LUMIERA.clone/src/backend/filedescriptor.h
2008-09-06 12:41:03 +02:00

113 lines
3.2 KiB
C

/*
filedescriptor.h - file handling
Copyright (C) Lumiera.org
2008, Christian Thaeter <ct@pipapo.org>
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; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef LUMIERA_FILEDESCRIPTOR_H
#define LUMIERA_FILEDESCRIPTOR_H
#include "lib/mutex.h"
#include "lib/psplay.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
typedef struct lumiera_filedescriptor_struct lumiera_filedescriptor;
typedef lumiera_filedescriptor* LumieraFiledescriptor;
#include "backend/filehandle.h"
#include "backend/file.h"
/**
* @file
* Filedescriptors.
* Filedescriptors are the underlying working horse in accessing files.
* All information associated with managing a file is kept here.
*/
struct lumiera_filedescriptor_struct
{
psplaynode node; /* node for the lookup tree */
struct stat stat; /* create after first open, maintained metadata */
int flags; /* open flags, must be masked for reopen */
lumiera_mutex lock; /* locks operations on this file descriptor */
unsigned refcount; /* reference counter, all users sans registry */
LumieraFilehandle handle;
//LumieraFileMap mappings;
//LumieraWriteBuffer writebuffer;
};
/**
* Initialize the global filedescriptor registry.
* All filedescriptors are looked up by dev/ino/open-flags in a hashtable. Opening hardlinked
* files will be targeted to the same filedescriptor.
* This function never fails but dies on error.
*/
void
lumiera_filedescriptor_registry_init (void);
/**
* Destroy and free the global filedescriptor registry.
* Never fails.
*/
void
lumiera_filedescriptor_registry_destroy (void);
/**
* Find existing filedescriptor or create one
* @param name name of the file
* @param flags opening flags for the filedescriptor
* @return descriptor on success or NULL on error
*/
LumieraFiledescriptor
lumiera_filedescriptor_acquire (const char* name, int flags);
/**
* Release a filedescriptor.
* @param self filedescriptor to be released
*/
void
lumiera_filedescriptor_release (LumieraFiledescriptor self);
/**
* Allocate a new filedescriptor cloned from a template
* @param template the source filedescriptor
* @return the constrccted filedescriptor
*/
LumieraFiledescriptor
lumiera_filedescriptor_new (LumieraFiledescriptor template);
/**
* Delete a filedescriptor
* Called whenever its reference count drops to zero.
* @param self the filedescriptor to be deleted
*/
void
lumiera_filedescriptor_delete (LumieraFiledescriptor self);
#endif