Superblock Class Reference

A Superblock records the completion of a checkpoint. More...

#include <storage.h>

List of all members.

Public Member Functions

void print ()

Public Attributes

unsigned signature

unsigned checkpoint_counter

unsigned block_directory

unsigned segment_directory

Size blocks_per_segment

unsigned curr_empty_segment

Static Public Attributes

const unsigned CORRECT_SIGNATURE = 0xbb66

Detailed Description

A Superblock records the completion of a checkpoint.

The Torsion storage system has two superblocks at fixed locations on the disk. Every time a checkpoint is completed, various storage meta-data are written to one of the superblocks so that the storage system's state can be easily recovered on boot. There are two superblocks so that at least one superblock is always in a consistent state.

Member Function Documentation

void Superblock::print ( )

Print basic information about this Superblock.

Member Data Documentation

unsigned Superblock::block_directory

first block of block directory

Size Superblock::blocks_per_segment

number of blocks per disk segment

unsigned Superblock::checkpoint_counter

ID number of recent checkpoint.

const unsigned Superblock::CORRECT_SIGNATURE = 0xbb66 [static]

unsigned Superblock::curr_empty_segment

first block of current empty segment

unsigned Superblock::segment_directory

first block of segment directory

unsigned Superblock::signature

magic num for a Torsion superblock

The documentation for this class was generated from the following files:


Public Member Functions
void	print ()
Public Attributes
unsigned	signature
unsigned	checkpoint_counter
unsigned	block_directory
unsigned	segment_directory
Size	blocks_per_segment
unsigned	curr_empty_segment
Static Public Attributes
const unsigned	CORRECT_SIGNATURE = 0xbb66