non/Timeline/Loggable.H

235 lines
6.2 KiB
C++

/*******************************************************************************/
/* Copyright (C) 2008 Jonathan Moore Liles */
/* */
/* This program is free software; you can redistribute it and/or modify it */
/* under the terms of the GNU General Public License as published by the */
/* Free Software Foundation; either version 2 of the License, or (at your */
/* option) any later version. */
/* */
/* This program is distributed in the hope that it will be useful, but WITHOUT */
/* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or */
/* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for */
/* more details. */
/* */
/* You should have received a copy of the GNU General Public License along */
/* with This program; see the file COPYING. If not,write to the Free Software */
/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/*******************************************************************************/
/* Master class for journaling. */
#pragma once
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <map>
#include <string>
#include <queue>
#include "types.h"
typedef void (progress_func)( int, void * );
typedef void (snapshot_func)( void * );
class Log_Entry;
class Loggable;
typedef Loggable *(create_func)(Log_Entry &, int id);
#define LOG_REGISTER_CREATE( class ) \
Loggable::register_create( #class, & class ::create );
#define LOG_NAME_FUNC( class ) \
virtual const char *class_name ( void ) const { return #class ; }
#define LOG_CREATE_FUNC( class ) \
static Loggable * \
create ( Log_Entry &e, int id ) \
{ \
class *r = new class; \
r->update_id( id ); \
r->set( e ); \
return (Loggable *)r; \
} \
LOG_NAME_FUNC( class ); \
#define LOG_NOT_LOGGABLE_FUNC( class ) \
virtual const char *class_name ( void ) const { return #class ; } \
class Logger;
class Loggable
{
static FILE *_fp;
static int _log_id;
static int _level;
static off_t _undo_offset;
static size_t _loggables_size;
static Loggable ** _loggables;
static std::map <std::string, create_func*> _class_map;
static std::queue <char *> _transaction;
static progress_func *_progress_callback;
static void *_progress_callback_arg;
static snapshot_func *_snapshot_callback;
static void *_snapshot_callback_arg;
private:
int _id;
Log_Entry *_old_state;
int _nest;
static void ensure_size ( size_t n );
void log_print( const Log_Entry *o, const Log_Entry *n ) const;
static void log ( const char *fmt, ... );
static void flush ( void );
static bool snapshot( FILE * fp );
static bool snapshot( const char *name );
static bool replay ( FILE *fp );
void init ( bool loggable=true )
{
// _new_state
_old_state = NULL;
_nest = 0;
if ( loggable )
{
_id = ++_log_id;
ensure_size( _id );
_loggables[ _id - 1 ] = this;
}
else
_id = 0;
}
/* not implemented */
const Loggable & operator= ( const Loggable &rhs );
static void compact_ids ( void );
public:
static void snapshot_callback ( snapshot_func *p, void *arg ) { _snapshot_callback = p; _snapshot_callback_arg = arg; }
static void progress_callback ( progress_func *p, void *arg ) { _progress_callback = p; _progress_callback_arg = arg;}
static const char *escape ( const char *s );
int id ( void ) const { return _id; }
static bool open ( const char *filename );
static bool close ( void );
static void undo ( void );
static void compact ( void );
static void block_start ( void );
static void block_end ( void );
static Loggable * find ( int id );
Loggable ( bool loggable=true )
{
init( loggable );
}
void update_id ( int id );
virtual ~Loggable ( )
{
_loggables[ _id - 1 ] = NULL;
}
static
void
register_create ( const char *name, create_func *func )
{
_class_map[ std::string( name ) ] = func;
}
/* log messages for journal */
virtual void get ( Log_Entry &e ) const = 0;
virtual void set ( Log_Entry &e ) = 0;
virtual const char *class_name ( void ) const = 0;
virtual void log_children ( void ) const { return; }
static bool do_this ( const char *s, bool reverse );
void log_create ( void ) const;
protected:
void log_start ( void );
void log_end ( void );
void log_destroy ( void ) const;
/* leaf subclasses *must* call log_create() at the end of their copy contructors */
Loggable ( const Loggable & )
{
init( true );
}
public:
friend class Logger;
};
class Logger
{
Loggable *_this;
Logger ( ) {}
/* not permitted */
Logger ( const Logger &rhs );
const Logger & operator= ( const Logger &rhs );
public:
Logger ( Loggable *l ) : _this( l )
{
_this->log_start();
}
~Logger ( )
{
_this->log_end();
}
void hold ( void )
{
_this->_nest++;
}
void release ( void )
{
_this->_nest--;
assert( _this->_nest );
}
};
#include "Log_Entry.H"