root/vowfsc/db.h

#pragma once

#include <postgresql/libpq-fe.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "xdelta3.h"

#define BUFFER_SIZE     1024

typedef struct file file_t;
struct file{
#define db_int( name)           int name;
#define db_long( name)          long name;
#define db_string( name )       char *name;
#include "file.db"
};

typedef struct dir dir_t;
struct dir{
#define db_int( name)           int name;
#define db_long( name)          long name;
#define db_string( name )       char *name;
#include "dir.db"
};

typedef struct stream stream_t;
struct stream{
#define db_int( name)           int name;
#define db_long( name)          long name;
#define db_string( name )       char *name;
#include "stream.db"
};


/* Given a file path, db_get_file_id splits it into
 * a directory and a file name, normalizes the directory
 * and then passes it onto the database to get the
 * file_id as an integer.
 */
int db_get_file_id( char *file_path ); // TESTED


/* Given a file id, db_get_file_max_revision queries the 
 * database to get the revision id of the most current
 * file.
 */
int db_get_file_max_revision( int file_id ); // TESTED


/* db_get_file returns a struct containing statistical
 * data on the file.  To see the contents of the struct,
 * look at the file.db file.
 */
file_t *db_get_file( int file_id ); // TESTED
file_t *db_get_file_rev( int file_id, int revision_id ); // TESTED


/* db_get_file_data returns the undiffed data from 
 * revision given, or if no revision is given, it
 * returns the data from the most current file.
 */
char *db_get_file_data( int file_id ); // TESTED
char *db_get_file_rev_data( int file_id, int revision_id ); // TESTED


/* Permissions and/or other meta data is stored in
 * the file's stream.  These functions work like
 * db_get_file_data
 */
stream_t *db_get_file_stream( int file_id );
stream_t *db_get_file_rev_stream( int file_id, int revision_id );


/* Looks first to see if the given stream exists, and
 * returns it's stream id if it does.  If not, it creates
 * a new stream and returns the new stream's id.
 */
int db_create_stream( char *stream_name, char *stream );


/* Copies the file to a new reversion, and sets the delete flag 
 * in the new file.  It then returns the revision number of the
 * new file.
 */
int db_remove_file(int file_id); // TESTED
#define db_delete_file(file_id) db_remove_file(file_id)


/* This creates a blank file for writing.  If the file
 * allready exists, then it removes the delete flag and
 * revisions it.  
 */
int db_create_file(char *file_path, int stream_id ); // TESTED


/* Branches a file by creating a new file based on a
 * given revision and a file_id.  This is used for 
 * moving files to new directories, etc.  
 *
 * db_branch_file returns the file_id of the new
 * file or NULL in the case of a failture.
 */
int db_branch_file(int file_id, int revision_id, char *new_file_path );


/* For revisioning an existing file, this function
 * modifies the data in an existing file given by 
 * file_id
 */
int db_modify_file_data(int file_id, char *data, int data_len ); // TESTED


/* For changing the permissions on an existing file
 * modifies the stream in an existing file given by 
 * file_id.  If either stream_name or stream are NULL,
 * they will be replaced with the current values.
 */
int db_modify_file_stream(int file_id, char *new_stream_name, char *new_stream );


/* Like db_get_file_id, db_get_dir_id returns the id
 * of a given directory string by first normalizing it
 * and then querying the database.
 */
int db_get_dir_id( char *dir_name ); // TESTED


/* Given a directory id, db_get_dir_max_revision queries
 * the database to get the revision id of the most current
 * file.
 */
int db_get_dir_max_revision( int dir_id );


/* db_get_dir returns a struct containing statistical
 * data on the directory.  To see the contents of the 
 * struct, look at the dir.db file.
 */
dir_t *db_get_dir( int dir_id ); // TESTED
dir_t *db_get_dir_rev( int dir_id, int revision_id );


/* Get subdirs and get files both return an array of 
 * either directories or files.  The length pointer
 * returns the number of elements in the array.
 */
dir_t *db_get_dir_subdirs( int dir_id, int *length );
file_t *db_get_dir_files( int dir_id, int *length );


/* Does what it says, creates a new directory.
 * Returns the dir_id of the new directory or null in
 * the case of a failture.
 */
int db_create_dir( char *dir_path ); // TODO


/* Copies the directory entry and sets the delete flag
 */
int db_remove_dif( int dir_id ); // TODO


/* db_init and db_destoy create and destroy connections
 * to the database respectivly.  They are wrappers around
 * the libpq functions and will return 0 on success and 
 * non-zero on failture.
 */
int db_init(char *host, int port, char *dbname, char *username, char *password); // TESTED
int db_destroy(); // TESTED


/* Creates a new blank file system
 */
int db_format_fs(); // TODO