io.mappedbus

Class MappedBusWriter

java.lang.Object

io.mappedbus.MappedBusWriter

public class MappedBusWriter
extends java.lang.Object

Class for writing messages to the bus.

Messages can either be message based or byte array based.

The typical usage is as follows:

 
 // Construct a writer
 MappedBusWriter writer = new MappedBusWriter("/tmp/test", 100000L, 32, true);
 writer.open();
 
 // A: write an object based message
 PriceUpdate priceUpdate = new PriceUpdate();

 writer.write(priceUpdate);
 
 // B: write a byte array based message
 byte[] buffer = new byte[32];

 writer.write(buffer, 0, buffer.length);

 // Close the writer
 writer.close();
 
 

Constructor Summary

Constructors

Constructor and Description
MappedBusWriter(java.lang.String fileName, long fileSize, int recordSize, boolean append) Constructs a new writer.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the writer.
void	open() Opens the writer.
void	write(byte[] src, int offset, int length) Writes a buffer of data.
void	write(MappedBusMessage message) Writes a message.

Methods inherited from class java.lang.Object

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

Constructor Detail

MappedBusWriter

public MappedBusWriter(java.lang.String fileName,
                       long fileSize,
                       int recordSize,
                       boolean append)

Constructs a new writer.

Parameters:

fileName - the name of the memory mapped file

fileSize - the maximum size of the file

recordSize - the maximum size of a record (excluding status flags and meta data)

append - whether to append to the file (will create a new file if false)

Method Detail

open

public void open()
          throws java.io.IOException

Opens the writer.

Throws:

java.io.IOException - if there was an error opening the file

write

public void write(MappedBusMessage message)
           throws java.io.EOFException

Writes a message.

Parameters:

message - the message object to write

Throws:

java.io.EOFException - in case the end of the file was reached

write

public void write(byte[] src,
                  int offset,
                  int length)
           throws java.io.EOFException

Writes a buffer of data.

Parameters:

src - the output buffer

offset - the offset in the buffer of the first byte to write

length - the length of the data

Throws:

java.io.EOFException - in case the end of the file was reached

close

public void close()
           throws java.io.IOException

Closes the writer.

Throws:

java.io.IOException - if there was an error closing the file