LUMIERA.clone/src/backend/filedescriptor.c

316 lines
7.9 KiB
C

/*
filedescriptor.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 "include/logging.h"
#include "lib/mutex.h"
#include "lib/safeclib.h"
#include "backend/file.h"
#include "backend/filedescriptor.h"
#include "backend/filehandle.h"
#include "backend/filehandlecache.h"
#include <sys/types.h>
#include <fcntl.h>
#include <limits.h>
#include <unistd.h>
#include <errno.h>
//NOBUG_DEFINE_FLAG_PARENT (filedescriptor, file_all);
/*
Filedescriptor registry
This registry stores all acquired filedescriptors for lookup, they will be freed when not referenced anymore.
*/
static PSplay registry = NULL;
static lumiera_mutex registry_mutex;
static int
cmp_fn (const void* keya, const void* keyb)
{
const LumieraFiledescriptor a = (const LumieraFiledescriptor)keya;
const LumieraFiledescriptor b = (const LumieraFiledescriptor)keyb;
if (a->stat.st_dev < b->stat.st_dev)
return -1;
else if (a->stat.st_dev > b->stat.st_dev)
return 1;
if (a->stat.st_ino < b->stat.st_ino)
return -1;
else if (a->stat.st_ino > b->stat.st_ino)
return 1;
if ((a->flags&LUMIERA_FILE_MASK) < (b->flags&LUMIERA_FILE_MASK))
return -1;
else if ((a->flags&LUMIERA_FILE_MASK) > (b->flags&LUMIERA_FILE_MASK))
return 1;
return 0;
}
static void
delete_fn (PSplaynode node)
{
TODO ("figure name out? or is the handle here always closed");
lumiera_filedescriptor_delete ((LumieraFiledescriptor) node, NULL);
}
static const void*
key_fn (const PSplaynode node)
{
return node;
}
void
lumiera_filedescriptor_registry_init (void)
{
//NOBUG_INIT_FLAG (filedescriptor);
TRACE (filedescriptor_dbg);
REQUIRE (!registry);
registry = psplay_new (cmp_fn, key_fn, delete_fn);
if (!registry)
LUMIERA_DIE (NO_MEMORY);
lumiera_mutex_init (&registry_mutex, "filedescriptor_registry", &NOBUG_FLAG (mutex_dbg));
}
void
lumiera_filedescriptor_registry_destroy (void)
{
TRACE (filedescriptor_dbg);
REQUIRE (!psplay_nelements (registry));
lumiera_mutex_destroy (&registry_mutex, &NOBUG_FLAG (mutex_dbg));
if (registry)
psplay_destroy (registry);
registry = NULL;
}
LumieraFiledescriptor
lumiera_filedescriptor_acquire (const char* name, int flags, LList filenode)
{
TRACE (filedescriptor_dbg, "%s", name);
REQUIRE (registry, "not initialized");
REQUIRE (llist_is_empty (filenode));
LumieraFiledescriptor dest = NULL;
LUMIERA_MUTEX_SECTION (mutex_sync, &registry_mutex)
{
lumiera_filedescriptor fdesc;
fdesc.flags = flags;
if (stat (name, &fdesc.stat) != 0)
{
if (errno == ENOENT && flags&O_CREAT)
{
errno = 0;
char* dir = lumiera_tmpbuf_strndup (name, PATH_MAX);
char* slash = dir;
while ((slash = strchr (slash+1, '/')))
{
*slash = '\0';
INFO (filedescriptor_dbg, "try creating dir: %s", dir);
if (mkdir (dir, 0777) == -1 && errno != EEXIST)
{
LUMIERA_ERROR_SET_CRITICAL (file, ERRNO, name);
goto error;
}
*slash = '/';
}
int fd;
INFO (filedescriptor_dbg, "try creating file: %s", name);
TODO ("creat mode from config");
fd = creat (name, 0666);
if (fd == -1)
{
LUMIERA_ERROR_SET_CRITICAL (file, ERRNO, name);
goto error;
}
close (fd);
if (stat (name, &fdesc.stat) != 0)
{
/* finally, no luck */
LUMIERA_ERROR_SET_CRITICAL (file, ERRNO, name);
goto error;
}
}
}
/* lookup/create descriptor */
dest = (LumieraFiledescriptor) psplay_find (registry, &fdesc, 100);
if (!dest)
{
dest = lumiera_filedescriptor_new (&fdesc);
if (!dest)
goto error;
psplay_insert (registry, &dest->node, 100);
}
llist_insert_head (&dest->files, filenode);
error: ;
}
return dest;
}
void
lumiera_filedescriptor_release (LumieraFiledescriptor self, const char* name, LList filenode)
{
TRACE (filedescriptor_dbg);
if (filenode)
LUMIERA_MUTEX_SECTION (mutex_sync, &self->lock)
{
REQUIRE (llist_is_member (&self->files, filenode));
llist_unlink (filenode);
}
if (llist_is_empty (&self->files))
lumiera_filedescriptor_delete (self, name);
}
int
lumiera_filedescriptor_handle_acquire (LumieraFiledescriptor self)
{
TRACE (filedescriptor_dbg);
int fd = -1;
LUMIERA_MUTEX_SECTION (mutex_sync, &self->lock)
{
if (!self->handle)
/* no handle yet, get a new one */
lumiera_filehandlecache_handle_acquire (lumiera_fhcache, self);
else
lumiera_filehandlecache_checkout (lumiera_fhcache, self->handle);
fd = lumiera_filehandle_handle (self->handle);
}
return fd;
}
void
lumiera_filedescriptor_handle_release (LumieraFiledescriptor self)
{
TRACE (filedescriptor_dbg);
REQUIRE (self->handle);
LUMIERA_MUTEX_SECTION (mutex_sync, &self->lock)
lumiera_filehandlecache_checkin (lumiera_fhcache, self->handle);
}
const char*
lumiera_filedescriptor_name (LumieraFiledescriptor self)
{
REQUIRE (!llist_is_empty (&self->files));
return ((LumieraFile)(llist_head (&self->files)))->name;
}
int
lumiera_filedescriptor_flags (LumieraFiledescriptor self)
{
return self->flags;
}
int
lumiera_filedescriptor_samestat (LumieraFiledescriptor self, struct stat* stat)
{
if (self->stat.st_dev == stat->st_dev && self->stat.st_ino == stat->st_ino)
return 1;
return 0;
}
LumieraFiledescriptor
lumiera_filedescriptor_new (LumieraFiledescriptor template)
{
LumieraFiledescriptor self = lumiera_malloc (sizeof (lumiera_filedescriptor));
TRACE (filedescriptor_dbg, "at %p", self);
psplaynode_init (&self->node);
self->stat = template->stat;
self->realsize = template->stat.st_size;
self->flags = template->flags;
self->handle = NULL;
self->mmapings = NULL;
llist_init (&self->files);
lumiera_mutex_init (&self->lock, "filedescriptor", &NOBUG_FLAG (mutex_dbg));
return self;
}
void
lumiera_filedescriptor_delete (LumieraFiledescriptor self, const char* name)
{
TRACE (filedescriptor_dbg, "%p %s", self, name);
LUMIERA_MUTEX_SECTION (mutex_sync, &registry_mutex)
{
REQUIRE (llist_is_empty (&self->files));
psplay_remove (registry, &self->node);
TODO ("destruct other members (WIP)");
if (self->handle && name && ((self->flags & O_RDWR) == O_RDWR))
{
TRACE (filedescriptor_dbg, "truncate %s to %lld", name, self->realsize);
lumiera_filehandlecache_checkout (lumiera_fhcache, self->handle);
int dummy = ftruncate (lumiera_filehandle_handle (self->handle), self->realsize);
(void) dummy; /* this is present to silence a warning */
TODO ("handle error case better");
lumiera_filehandlecache_checkin (lumiera_fhcache, self->handle);
}
lumiera_mmapings_delete (self->mmapings);
TODO ("release filehandle");
lumiera_mutex_destroy (&self->lock, &NOBUG_FLAG (mutex_dbg));
lumiera_free (self);
}
}