diskutils.hpp

#ifndef DISKUTILS_HPP
#define DISKUTILS_HPP

#include <iostream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <unistd.h>
#include <vector>
#include <sstream>

// Virtual Disk Specifications
const unsigned int DISK_SIZE    = 64 * 1024 * 1024; // 64 MB
const unsigned int BLOCK_SIZE   = 1024;              // 1 KB blocks
const unsigned int TOTAL_BLOCKS = 65536;             // 64MB / 1KB

// Layout / Block locations
const unsigned int SUPERBLOCK     = 0;
const unsigned int BITMAP_START   = 1;
const unsigned int FAT_START      = 9;
const unsigned int ROOT_DIR_BLOCK = 265;

// The metadata structure exactly as specified (32 bytes)
#pragma pack(push, 1)
struct metadata {
    char         type;         // 'f' for file, 'd' for directory
    char         name[23];     // 23-byte null-terminated string
    unsigned int size;         // bytes for files, entry count for directories
    unsigned int firstblock;   // pointer to the first block
};
#pragma pack(pop)

// Global Variables
extern unsigned char* D;
extern unsigned int   NBLOCKS;
extern unsigned int   NFREEBLOCKS;
extern unsigned int   RBN;

// Core disk management 
void         joindisk();
void         leavedisk();
unsigned int getfreeblock();
void         freeblock(unsigned int block_num);

// Internal helpers 
unsigned int get_next_fat_block(unsigned int current_block);
void         set_fat(unsigned int block_num, unsigned int next_block);

std::vector<std::string> split_path(const std::string& path);

// Returns true and fills out_meta if the named entry is found in dir_first_block.
bool find_dir_entry(unsigned int dir_first_block, const std::string& target_name, metadata& out_meta);

// Resolves a path (relative or absolute) starting from cbn / cwd.
// Returns true and sets out_block to the first block of the target dir/file and out_meta to its metadata.
bool resolve_path(const std::string& path, unsigned int cbn, const std::string& cwd, unsigned int& out_block, metadata& out_meta, bool silent = false);

// File system operations called from foosh

// md / mkdir  – create a new directory
void fs_mkdir(const std::string& path, unsigned int cbn, const std::string& cwd);

// ls          – detailed listing of a directory (or a single file)
void fs_ls(const std::string& path, unsigned int cbn, const std::string& cwd);

// dir         – names-only listing of current directory
void fs_dir(unsigned int cbn, const std::string& cwd);

// cp / copy   – three-way copy: HD→VD, VD→HD, VD→VD
// Back-tick prefix on a name means it lives on the HD.
void fs_cp(const std::string& src, const std::string& dst, unsigned int cbn, const std::string& cwd);

// prn / type  – print a VD text file to stdout
void fs_prn(const std::string& path, unsigned int cbn, const std::string& cwd);

#endif // DISKUTILS_HPP