nachos.machine
Class ArrayFile

java.lang.Object
  |
  +--nachos.machine.OpenFile
        |
        +--nachos.machine.OpenFileWithPosition
              |
              +--nachos.machine.ArrayFile

public class ArrayFile

extends OpenFileWithPosition

A read-only OpenFile backed by a byte array.

Fields inherited from class nachos.machine.OpenFileWithPosition

position

Constructor Summary

ArrayFile(byte[] array)
Allocate a new ArrayFile.

Method Summary

void	close() Close this file and release any associated system resources.
int	length() Get the length of this file.
int	read(int position, byte[] buf, int offset, int length) Read this file starting at the specified position and return the number of bytes successfully read.
int	write(int position, byte[] buf, int offset, int length) Write this file starting at the specified position and return the number of bytes successfully written.

Methods inherited from class nachos.machine.OpenFileWithPosition

read, seek, tell, write

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayFile

public ArrayFile(byte[] array)

Allocate a new ArrayFile.

Parameters:

array - the array backing this file.

Method Detail

length

public int length()

Description copied from class: OpenFile

Get the length of this file.

Overrides:

length in class OpenFile

Tags copied from class: OpenFile

Returns:

the length of this file, or -1 if this file has no length.

close

public void close()

Description copied from class: OpenFile

Close this file and release any associated system resources.

Overrides:

close in class OpenFile

read

public int read(int position,
                byte[] buf,
                int offset,
                int length)

Description copied from class: OpenFile

Read this file starting at the specified position and return the number of bytes successfully read. If no bytes were read because of a fatal error, returns -1

Overrides:

read in class OpenFile

Tags copied from class: OpenFile

Parameters:

pos - the offset in the file at which to start reading.

buf - the buffer to store the bytes in.

offset - the offset in the buffer to start storing bytes.

length - the number of bytes to read.

Returns:

the actual number of bytes successfully read, or -1 on failure.

write

public int write(int position,
                 byte[] buf,
                 int offset,
                 int length)

Description copied from class: OpenFile

Write this file starting at the specified position and return the number of bytes successfully written. If no bytes were written because of a fatal error, returns -1.

Overrides:

write in class OpenFile

Tags copied from class: OpenFile

Parameters:

pos - the offset in the file at which to start writing.

buf - the buffer to get the bytes from.

offset - the offset in the buffer to start getting.

length - the number of bytes to write.

Returns:

the actual number of bytes successfully written, or -1 on failure.