read/write request occurs. The fileBytePos can exceed the end of the file. Setting the fileBytePos higher than the end of the file does not expand the file size. The size will change by writing after the offset has been set beyond the end of the file.

Specified by:

seek in interface DBFile

Throws:

DBException

write

public void write(byte[] buffer,
                  int offset,
                  int byteSize)
           throws DBException

Description copied from interface: DBFile

Writes the given data into the file

Specified by:

write in interface DBFile

Parameters:

buffer - the data

offset - the start offset in the data

byteSize - the bytes to write

Throws:

DBException

close

public void close()
           throws DBException

Description copied from interface: DBFile

Closes the file.

Specified by:

close in interface DBFile

Throws:

DBException