Class Inode

java.lang.Object

Inode

public class Inode
extends java.lang.Object

This class reads an Inode and all the metadata it provides

Author:

Petros Soutzis (p.soutzis@lancaster.ac.uk)

Field Summary

Fields

Modifier and Type	Field and Description
private java.nio.ByteBuffer	buffer
private int	i_atime
private int[]	i_block_pointer
private int	i_ctime
private int	i_dtime
private short	i_gid
private short	i_links_count
private short	i_mode
private int	i_mtime
private int	i_size_lower
private int	i_size_upper
private short	i_uid

Constructor Summary

Constructors

Constructor and Description
Inode(byte[] bytes) Constructor of the inode class

Method Summary

Modifier and Type	Method and Description
private static int	findInodeOffset(java.lang.String path, Inode inode, Ext2File ext2) This class calculates the inode number, needed to readBytes the data contained in the block that the inode points to If there was no match, method returns integer 0
(package private) int[]	getBlockPointers()
(package private) static int	getContainingBlock(int rootInodeOffset, Superblock superblock, GroupDescriptor groupDescriptor) A static method, used for fetching the block number (offset), that an inode points to.
(package private) static Inode	getContainingInode(java.lang.String[] pathArray, int inodeSize, Ext2File ext2, Inode inode, Superblock superblock, GroupDescriptor groupDescriptor) This method will get the number of the inode, if the names in pathArray array match the names in the volume If the inode number is 0, the program will be terminated.
java.util.Date	getDate()
(package private) java.lang.String	getGid()
(package private) short	getHardLinks()
(package private) int	getSizeLower()
(package private) int	getSizeUpper()
(package private) java.lang.String	getUid()
boolean	isFile()
private void	read() This method will readBytes all the data that is contained in the inode, from the buffer, in which the byte array was parsed
(package private) java.lang.String	readPermissions() This method uses bitwise ANDing on FileSystem's i_mode variable value, to determine what permissions a directory or file has.

Methods inherited from class java.lang.Object

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

Field Detail

i_mode

private short i_mode

i_uid

private short i_uid

i_size_lower

private int i_size_lower

i_atime

private int i_atime

i_ctime

private int i_ctime

i_mtime

private int i_mtime

i_dtime

private int i_dtime

i_gid

private short i_gid

i_links_count

private short i_links_count

i_block_pointer

private int[] i_block_pointer

i_size_upper

private int i_size_upper

buffer

private java.nio.ByteBuffer buffer

Constructor Detail

Inode

public Inode(byte[] bytes)

Constructor of the inode class

Parameters:

bytes - is the byte array that contains the inode's data

Method Detail

read

private void read()

This method will readBytes all the data that is contained in the inode, from the buffer, in which the byte array was parsed

readPermissions

java.lang.String readPermissions()

This method uses bitwise ANDing on FileSystem's i_mode variable value, to determine what permissions a directory or file has.

Returns:

a String with the full permissions of a file or directory

findInodeOffset

private static int findInodeOffset(java.lang.String path,
                                   Inode inode,
                                   Ext2File ext2)
                            throws java.io.IOException

This class calculates the inode number, needed to readBytes the data contained in the block that the inode points to If there was no match, method returns integer 0

Parameters:

path - is the name of the directory or file to look for

Returns:

the inode number that points to the data requested in the path

Throws:

java.io.IOException - e

getContainingInode

static Inode getContainingInode(java.lang.String[] pathArray,
                                int inodeSize,
                                Ext2File ext2,
                                Inode inode,
                                Superblock superblock,
                                GroupDescriptor groupDescriptor)
                         throws java.io.IOException

This method will get the number of the inode, if the names in pathArray array match the names in the volume If the inode number is 0, the program will be terminated. The method will then parse the bytes to readBytes, to the Inode instance, by calculating the offset based on the inode number that the path returns. If data exists, this method will call the readBlockData() method, to readBytes and print the data in a human-readable way and then it will call the readHexData, in order to readBytes and print that same data in Hexadecimal format

Parameters:

pathArray - is the array of names of directories and files, that the

Throws:

java.io.IOException - ioe

getContainingBlock

static int getContainingBlock(int rootInodeOffset,
                              Superblock superblock,
                              GroupDescriptor groupDescriptor)

A static method, used for fetching the block number (offset), that an inode points to. Otherwise, it returns 0

Parameters:

rootInodeOffset - The number of the inode, with which this method will calculate the containing block number

Returns:

the offset of the containing block

getBlockPointers

int[] getBlockPointers()

Returns:

the array of all the data pointers in an inode

getUid

java.lang.String getUid()

Returns:

If the user has root access or not

getGid

java.lang.String getGid()

Returns:

If the guest has root access or not

getSizeLower

int getSizeLower()

Returns:

the file size (lower 32 bits)

getSizeUpper

int getSizeUpper()

Returns:

the file size (upper 32 bits)

isFile

public boolean isFile()

Returns:

true, if this is a file. Otherwise, return false.

getDate

public java.util.Date getDate()

Returns:

the date that this file was lastly modified

getHardLinks

short getHardLinks()

Returns:

the number of hard link references to a file