LUMIERA.clone/src/backend/file.c

130 lines
3.3 KiB
C

/*
file.c - 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.
*/
#include "lib/mutex.h"
#include "lib/safeclib.h"
#include "backend/file.h"
#include "backend/filehandlecache.h"
#include "backend/filedescriptor.h"
#include <limits.h>
#include <unistd.h>
NOBUG_DEFINE_FLAG_PARENT (file, file_all);
LUMIERA_ERROR_DEFINE(FILE_CHANGED, "File changed unexpected");
LumieraFile
lumiera_file_init (LumieraFile self, const char* name, int flags)
{
TRACE (file);
if (!(self->descriptor = lumiera_filedescriptor_acquire (name, flags)))
return NULL;
self->name = lumiera_strndup (name, PATH_MAX);
return self;
}
LumieraFile
lumiera_file_destroy (LumieraFile self)
{
TRACE (file);
lumiera_filedescriptor_release (self->descriptor);
lumiera_free (self->name);
return self;
}
LumieraFile
lumiera_file_new (const char* name, int flags)
{
TRACE (file);
LumieraFile self = lumiera_malloc (sizeof (lumiera_file));
return lumiera_file_init (self, name, flags);
}
void
lumiera_file_delete (LumieraFile self)
{
TRACE (file);
lumiera_free (lumiera_file_destroy (self));
}
int
lumiera_file_handle_acquire (LumieraFile self)
{
TRACE (file);
REQUIRE (self);
REQUIRE (self->descriptor);
REQUIRE (lumiera_fhcache);
LUMIERA_MUTEX_SECTION (file, &self->descriptor->lock)
{
if (!self->descriptor->handle)
/* no handle yet, get a new one */
lumiera_filehandlecache_handle_acquire (lumiera_fhcache, self->descriptor);
else
lumiera_filehandlecache_checkout (lumiera_fhcache, self->descriptor->handle);
if (self->descriptor->handle->fd == -1)
{
int fd;
fd = open (self->name, self->descriptor->flags & LUMIERA_FILE_MASK);
if (fd == -1)
{
LUMIERA_ERROR_SET (file, ERRNO);
}
else
{
struct stat st;
if (fstat (fd, &st) == -1)
{
close (fd);
LUMIERA_ERROR_SET (file, ERRNO);
}
else if (self->descriptor->stat.st_dev != st.st_dev || self->descriptor->stat.st_ino != st.st_ino)
{
close (fd);
/* Woops this is not the file we expected to use */
LUMIERA_ERROR_SET (file, FILE_CHANGED);
}
}
self->descriptor->handle->fd = fd;
}
}
return self->descriptor->handle->fd;
}
void
lumiera_file_handle_release (LumieraFile self)
{
TRACE (file);
LUMIERA_MUTEX_SECTION (file, &self->descriptor->lock)
{
lumiera_filehandlecache_checkin (lumiera_fhcache, self->descriptor->handle);
}
}