// See COPYRIGHT for copyright information.

#ifndef _FS_H_
#define _FS_H_ 1

#include <inc/types.h>

// File nodes (both in-memory and on-disk)

// Bytes per file system block - same as page size
#define BY2BLK		BY2PG
#define BIT2BLK		(BY2BLK*8)

// Maximum size of a filename (a single path component), including null
#define MAXNAMELEN	128

// Maximum size of a complete pathname, including null
#define MAXPATHLEN	1024

// Number of (direct) block pointers in a File descriptor
#define NDIRECT		10
#define NINDIRECT	(BY2BLK/4)

#define MAXFILESIZE	(NINDIRECT*BY2BLK)

#define BY2FILE		256
struct File {
  union {
    struct {
	uint8_t f_name[MAXNAMELEN];	// filename
	uint32_t f_size;		// file size in bytes
	uint32_t f_type;		// file type
	uint32_t f_direct[NDIRECT];
	uint32_t f_indirect;

	struct File *f_dir;		// valid only in memory
    };
    uint8_t f_pad[BY2FILE];		// make sizeof(struct File) == BY2FILE
  };
};

#define FILE2BLK	(BY2BLK/sizeof(struct File))

// File types
#define FTYPE_REG		0	// Regular file
#define FTYPE_DIR		1	// Directory


// File system super-block (both in-memory and on-disk)

#define FS_MAGIC	0x68286097	// Everyone's favorite OS class

struct Super {
	uint32_t s_magic;	// Magic number: FS_MAGIC
	uint32_t s_nblocks;	// Total number of blocks on disk
	struct File s_root;	// Root directory node
};

// Definitions for requests from clients to file system

#define FSREQ_OPEN	1
#define FSREQ_MAP	2
#define FSREQ_SET_SIZE	3
#define FSREQ_CLOSE	4
#define FSREQ_DIRTY	5
#define FSREQ_REMOVE	6
#define FSREQ_SYNC	7

struct Fsreq_open {
	uint8_t req_path[MAXPATHLEN];
	uint32_t req_omode;
};

struct Fsreq_map {
	int32_t req_fileid;
	uint32_t req_offset;
};

struct Fsreq_set_size {
	int32_t req_fileid;
	uint32_t req_size;
};

struct Fsreq_close {
	int32_t req_fileid;
};

struct Fsreq_dirty {
	int32_t req_fileid;
	uint32_t req_offset;
};

struct Fsreq_remove {
	uint8_t req_path[MAXPATHLEN];
};

#endif // _FS_H_